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Chewing gum selectively improves aspects of memory in healthy volunteers

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... The two reviewers disagreed over the classification of 47/927 papers in their independent reviews (5.64%). A consensus meeting was used to decide on the ultimate inclusion and exclusion of the disputed papers resulting in a final list of 21 publications [1][2][3][4][5]14,18,21,22,24,38,[50][51][52][53][54]57,59,60,62,64]. ...
... Previous research has suggested that heart rate declines over time during a sustained attention task [44]. Wilkinson et al. found that heartrate was increased when chewing gum compared with when participants did not chew gum [64]. They also observed improvements in cognitive function and suggested that mastication may have increased regional cerebral blood flow and increased insulin release [64]. ...
... Wilkinson et al. found that heartrate was increased when chewing gum compared with when participants did not chew gum [64]. They also observed improvements in cognitive function and suggested that mastication may have increased regional cerebral blood flow and increased insulin release [64]. However, to investigate whether these effects were linked to stress, Allen & Smith measured cortisol and heart-rate during the course of a working day. ...
Article
The aims of this paper are to conduct: 1) a systematic review of the effects of mastication on sustained attention, and 2) a meta-analysis of the effects of mastication on the performance of participants undertaking cognitive tests. Papers were obtained from MEDLINE and PsycInfo using a systematic approach incorporating defined inclusion and exclusion criteria. Twenty-one papers linking mastication and sustained attention were reviewed. Meta-analysis detected a weak, but statistically significant, improvement in levels of sustained attention when chewing with low between-study heterogeneity (mean Cohen's d = −0.1479 standard deviations, 95% CI [−0.2913, −0.0045], p = 0.043 & I² = 0.00%), and a tendency for feelings of alertness to decrease less during cognitive demanding tasks when chewing (mean Cohen's d = 0.3797 standard deviations, 95% CI [−0.0053, 0.7647], p = 0.052 & I² = 70.94%). To better understand the effects of mastication on sustained attention and alertness, further research is required which refines existing protocols, eliminates confounding effects such as gum formulation and constituents, and investigates the effects of contiguity, rate, and intensity of chewing.
... There are a range of theoretical perspectives considering why chewing gum might facilitate cognitive performance. The first major account holds that chewing gum induces arousal; thus, several studies have reported chewing gum increases/improves cerebral blood flow (Hirano & Onozuka, 2015;Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004;Wilkinson, Scholey, & Wesnes, 2002) as well as brain activity (Hirano et al., 2008) and an increase in heart rate, and blood pressure (Allen, Jacob, & Smith, 2014;Smith, 2010;Wilkinson et al., 2002). A few studies have reported that chewing gum increases levels of arousal by affecting the central and sympathetic nervous systems (Allen et al., 2014;Sakamoto, Nakata, & Kakigi, 2009). ...
... There are a range of theoretical perspectives considering why chewing gum might facilitate cognitive performance. The first major account holds that chewing gum induces arousal; thus, several studies have reported chewing gum increases/improves cerebral blood flow (Hirano & Onozuka, 2015;Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004;Wilkinson, Scholey, & Wesnes, 2002) as well as brain activity (Hirano et al., 2008) and an increase in heart rate, and blood pressure (Allen, Jacob, & Smith, 2014;Smith, 2010;Wilkinson et al., 2002). A few studies have reported that chewing gum increases levels of arousal by affecting the central and sympathetic nervous systems (Allen et al., 2014;Sakamoto, Nakata, & Kakigi, 2009). ...
... One of the first empirical studies to examine the effects of chewing gum on memory by Wilkinson et al. (2002) used immediate and delayed recall of words to examine short-term and long-term memory performances and found that participants who chewed gum displayed significantly better performance results. Following the success of this study, there were a number of attempts to replicate these effects of chewing gum on memory. ...
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Recent research has demonstrated chewing gum can enhance various cognitive processes associated with learning, but most studies have used cognitive functioning tasks (e.g., selective attention, working memory) as outcomes. Across two experiments, we investigated effects of chewing gum on self‐reports of alertness and test performance following study of realistic educational materials. In Experiment 1 (n = 40), adult participants who chewed gum while studying a 20‐minute physiology lesson outperformed a non‐chewing condition on subsequent terminology and comprehension tests, but did not report higher levels of post‐lesson alertness as hypothesised. In Experiment 2 (n = 39), adult participants who chewed gum while studying a 9‐minute lesson on a mental mathematics strategy outperformed a non‐chewing condition on a subsequent problem‐solving test, while also reporting higher levels of post‐lesson alertness. The results provide initial support for chewing gum while studying realistic educational materials across a range of topics and study durations.
... Zibell & Madansky, 2009), or that it will aid concentration (e.g. Wilkinson, Scholey, & Wesnes, 2002), so it is worthwhile establishing if these beliefs are wellfounded. ...
... It would be of interest to see if either of these specific reaction time effects could be replicated. Wilkinson et al. (2002) found that participants in a sham-chewing group did worse than the quiet control group on a simple reaction time task. Although this has been interpreted as indicating that the level of resistance in what one is chewing may have an effect on reaction time (Scholey, 2003), Wilkinson et al. themselves pointed out that participants in the sham-chewing group could have been distracted by having to perform the novel task of making chewing movements with nothing in their mouths. ...
... Recall: Immediate and delayed recall have been found to be better in a gum condition than in a no-gum control (Baker et al., 2004, experiment one;Wilkinson et al., 2002), although later research has not supported this finding (Smith, 2009c(Smith, , 2010O. Tucha, et al., 2004). ...
... Numerous studies have reported the influence of chewing on the cognitive function (Endo et al., 1982;Nageishi et al., 1993;Otomaru et al., 2003;Yokoyama et al., 2017;Suzuki et al., 1992Suzuki et al., , 1994Chu, 1994;Wilkinson et al., 2002;Baker et al., 2004;Stephane and Tunney, 2004). It has been suggested that chewing results in increased brain activity (Endo et al., 1982;Nageishi et al., 1993;Otomaru et al., 2003;Yokoyama et al., 2017), increased energy consumption (Suzuki et al., 1992;Suzuki et al., 1994), shortened selective reaction time (Chu, 1994), and increased working memory (Wilkinson et al., 2002;Baker et al., 2004;Stephane and Tunney, 2004) along with other effects. ...
... Numerous studies have reported the influence of chewing on the cognitive function (Endo et al., 1982;Nageishi et al., 1993;Otomaru et al., 2003;Yokoyama et al., 2017;Suzuki et al., 1992Suzuki et al., , 1994Chu, 1994;Wilkinson et al., 2002;Baker et al., 2004;Stephane and Tunney, 2004). It has been suggested that chewing results in increased brain activity (Endo et al., 1982;Nageishi et al., 1993;Otomaru et al., 2003;Yokoyama et al., 2017), increased energy consumption (Suzuki et al., 1992;Suzuki et al., 1994), shortened selective reaction time (Chu, 1994), and increased working memory (Wilkinson et al., 2002;Baker et al., 2004;Stephane and Tunney, 2004) along with other effects. In addition, the results of neurophysiological studies report that brain activity increases during chewing (Hasegawa et al., 2013) and that cognitive processing time, such as P300, which is event related potential, shortens after chewing (Sakamoto et al., 2009). ...
... It is said that an increase in the blood glucose level affects brain activity. Many previous studies have reported that an increased blood glucose level shortens the cognitive processing time (Sakamoto et al., 2009), increases the working memory (Wilkinson et al., 2002;Baker et al., 2004;Stephanes and Tunney, 2004), shortens the selection reaction time (Chu, 1994). Insulin is secreted from the pancreas in response to elevated blood glucose levels and acts to lower blood glucose level. ...
... A recent review showed that mastication is indeed related to cognition [5]. Even in younger adults, chewing gum has been shown to improve cognitive task performance for cognitive domains such as short-term memory [17,18], long-term memory [17], and the executive function working memory [18]. However, beneficial effects on these functions are not found for all tests [18] or in all studies [19,20], and are also not necessarily generalizable to all cognitive domains [21]. ...
... A recent review showed that mastication is indeed related to cognition [5]. Even in younger adults, chewing gum has been shown to improve cognitive task performance for cognitive domains such as short-term memory [17,18], long-term memory [17], and the executive function working memory [18]. However, beneficial effects on these functions are not found for all tests [18] or in all studies [19,20], and are also not necessarily generalizable to all cognitive domains [21]. ...
... Even in younger adults, chewing gum has been shown to improve cognitive task performance for cognitive domains such as short-term memory [17,18], long-term memory [17], and the executive function working memory [18]. However, beneficial effects on these functions are not found for all tests [18] or in all studies [19,20], and are also not necessarily generalizable to all cognitive domains [21]. For example, one study found no significant effects of chewing gum on spatial task performance [21]. ...
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Background Masticatory functioning alters with age. However, mastication has been found to be related to, for example, cognitive functioning, food intake, and some aspects of activities of daily living. Since cognitive functioning and activities of daily living show a decline in older adults with dementia, improving masticatory functioning may be of relevance to them. A possible way to improve mastication may be showing videos of people who are chewing. Observing chewing movements may activate the mirror neuron system, which becomes also activated during the execution of that same movement. The primary hypothesis is that the observation of chewing has a beneficial effect on masticatory functioning, or, more specifically, masticatory ability of older adults with dementia. Secondary, the intervention is hypothesized to have beneficial effects on food intake, cognition, activities of daily living, depression, and quality of life. Methods/Design An adjusted parallel randomized controlled trial is being performed in dining rooms of residential care settings. Older adults with dementia, for whom also additional eligibility criteria apply, are randomly assigned to the experimental (videos of chewing people) or control condition (videos of nature and buildings), by drawing folded pieces of paper. Participants who are able to watch each other’s videos are assigned to the same study condition. The intervention takes place during lunchtime, from Monday to Friday, for 3 months. During four moments of measurement, masticatory ability, food intake, cognitive functioning, activities of daily living, depression, and quality of life are assessed. Tests administrators blind to the group allocation administer the tests to participants. Discussion The goal of this study is to examine the effects of video observation of chewing on masticatory ability and several secondary outcome measures. In this study, the observation of chewing is added to the execution of the same action (i.e., during eating). Beneficial effects on masticatory ability, and consequently on the other outcome measures are hypothesized. The intervention may be easily integrated into daily care, and might add to the lives of the increasing number of older adults with dementia by beneficially influencing multiple daily life functions. Trial registration NTR5124. Registration date: 30 March 2015.
... Positive effects of chewing gum on cognitive functions have been described in numerous studies. Chewing gum can improve memory and concentration functions in healthy children and adults [18][19][20]. It has been suggested that gum chewing can influence cerebral blood flow and suppression of insulin secretion [21]. ...
... In the research by Sakamoto et al. [18], improvements in concentration were only noticeable when chewing took place before the work began and remained only during the first twenty minutes of cognitive work. There are also data that do not confirm the relationship between chewing gum and improvement in attention among ADHD children [19,22,23]. ...
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Objectives: The aim of the study was to compare the prevalence of parafunctions and signs and symptoms of TMD in a population group of children with and without ADHD. Methods: The study included all 5th grade children of all public primary schools in Sopot (untreated, unguided children). The reporting rate was 91%. At the first stage of the psychological-psychiatric study both parents and children filled in the CBCLand YSR questionnaires. At the next stage, in the group of children selected during the screening, aqualified child psychiatrist conducted asemi-structured diagnostic interview K-SADS-PLand diagnosed ADHD. Parafunctions, signs and symptoms of TMD were assessed by conducting a direct interview with a child and a clinical examination by a dentist. Results: There were significant differences (p < 0.05) between children with ADHD and without ADHD associated with parafunctions such as chewing gum (76.47% vs. 46.07%), nail biting (70.59% vs. 40.45%) and bruxism (52.54% vs. 26.22%), the number of signs and symptoms of TMD (1 sign or symptom 0.0% vs. 32.21%; 4-7 signs or symptoms 17.65% vs. 3.75%). Conclusions: In children with ADHD, symptoms of temporomandibular joint disorders and parafunctions were significantly more frequent. These studies suggest that children with ADHD constitute agroup of increased risk for TMD in the future. Interdisciplinary treatment of an ADHD patient by a psychiatrist and a dentist is necessary.
... Possible explanations for the effect of chewing gum on cognitive function may be related to a bilateral increases of neuronal activity within some areas of the brain (e.g., sensorimotor cortex, supplementary motor area, prefrontal cortex, insula, cerebellum, and thalamus) [15,16], as well as an increased release of insulin and an increased cerebral blood flow [7,14,15,17]. Shiba et al. [18] also found suppression of the parasympathetic nervous activity and/or enhancement of the sympathetic nervous activity for the heart of healthy adults after chewing gum. Thus, it seems that chewing gum might play a role in the modulation of autonomic nervous activity in healthy adults. ...
... Also, chewing gum by itself might lead to positive behavioral changes in healthy individuals [6,7]. Indeed, a recent systematic review and meta-analysis reported that there is a modest link between chewing gum and sustained attention in healthy adults [8]. ...
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Background: There is some evidence showing significant correlations between acute chewing gum and orofacial function, and between acute chewing gum and cognitive function; however, as far as we are aware, little is known about the chronic effects of chewing gum training on cognitive and orofacial functions in healthy adults. Objectives: To evaluate the chronic effects of chewing gum training on orofacial and cognitive functions in healthy adults. Method: Searches of the electronic databases PubMed, Scopus, BVS, CENTRAL, Scopus, and Google Scholar were conducted from inception to 14 January 2020. The inclusion criteria used were: clinical trial or randomized controlled trial lasting a minimum of four weeks, chewing gum intervention in at least one arm of the study, presence of a non-exercise control group, study population consisting of healthy adults, study outcomes consisting of orofacial function and/or cognitive function. Results: Starting from 5973 sources, a total of six articles met the inclusion criteria, and they were subjected to a systematic review. The main findings were that chewing gum training improved some variables related to orofacial function. No clear effect of chewing gum training on cognitive function was found. Conclusions: Chronic chewing gum training has an unclear positive effect on specific variables related to orofacial and cognitive function in healthy adults.
... In addition to being a useful model of extra-to-intracranial signal conduction, ChREs in iEEG constitute a rather frequent and inevitable artefact to be accounted for in the development of clinical BCI applications for paralyzed patients, because self-feeding is a vitally important application area that needs to be covered by future BCI technology (Velliste et al., 2008). Moreover, the present thesis focuses on ChREs, because it was found that chewing has effects on cognitive functions (Wilkinson et al., 2002;Smith, 2009;Tucha and Simpson, 2011;Onyper et al., 2011). However, these effects were previously attributed to indirect psychological effects such as unspecific arousal. ...
... Nevertheless, chewing has repeatedly been reported to have effects on cognitive functions (Wilkinson et al., 2002;Tucha et al., 2004;Onyper et al., 2011) that occur in a similar time window as the effects evoked by tRNS. By administering a battery of cognitive tasks to participants who chewed a chewing gum either prior to or throughout testing, it was recently confirmed that chewing is associated with changes in cognitive performance that are not present in non-chewing controls. ...
Thesis
Hintergrund. Intrakranielle Elektroenzephalographie (iEEG) spielt eine zunehmend wichtige Rolle in den Neurowissenschaften und könnte als Kontrollsignal bei zukünftigen Hirn-Computer-Schnittstellen (BCI) für gelähmte Patienten angewendet werden. Ein wichtiger Aspekt ist dabei Stabilität gegenüber Störungen durch Alltagsaktivitäten wie z.B. elektromyographischen Signalen (EMG). Bisher gibt es nur wenige Studien zur Signalqualität von iEEG. In dieser Arbeit haben wir Kauen als Modell für EMG-Effekte, die hochamplitudig und häufig im Elektroenzephalogramm (EEG) auftreten, genutzt. Die Hauptziele der Arbeit sind: (1) zu untersuchen, ob Kauassoziierte Effekte (KAE) reproduzierbar in iEEG Signalen nachweisbar sind, (2) die Unterschiede zwischen KAE und neuraler Aktivität darzulegen, und (3) die Wege von extra- zu intrakranieller Volumenleitung zu analysieren, die für die beobachteten Effekte verantwortlich sind. Methoden. Wir haben die Daten von dreizehn Epilepsiepatienten die mit intrakraniellen Elektroden (Gitter-, Streifen- und Tiefenelektroden) implantiert waren untersucht. iEEG, EEG und Videoaufnahmen wurden synchronisiert aufgezeichnet. Daraufhin wurden Kauereignisse manuell entsprechend den EMG Signalen an temporalen EEG Elektroden ausgewählt und die KAE hinsichtlich spektraler und topographischer Eigenschaften untersucht. Für die Vergleiche mit neuraler Aktivität wurden Datensätze, die im Rahmen früherer Studien erhoben wurden, analysiert. Ergebnisse. Wir haben breitbandige, hochamplitudige KAE mit einer flachen örtlichen Ausbreitung gefunden, die sich auf fast alle iEEG Elektroden verteilten. Die stärksten KAE wurden an iEEG-Elektroden direkt unter dem Musculus temporalis gemessen, unabhängig von der individuellen Anordnung der Kraniotomiedefekte und ohne Rücksicht auf anatomische Grenzen (z.B. Sulcus centralis). Im Gegensatz dazu wurden bei der Analyse der neuralen Aktivitäten deutlich fokalisierte Effekte festgestellt, die zudem eine andere Frequenzverteilung aufwiesen. Diskussion. Dies ist die erste Untersuchung nicht-okulärer Auswirkungen von EMG-Artefakten auf iEEG-Signale, die auf einer größeren Patientenanzahl basiert. Die Ergebnisse dieser Arbeit zeigen, dass KAE mit iEEG interferieren können, sich jedoch hinsichtlich ihrer spektralen und zeitlichen Eigenschaften von neuraler Aktivität unterscheiden. In zukünftigen BCI Studien müssen daher intrakranielle EMG-Artefakte durch Alltagsaktivitäten berücksichtigt werden, insbesondere wenn diese auf hochfrequenten iEEG-Komponenten beruhen. Da die KAE in Frequenzbereichen gefunden wurden, für die in früheren exogenen Hirnstimulationsstudien Verbesserungen in Lernaufgaben gezeigt haben, könnte es sein, dass KAE als endogene Hirnstimulation wirken könnten und somit zur Klärung von kognitiven Auswirkungen in Verbindung mit Kauaktivität beitragen könnten.
... Chewing gum is quite affordable and students report using it for many reasons. Students, especially college students, eat chewing gum, not just as mere snack, but also as substance that can help to improve concentration (Wilkinson, Scholey, & Wesnes, 2002), reduce stress (Zibell & Madansky, 2009), and to increase alertness (Johnson, Jenks, Mills, Albert, & Cox, 2011), especially when feeling sleepy (Wenk, 2012). ...
... The findings of this research have some practical applications to teaching and learning. One of the most important educational implication of this study is in a large body of evidence (e.g., Allen & Smith, 2011;Onyper, et. al., 2011;Wilkinson, et. al., 2002), which show that chewing gum improves memory when taken prior to a test. Chewing gum results in significant improvement of memory, it improves regional cerebral blood flow in the frontal-temporal regions, which are believed to mediate aspects of memory functioning (Sesay, et. al., 2000). Also, eating chewing gum promotes the release of ...
Article
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The study examined whether chewing gum would facilitate recall performance and if females would perform better than males on verbal recall. Participants for the study were 120 undergraduate students of University of Nigeria, Nsukka. There were 60 males and 60 females (Mean age = 21.13 years; SD = 2.17). Oral prose assessment test 1 (OPAT 1) was the source for data collection. A between-groups ANOVA statistics was used for data analyses, and results showed that neither chewing gum nor gender has a simple independent effect on recall memory (p <0.05; ŋ2 = 0.31). The implication of the finding is that chewing gum has some facilitating influence on recall, but that is only for female participants. Also, overall performance on the OPAT 1 showed that females were better than males recall memory (p <0.05). Discussion implores teachers not to discourage the consumption of chewing gum in the classrooms, since it has the possibility to enhance recall ability.
... However, randomized controlled trials specifically investigating the effects of aqueous spearmint (Mentha spicata L.) extracts, a member of the Lamiaceae family, on cognitive function are limited. A few studies have been conducted evaluating the effects of small quantities of spearmint oil in spearmint chewing gum on memory in healthy volunteers, which report conflicting results [14][15][16]. Previous work in rodents with an aqueous spearmint extract found that 320 and 640 mg/kg body weight of the extract (16 and 32 mg rosmarinic acid/kg body weight), equivalent to 600-1200 mg of the spearmint extract on average for humans, were effective in improving memory and learning in a SAMP8 mouse model of accelerated aging [17,18]. ...
... Conflicting evidence exists regarding the effects of spearmint on cognitive function and are limited to spearmint chewing gum specifically. Mint chewing gum is commonly formulated with oil extracts and contains small amounts of extract, typically 0.1-5% (w/w), but the composition and quantity of spearmint extract used in these trials were not described [14,15]. Furthermore, the interpretation of these results is difficult, due to the absence of dosing information; it is also uncertain whether the improvement in memory and attention/concentration is the result of spearmint or the act of chewing, as a number of studies suggest the act of chewing alone may support cognitive function [47]. ...
Article
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Background:Cognitive function can decline during theagingprocess andsignificantly reducequality of life. Although a number of interventionshave been investigatedforcognitive dysfunction, including antioxidants,this prominent health concern warrants further explorationof additionalmethods to support cognitive health later in life. An aqueous extract from a proprietary spearmint line has been developed which contains a number of antioxidant compounds, including rosmarinic acid,athigherlevels than typically found incommercially-bred spearmint. Therefore, this pilot trialassessedthe tolerance, bioavailability,andpotential cognitive health implications ofa proprietary spearmint extractin men and women with self-reported memory impairment.Methods:Subjectsconsumed 900 mg/dayspearmint extract for 30 days. The sample population (N = 11) was73% femaleand 27% male with amean age of 58.7± 1.6 y. Tolerabilityparameters were assessed at baseline and end of treatmentvisits. Computerized cognitive function tests were completed and blood was drawnat pre-and post-dose (0.5 to4 h) timepoints duringbaseline and end of treatmentvisits.Subjective cognitionwas also assessed atthe end of treatment.Results:Neitherserious adverse events nor clinically relevant findings were observed in anytolerabilityparameters.Plasmavanillic, caffeic, and ferulic acid sulfates, rosmarinic acid, and methyl rosmarinic acid glucuronide were detected in plasma following acute administration of the spearmint extract. Computerized cognitive function scores improved in reasoning(P =0.023)and attention/concentration(P = 0.002) after 30 days of supplementation.After acute administration,subjects had improvedattention/concentrationin two tests at 2 (P = 0.042and P = 0.025) and 4 h (P = 0.001 and P = 0.002).Conclusions: The results from this pilot trial suggestthatthe spearmint extract,which containshigherrosmarinic acid contentrelative to extracts from typical commercial lines, was well-toleratedat 900 mg/day. The extract was alsobioavailable.Further investigation is warranted regarding its potential for supporting cognitive health.
... Chewing gum has repeatedly been reported to have effects on cognitive functions [27], [68]- [70]. By administering a battery of cognitive tasks to participants who chewed gum either prior to or during testing, it was recently confirmed that chewing is associated with changes in cognitive performance that are not present in non-chewing controls. ...
Article
Objective: Electric fields (EF) of approx. 0.2 V/m have been shown to be sufficiently strong to both modulate neuronal activity in the cerebral cortex and have measurable effects on cognitive performance. We hypothesized that the EF caused by the electrical activity of extracranial muscles during natural chewing may reach similar strength in the cerebral cortex and hence might act as an endogenous modality of brain stimulation. Here, we present first steps toward validating this hypothesis. Methods: Using a realistic volume conductor head model of an epilepsy patient having undergone intracranial electrode placement and utilizing simultaneous intracranial and extracranial electrical recordings during chewing, we derive predictions about the chewing-related cortical EF strength to be expected in healthy individuals. Results: We find that in the region of the temporal poles, the expected EF strength may reach amplitudes in the order of 0.1-1 V/m. Conclusion: The cortical EF caused by natural chewing could be large enough to modulate ongoing neural activity in the cerebral cortex and influence cognitive performance. Significance: The present study lends first support for the assumption that extracranial muscle activity might represent an endogenous source of electrical brain stimulation. This offers a new potential explanation for the puzzling effects of gum chewing on cognition, which have been repeatedly reported in the literature.
... Many people chew gum partly due to the belief that it in-creases aspects of mental performance, including concentration . 3 As chewing gums are taken orally and oral route of drug delivery is the most preferred route amongst the patient and clinicians due to various advantages it offers.4 ...
Article
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Chewing gums are mobile drug delivery systems. It is a potentially useful means of administering drugs either locally or systemically via, the oral cavity. The medicated chewing gum has through the years gained increasing acceptance as a drug delivery system. Several ingredients are now incorporated in medicated chewing gum, e.g. Fluoride for prophylaxis of dental caries, chlorhexidine as local disinfectant, nicotine for smoking cessation, aspirin as an analgesic, and caffeine as a stay alert preparation. MCGs are solid, single dose preparations with a base consisting mainly of gums that are intended to be chewed but not swallowed. They contain one or more active substances which are released by chewing and are intended to be used for local treatment of mouth diseases or systemic delivery after absorption through the buccal mucosa.
... Par ailleurs, une collection éclectique de recherches a montré des corrélations entre la capacité en mémoire de travail, et... à peu près tout -régulation émotionnelle (Schmeichel et al., 2010), précision du tir avec un pistolet (G. Wood et al., 2016), apprentissage d'un langage informatique (Lehrer et al., 1988), performance au basketball (Buszard et al., 2017), écriture d'essais littéraires (Benton et al., 1984), suppression des pensées intrusives (Geraerts et al., 2007), modération des effets de la dépression (Noreen et al., 2019), ou encore qualité de l'improvisation au violoncelle (De Dreu et al., 2012) ; sans compter les travaux en sens inverse qui proposent que la capacité en mémoire de travail est augmentée par le fait de pratiquer l'aérobic (Pontifex et al., 2009), courir pieds nus (Alloway et al., 2016), ou mâcher du chewinggum (Wilkinson et al., 2002). Ce pattern très général de corrélations peut être vu, au choix, comme un argument en faveur de la centralité de la mémoire de travail pour l'activité cognitive , ou comme un sérieux problème de validité divergente dans la constitution d'un réseau nomologique cohérent (Cronbach & Meehl, 1955). ...
... Wilkinson et al. found that heart-rate was increased when chewing gum compared with when participants did not chew gum. They also observed improvements in cognitive function and suggested that mastication may have increased regional cerebral blood flow and increased insulin release [116]. ...
... Hollingworth [3] in 1939 demonstrated the relationship between mastication and cognitive functions through elec- troencephalography and stated that there is an increase in performance of cognitive function during mastication. In 2002, Wilkinson et al. [4] carried out an experimen- tal study between chewing and non-chewing groups, and found an increase in episodic, spatial and numeric work- ing memory in chewing group when compared with that of the non-chewing control group. Numerous such studies have been carried out which associate the reduced number of residual teeth and decreased use of dentures to cognitive deficits [5,6]. ...
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Mastication as we all know has always been related to its primary function of digestion, but little do we know that it produces an enhancing effect on general health, especially the cognitive performance related aspects of memory. Recent studies have shown its association with activation of various brain regions, however little is known about its effects on neuronal activity in these specified regions. According to the enormous evidences collected so far, mastication has proved to be effective in conducting huge amount of sensory information to the brain, and maintaining learning and memory functions of hippocampus. Therefore it is essential that we maintain normal occlusion and preserve the masticatory function as long as possible to prevent the attenuation of hippocampus, caused by occlusal disharmony and reduced mastication. We provide an overview on how mastication activates various cortical areas of the brain and how an increase in the cerebral blood oxygen level of hippocampus and prefrontal cortex (PFC) accentuates the learning and memory process. We also justify why maintaining and establishing a normal occlusion is important from neurological point of view.
... Previous studies reported the effects of mastication on psychological tests related to arousal (Endo et al., 1982;Nageishi et al., 1993;Otomaru et al., 2003), energy expenditure and heart rate (Suzuki et al., 1992(Suzuki et al., , 1994, choice reaction time (RT) (Chu, 1994), positive mood (Smith, 2009), and working memory (Wilkinson et al., 2002;Baker et al., 2004;Stephens and Tunney, 2004;Hirano et al., 2008). For example, Nageishi and colleagues (1993) investigated the effects of mastication on arousal using the UWIST test, which consists of three-dimensional scales, energetic arousal (active-tired), tense arousal (nervous-calm), and hedonic tone (pleasure-displeasure). ...
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Mastication is a complicated movement generated from a neural population in the brainstem and a neural network involving several brain regions. Recently, attention has been focused on the relationship between mastication and age-related decline in human cognitive function, but the neural mechanisms underlying this association remain unknown. In this article, we review research on the effect of mastication based on data obtained using event-related potentials (ERPs), including the P300 component and contingent negative variation (CNV), motor-related cortical potentials (MRCPs), and reaction time (RT) as behavioral data. The peak latency of P300 and RT clearly shortened with the repetition of sessions in Mastication, but not in Control, Jaw Movement, or Finger Tapping. The mean amplitude of CNV differed between the Mastication and Control conditions with the repetition of sessions. By contrast, there was no significant difference in the amplitude of MRCP between Mastication and Control in any of the sessions. These results suggest that mastication is associated with cognitive processing rather than movement-related processing in the human brain. We believe that non-invasive recording methods, such as electroencephalography (EEG), magnetoencephalography (MEG), transcranial magnetic stimulation (TMS), functional magnetic resonance imaging (fMRI), and near-infrared spectroscopy (NIRS), will supply valuable evidence in support of a positive relationship between mastication and cognition.
... A large number of studies have reported the effects of mastication in tests such as positive mood (Smith, 2009), arousal (Endo et al., 1982;Nageishi et al., 1993;Otomaru et al., 2003), working memory (Wilkinson et al., 2002;Baker et al., 2004;Stephens and Tunney, 2004;Hirano et al., 2008), and background EEG (Endo et al., 1982;Masumoto et al., 1998Masumoto et al., , 1999Morinushi et al., 2000). However, the mechanisms responsible for these effects are still unclear. ...
Article
The aim of the present study was to investigate the effects of mastication on somatosensory processing using somatosensory-evoked potentials (SEPs). Fourteen healthy subjects received a median nerve stimulation at the right wrist under two conditions: Mastication and Control. SEPs were recorded in five sessions for approximately seven minutes: Pre, Post 1, 2, 3, and 4. Subjects were asked to chew gum for five minutes after one session in Mastication. Control included the same five sessions. The amplitudes and latencies of P14, N20, P25, N35, P45, and N60 components at C3′, frontal N30 component at Fz, and P100 and N140 components at Pz were analyzed. The amplitude of P45-N60 was significantly smaller at Post 1, 2, 3, and 4 than at Pre in Control, but not in Mastication. The latency of P25 was significantly longer at Post 2, 3, and 4 than at Pre in Control, but not in Mastication. The latency of P100 was significantly longer at Post 2 than at Pre in Control, but not in Mastication. These results suggest the significant effects of mastication on the neural activity of human somatosensory processing.
... It significantly increases bilateral middle cerebral artery blood velocity and oxygen levels [30,31]. Moreover, it has been shown to increase heart rate and improve memory function possibly due to upregulated delivery of metabolic substrates to the brain (Wilkinson, Scholey and Wesnes, 2002). The movement of masticatory muscles may be also considered a physical activity constituting a mild form of exercise which is a well-established modulator of not only AHN but cognitive health in general [32,33]. ...
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BACKGROUND: Decreased mastication due to edentulism in both humans and animals have a negative impact on brain function and cognition. Human populations have shown a close association between masticatory function, cognitive status and age-related neurodegeneration in the elderly. Evidence shows that mastication during tasks may have an acute positive impact on normal cognitive function, such as sustained attention. However, there is a lack of evidence showing the long-Term effects of changes in habitual masticatory behaviour on cognition. OBJECTIVE: To investigate the impact of a 3-month mastication intervention on cognitive function in healthy older adults. METHODS: 53 participants aged 45-70 years old were required to chew mint-flavoured sugar free chewing gum for 10 minutes, 3 times a day over 3 months. Pattern separation and recognition memory was measured using the Mnemonic Similarity Task. Questionnaires were administered to measure changes in mood, anxiety, and sleep quality. RESULTS: Extended periods of mastication gave rise to a significant improvement in recognition memory compared to a non-chewing control group. CONCLUSION:With an ageing population, non-medical interventions are imperative to delay age-related cognitive decline. Further work needs to be carried out in larger populations to validate the findings in this study and elucidate potential mechanisms.
... Fig. 7 provides and overview of the spectral power and topography of ChRE in relation to craniotomy defects. Mastication has also been described to have effects on cognitive performance in healthy volunteers (Wilkinson et al., 2002;Smith, 2009;Onyper et al., 2011;Tucha and Simpson, 2011). Endogenous brain stimulation by ChRE might be a likely candidate to explain the modified cognitive performances of healthy volunteers after mastication, which up to now have been attributed to unspecific arousal effects. ...
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In this work, the propagation of electric potentials from source to measurement points was investigated with three finite element method (FEM) models which were based on magnetic resonance imaging (MRI) data sets of increasing spatial resolution. The spatial observation scales of the electrophysiological imaging modalities of electroencephalography (EEG), micro EEG (μEEG), electrocorticography (ECoG) and micro ECoG (μECoG) were modeled. The Leitmotiv of this work is to understand how neuronal and other sources are reflected in high-resolution multi-scale electrophysiological neuroimaging. In the process, anatomical details like foramina, craniotomy defects and cortical depth of modeled dipoles were specifically addressed. In the first part of this work, it was investigated how electrical potentials propagate from outside of the skull into the brain. This approach is based on the observation that in subdurally implanted epilepsy patients electromyographic (EMG) artifacts are measurable within the skull with ECoG electrodes. To simulate the propagation of those artifacts from the temporal muscle to the ECoG electrodes, we created an individualized FEM model based on MRI data recorded before and after the electrode implantation. Craniotomy defects and highly insulating silicon ECoG grid were implemented. By relating simulation results and measurements in epilepsy patients, it was possible to show that propagation of EMG artifacts into the brain is indeed facilitated by the presence of craniotomy defects, but that even in their absence, the artifacts would still generate 0.11V/m. In the second part of this work, propagation of cortical potentials to the surface of the head was investigated. To this end, naturally present skull foramina were modeled. Because the spatial resolution of standard 1.5 Tesla (T) diagnostic MRI is not sufficient to resolve skull foramina induced by highly conductive blood vessels which might influence electric propagation, 7T MRI measurements were used to create for the first time a ultra-high resolution FEM model. EEG and μEEG electrodes were added to it. The results of the simulations show that foramina located close to the electrodes have a dual effect. They increase the amplitudes of potentials measured on the surface of the head and distort the electrical field into their direction. The second effect could only be measured using μEEG, the spatial resolution of EEG being to low to capture the electric field shift. This finding highlights the usefulness of spatial multiscale approaches. After having simulated EEG, μEEG, and ECoG measurements, the last part of this work investigates spatially highly resolved μECoG measurements. As μECoG is not yet medically established, no human measurements exist for comparison. We therefore created a Göttingen minipig brain FEM model. Comparison of in vivo measurements and simulations show that, in Göttingen minipigs, dipolar cortical activity generated at a depth of 0.6mm best fits the spatial profiles measured by μECoG. In summary the present thesis shows that (i) placement of cortical dipoles at realistic depths and (ii) incorporation of individual skull anatomy, down to millimeter wide foramina, are necessary for realistic multiscale modeling both of electrophysiological signal propagation to and from the brain.
... Although, a number of studies have shown the vast positive impacts of chewing gum on memory, multi-tasking and mood but it has not received worldwide acceptance. 4,5 There can be a number of valid reasons for this under-rating that include funding of a number of such studies by the lucrative manufacturers of chewing gum acting as demagogues for the society, creating an impression of biasing. It can also be due to ignorance of general population regarding these studies or it can be a mere lack of evidence provided by various studies. ...
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Background: Chewing gum has multidimensional effects on the body that work in harmony to improve one's abilities. The present study was aimed to focus at the authenticity of the myth that chewing gum reduces stress, elevates mood and increases concentration. Methodology: This descriptive cross-sectional survey and observational analytic study was carried at Rawalpindi Medical College, Rawalpindi over a period of 3 weeks. A total of 200 subjects participated in the study. They filled in their demographic details and self-rated their stress levels in various situations. The group was equally divided into a control and a study group. All the participants were subjected to a mental arithmetic test. The participants of the study group were provided with a gum during their examination. A comparison of the marks scored was done. Results: Out of the entire group only 13.3% were non-chewers whereas 50% replied that they chewed gum 'sometimes'. Majority of the people felt mild, moderate and severe stress in general, while in college and during examination respectively. A large number of subjects chewed gum for the reason that it makes them feel elated (43.3%). In the mental arithmetic test, the non-chewer group scored more than the chewer group with a highly significant statistical difference (p=0.001). Conclusion: Chewing gum has no or minimal role in reducing stress. However, as it cherishes ones' mood, it can be chewed to get rid of the acute anxiety states faced during various stressful conditions. Nevertheless, the study strongly denounces the concept that chewing gum enhances ones attention and cognition.
... Many studies have reported on the positive effects of chewing gum on cognition, including alertness, attention, cognitive processing speed, and memory (Wilkinson et al. 2002;Tucha et al. 2004;Miles and Johnson 2007;Ono et al. 2007;Scherder et al. 2008;Kushiro and Goto 2011;Tucha and Simpson 2011;Hirano et al. 2013). By contrast, only a few studies have reported on the effect on motor function (Ono et al. 2007;Kushiro and Goto 2011) and no study on the cortical effect of chewing gum on a motor task has been reported. ...
Article
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Nine right-handed normal subjects were recruited for this study. We compared the cortical activation during execution of hand movements (right finger flexion-extension) with that during execution of hand movements while chewing gum (right side chewing). We found that execution of hand movements while chewing gum induced less activation in the contralateral SM1 than hand movements alone. Based on our findings, it appears chewing gum during execution of hand movements enhanced the efficiency of hand movements.
... The small increase in BP and HR observed with chewing gum compared to not chewing gum after the nitrate rich meal was contrary to our hypothesis and other clinical trials where reductions in BP are observed after a nitrate-rich meal (8). Two previous studies have, however, observed that chewing gum can result in substantial acute increases in BP and HR (27,28), including during cognitive processing (49). These studies have indicated that the increase in BP and HR are similar to those observed for exercise and is likely due to jaw muscle activity (27,28). ...
Article
Objectives Cardiovascular and neurocognitive responses to chewing gum have been reported, but the mechanisms are not well understood. Chewing gum after a nitrate-rich meal may upregulate the reduction of oral nitrate to nitrite and increase nitric oxide (NO), a molecule important to cardiovascular and neurocognitive health. We aimed to explore effects of chewing gum after a nitrate-rich meal on nitrate metabolism (through the enterosalivary nitrate-nitrite-NO pathway), endothelial function, blood pressure (BP), neurocognitive performance, mood and anxiety. Methods Twenty healthy men (n = 6) and women (n = 14) with a mean age of 48 years (range: 23–69) were recruited to a randomized controlled cross-over trial. After consumption of a nitrate-rich meal (180 mg of nitrate), we assessed the acute effects of chewing gum, compared to no gum chewing, on (i) salivary nitrate, nitrite and the nitrate reductase ratio (100 x [nitrite]/([nitrate] + [nitrite]); (ii) plasma nitrite, S-nitrosothiols and other nitroso species (RXNO); (iii) endothelial function (measured by flow mediated dilatation); (iv) BP; (v) neurocognitive performance; (vi) mood; and (vii) anxiety. Results Consumption of the nitrate-rich meal resulted in a significant increase in markers of nitrate metabolism. A significantly higher peak flow mediated dilatation was observed with chewing compared to no chewing (baseline adjusted mean difference: 1.10%, 95% CI: 0.06, 2.14; p = 0.038) after the nitrate-rich meal. A significant small increase in systolic BP, diastolic BP and heart rate were observed with chewing compared to no chewing after the nitrate-rich meal. The study did not observe increased oral reduction of nitrate to nitrite and NO, or improvements in neurocognitive performance, mood or anxiety with chewing compared to no chewing. Conclusion Chewing gum after a nitrate-rich meal resulted in an acute improvement in endothelial function and a small increase in BP but did not result in acute effects on neurocognitive function, mood or anxiety.
... Whether that was due to sympathetic nerve inhibition or parasympathetic nerve activity had been unclear; however, we concluded that it was most likely due to the predominating parasympathetic nerve activity. Furthermore, previous studies have demonstrated that mastication affects human cognitive processing, including choice reaction time [16], positive mood [17], working memory [18,19], somatosensory processing [20], motor preparation [21], and Go/No-go decision-making [22]. One factor involved in the mechanism of eye fatigue is central fatigue due to processing visual information associated with cognitive function. ...
Article
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Purpose: To investigate the effects of chewing gum and tablet candy to reduce eyestrain in healthy individuals. Materials and methods: A double-blinded crossover trial was conducted. Forty-six healthy individuals (23 men, 23 women) between 20 and 59 years old, feeling eyestrain, were enrolled. Each 10-year age group included 12 individuals except the 30s group, which included 10 individuals. A visual task was performed on reading material displayed on a computer screen at a fixed distance for 60 min. Gum or tablet candy of two pieces were chewed for two 15-min periods starting 15 and 45 min after starting to read. Subjects chewed gum on Day 1 and tablet candy on Day 2, and vice versa. Primary outcome is as follows: subjective eye fatigue (eye tiredness, eye heaviness, blurred vision, double vision, and eye dryness) using a visual analog scale (VAS). Secondary outcomes are as follows: subjective accommodation from near and far points of accommodation measured with a D'ACOMO, spherical equivalent refraction, and eye dryness by analyzing ring break-up time (RBUT) measured with the RT-7000 Auto Ref-Topographer. Results: The VAS scores of subjective eye fatigue were not significantly changed between chewing gum and tablet candy (P = 0.397 - P = 0.909). Those scores of eye tiredness and eye heaviness were significantly longer before and after the visual task with tablet candy (P = 0.013 and P = 0.025, respectively) but not with chewing gum. The changes of subjective accommodation were significantly lower after the visual task between chewing gum and candy (P = 0.043). There were significant differences among each age group (20 s vs. 30 s, P = 0.594; 20 s vs. 40 s, P = 0.002; 20 s vs. 50 s, P = 0.002). After reading, the changes of spherical equivalent refraction did not indicate a shift toward myopia (P = 0.267). In the RBUT, there were no significant differences between the samples (P = 0.680). Conclusions: Chewing gum helps improve the ability of the eye to focus, especially in young adults.
... Researchers reported that waking up due to mastication [7] [8] [9] results in an increase in energy consumption [10] [11]. Re-searchers also reported that performance reaction time [12] and working memory may also improve [13] [14] [15] because of mastication. Other reports involving neuro-scientific measurements indicate that mastication increases brain activity [5] and shortens cognitive processing time (e.g., the P300 wave of event-related potential after mastication [4]). ...
... However, it remains unclear how such systems are involved in eating behavior. Previous studies have reported several effects of mastication and gum chewing on functions such as arousal (Otomaru et al., 2003), energy expenditure (Suzuki, Shibata, & Sato, 1992), choice reaction time (Chu, 1994), and working memory (Moss & Scholey, 1996; Wilkinson, Scholey, & Wesnes, 2002 ). Using eventrelated potentials, Sakamoto, Nakata, and Kakigi (2009) discovered that gum chewing may improve central nervous system function. ...
Article
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Since increased cerebral oxygenation reflects cerebral activation, this study investigated the effect of mastication frequency on prefrontal cortex oxygenation. Eleven young volunteers (nine women, two men; M age = 20.9 years, SD = 0.9) carried out three trials in which they were asked to chew a tasteless gum for 3 min at varying (rates of mastication frequency: 30, 70, and 110). Breaks of 2 min each were interleaved between trials. The oxygenation of the left prefrontal cortex was monitored by near-infrared spectroscopy. We found a significant increase in cortical oxygenation during gum chewing in all three conditions (p < .05), compared with a resting level; we also found a significant difference between the Fast and Slow chewing conditions, and between the Fast and Normal (70 rpm) conditions, both findings seemingly related to activation of a motor command in frontal brain regions. To our knowledge, this is the first report on the effect of mastication frequency on cerebral oxygenation. Possible implications of this finding are discussed.
... Based on these findings, the authors speculate that these two behaviors may produce similar changes to cognitive processing. Although connections between gum chewing and cognition are mixed (Allen & Smith, 2011), evidence suggests that working memory performance can be enhanced by this behavior (e.g., Wilkinson, Scholey, & Wesnes, 2002;Stevens & Tunney, 2004;Hirano et al., 2008). This is noteworthy given previous research has suggested that, by cooling the brain, yawns could enhance mental processing efficiency on tasks evoking working memory (i.e., vigilance) (Gallup & Gallup, 2007). ...
... A recent study a has also shown interesting negative associations between body mass index (BMI) and the number of chewing cycles, as well as chewing duration before swallowing in fully dentate healthy adults [10]. In addition, several epidemiological studies in the young adults [11,12] and the elderly [13][14][15] have shown a positive relationship between mastication and cognitive functions. ...
Article
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The purpose of this study is to clarify the effects of chronic powder diet feeding on sleep patterns and other physiological/anatomical changes in mice. C57BL/6 male mice were divided into two groups from weaning: a group fed with solid food (SD) and a group fed with powder food (PD), and sleep and physiological and anatomical changes were compared between the groups. PD exhibited less cranial bone structure development and a significant weight gain. Furthermore, these PD mice showed reduced number of neurogenesis in the hippocampus. Sleep analysis showed that PD induced attenuated diurnal sleep/wake rhythm, characterized by increased sleep during active period and decreased sleep during rest period. With food deprivation (FD), PD showed less enhancement of wake/locomotor activity compared to SD, indicating reduced food-seeking behavior during FD. These results suggest that powder feeding in mice results in a cluster of detrimental symptoms caused by abnormal energy metabolism and anatomical/neurological changes.
... In the case of nicotine a complex interaction with attention and memory occurs [12]- [14] while caffeine reduces tiredness [15]- [17] Even common, traditional, and unregulated herbs and spices, such as sage, can improve memory and mood through chemical effects [18] .Chewing gums may also affect memory probably by heightening arousal or increasing blood sugar level. [19] Neurotechnical Enhancement: ...
Article
Er zijn publicaties die suggereren dat kauwgom kauwen een positief effect zou kunnen hebben op aandacht en concentratie. Door het toestaan van kauwgom tijdens proefwerken zouden leerlingen van middelbare scholen misschien hogere cijfers kunnen halen. Eerdere studies gebruikten echter kleine steekproeven en de resultaten waren niet eenduidig. Om het gebruik van kauwgom goed uit te zoeken, randomiseerden wij een grote groep middelbare scholieren naar kauwgom/geen kauwgom kauwen tijdens het maken van proefwerken. 378 havo/vwo-leerlingen werden gerandomiseerd in twee groepen van gelijke grootte. Vlak voor een toets kreeg de ene groep kauwgom, de andere groep niet. De toetsresultaten tussen deze groepen werden per klas met elkaar vergeleken. Ook werden effecten van kauwgom kauwen bestudeerd op het resultaat van proefwerken in alfa- en bètavakken en bij jongens en meisjes. Er bleek geen significant verschil in score te zijn tussen de groepen met en zonder kauwgom, op proefwerken van verschillende vakken. Er werd eveneens geen effect van kauwgom kauwen gevonden op toetsresultaten, noch in bèta-, noch in alfavakken. Wanneer de leerlingen naar geslacht werden onderverdeeld, bleek er een significant negatief effect te zijn van kauwgom kauwen op de toets resultaten van de meisjes (n = 90), maar niet op die van de jongens (n = 64). De overall conclusie is dat er geen effect werd gevonden van kauwgom kauwen op de toetsprestaties. Er lijkt daarom geen reden om schoolbeleid ten aanzien van kauwgom tijdens het maken van een proefwerk aan te passen.
Article
The masticatory organ, originally developed as a branchial system, has evolved over a long period of geological time through a stage in which it was predominantly a tool for expressing aggression into an organ for emotional management. In humans, the strong grinding and clenching function of the masticatory muscles, known as bruxism, plays a role in mitigating stress-induced psychosomatic disorders by down-regulating the limbic system, the autonomic nervous system, and the hypothalamic-pituitary-adrenal (HPA) axis. Experimental research results showed that bruxism-like activity (BLA) has beneficial effects on stress-induced reactions, such as increased expression of Fos, neuronal nitric oxide synthase (nNOS), dual phosphorylated extracellular signal-regulated kinase (pERK1/2), corticotropin-releasing factor (CRF), and free radicals in the paraventricular nucleus (PVN) of the hypothalamus. It has also been shown to cause alterations in the blood neutrophil/lymphocyte ratio, adrenocorticotropic hormone (ACTH) level, and stomach ulcer formation in animals studies and has increased amygdala neuronal activity and salivary chromogranin A level in human studies. These findings strongly suggested that parafunctional activity of the masticatory organ-aggressive BLA behavior-has the ability to decrease stress-induced allostatic overload. The health of the masticatory organ depends critically on occlusion, which must be of sufficient quality to carry out its important role in managing stress successfully. Occlusion and the brain must function in harmony. For these reasons, we must integrate the study of occlusion into the broader scope of medical science; in so doing, we can meaningfully advance the state of the art of dental care and general health care.
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Gestión pedagógica centrada en el aprendizaje: Remontar, Revisar, Reflexionar, Resolver y Rendir cuentas.
Article
Objectives: Stress might be caused by various lifestyle factors and physical challenges and can result in severe diseases. The body responds to stressful events by release of hormones, like cortisol, as well as reaction of the sympathetic nervous system. One strategy to counteract stress is chewing gum. The present study aimed at investigating the influence of mastication on biomarkers of stress during performance of a stress test. Methods: A two-armed cross-over study with 40 young male volunteers was performed. Hormone plasma concentrations were determined after an initial resting phase (2:30p.m.), immediately before (3:00p.m.) and two times after (3:20, 3:50p.m.) performance of a multitasking test using magnetic beads and ELISA methods. In addition, visual analog scales were used to rate subjective mood and the breathing and heart rates were monitored throughout the entire study period using a sensor chest belt. Results: Performance of the stress test led to an increase in plasma cortisol concentrations from 223±23.3 to 325±38.4ng/ml (p=0.023) and caused changes in subjective mood ratings as well as breathing rates. Although chewing gum base had no impact on the plasma hormone concentrations, it induced a stronger elevation of average heart rates compared to not chewing (p=0.016). Discussion: The effect of chewing gum on a mild stress load was less pronounced than in previous studies. Besides the detection of cortisol in saliva, not in plasma, in previous studies, flavored gum was used. Aroma active compounds might have substantially contributed to the beneficial effects of gum on biomarker of stress shown before.
Article
We evaluated the effects of gum chewing on the response to psychological stress induced by a calculation task and investigated the relationship between this response and masticatory performance. Nineteen healthy adult volunteers without dental problems undertook the Uchida-Kraepelin (UK) test (30min of reiterating additions of one-digit numbers). Before and immediately after the test, saliva samples were collected from the sublingual area of the participants. Three min after the UK test, the participants were made to chew flavorless gum for 3min, and the final saliva samples were collected 10min after the UK test. The experiment was performed without gum chewing on a different day. Masticatory performance was evaluated using color-changing chewing gum. Salivary CgA levels at immediately and 10min after the UK test were compared with and without gum chewing condition. Two-way repeated measures analysis of variance revealed significant interaction between gum chewing condition and changes in CgA levels during post 10min UK test period. A significant correlation was found between changes in CgA levels and masticatory performance in all participants. Our results indicate that gum chewing may relieve stress responses; however, high masticatory performance is required to achieve this effect. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.
Chapter
The sugar replacers currently permitted in EU-approved health claims for sugar-free chewing gum (SFCG) include intense sweeteners (such as aspartame and sucralose), erythritol, xylitol, sorbitol, mannitol, maltitol, lactitol, isomalt, polydextrose, D-tagatose and isomaltulose. Article 13.1 states for SFCG three claims related to tooth mineralisation, neutralisation of plaque acids, and reduction of oral dryness, and a fourth claim for SFCG with carbamide concerning neutralisation of plaque acids. Article 14.1(a) enounces a ‘plaque reduction’ claim for chewing gum sweetened with 100% xylitol. Two other Article 14.1(a) claims for SFCG relate to neutralisation of plaque acids and reduction of tooth demineralisation, both risk factors for the development of dental caries. The current EU-based legislation allows manufacturers to make claims for 100% xylitol chewing gum to reduce dental plaque, which is a risk factor in the development of caries. This results from the approved claim stating ‘chewing gum sweetened with 100% xylitol has been shown to reduce dental plaque’.
Article
This review discusses the clenching-grinding spectrum from the neuropsychiatric/neuroevolutionary perspective. In neuropsychiatry, signs of jaw clenching may be a useful objective marker for detecting or substantiating a self-report of current subjective emotional distress. Similarly, accelerated tooth wear may be an objective clinical sign for detecting, or substantiating, long-lasting anxiety. Clenching-grinding behaviors affect at least 8% of the population. We argue that during the early paleolithic environment of evolutionary adaptedness, jaw clenching was an adaptive trait because it rapidly strengthened the masseter and temporalis muscles, enabling a stronger, deeper and therefore more lethal bite in expectation of conflict (warfare) with conspecifics. Similarly, sharper incisors produced by teeth grinding may have served as weaponry during early human combat. We posit that alleles predisposing to fear-induced clenching-grinding were evolutionarily conserved in the human clade (lineage) since they remained adaptive for anatomically and mitochondrially modern humans (Homo sapiens) well into the mid-paleolithic. Clenching-grinding, sleep bruxism, myofacial pain, craniomaxillofacial musculoskeletal pain, temporomandibular disorders, oro-facial pain, and the fibromyalgia/chronic fatigue spectrum disorders are linked. A 2003 Cochrane meta-analysis concluded that dental procedures for the above spectrum disorders are not evidence based. There is a need for early detection of clenching-grinding in anxiety disorder clinics and for research into science-based interventions. Finally, research needs to examine the possible utility of incorporating physical signs into Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition posttraumatic stress disorder diagnostic criteria. One of the diagnostic criterion that may need to undergo a revision in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition is Criterion D (persistent fear-circuitry activation not present before the trauma). Grinding-induced incisor wear, and clenching induced palpable masseter tenderness may be examples Of such objective physical signs of persistent fear-circuitry activation (posttraumatic stress disorder Criterion D).
Article
Wrigley Science Institute (WSI) is funding cutting-edge research by independent experts to explore the health benefits of chewing gum. Consumer trend data from the 2005 NPD Group Snack Track in the US shows that chewing gum is the number-one snack choice among adults age 18-54. Research has shown that chewing gum has a number of benefits in oral health, including removing food debris, neutralizing plaque acids, aiding in the remineralization of tooth enamel, and even helping reduce tooth decay. The global advisory panel of renowned scientific experts is committed to supporting research related to the potential health and lifestyle benefits of chewing gum and to understanding the aftereffects of the chewing of the gum physiologically and psychologically. WSI is funding research on the benefits of chewing gum in four primary areas including reducing situational stress, managing weight, increasing focus, alertness, and concentration, as well as improving oral health.
Article
The aim of this study was to determine whether chewing gum affects cognitive function and stress relief. Sixty volunteers (mean age 23.3±3.01 years) without general or neuropsychiatric disease were recruited, and Stroop tests and stress surveys were conducted. Volunteers were administered performed a General and Emotional Stroop test with and without chewing gum, and the response time was recorded. The response time after chewing gum was significantly faster while conducting the General Stroop test. Stimulation of chewing gum may increase blood flow to the brain, which results in increased cognitive function. The response time was longer in the incongruent stimuli test compared to the congruent stimuli test, due to the effect of Stroop interference. However, when the chewing gum stimulus was introduced, the possibility of effectively reducing this effect. Stress index and response time of negative stimuli test showed weak positive correlation. This study suggests that chewing gum may play a positive role in increasing cognitive function and relieving stress.
Article
Spearmint (Mentha spicata L.) and spearmint extracts are Generally Recognized as Safe (GRAS) for use as flavoring in beverages, pharmaceuticals, and confectionaries. Studies of spearmint extracts in humans and animals have reported conflicting results with respect to toxicity. Since the chemical composition of these extracts was not reported and the spearmint source material was different, the relevance of these existing data to evaluating the risks associated with ingestion of a dried aqueous spearmint extract standardized to rosmarinic acid is not clear. Hence, the safety and tolerability of the dried aqueous spearmint extract was evaluated as part of a double-blind, randomized, placebo-controlled trial in healthy adults with age-associated memory impairment. Ingestion of both 600 and 900 mg/day for 90 days had no effect on plasma levels of follicular stimulating hormone, luteinizing hormone, or thyroid stimulating hormone, or other safety parameters including vital signs, plasma chemistry or whole blood hematology values. Additionally, there were no reported severe adverse events, no significant between-group differences in the number of subjects reporting adverse effects and the adverse events reported could not be attributed to ingestion of the extract. These results therefore show that ingestion of the aqueous dried spearmint extract is safe and well-tolerated.
Article
Chewing gum is one of the very popular oral confectionary products. It is a potentially useful means of administering drugs either locally or systematically via, the oral cavity. The medicated chewing gum (anti-smoking chewing gum) has through the recent years gained increasing acceptance as a drug delivery system. The use of the chewing gums is also suggested for other disorders like the gingivitis, plaque, flow of saliva, as a mouth freshener and prescribed mostly by dental physicians. It is having a wider acceptability with the patients and that is why its popularity is increasing. From 3,000years the smoking habit has been the favorite pass time of people from different civilizations. People still posses this habit and the intake of NICOTINE is increasing in different forms like the cigarette, pure tobacco and cigar. Due to the increasing intake of tobacco, there is need for the development of the novel drug delivery systems for the smoking cessation. This review tries to explain the chewing gum as a dosage form and ASTS, also popularly known as the nicotine replacement therapy, considering the application of the gum to it and its other components which may be great help in future for smoking cessation.
Article
The impact of chewing gum on fasting appetite or meal intake has not been studied. We tested the hypothesis that chewing gum would decrease lunch intake after a controlled breakfast, and reduce hunger in fasting and fed states. Seventeen males and sixteen females (21.4 ± 6.3y, BMI 23.8 ± 2.7 kg/m²) participated in a randomized crossover study in which subjects chewed sugar-free gum a total of one hour on the test day (GC), and did not chew gum on a control day (NG). The 1 h of gum chewing included 20 min while fasting, and two 20-min sessions between breakfast and lunch. Subjects rated their appetite and mood on visual analog scales. After completing the fasting measures, subjects consumed a breakfast shake containing 30% of their measured resting energy expenditure. Three hours later they consumed an ad libitum lunch with water. Fasting ratings of hunger were lower in GC than NG (t = 2.66, p = 0.01). Subjects consumed significantly less pasta (41 g, 68 kcals, t = 2.32, p = 0.03) during GC than NG. In conclusion, gum chewing decreased fasting hunger ratings and lunch energy consumed. Chewing gum may be a useful tool impacting energy balance in this population. Longer studies, especially in other populations, will be required.
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Rough notes of a clinical oral presentation of our comprehensive published review article. PLEASE download and CITE the published version as a reference. The published review is downloadable below. HS Bracha MD. ............................................................................. . INTENSE, PROLONGED JAW CLENCHING; it can be clinically observed during fear or rage in developmentally disabled individuals (and may be mistaken for dystonia). displays of jaw clenching can also be seen in preverbal healthy toddlers, which may also be a manifestation of fear or rage in the preverbal period. such clench- ing displays, both in patients with mental retardation and in healthy preverbal toddlers, precdict imminent actual bit- ing of others. ..................> ALSO, ANECDOTALLY, INFORMATION FROM EMERGENCY DEPARTMENTS suggests that physically assaulted individuals, and especially sexually assaulted individuals, may use biting as a means of self-defense.22 This may even be relevant in the assessment of individuals presenting in emergency departments with severe human bites, especially to the head and neck. TEMPORAL-LIMBIC STRUCTURES AND JAW CLENCHING We posit a second role for jaw clenching in the distressed/anxious individuals based on recent literature3.29 We hypothesize that jaw clenching increases the blood flow to anterior temporal lobe structures during acute activation of the limbic fear circuits. Jaw clenching may increase the blood flow to the hemodynamically vulnerable temporal lobe structures especially the hippocampus by pumping blood through the temporal bone emissary veins, thus enhancing immediate memory retrieval and night time memory consolidation and also conferring survival advantage during activation of the limbic fear-circuits in expect tion of situations requiring the freeze, flight, fight, fright acute fear response.18,19,30 This is consistent with new research, 29,31-33 which demonstrates a possible beneficial affect of masticatory movements (eg, non-nutritive chewing) on both hippocampal function and hippocampal structure. Based on pioneering work by Dr Andrew Gallup and associates which they concluded that yawning causes 'cooling of the brain', we propose that another way to produce such emmisery vein blood flow to the temporal lobe is yawning.). INTENTIONAL YAWNING may suppress the urge to clench. And remind people of the habit of police investigators (see Hollywood movies) to bite on a toothpick while concentrating and which prevents clenching-induced damage to the teeth. Tell man that women find biting a wooden toothpick sexually attractive. And strongly recommend non-nutritive gum such as SPRY green tea flavored dental defense system gum to reduce systemic inflammation and minimize contact between upper and lower teeth. ............................................................................ ..... IMPLICATIONS FOR PSYCHIATRIC DIAGNOSIS. Assessment Implication: “Hard to Hide” and “Hard to Fake” Physical Signs of Stress and Anxiety In addition to shifting focus from disorders to spec- trums, Psychiatry needs to include a larger number of physical examination signs in the “Associated Physical Examination Findings” sec tions of the DSM text and possiblly as subcriteria for the diagnoses of some disorders. Assessments of anxiety spectrum disorders currently depends almost exclusively on retrospective self-report. Extensive psychometric literature has demonstrated that paper and pencil instruments (particularly questionnaires and also structured interviews) for trait anxiety and recent subjective distress can be highly vulnerable to both over-reporting35-37 and under-reporting.37-42 This diminishes both the positive predictive value and the negative predictive value of questionnaires and structured interviews. We posit that easily observable physical signs, such as incisor tooth wear, may augment the clini- cal assessment of fear-circuitry disorders such as posttraumatic stress disorder (PTSD)....... . In clinical psychiatric settings, objective physical “hard to hide” signs of stress-induced and fear-circuitry dis- orders are also rare. Wear of the incisors’ enamel invari- ably results from chronic grinding and may be one such hard to hide sign. Clinicians practicing in settings where individuals tend to under-report symptoms due to stigma, cultural, or other reasons, may especially benefit from hard-to-hide indica- tors of under-reported anxiety. Self-imposed cultural barriers of access to men- tal healthcare may also exist in other “bushido” (warrior) male cultures. The United States Armed Forces active duty-enlisted personnel appears to be another American male culture that under-reports emotional distress due to stigma and deep-rooted beliefs about masculinity. This can impede clinical assessment (eg, suicide risk), early intervention, and primary prevention...... ....Furthermore, incisor tooth wear is also a “hard- to-fake” indicator of anxiety. Such objective signs are much needed in the clinical armamentarium in settings, such as litigation and compensation and substance abuse treatment centers where patients may over-report anxiety symptoms. Assessment of observable signs of clenching-grinding can be easily incorporated into the examination of the anxious patient in psychiatric medicine and general medi- cal settings, as well as in substance abuse settings. Even before tooth wear is noted in incisors, bilat- eral hypertrophy and tenderness of the masseter and especially the temporalis muscle can often be identi- fied by inspection and palpation in acutely distressed patients unaware of their clenching. .... Please download and please cite the full text tutorial review article that expands on this lecture. It is below. Also since you read this presentation all the way to the end you obviously found it useful So please recommend it. You will help your friends and colleagues notice it.
Article
Background There is increasing evidence of causal links between poor mastication and cognitive impairment, but possible effects of dietary hardness, which clearly affects mastication, on cognitive function is unknown. Objective We investigated the hypothesis that hardness of the habitual diet would be associated with cognitive function among older Japanese adults. Methods The subjects of this cross‐sectional study were 635 Japanese community‐dwelling people aged 69‐71 years. The masticatory muscle activity required for the habitual diet was used to determine dietary hardness. Consumption of 38 foods was assessed by a validated, brief‐type, self‐administered diet history questionnaire. A published database was then used to estimate the masticatory muscle activity involved in the ingestion of these foods. The Japanese version of the Montreal Cognitive Assessment (MoCA‐J) was used for the measurement of cognitive function. Results The principal contributors to dietary hardness were cooked rice (28.0%), green leafy vegetables (5.1%), dried fish (4.9%), and pork and beef (4.6%). There was a positive association between dietary hardness and MoCA‐J score that was robust to adjustment for potential confounders (MoCA‐J score per 100‐unit increase in dietary hardness: β=0.83 [95% CI: 0.08, 1.59], P=0.03). These results did not change materially even after exclusion of subjects who reported substantial changes in their diet for any reason (β=0.94 [95% CI: 0.02, 1.86], P=0.04). Conclusion This preliminary cross‐sectional study suggests that dietary hardness might have a beneficial effect on cognitive function in older Japanese people. Further prospective studies with more accurate measurements are needed to confirm this finding. This article is protected by copyright. All rights reserved.
Chapter
It has often been suggested that verbal short-term memory, the ability to maintain verbal information for a brief period of time, is based on the upload of to-be-remembered material into passive, dedicated, information stores. Alternatively, it has been claimed that all information is remembered but that access to it gets obstructed because of interference by subsequent similar material. The aim of this chapter is to present both approaches and to examine the viability of a different, perceptual-gestural, view of information buffering over the short term. This approach conceptualizes verbal short-term storage as an active process that emerges from, and is defined by, the recruitment of receptive and (speech) productive mechanisms. Experimental results actually suggest an active involvement of productive mechanisms. These experiments also cast doubt on the proposal that forgetting occurs because of interference by similar content. Another experiment expands upon this challenge of the interference-based view by showing that a temporary lesion of a brain area involved in speech planning (Broca’s area) affects verbal short-term memory performance in the absence of any additional potentially interfering verbal input. Further, challenging the store-based view, the virtual lesion of Broca’s area also attenuated the phonological similarity effect, a hallmark effect of the function of the hypothetical language-independent store. Finally, based on further experiments, it is concluded that only the perceptual-gestural approach can offer an account of presentation-type-based differences in verbal list recall that goes beyond a redescription of the observed effects.
Article
Aim: As our society ages, the number of people living with dementia also steadily increases. Some work has focused on masticatory behaviour as a form of daily health care that could help prevent cognitive impairment and dementia. However, it is not yet clear how masticatory behaviour influences various cognitive functions. Therefore, the purpose of this study was to examine the effect of masticatory behaviour on the decline of generalized attention, an important cognitive function. Methods: Participants were 35 healthy, dentulous individuals without stomatognathic abnormalities (24 men, 11 women; mean age: 56.8 ± 4.8 years). All participants completed three interventions: mastication, foot-stepping, and none (control). Pre- and post-intervention measures of generalized attention were measured by using neuropsychological tests to examine general attention; the results were then compared. Simultaneously, during the generalized attention task, the functional activity of the prefrontal cortex was observed on functional near-infrared spectroscopy. Results: Response time of generalized attention improved in both the masticatory and foot-stepping interventions. There was a transient increase in oxyhaemoglobin activity in the right and left prefrontal cortices in the masticatory intervention. Conclusions: Masticatory behaviour may be involved in a partial improvement of generalized attention and may induce prefrontal cortex activity in middle-aged and older adults.
Article
Background Several studies have examined the relationship between cognition and oral health in older populations. To further understand this relationship, we examined the associations between cognitive function, chewing capacity and the number of teeth present in community‐dwelling older males in Australia. Methods Data were obtained from cross‐sectional analysis of fourth wave of the Concord Health and Ageing in Men Project (CHAMP). Participants were 369 community‐dwelling males aged 78 years or over. Cognitive function was measured utilising the Mini‐Mental State Examination (MMSE). Chewing capacity was determined on ability to chew food items of different textures, and oral health data were collected. Ordinal regression was used to analyse associations between MMSE (four categories) and chewing capacity and number of natural teeth present. Results Overall, 67.5% of participants reported that they could chew all 11 listed food items. Participants with fewer than 20 teeth were statistically significantly more likely to have cognitive impairment (unadjusted odds ratio (OR) 1.87; 95% confidence interval (CI) 1.25‐2.79, adjusted OR 1.62; 95% CI 1.07‐2.43). Participants with limited chewing capacity were also more likely to have cognitive impairment (unadjusted OR 1.91; 95% CI 1.25‐2.94, adjusted OR 1.61; 95% CI 1.03‐2.49). Conclusions This study suggests either that older men with fewer than 20 natural teeth and those with limited chewing capacity are more likely to have an associated cognitive impairment or that those with cognitive impairment are more likely to have fewer teeth and limited chewing capacity. Further longitudinal studies should clarify these relationships.
Article
Innovative flavors are trends in the chewing gums market. Nine formulation on gums made with different kinds of yerba mate and flavors were evaluated. A time‐intensity test was carried out to estimate how long the taste lasted. The MDPREF PCA graph showed that de first two dimensions explained 45.42% of the total variance. Three groups were noted: samples elaborated with chamomile (forced and aged yerba mate); samples with toasted/chamomile and natural/green apple; and all the samples flavored with orange and flavored with green apple (forced aged and toasted). Yerba mate forced aged with orange and green apple flavors were preferred by the consumers. The total duration of the stimulus was just over 5 min. This study suggests that the combination of yerba mate with other flavors has potential for use in chewing gums, however, it needs to be optimized to improve the acceptance and the duration of the flavor.
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Background: Mastication improves cognitive function by activating cerebral cortical activity, and it is important to demonstrate the cognitive effects of masticatory training using a variety of different interventions. Objective: This study aimed to evaluate the effects of masticatory exercise on cognitive function in healthy older adults living in the community. Methods: For six weeks, twelve participants performed a masticatory exercise using a NOSICK exerciser device, and thirteen subjects performed daily life without masticatory exercises. Trail Making Test, Digit Span Test, and Stroop test were used to measure the cognitive function. Results: The participants in the experimental group showed significant improvements in TMT-A/B (p= 0.001 and 0.004), DST-forward (p= 0.001), and ST-word (p= 0.001). The effect sizes after the intervention were calculated as (1.2 and 0.8) for TMT-A/B, (0.8 and 0.2) for Digit Span Test forward/backward, and (0.6 and 0.2) for Stroop test color/word. Conclusions: We suggest that the masticatory exercises improve cognitive function in healthy older adults. Therefore, masticatory exercises can be used as a therapeutic exercise during cognitive rehabilitation.
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In the present study, we examined the cognitive function during mastication of lemon flavored gum, which is said to enhance mind flavor gum and especially cerebral blood flow. Nine healthy subjects (8 female and a male) participated in this study. Subjects chewed the gum for 3 min after fasting for 2 hours and conducted a stoop test while continuing chewing as it was. At the end of all answers, gum chewing ended. The response time in the Stroop test was used as an indicator of cognitive function. We sat the three conditions (Lemon flavored gum, Mint flavored gum, Without gum chewing). There was no significant difference in reaction time between mint flavor gum chewing and without gum chewing (p > 0.05). However, the response time during chewing gum with lemon flavor was significant slower than the conditions with mint without gum and with without gum chewing (p < 0.05, in both). From the results of the present study, it was suggested that the response time delay of the Stroop test during chewing of lemon-flavored gum was observed, suggesting temporary decay of cognitive function during lemon-flavored gum chewing. It is suggested that lemon- flavored chewing gum forces the brain to act loadfully, resulting in a temporary decrease in cognitive function.
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It is suggested that mastication stimulates the brain and accelerates its energy-consuming metabolism. This study was designed to determine its effects on regional cerebral blood flow (rCBF) using xenon-enhanced computed tomography (Xe-CT). Seven male volunteers, aged 24-57 years, inhaled 30% xenon in a 4 minutes wash-in and 4 minutes wash-out protocol. CT was scanned every 54.5 seconds. The subjects were instructed to chew a gum continuously at a rate of 1 bite per second except at the time of CT scanning (5.5 seconds). A second CBF was done 20 minutes later. Subtraction (mastication-baseline) maps were created. CT images were taken at three levels so as to include the cortex, basal ganglia, limbic system, brainstem and cerebellum. The results demonstrated a significant rCBF increase in the fronto-temporal cortex, caudate nucleus, thalamus and minor increase in the rolandic areas, insula, cingulate and cerebellum. Further studies are needed to validate the clinical significance of these findings.
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It is known that glucose administration is capable of improving performance on tests of declarative verbal memory and non-mnemonic tasks requiring high "mental effort". At the same time, cognitively demanding tasks are associated with elevated heart rate, a response that could feasibly be part of a physiological mechanism serving to increase the delivery of glucose to active brain substrates. The present placebo-controlled, double-blind, balanced, crossover study examined the interaction between glucose administration, cognitive performance and heart rate during three tasks of differing mental demand and somatically-matched control tasks. The effects of a glucose drink on participants' performance on two serial subtraction tasks (Serial Threes and Serial Sevens) and a Word Retrieval (Verbal Fluency) task were assessed. Heart rates were monitored throughout the experiment, and participants rated each task in terms of its perceived mental demand. Serial Sevens was rated as the most mentally demanding task, followed by Word Retrieval, then Serial Threes. Glucose consumption significantly improved performance on Serial Sevens, with a trend for improved performance on Word Retrieval. Both Serial Sevens and Serial Threes were associated with significant heart rate elevation above that seen in somatically matched control tasks (ruling out the possibility that accelerated heart rate was due to peripheral mechanisms alone). Unexpectedly, participants in the glucose condition had higher heart rates during cognitive processing. Additionally, individuals whose baseline heart rates were below the median performed better on Serial Threes and Serial Sevens. We suggest that supplemental glucose preferentially targets tasks with a relatively high cognitive load, which itself (through unknown mechanisms) mobilises physiological reserves as part of a natural response to such tasks. Furthermore, baseline heart rate and responses to cognitive demand and glucose administration may represent important physiological individual differences.
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Chronic administration of extracts from the leaves of the tree Ginkgo biloba is known to improve aspects of cognitive performance. However, little is known about the effects of acute doses of Ginkgo on coherent cognitive domains. Recent factor analysis of test measures from subtasks of the Cognitive Drug Research (CDR) computerised assessment battery has revealed that four primary cognitive 'factors' corresponding to speed of attention, accuracy of attention, speed of memory and quality of memory can be useful to describe cognitive function changes. The present study aimed at assessing whether acute administration of Ginkgo biloba had any consistent effect on the four CDR factors. The study utilised a placebo-controlled, multi-dose, double-blind, balanced, crossover design. Twenty participants received 120 mg, 240 mg and 360 mg of a standardised extract of Ginkgo (GK501, Pharmaton, SA) or a matching placebo. Cognitive performance was assessed using the CDR computerised test battery immediately prior to dosing and at 1, 2.5, 4 and 6 h thereafter. The primary outcome measures were the four aspects of cognitive performance, which have previously been derived by factor analysis of CDR subtests. Compared with the placebo, administration of Ginkgo produced a number of significant changes on the performance measures. The most striking of these was a dose-dependent improvement of the 'speed of attention' factor following both 240 mg and 360 mg of the extract, which was evident at 2.5 h and was still present at 6 h. Additionally, there were a number of time- and dose-specific changes (both positive and negative) in performance of the other factors. We conclude that acute administration of Ginkgo biloba is capable of producing a sustained improvement in attention in healthy young volunteers.
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Although the cardiovascular effects of exercise have been extensively investigated in man, little attention has been paid to such responses to jaw muscle activity. The aim here was to investigate the general cardiovascular effects of chewing activity in a single-blind, cross-over design. Ten healthy individuals performed one of the following chewing tasks in four separate sessions: chewing a very hard gum, chewing a moderately hard gum, chewing a soft gum, and "empty chewing" without a bolus. Unilateral chewing of gum or empty chewing was performed for 20 min on the participant's most convenient chewing side at a constant rate of 80 cycles/min. In each session, heart rate and arterial blood pressure were recorded together with electromyographic activity in the masseter and anterior temporalis muscles on the chewing side. Ratings of perceived masticatory fatigue were recorded with visual analogue scales. The heart rate and blood pressure were significantly increased (ANOVA; p < or= 0.01) during the chewing tasks and the increases were, in parallel with the muscle activity, more pronounced the harder the gum. With the very hard gum, heart rate increased by up to 11 beats/min, the systolic blood pressure was 14 mmHg (1.9kPa) higher, and the diastolic blood pressure was 11 mmHg (1.5kPa) higher. The perceived fatigue was proportional to the level of muscle activity. After 10 min of recovery from exercise, heart rate and arterial blood pressures were slightly but still significantly elevated. The results demonstrate that chewing is associated with general circulatory effects proportional to the bolus resistance.
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Previous research has identified that glucose administration can enhance cognitive performance, especially during more intense cognitive processing. There appears to be a reciprocal relationship between falling glucose levels and cognitive performance, particularly under conditions of cognitive demand. The present placebo-controlled, double-blind, balanced, crossover study examined the possibility that a high cognitive load may produce changes in blood glucose levels. A secondary aim was to examine the effects of glucose on tasks of varying cognitive demand load. The effects of a glucose drink on participants' performance of a serial subtraction task (computerised Serial Sevens), a somatically matched control task (key-pressing), a short interval Word Memory task and a Word Retrieval (Verbal Fluency) task were assessed. The change in blood glucose during the demanding computerised Serial Sevens was compared to the change occurring during the key-pressing control. Glucose consumption significantly improved performance on Serial Sevens, with a trend for improved performance on Word Retrieval and no effect on the Word Memory task. Compared with the control task, Serial Sevens resulted in a significant reduction in blood glucose in both drink conditions. This accelerated decay was significantly greater following glucose than placebo. It is suggested that the amount of cognitive load associated with task performance is an index of its sensitivity to enhancement by glucose. Furthermore, a period of intense cognitive processing leads to a measurable decrease in levels of peripherally measured blood glucose, which may be linked to increased neural energy expenditure. However, the relative contribution of central and peripheral (e.g. cardiac) activity to this effect has yet to be determined.