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Body and Odors
Abstract
Interpersonal interactions are primarily mediated through vision. However, crucial information concerning other individuals is also captured through different senses. New evidence suggests that body odors can implicitly initiate, filter, and guide the integrated perceptions that characterize real human impressions. Human body-odor processing helps rapidly differentiate kin from friends and friends from foes, as well as identify potential threats or increase alertness to the proximity of strangers, thereby guiding social preference. Body odors, which are potent sources of discriminative, affective, and motor knowledge, elicit neural activity partly or exclusively outside the primary olfactory cortices in the brain areas responsible for the processing of social information, which are activated by equivalent visual signals. Body odors, which can act as an authenticator of truth and are reliably invoked to shape social relations, require us to revise our view of the traditional body-communication models.
... For example, people have difficulty identifying their own body odor amongst others' body odor (Pause, Krauel, Sojka, & Ferstl, 1998). At the same time, scent can drastically impact who a person is likely to interact with (Lübke & Pause, 2015;Pazzaglia, 2015). Thus, while people are unaware of their own scent, others remain aware and influenced by it. ...
People are hyperaware of themselves. Research on the spotlight effect has shown that hyperawareness leads people to overestimate how much others notice about themselves. However, people are not always self-aware. What happens to the spotlight effect when people lack self-awareness? Across two studies, we attempt to elicit a reverse spotlight effect by taking advantage of people’s failure to notice their own body odor. As expected, participants in both studies underestimated how much others would notice their scent. However, participants who were alerted to potential failures of self-awareness before being sprayed with a scent showed a diminished reverse spotlight effect. Our findings suggest that when people lack self-awareness, they will underestimate how much others are aware of them. People who are made aware of the spotlight shining on them can overcome this effect.
... Although research originally focused on the relationship between performed and observed actions, more recent studies highlight the importance of multimodal experiences modulated by auditory [27], somatic [24,28,29], and even olfactory inputs [30]. The study of Grant et al. [31] suggest that audiohaptic stimuli enhance motor performance and subjective ratings of realness in a drilling simulation, providing further evidence that action is inherently linked to the internal reproduction of perceptuo-motor states called 'simulation,' a process that supposedly enables the interindividual sharing of multisensory experiences. ...
Our bodily experience arises primarily from the integration of sensory, interoceptive, and motor signals and is mapped directly into the sensorimotor cortices [...]
... In line with the embodied cognition theory, the experience of contemplating a piece of art is grounded in neural activity that relates to perception, action, and emotions (Di Dio and Gallese, 2009). For example, an embodiment effect may be derived from the inferred simulation of a painter's limb movements (Gallese and Di Dio, 2012;Pazzaglia, 2015). Restorers sometimes physically integrate lacunae and the entirety of a painting by simulating the unique gestural traces of the original painter (Di Dio and Gallese, 2009;Gallese, 2017). ...
Lacunae are the voids left by missing or damaged pieces of artwork, and their presence constitutes a central problem in the aesthetic experience of viewing artwork. However, we hypothesize that experience and knowledge of art might differentially modify viewer reactions to degraded artwork. Here, we investigated the implicit and explicit attitudes of art experts and non-experts towards the aesthetics of perfectly intact and lacunar artwork. Sections of Flemish oil paintings were displayed with or without a degradation mask, which mimics lacunae. Three groups differing in their interaction with art were assessed: art restorers, art historians, and art viewers lacking any art-related professional expertise. We found that (1) professional experience/expertise in art restoration affected implicit, but not explicit, attitudes among restorers, (2) art historians had positive explicit, but not implicit, attitudes toward intact artwork, and (3) it was difficult for non-specialist viewers to understand or appreciate artwork that was not perfectly intact. We further discuss the implications of these results to other forms of aesthetic evaluation and expertise. Modified preferences in experts may improve knowledge of the plastic changes that occur in the cognition of aesthetics and may thus be of significant relevance to enhance the effectiveness of art conservation programs.
... Neuroimaging studies have demonstrated that the sense of bodily self-consciousness involves a multisensory integration of input that is realigned and integrated in a unique body-centered reference frame in the frontoparietal and temporal-parietal regions [4,15]. In particular, the parietal lobe in the right hemisphere is central to the representation of various parameters of bodily knowledge [16]. ...
The multisensory regions in frontoparietal cortices play a crucial role in the sense of body and self. Disrupting this sense may lead to a feeling of disembodiment, or more generally, a sense of disownership. Experimentally, this altered consciousness disappears during illusory own-body perceptions, increasing the intensity of perceived ownership for an external virtual limb. In many clinical conditions, particularly in individuals with a discontinuous or absent sense of bodily awareness, the brain may effortlessly create a convincing feeling of body ownership over a surrogate body or body part. The immediate visual input dominates the current bodily state and induces rapid plastic adaptation that reconfigures the dynamics of bodily representation, allowing the brain to acquire an alternative sense of body and self. Investigating strategies to deconstruct the lack of a normal sense of bodily ownership, especially after a neurological injury, may aid the selection of appropriate clinical treatment.
... 22 Pain is therefore a complex, subjective, and multifaceted experience that depends on a mutual interaction of sensory input and cognitive processes. Alterations in bodily states might modulate pain perception, and suffering from chronic pain might alter a broad range of cognitive processes and behaviors [23][24][25] that are highly dependent on communication. Despite the fact that pain is typically a marker of a negative body state, positive aspects of pain can be associated with increased body awareness and facilitation of cognitive control. ...
Background: Pain is a marker of bodily status, that despite being aversive under most conditions, may also be perceived as a positive experience. However, how bodily states represent, define, and interpret pain signals, and how these processes might be reflected in common language, remains unclear.
Methods: Qualitative and quantitative methods were used to explore the relationship between bodily awareness, pain reactions, and descriptions. A list of pain-related terms was generated from open-ended interviews with persons with spinal cord injury (SCI), and 138 participants (persons with SCI, health professionals, and a healthy control group) rated each descriptor as representative of pain on a gradated scale. A lexical decision task was used to test the strength of the automatic association of the word “pain” with positive and negative concepts. The behavioral results were related to body awareness, experience of pain, and exposure to pain, by comparing the three groups.
Results: Higher positive and lower negative pain descriptors, as well as slower response times when categorizing pain as an unpleasant experience were found in the SCI group. The effect was not modulated by either the time since the injury or the present pain intensity, but it was linked to the level of subjective bodily awareness. Compared with the SCI group, health experts and non-experts both associated more quickly the word “pain” and unpleasant in the lexical decision task. However, while health professionals attributed positive linguistic qualities to pain, pain was exclusively associated with negative descriptors in healthy controls group.
Conclusions: These findings are discussed in terms of their theoretical and clinical implications. An awareness of bodily signals prominently affects both the sensory and linguistic responses in persons with SCI. Pain should be evaluated more broadly to understand and, by extension, to manage, experiences beyond its adverse side.
... The observation of actions through a process of visual retrieval may help in the selection of the most probable action, providing a powerful tool for overcoming intentional motor-gestural difficulties (55). Moreover, tailored interventions based on individual's ability to acquire new (or relearn old) motor-memory traces through multisensory [i.e., auditory (35,147), olfactory (148,149), and tactile (150)(151)(152)(153)(154)(155)] feedback may be the most promising approach for a normal temporal integration action (156,157). Multisensory stimulation can activate multiple cortical brain structures, inducing cortical reorganization and modulating motor cortical excitability for the stimulated afferents (158,159). ...
Neurorehabilitation and brain stimulation studies of post-stroke patients suggest that action-observation effects can lead to rapid improvements in the recovery of motor functions and long-term motor cortical reorganization. Apraxia is a clinically important disorder characterized by marked impairment in representing and performing skillful movements [gestures], which limits many daily activities and impedes independent functioning. Recent clinical research has revealed errors of visuo-motor integration in patients with apraxia. This paper presents a rehabilitative perspective focusing on the possibility of action observation as a therapeutic treatment for patients with apraxia. This perspective also outlines impacts on neurorehabilitation and brain repair following the reinforcement of the perceptual-motor coupling. To date, interventions based primarily on action observation in apraxia have not been undertaken.
... Furthermore, the strong connection between tool and body perception, often termed embodiment (8,9,11,(13)(14)(15)(16)(17), may be one of the most crucial factors affecting functional recovery (18)(19)(20)(21)(22). Recent studies have demonstrated that establishing a sense of embodiment for prostheses in patients with limb amputation is associated with enhanced competence and patients' ease of use of such devices. Conversely, a low level of embodiment impedes the efficient use of assistive tools and contributes to their rejection (11,23). ...
Although several outcome measures are used to assess various areas of interest regarding spinal cord injuries (SCIs), little is known about the frequency of their use, and the ways in which they transform shared knowledge into implemented practices. Herein, 800 professionals from the International Spinal Cord Society, especially trained for caring in patients with SCI, were invited to respond to an Internet survey collecting information on the use of standardized measures in daily clinical practices. We asked both clinicians and researchers with different areas of interest about their use of functional outcome measures, and, in particular, which scales they habitually use to assess various aspects of clinical practice and rehabilitation. We selected a set of rating scales, which were validated for measuring SCIs (http://www.scireproject.com/outcome-measures). The results show that the areas of interest assessed by most of the participants were neurological status, upper limb, lower limb gait, pain, spasticity, self-care, and daily living. The most widely used rating scales were the spinal cord independence measure, the functional independence measure and the International Standards for Neurological Classification of Spinal Cord Injury. Instead, the majority of respondents did not evaluate the use of assistive technology. Despite the availability of several outcome scales, the practice of evaluating SCIs with standardized measures for assistive technologies and wheelchair mobility is still not widespread, even though it is a high priority in the rehabilitation of SCI patients. The results emphasize the need for a more thorough knowledge and use of outcome scales, thus improving the quality of assistive device evaluation.
... A brachial plexus avulsion injury and brachial plexus anesthesia can represent effective models for studying deafferentation effects on the nervous system. Understanding adaptive brain plasticity and its impact on the overall perception process may guide the development of multimodal interventions focused on phantom limb control, as well as the exploitation of residual motor ability and sensory afferences [71,72]. Brachial plexus damage has a higher incidence rate, a more selective impact on health, and a greater promise of recovery, relative to other deafferentation conditions, such as amputations or spinal cord injuries. ...
Many neuropsychological theories agree that the brain maintains a relatively persistent representation of one’s own body, as indicated by vivid “phantom” experiences. It remains unclear how the loss of sensory and motor information contributes to the presence of this representation. Here, we focus on new empirical and theoretical evidence of phantom sensations following damage to or an anesthetic block of the brachial plexus. We suggest a crucial role of this structure in understanding the interaction between peripheral and central mechanisms in health and in pathology. Studies of brachial plexus function have shed new light on how neuroplasticity enables “somatotopic interferences”, including pain and body awareness. Understanding the relations among clinical disorders, their neural substrate, and behavioral outcomes may enhance methods of sensory rehabilitation for phantom limbs.
Corporeal awareness of body unity, continuity, and integrity is hardwired in the brain, even following massive deafferentation. Following peripheral limb injury, referred phantom sensations are reported frequently on the cheek and, rarely, on the ear. Here, we explore how brain plasticity mechanisms induced by multisensory stimulation of different facial regions (cheek and ear) modulate the feeling that a complete missing limb is still attached to the body. We applied the modified rubber hand illusion (RHI) paradigm following synchronous and asynchronous stimulation of the face–hand and ear–hand in the unusual case of a patient with a brachial plexus lesion, who had lost upper-left limb sensation and developed a phantom sensation of the arm restricted to the ear. He experienced a strong illusion of ownership of the rubber hand during synchronous stroking of the ear but not the cheek and reported more defined tactile sensations in his previously numb body part during the illusion than when simply touching the ear. Phantom experiences are not exclusively based on sensory memories of the once-present body periphery, they are organized into a topographic cortical map with the ear–hand area adjoining but separate from the face. Multimodal experiences specifically modulate possible remapping of ear–hand representations and generate a more defined connection between the brain’s memory of the body and what one feels of the actual physical body. We suggest that RHI is a form of sensory intervention that makes the best use of residual signals from disconnected body parts after peripheral injury, evoking and controlling the limb sensations.
Growing evidence indicates that perceptual-motor codes may be associated with and influenced by actual bodily states. Following a spinal cord injury (SCI), for example, individuals exhibit reduced visual sensitivity to biological motion. However, a dearth of direct evidence exists about whether profound alterations in sensorimotor traffic between the body and brain influence audio-motor representations. We tested 20 wheelchair-bound individuals with lower skeletal-level SCI who were unable to feel and move their lower limbs, but have retained upper limb function. In a two-choice, matching-to-sample auditory discrimination task, the participants were asked to determine which of two action sounds matched a sample action sound presented previously. We tested aural discrimination ability using sounds that arose from wheelchair, upper limb, lower limb, and animal actions. Our results indicate that an inability to move the lower limbs did not lead to impairment in the discrimination of lower limb-related action sounds in SCI patients. Importantly, patients with SCI discriminated wheelchair sounds more quickly than individuals with comparable auditory experience (i.e. physical therapists) and inexperienced, able-bodied subjects. Audio-motor associations appear to be modified and enhanced to incorporate external salient tools that now represent extensions of their body schemas.
Observational studies have suggested that with time, some diseases result in a characteristic odor emanating from different sources on the body of a sick individual. Evolutionarily, however, it would be more advantageous if the innate immune response were detectable by healthy individuals as a first line of defense against infection by various pathogens, to optimize avoidance of contagion. We activated the innate immune system in healthy individuals by injecting them with endotoxin (lipopolysaccharide). Within just a few hours, endotoxin-exposed individuals had a more aversive body odor relative to when they were exposed to a placebo. Moreover, this effect was statistically mediated by the individuals' level of immune activation. This chemosensory detection of the early innate immune response in humans represents the first experimental evidence that disease smells and supports the notion of a "behavioral immune response" that protects healthy individuals from sick ones by altering patterns of interpersonal contact.
Gerche beeinflussen das menschliche Verhalten. Die Wahrnehmung sog. "Pheromone" wurde vielfach in Zusammenhang mit der Funktion des vomeronasalen Organs gebracht. Etwa die Hlfte aller Menschen besitzt einen Ductus vomeronasalis (VND). Die Funktionalitt des VND ist unklar, ist aber, zumindest nach der Geburt, als eher unwahrscheinlich anzusehen. Die Vermittlung von duftstoffinduzierten Verhaltens- oder Hormonvernderungen beim Menschen nach Stimulation mit "Pheromonen" ist auch ber Rezeptoren in der Regio olfactoria vorstellbar.Odors influence human behavior. The perception of so-called pheromones is frequently mentioned in the context of a functional vomeronasal organ. Vomeronasal ducts can be detected in approximately half of the population. Its functionality, still a matter of debate, seems to be unlikely, at least after birth. It is easily conceivable that pheromone-induced changes in behavior are mediated through receptors in the human olfactory epithelium.
Our natural body odor goes through several stages of age-dependent changes in chemical composition as we grow older. Similar changes have been reported for several animal species and are thought to facilitate age discrimination of an individual based on body odors, alone. We sought to determine whether humans are able to discriminate between body odor of humans of different ages. Body odors were sampled from three distinct age groups: Young (20-30 years old), Middle-age (45-55), and Old-age (75-95) individuals. Perceptual ratings and age discrimination performance were assessed in 41 young participants. There were significant differences in ratings of both intensity and pleasantness, where body odors from the Old-age group were rated as less intense and less unpleasant than body odors originating from Young and Middle-age donors. Participants were able to discriminate between age categories, with body odor from Old-age donors mediating the effect also after removing variance explained by intensity differences. Similarly, participants were able to correctly assign age labels to body odors originating from Old-age donors but not to body odors originating from other age groups. This experiment suggests that, akin to other animals, humans are able to discriminate age based on body odor alone and that this effect is mediated mainly by body odors emitted by individuals of old age.
While the determination of age has been primarily mediated visually, the ambient odour may also have an influence. To investigate this in a single blinded, randomised fashion, thirty-seven subjects (age average of 28 years, ranging from 13 years to 71 years) estimated the age of models in twenty photographs while wearing either blank masks or masks impregnated with a grape, cucumber or grapefruit aroma. The grape odour (p = 0.198) and the cucumber odour (p = 0.244) had no significant effects. The grapefruit aroma reduced subjects' perception of overall models' ages by an average of approximately three years (p = 0.025) and of female models' age by five years (p = 0.053). Possible mechanisms whereby the grapefruit aroma created a rejuvenating effect with relationship to perceived age includes induction of positive effect, expectancy effect, sexual arousal, anxiolysis, change in cognitive set and odour induced visual distortion. The perceived rejuvenating effect of the grapefruit aroma may have utility in facilitating intergenerational communication or act as an adjuvant like Botoxial toxins in cosmetic and pharmaceutical usage to affect age perception.
The purpose of this study was to assess the effects of odorants on men's perception of a woman's weight. A five foot nine inch (1.75 m), 245 pound (111 kg) woman model wore a floral-spice odorant, a citrus-floral odorant, and a sweet pea and lily of the valley odorant. One hundred and ninety-nine males assessed the woman's weight. Compared to the non-odorant control perceived weight, the floral-spice mixture reduced the men's perception of the woman's weight by 4.1 pounds (1.86 kg) (p = 0.02). In those who viewed this odour hedonically positively, the reduction in weight was 12 pounds (5.44 kg) (p = 0.02). Wearing a floral-spice odour can reduce a woman's perceived weight by as much as seven percent.
A fundamental problem in systems neuroscience is mapping the physical properties of a stimulus to perceptual characteristics. In vision, wavelength translates into color; in audition, frequency translates into pitch. Although odorant concentration is a key feature of olfactory stimuli, we do not know how concentration is translated into perceived intensity by the olfactory system. A variety of neural responses at several levels of processing have been reported to vary with odorant concentration, suggesting specific coding models. However, it remains unclear which, if any, of these phenomena underlie the perception of odor intensity. Here, we provide an overview of current models at different stages of olfactory processing, and identify promising avenues for future research.
This article considers smell as a social intermediary with regard to the body, presentation of self, and social/moral order. Employing the trajectory of a sociology of everyday life, the data presented here are collected from narrative interviews conducted with twelve respondents. The study looks at how respondents react to bodily odors and how they go about maintaining acceptable bodily scents to facilitate social interaction. The discussion is framed within Goffmanian sociology on the interaction order and corporeal scholarship. The findings show that respondents equate foul odors with social and moral defilement, and this affects how they view social others, adopting attitudes and behaviors of social inclusion and exclusion. Managing bodily odors also points to the idea that instead of approaching the body as an object of analysis, the body should also be analyzed as an active and acting subject, located and influenced by sociocultural conditions. This article thus contributes to discussions on a sociology of the body by linking them with olfactory analyses and also aims to supplement the dearth of olfactory research in the Southeast Asian region by using Singapore as an empirical case study. © 2006 by Pacific Sociological Association. All rights reserved.
I evaluate the bottlenecks involved in the simulation mechanism underpinning superior predictive abilities for upcoming actions. This perceptual-motor state is characterized by a complex interrelationship designed to make predictions using a highly fine-tuned and constrained motor operation. The extension of such mechanisms to language may occur only in sensorimotor circuits devoted to the action domain.
Background:
Autism spectrum disorders comprise a range of neurodevelopmental pathologies characterized, among other symptoms, by impaired social interactions. Individuals with this diagnosis are reported to often identify people by repetitively sniffing pieces of clothing or the body odor of family members. Since body odors are known to initiate and mediate many different social behaviors, smelling the body odor of a family member might constitute a sensory-based action promoting social contact. In light of this, we hypothesized that the body odor of a family member would facilitate the appearance of automatic imitation, an essential social skill known to be impaired in autism.
Methods:
We recruited 20 autistic and 20 typically developing children. Body odors were collected from the children's mothers' axillae. A child observed a model (their mother or a stranger mother) execute (or not) a reach-to-grasp action toward an object. Subsequently, she performed the same action. The object was imbued with the child's mother's odor, a stranger mother's odor, or no odor. The actions were videotaped, and movement time was calculated post hoc via a digitalization technique.
Results:
Automatic imitation effects-expressed in terms of total movement time reduction-appear in autistic children only when exposed to objects paired with their own mother's odor.
Conclusions:
The maternal odor, which conveys a social message otherwise neglected, helps autistic children to covertly imitate the actions of others. Our results represent a starting point holding theoretical and practical relevance for the development of new strategies to enhance communication and social behavior among autistic individuals.