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Effects of olfactory stimulation on performance and stress in a visual sustained attention task



Synopsis Subjects performed a visual sustained attention (vigilance) task for 40 minutes during which they received periodic 30-second whiffs of pure air or a hedonically positive fragrance, Muguet or Peppermint, through a modified oxygen mask. The former fragrance had been independently judged as relaxing, the latter as alerting. Subjects receiving either fragrance detected significantly more signals during the vigil than unscented air controls. Subjective reports of mood and workload indicated that the subjects experienced the vigilance task as stressful and demanding. However, the fragrances had no impact on the latter measures. These results provide the initial experimental evidence to indicate that fragrances can enhance signal detectability in a task demanding sustained attention, though the exact characteristics of effective fragrances have yet to be determined.
j. Soc. Cosmet. Chem., 42, 199-210 (May/June 1991)
Effects of olfactory stimulation on performance and stress
in a visual sustained attention task
RAJA PARASURAMAN, Department of Psychology, University of
Cincinnati, Cincinnati, OH 45221 (J.S.W., W.N.D.), and
Department of Psychology, The Catholic University of America,
Washington, DC 20064 (R.P. ).
Received December 5, 1990. Presented at the Annual Meeting of the
Society of Cosmetic Chemists, San Francisco, May 1990.
Subjects performed a visual sustained attention (vigilance) task for 40 minutes during which they received
periodic 30-second whiffs of pure air or a hedonically positive fragrance, Muguet or Peppermint, through
a modified oxygen mask. The former fragrance had been independently judged as relaxing, the latter as
alerting. Subjects receiving either fragrance detected significantly more signals during the vigil than
unscented air controls. Subjective reports of mood and workload indicated that the subjects experienced the
vigilance task as stressful and demanding. However, the fragrances had no impact on the latter measures.
These results provide the initial experimental evidence to indicate that fragrances can enhance signal
detectability in a task demanding sustained attention, though the exact characteristics of effective fragrances
have yet to be determined.
Vigilance, or sustained attention, tasks require observers to remain alert and to detect
infrequent and unpredictable stimulus events over prolonged periods of time (1-2).
Although subjects engaged in such tasks are required only to dedicate themselves to
looking or listening for the specified events that constitute signals for detection, their
performance on these tasks is remarkably fragile, and the tasks tend to induce consid-
erable stress.
The brittle character of vigilant behavior is revealed through the decrement function, a
decline in the frequency and/or speed of signal detections over time. This decline is often
complete from 20 to 35 minutes after the initiation of the vigil (1-2); in some cases, it
can even be observed as early as the first five minutes of watch (3). Along with the
decrement function, vigilance performance is accompanied by increased catecholamine
and cortisol output, indicating physiological stress (4-5), and by subjective reports
indicating that monitors feel less energetic, more strained, bored, irritated, drowsy, and
headachy at the end of a vigil than at the beginning (6-7). Moreover, measures of
subjective workload show that what may appear to be a simple assignment is in fact
quite demanding (8-9).
For obvious practical reasons, it would prove very useful to develop techniques for
improving the overall level of vigilance performance, for moderating the vigilance
decrement, and for alleviating the feelings of stress attendant on engaging in vigilance
tasks. Such tasks can be found in many work settings, including those confronting radar
and sonar operators, quality control inspectors, system monitors in power plants, med-
ical personnel in intensive care units, long distance drivers, and so on. Failure to detect
and respond to critical signals in these settings can sometimes have disastrous conse-
quences (2). Efforts to moderate the vigilance decrement and combat the feelings of
stress induced by vigilance tasks have utilized exercise (10), added stimulation such as
music in a visual vigilance task or visual stimulation in an auditory task (11-12), and
stimulant drugs (13-14) to keep monitors aroused. While somewhat successful, these
techniques have limitations. Exercise at the workstation is not always possible, added
stimulation can be distracting and impair working memory (15), and drugs can produce
unwanted side effects and addiction (16).
To our knowledge, no one, prior to the present study, has appealed to the olfactory sense
as a source of stimulation for the maintenance of sustained attention. Olfactory stimuli
can be quite salient and can play important roles in emotion and in recall and recog-
nition (17-18). There is also evidence that some fragrances can enhance alertness and
that some can reduce stress, at least on a short-term basis. While this evidence is in part
anecdotal (19), much of it comes from empirical research using both psychophysiological
and self-report techniques (20-21). If the purported alerting and stress-reducing prop-
erties of fragrances can operate over extended periods of time, fragrance administration
might serve as a benign vehicle for enhancing the quality of sustained attention and/or
reducing the stressful feelings that accompany vigilance performance.
Our hypothesis was that fragrances assessed as alerting might beneficially affect vigilance
performance and that fragrances assessed as relaxing might reduce the tension and
feelings of stress consequent on performing a vigilance task. Moreover, we were prepared
to speculate that alerting fragrances might also reduce the stress of vigilance by creating
a closer match between task demands and subjects' ability to perform those tasks; that
is, part of the stress may arise from subjects' need, but inability, to remain sufficiently
alert to do well on the vigilance task. Fragrances that help them stay alert might
therefore also help them feel better. Similarly, relaxing fragrances might affect perfor-
mance efficiency as well as feelings, since subjects who are tense and uncomfortable may
find it hard to concentrate on the task.
In short, it seemed reasonable to expect that both alerting and relaxing fragrances might
have both performance- and mood-enhancing effects, albeit for somewhat different
reasons. But our main concern, at the outset, was whether we could find any effects of
fragrance at all in comparison with an appropriate control condition.
For our initial investigation, we decided to use two hedonically positive fragrances, one
assessed as alerting and the other as relaxing. Toward that end, the initial phase of the
research involved an evaluation of the hedonic and mood-inducing qualities of seven
fragrances supplied by International Flavors and Fragrances, Inc.: Benzoin, Cashmeran,
Forest-Plus, Muguet, Peppermint, Sandiewood, and Spiced-Apple. We report below
details of that evaluation study, and we then describe the main experiment.
Forty subjects, 20 male and 20 female students from the University of Cincinnati,
judged each of the seven candidate fragrances on two scales, a hedonic, or pleasantness
scale, and a scale of alertness/relaxation. The hedonic scale was a 16-cm line, with the
zero point labeled "very unpleasant" and the 16-cm point "very pleasant." Subjects
placed a mark on the line corresponding to their judgment of how pleasant or unpleasant
each fragrance was. The other scale, a 15-cm line, was labeled "more alerting/
stimulating" at the zero point and "more relaxing" at the 15-cm point. To aid in
making the latter judgment, subjects were asked to imagine that they were engaged in
a tedious task and to note whether each fragrance, if present during the conduct of that
task, would be more relaxing or more alerting/stimulating. For the hedonic scale, marks
above the midpoint of 8 cm were considered to designate a pleasant fragrance; for the
other scale, marks above the midpoint of 7.5 cm were considered to designate a relaxing
Each subject judged each fragrance once on each of the scales. The order in which
subjects experienced the fragrances as they progressed through the experiment was
varied at random for each individual, while the sequence in which they responded to the
two scales was balanced within the gender groups. Subjects sampled each fragrance once
via a squeeze bottle containing fragrance-impregnated polyethylene pellets. Preliminary
inspection of the data for both types of scales revealed that ratings were similar for the
male and female subjects. Accordingly, the data were collapsed across gender prior to
further analysis.
Overall mean hedonic and alerting/relaxing ratings are displayed in Table I.
Separate analyses of variance revealed statistically significant differences among the
fragrances on both dimensions. For hedonic ratings, F(6,234) = 21.31, p ( 0.001; for
alerting/relaxing ratings, F(6,234) = 5.08, p ( 0.001. On the basis of these ratings,
Table I
Means and Standard Errors for Hedonic and Alertness/Relaxation Ratings
Hedonic rating Alertness/relaxation rating
Fragrance M SE M SE
Benzoin 8.02 0.57 7.88 0.43
Cashmeran 5.26 0.59 5.27 0.52
Forest-Plus 6.09 0.56 6.07 0.47
Muguet ! !.40 0.59 8.34 0.56
Peppermint ! !. 02 0.56 5.63 0.56
Sandiewood 5.22 0.55 6.04 0.45
Spiced-Apple 7.6 ! 0.65 6.65 0.45
H Scale: (8, unpleasant; 8, neutral; )8, pleasant.
A/R Scale: (7.5, stimulating; 7.5, neutral; )7.5, relaxing.
we selected two fragrances, both with high mean hedonic values. One, Peppermint, had
a high alertingness rating; the other, Muguet, was rated as relaxing. In both instances,
the mean ratings were at least one standard error beyond the neutral point, as illustrated
in Table I.
Thirty-six subjects, 18 men and an equal number of women, from the Cincinnati
metropolitan area participated in the experiment. The subjects were solicited through a
newspaper advertisement and were paid $ ! 5 for serving in the study. They ranged in age
from 18 to 30 years, with a mean of 26.6 years. The sample reflected a variety of
educational and occupational backgrounds. All subjects had normal or corrected-
to-normal vision and passed a test for anosmia, designed by International Flavors and
Fragrances, Inc., as a condition for gaining entry into the study. Six male and six female
subjects were assigned at random to one of three fragrance groups, a control group which
received unscented air and groups receiving air scented with either Muguet or Pepper-
All subjects participated in a continuous 40-minute vigil divided into four consecutive
10-minute periods during which they monitored the repetitive presentation of a pair of
! X 13-mm lines with a 1-mm dot centered vertically and horizontally between them.
The distance between each line and the centering dot was normally 10 mm. Critical
signals for detection were configurations in which both lines were 2 mm farther from the
centering dot than usual. Stimuli were presented at the rate of 24 events/minute, with
an exposure time of 150 msec. In all conditions, five critical signals were presented
during each 10-minute period of watch (signal probability = 0.02). Intersignal inter-
vals ranged from 20 to 240 seconds, with a mean of 120 seconds.
An Apple IIe microcomputer was used to generate the stimuli and to control the
presentation of critical signals and neutral events in all experimental conditions. The
computer also recorded the subjects' responses. The subjects indicated their detection of
critical signals by depressing the spacebar on the computer's keyboard. In all conditions,
responses occurring within 1.25 seconds after the onset of a critical signal were recorded
automatically as correct detections. All other responses were recorded either as errors of
commission (failing to detect a signal) or false alarms (calling a neutral event a signal).
Subjects were tested individually in a 1.9 X 1.8 X 2.0-meter Industrial Acoustics
sound chamber. Each subject was seated in front of a table containing a video display
terminal (VDT). Viewing distance was approximately 43.5 cm. A glare reduction screen
was mounted on the VDT to enhance the clarity of the display and to minimize visible
phosphor decay following offset of the pixels that made up the stimulus configuration.
Ambient illumination was provided by a 40-watt bulb mounted in an aluminum
cone-shaped fixture that was positioned to diffuse light evenly within the chamber.
The fragrance delivery system consisted of a pair of aquarium pumps (Hagen Optima
and Whisper 1000) that forced air through Teflon tubing into a charcoal filter and then
into a 35-ml glass reservoir housed in a refrigerator that was maintained at 70 ø F. The
reservoir contained 9 x 9-mm polyethylene pellets that incorporated the fragrance to be
used. Air from the reservoir was transmitted through additional tubing under pressure
from the pumps to a modified home oxygen mask worn by the subject while seated in
the experimental chamber.
The fragrance delivery equipment was located outside the chamber. Total travel distance
from the reservoir to the mask was 2.15 meters. Odor concentration at the mask was
controlled by the air flow (0.80 liters/minute) and by the number of pellets in the
reservoir. Five pellets were used for delivering the Peppermint fragrance and 10 for
Muguet. The concentration of Peppermint was 0.05 parts/million, while that for
Muguet was 0.13 parts/million. Fragrance concentration was determined by pilot work
that equated the fragrances for salience when delivered against an unscented back-
ground. In the control condition, unscented air was delivered to the mask by forcing the
air through an empty reservoir in the refrigerator. The duration of air flow through the
mask was controlled by a decade interval timer in conjunction with a Gerbrands tape
timer. The timing system activated the air pumps for limited intervals at specified times
during the experimental session. In the course of the experiment, subjects experienced
30-second whiffs of either scented or unscented air through the mask 4.5 minutes after
the start of the vigil and every five minutes thereafter. At other times the fragrance
delivery system was dormant.
The masks used in the study were modified by cutting triangular openings (with a base
of 6 cm and an altitude of 4 cm) in both sides, which permitted subjects to breathe room
air comfortably when the fragrance delivery system was not engaged. Fresh air was
provided to the experimental chamber through a ceiling fan. An electronic air cleaner
(Sears Model 635.830000) cleansed the air within the chamber and insured against
contamination by lingering odors. Containers of charcoal and baking soda placed within
the refrigerator offered similar protection for air entering and leaving the fragrance
reservoir. To further insure against contamination, three separate reservoirs were used
for the Muguet and Peppermint pellets and in the unscented control condition. These
reservoirs had separate tubing leading to masks reserved for them. To protect against the
possibility of infection, masks were bathed in alcohol after being used. Subjects reported
little discomfort in wearing the masks. The tubing leading to each mask was of suffi-
cient length to permit the subjects considerable freedom of movement as they sat at their
workstation. Schematic drawings of the fragrance delivery system and of the experi-
mental chamber are presented in Figures 1 and 2, respectively.
Stress measures were obtained from three scales. They included (a) the Thackray Mood
Scales--a nine-point rating scale measuring attentiveness, sleepiness, strain, boredom,
and irritation, in which values below five reflect negative feelings (22); (b) the Yoshitake
Symptoms of Fatigue Scale•a 30-item checklist of fatigue indicants such as headache,
dizziness, eye strain, etc. (23); and (c) the Stanford Sleepiness Scale•a seven-item rating
Figure 1. Schematic drawing of the fragrance delivery system.
scale ranging from "wide awake { 1}" to "almost in reverie {7}" (24). Subjective workload
assessments were obtained from the NASA TLX, which measures the degree of pro-
cessing capacity that is expended during the performance of a task on a scale from 0 to
100 (25).
Upon reporting to the laboratory, subjects were asked to complete an informed consent
form, screened for allergies, and tested for anosmia. They then completed a paper and
pencil version of the Thackray, Stanford, and Yoshitake scales. The order in which they
received these scales was counterbalanced within groups. Afterwards, subjects were
given a 10-minute training period that duplicated the first period of the vigilance task
and then assessed the workload of the training phase using a computer-generated version
of the TLX.
Prior to the start of the main part of the session, subjects were given time to become
acclimated to the oxygen mask and to experience the flow of fragrance or unscented air
through the mask. Immediately following the main session, the subjects again assessed
their workload and then responded to the Thackray, Stanford, and Yoshitake scales.
Testing was accomplished between 0730 and 1100 hours and between 1230 and 1700
hours. Half of the male and female subjects in each group were tested during these
morning and afternoon periods in order to control the possibility of circadian effects that
have been found to influence vigilance performance (26). Prior to coming to the labo-
Apple lie Storage
Intercom M•crocomputer Box
Figure 2. Schematic drawing of the experimental chamber.
ratory, subjects were requested not to wear cologne or perfume. All subjects complied
with this request.
Percentages of correct detections and false alarms were determined for each subject
during each period of watch. Preliminary inspection of the data revealed that gender and
time of day had little effect upon performance. Accordingly, the data were collapsed
across these factors for further analyses.
Mean percentages of the correct detections for the air, Muguet, and Peppermint groups
are plotted as a function of periods in Figure 3. It is evident in the figure that the
detection scores for both fragrance groups were similar and that for both groups the
percentage of detections was substantially and consistently greater than that for the
unscented air control. The figure also shows that the detection percentage in all groups
declined over time. An analysis of variance of the detection scores revealed that the
1 2 3 4
I Air
ß Peppermint
Figure 3. Percentage of correct detections as a function of periods of watch for subjects in the air, Muguet,
and Peppermint conditions.
difference between groups reached statistical significance [F(2,33) = 3.25; p = 0.05]
and that performance efficiency deteriorated significantly over time [F(3,99) = 6.30; p
< 0.001]. The groups X periods interaction lacked significance [F(6,99) = 1.17; p >
False alarms were generally few in all conditions. Mean percentages of false alarms for
the four periods of watch were 2.7%, 1.8%, 2.0%, and 2.3 %, respectively, for the air
group; 8.9%, 6.7%, 6.2%, and 5.9%, respectively, for the group exposed to Muguet;
and 12.4%, 7.2%, 9.3%, and 7.0%, respectively, for subjects exposed to Peppermint.
An analysis of variance of the percentage of false alarms showed that their overall
frequency declined significantly over time [F(3,99) = 7.42; p ( 0.001], a typical
finding in vigilance experiments (1). All of the remaining sources of variance in the
analysis lacked significance (p) 0.05).
Mean pre-test and post-test scores on the Thackray, Stanford, and Yoshitake scales are
presented for each fragrance group in Table II.
Preliminary inspection of the data for the Thackray ratings of attention, sleepiness,
strain, boredom, and irritation indicated that the results for the five subscales were
similar. Consequently, the scores in Table II for this instrument represent summated
values (possible range is 5-45, with 25 as the midpoint) across the subscales. Increments
in negative feelings are reflected in lower post-test as compared to pre-test scores. In the
case of the Stanford and Yoshitake scales, however, increments in fatigue and sleepiness
are revealed through higher post-test as compared to pre-test scores.
Perusal of Table II will show that the subjects in this study found the vigil to be quite
stressful. Composite feelings of increased inattentiveness, sleepiness, strain, boredom,
and irritability after the vigil are evident in the Thackray ratings, along with increased
feelings of sleepiness and fatigue on the Stanford and Yoshitake scales. In the case of the
Yoshitake scale, pre-test and post-test differences were dramatic. On average, symptoms
of fatigue increased by 257% in the post-test measure. Analyses of variance performed
on the data of all three scales revealed significant phase effects [F(1,33) ) 48; p (
0.001] in each case. In no case, however, were the groups or the groups X phase
components of the analyses significant (p) 0.05), indicating that the self reports of
stress in this study were not attenuated by exposure to accessory olfactory stimulation.
Mean workload scores for the practice period and for the main task in the three fragrance
conditions are displayed in Table III.
It is evident in the table that the subjects rated the workload of both the 10-minute
practice period and the 40-minute vigil to be high. All scores are in the upper range of
the TLX scale. Moreover, there is a trend for the air group to show a greater increment
in workload from the 10-minute practice session to the 40-minute vigil than for the
Table II
Mean Pre-Test and Post-Test Scores on the Thackray, Stanford, and Yoshitake Scales for Subjects in the
Air, Muguet, and Peppermint Groups
Thackray Stanford Yoshitake
Groups Pre Post Pre Post Pre Post
Air 32.5 25.6 2.3 3.6 2.5 7.4
Muguet 33.6 25.1 2.4 3.8 3.3 7.1
Peppermint 34.2 25.7 2.2 3.3 2.7 7.2
Mean 33.4 25.5 2.3 3.6 2.8 7.2
Table III
Mean Workload Scores in Practice and the Main Watch for Subjects in the Air, Muguet,
and Peppermint Groups
Groups Practice Main watch Mean
Air 64.7 68.2 66.4
Muguet 69.4 68.0 68.7
Peppermint 63.6 62.3 63.0
Mean 65.9 66.2
Muguet or Peppermint groups. An analysis of variance of the data of Table III, however,
failed to reveal any significant differences between groups or between phases (p > 0.05).
The results of this experiment indicate that two fragrances, Peppermint and Muguet,
when delivered periodically during the course of a 40-minute vigil, can have beneficial
effects on subjects' performance in a vigilance task. Specifically, subjects exposed to
either of the two fragrances showed greater overall sensitivity to signals than those
receiving periodic whiffs of unscented air; that result cannot be attributed to a change
in subjects' willingness to emit detection responses, since the false alarm rates were
equivalent in all groups. Moreover, the result cannot be due to differences among groups
in the initial level of detectability of signals, since an analysis of variance revealed no
group differences in hit rate during the practice task [F(2,33) = 2.16; p > 0.05]. The
data did not show an effect on the vigilance decrement itself: Subjects in all three groups
performed less well as the vigil progressed than at the outset. Finally, there were no
differences between men and women in performance efficiency, no interactions between
gender and fragrance condition, and no effects involving time of day. So, we can
conclude with some confidence that the effect of the two fragrances on ability to
discriminate signals from non-signals has generality over sex and time of day.
While we had reason to expect Peppermint (characterized as alerting) to be more
effective than Muguet on performance measures, and Muguet (characterized as relaxing)
to be the more effective on subjective reports of stress and workload, it is apparent that
there was no difference between the two fragrances in their effect on performance
efficiency and that neither had any dramatic impact on subjective reports. These latter
results call into question the complicated scenario outlined earlier, that Peppermint
facilitates vigilance performance by directly raising arousal level, whereas Muguet works
through its ability to reduce the perceptually distracting effects of the symptoms of
fatigue, tension, strain, headache, and so on, that typically arise in the vigilance
situation. There are three simpler hypotheses that need to be tested: (a) given that both
Peppermint and Muguet are assessed as very pleasant, perhaps any pleasant fragrance
will suffice, and there is nothing physiologically/chemically special about these two
fragrances; (b) given that Peppermint and Muguet are both fragrances, perhaps any
fragrance will suffice, pleasant, neutral or unpleasant, so long as it is judged either
alerting or relaxing; and finally, (c) it is possible that any perceptually salient fragrance
will work by temporarily increasing subjects' alertness level via connections from olfac-
tory centers to the midbrain reticular area (27), a brain region that plays an important
role in the regulation and maintenance of vigilance (28). These possibilities warrant
further investigation.
Finally, note that beyond providing the initial experimental demonstration that certain
fragrances can bolster sustained attention, our results have meaning for an even broader
issue, that of intersensory interaction. Studies of interactions among stimuli in different
sense modalities have, for the most part, been confined to combinations drawn from the
auditory, visual, and tactual modes (29). To our knowledge, the data described in this
paper are the first to show that accessory olfactory stimulation can enhance the detection
of visual stimuli.
The results of this study indicate that exposure to whiffs of air scented with the fragrance
of Muguet or Peppermint can enhance the rate of signal detections in a vigilance task
without a concomitant increase in errors of commission. These findings suggest that
exposure to fragrance may serve as an effective form of ancillary stimulation in tasks
demanding close attention for prolonged periods of time.
This paper is based on an invited address given at the Annual Scientific Seminar of the
Society of Cosmetic Chemists, San Francisco, CA, May 11, 1990, and a talk given at
the Annual Meeting of the Psychonomic Society, New Orleans, LA, Nov. 17, 1990.
We are grateful to Marina Munteanu, Craig Warren, and Steven Warrenberg of Inter-
national Flavors and Fragrances, Inc., for suggesting that we undertake the research and
for providing extensive technical assistance; to Jonathan Gluckman, Sandy Matthews,
Judith A. Thiemann, and Mary Anne Toledo, for invaluable help with instrumentation
and data collection; and to the Fragrance Research Fund for financial support.
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... For the user study, we selected peppermint as the olfactory stimulus. Peppermint scent has been proven to have an arousing effect on the central nervous system and has been used in a previous study on attention (Warm et al., 1991;Dember et al., 2001), as well as on workload, work efficiency, and alertness, for example in driving tasks (Raudenbush et al., 2009). To ensure semantic congruency between visual and olfactory stimuli, based on a prior study (Raudenbush et al., 2009), we replaced the traditional "bells" in the Bells Test with a new target symbol (i.e., two small mint leaves, see Figure 2). ...
... For the investigation of the effect of unimodal and multimodal stimuli on visuospatial attention in VR, we used peppermint (i.e., essential oil from Holland and Barrett) as the olfactory stimulus due to its above-described effect on the central nervous system and its prior use in studying attention (Warm et al., 1991;Dember et al., 2001). As an auditory stimulus, we opted for a simple sequence of three piano G tones, where the first and third tones were the same, while the second was an octave higher of the other two. ...
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When interacting with technology, our attention is mainly driven by audio-visual and increasingly haptic stimulation. Olfactory stimuli are widely neglected, although our sense of smell influences many of our daily life choices, affects our behavior, and can catch and direct our attention. In this paper, we investigated the effect of smell and sound on visuospatial attention in a virtual environment. We implemented the Bells Test, an established neuropsychological test to assess attentional and visuospatial disorders, in Virtual Reality (VR). We conducted an experiment with 24 participants comparing users’ performance in three experimental conditions (smell, sound, smell and sound). Our results show that multisensory stimuli play a key role in driving participants’ attention and highlight asymmetries in directing spatial attention. We discuss the relevance of our results within and beyond Human-Computer Interaction (HCI), particularly with regards to the opportunity of using VR for rehabilitation and assessment procedures for patients with spatial attention deficits.
... Furthermore, neuro-imaging studies have shown that oral CO 2 triggers the immediate activation of a wide network of brain regions mediating alertness and cognitive functions [25,26]. For example, other trigeminal stimulations, such as the cooling compound of mint (menthol, TRPM8 agonist), have been consistently associated with rapid and immediate stimulatory effects in humans, including reduced sleepiness [27], increased sustained attention [28][29][30], improved alertness [30] and enhanced physiological arousal (cortical excitability) [31][32][33]. Despite this evidence, it is surprising that only one study [2] has investigated the acute effect of a carbonated caffeinated product on mood and cognition. ...
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Both caffeine and the perception of refreshment delivered by cooling, tingling, and mouth-watering flavors have individually been shown to positively impact cognitive performance and mood, though presently there is limited evidence on their possible combined effects. This study explored the contribution of refreshing compounds in beverages, namely, carbon dioxide and citric acid, on the acute effects of caffeine on sustained attention and self-rated physical and mental energy. A randomized, controlled crossover trial was conducted by testing three products: a carbonated caffeinated beverage; a comparator caffeinated beverage; and a flavor-matched control beverage. Findings from 24 healthy adults revealed product-dependent variations in cognitive performance during a 60-min visual sustained-attention task, suggesting that the carbonated-caffeinated beverage led to faster, greater and more consistent levels of accuracy, compared to the control beverage. Specifically, significant differences were found between: (1) the carbonated-caffeinated beverage and the caffeinated beverage, and (2) between the caffeinated beverage and the control beverage for number of hits, reaction time and false alarm scores. Both caffeinated beverages led to higher physical and mental energy, and lower physical and mental fatigue 60-min post-consumption. These findings suggest beneficial effects on sustained attention through the combination of caffeine with refreshing compounds.
... In the with scent condition, both participants wore a device that released a timed scent. Similar to Essence [1] and inScent [10], we used peppermint scent because it enhances alertness, focus, and concentration [39]. Each device was flled with 5 drops of peppermint essential oil diluted in 15 ml of fltered water. ...
Conference Paper
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Social interactions are multisensory experiences. However, it is not well understood how technology-mediated smell can support social interactions, especially in collaborative tasks. To explore its effect on collaboration, we asked eleven pairs of users to work together on a writing task while wearing an interactive jewellery designed to emit scent in a controlled fashion. In a within-subjects experiment, participants were asked to collaboratively write a story about a standardized visual stimulus while exposed to with scent and without scent conditions. We analyzed video recordings and written stories using a combination of methods from HCI, psychology, sociology, and human communication research. We observed differences in both participants' communication and creation of insightful stories in the with scent condition. Furthermore, scent helped participants recover from communication breakdown even though they were unaware of it. We discuss the possible implications of our findings and the potential of technology-mediated scent for collaborative activities.
... This network is associated with the norepinephrine/locus coeruleus system and involves the main areas of the frontal cortex and the dorsal visual pathway leading to the parietal lobe. The orienting network selects attentional information from that obtained by the senses to direct attention to the location of a relevant The pleasantness of odors plays important roles in human cognition, behavior, and emotion (Holland et al., 2005), and the pleasantness of odors has demonstrated effects on shifting visuospatial attention (Rinaldi et al., 2018), enhancing alertness (Warm and Dember, 1991;Shimizu et al., 2008), improving attention accuracy or task efficiency (Scholey et al., 2008;Liu et al., 2019), and attentional wayfinding (Hamburger and Knauff, 2019). However, the meta-analysis study demonstrated that the studies of olfactory odor processing leading a study bias which are more based on pleasant odor stimuli and few studies taking a contrast study between pleasant odors and unpleasant odors (Zou et al., 2016). ...
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Attention to unpleasant odors is crucial for human safety because they may signal danger; however, whether odor concentration also plays a role remains debated. Here, we explored the effects of two concentrations of pleasant and unpleasant odors on the attention network, comprising the alerting, orienting, and executive control networks. Behavioral responses were examined using the Attention Network Test, while electrophysiological responses were examined by assessing N1 and N2 amplitudes in 30 young men. We found that irrespective of odor concentration, an unpleasant odor induced larger cue-related N1 and N2 amplitudes in the alerting and executive control networks at occipital and frontal electrode sites and that was only paralleled by a reduced behavioral response time of cue-related trails in the alerting network. Thus, our results do not provide supporting evidence for a concentration-dependent effect, but they do suggest that more attentional resources are allocated to alerting-relevant stimuli to improve behavioral response times to a potential threat in young men.
... Might the release of synthetic chemosensory fear signals, for example, make certain games more exciting, or at the very least improve a player's performance ? Releasing the scent of peppermint has also been documented to improve people's performance in a range of tasks (e.g., Barker et al., 2003;Ho & Spence, 2005;Warm et al., 1991; see also Amores & Maes, 2017). In this case, though, scent might not necessarily need to present a semantically congruent signal but rather just something that delivers a functional benefit to the gamer's performance. ...
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There has long been interest in both the tonic and phasic release of scent across a wide range of entertainment settings. While the presentation of semantically congruent scent has often been used in order to enhance people’s immersion in a particular context, other generally less successful attempts have involved the pulsed presentation of a range of scents tied to specific events/scenes. Scents have even been released in the context of the casino to encourage the guests to linger for longer (and spend more), at least according to the results of one controversial study. In this narrative review, I want to take a closer look at the use of scent in a range of both physical and digital environments, highlighting the successes (as in the case of scented theme park rides) and frequent failures (as, seemingly, in the context of scent-enabled video games). While digitally inducing meaningful olfactory sensations is likely to remain a pipe dream for the foreseeable future, the digital control of scent release/delivery provides some limited opportunities to enhance the multisensory experience of entertainment. That said, it remains uncertain whether the general public will necessarily perceive the benefit, and hence be willing to pay for the privilege.
... So while you might notice the scent as you open your car door, my guess is that you probably won't think about it much after that. Several studies have demonstrated how the periodic delivery of pulsed scent (e.g., peppermint) can help enhance operator performance (e.g., Warm et al., 1991;Spence, 2005, 2008;Mahachandra et al., 2015). The Aroma Shooter ( ...
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There is undoubtedly growing interest in the role of scent in the design of multisensory experiences. However, to date, the majority of the research has focused on its use in the (static) built environment. As highlighted by this narrative review, somewhat different challenges and opportunities arise just as soon as one starts to consider olfaction in the case of transportation–what might be called “scent in motion.” For instance, levels of anxiety/stress while traveling are often higher (especially in the case of air travel), while, at the same time, the passenger's personal space is frequently compromised. Four key functional roles for scent in the context of passenger transportation are outlined. They include the masking of malodour, the introduction of branded signature scents, short-term olfactory marketing interventions, and the functional use of scent to enhance the experience of travel. In the latter case, one might consider the use of scent to help reduce the stress/anxiety amongst airplane passengers or to give the impression of cleanliness. Meanwhile, in the case of driving, scents have been suggested as an inoffensive means of alerting/relaxing the driver and may also help tackle the problem of motion sickness. The specific challenges associated with scent in motion are reviewed and a number of future opportunities highlighted.
... Peppermint is known to open the mind, improve concentration, release mental fatigue, and reduces stress (Pitman 2019;Tucker 2015). Supporting these therapeutic effects is the study of Warm et al. (1991) as the authors state that inhalation of peppermint essential oil aids focused attention. ...
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This study looks at the effects of the combined practice of mindful meditation and aromatherapy on the wellbeing of MCAST ICS lecturers, potentially providing resources that can help them deal with various stressors. Each practice is supported with literature underlining its effects towards a holistic wellbeing. The researcher uses a qualitative narrative inquiry approach to draw meaning and understanding out of the participants’ experiences. Three MCAST ICS lecturers participated in this study. Their background in health care enables them to relate better with the benefits of mindful meditation and aromatherapy. The research design of this study consists of four stages; a pre-session held with the three participants, weekly mindful meditation sessions for six weeks, individual interviews with each participant, followed by a focus group. Three of the six sessions included aromatherapy and a mindful journal was kept throughout the sessions. The analysis format could either develop as an analysis of narrative or narrative of analysis. In this study both formats were used, however, due to the word count limit only the analysis of narrative is seen. The researcher elicited whole segments from the individual transcripts to develop various themes. To examine the data for the emergent themes the researcher chose to use thematic narrative analysis as it focuses on the ‘told’ (Riessman 2008). In this case the ‘told’ is what helped identify the common patterns found across the narratives. As themes started to emerge, whenever possible the researcher used the MAXQDA software to facilitate the process. Mindful meditation was found to lead to a series of events that enhance self-awareness, thus enhancing holistic wellbeing and positively effecting the individual’s approach towards work and family. This can be achieved because mindful meditation has the potential to enhance one’s social skills, soft skills, and emotional intelligence. Furthermore, combining aromatherapy with mindful meditation was found to positively enhance one’s experience. However, it was not the only decisive factor since the ambience was also an influencer.
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Today, one of the most important issues in big cities is transportation and city traffic. The development of all countries in the world depends on the development of transport systems. One of the most effective solutions to this problem is to develop and strengthen urban public transportation systems. Also, deficiencies and inadequacies in the land transportation system, especially urban transportation, are considered as one of the obstacles to the growth and development of any country. Due to the urbanization phenomenon in Afghanistan and the increase in the number of cars in cities, we are witnessing exponentially increasing traffic and environmental pollution on the streets of cities, which has become a major problem for city administrators in Mazar-e-Sharif city. This research first mentions the city of Mazar-e-Sharif in terms of location, type of urban roads, existing public transport systems and traffic management. Then, the performance of existing systems, problems, existing challenges and high influencing factors of Mazar e-Sharif transportation system are examined. Finally, after the analysis, logical solutions to the existing problems are presented using the experiences of developed countries. Keywords: transportation, sustainable system, traffic, public transport system, road network
Conference Paper
In this study, I aimed to consider how and in what ways the sense of smell could support the education of pupils with Profound and Multiple Learning Disabilities (PMLD). I had two aims: first, I wanted to explore an approach to supporting teaching and learning for the PMLD cohort. Second, since the sense of smell is an under-researched and under-valued subject, I wanted to make my own contribution to providing evidence of the potential of this sense as an important tool for learning. At the centre of this study were seven pupils with PMLD all but one of whom I had taught before the research commenced. Although their difficulties were such that it was not possible to interview them, I was able to conduct interviews and joint observations with their parents and teaching professionals. I adopted a qualitative, interpretivist methodology, which was well suited to this close and detailed interview- and observation- focussed investigation. The fieldwork for this study was conducted over an eight-week period, in one London special school, in the spring and summer terms of 2014. I used three main methods to generate data: firstly, sourcing of information about the pupils from educational and healthcare documents and conducting initial observations (Spring Term, 2014); secondly, interviewing 15 adult participants including five teachers, seven parents, two senior leaders and the school therapist (Summer Term, 2014); thirdly, carrying out 92 video-recorded observations of pupils’ reactions to smell within sensory based activities over the eight-week fieldwork period and individually interviewing the parents, teachers and school therapist on their perceptions of the video-recordings (Summer Term, 2014). This research provided evidence to suggest that the use of smell was performing useful functions in supporting cognitive development and in the experience of eating and drinking. What also emerged was that the use of this sense offered an additional means through which pupils with PMLD could better understand and gain information about their immediate environment. The evidence and insights presented in this thesis have already been used to inform teaching and learning practices within my own school context and it is hoped that they can be used to better support the teaching and learning of other cohorts of pupils with PMLD.
Basic science studies indicate that menthol can enhance the cognitive effects of nicotine to increase nicotine dependence; however, the effect of menthol and nicotine on cognitive functioning among humans has been understudied. This double-blind, placebo-controlled study examined the dose-dependent effects of inhaled menthol flavoring and intravenous nicotine on cognitive task performance. Twenty menthol (MS) and 18 non-menthol (NMS) cigarette, young-adult smokers (21% female; 7.9% Hispanic, 44.7% Non-Hispanic/White, 47.4% Non-Hispanic/Black) completed three sessions with randomized order of menthol flavoring (between-sessions: 0.0%/tobacco control, 0.5%/low, 3.2%/high) and intravenous nicotine (within-session: 0.0 mg/saline control, 0.25 mg/low, 0.5 mg/high). After each administration, participants completed three cognitive tasks: Continuous Performance Task (CPT), Mathematical Processing Task (MPT), and Stroop Task. Mixed effects models were used to examine interactive effects of cigarette type preference and menthol and nicotine doses. MS vs. NMS had decreased accuracy on CPT and MPT and efficiency during Stroop. No significant effects of cigarette type preference by menthol or nicotine were found for any task. Significant effects of nicotine by menthol were found during Stroop, where participants had greater accuracy for high nicotine compared to saline during the low menthol session. Significant effects of menthol by timepoint were seen during Stroop, where participants improved across timepoints during the low menthol session. Findings did not support significant effects of inhaled menthol, alone or with nicotine, on cognitive performance. Further research clarifying the impact of varying menthol and nicotine levels in nicotine products may help to elucidate menthol’s role in smoking sustainment.
Sensory and cognitive vigilance were directly compared in two experiments. The question of whether sensory and cognitive vigilance task demands can be differentiated on the basis of perceived workload was also addressed. A third focus of the study was to investigate changes in sensory and cognitive vigilance across the adult life span. In Experiment 1 60 subjects from three age categories—young, middle, and elderly were studied. Experiment 2 consisted of 20 subjects from only the young and old age categories. Subjects performed a visual sensory and a cognitive vigilance task at low and high event rates. Each task used identical stimulus sets (pairs of digits) and differed only in the definition of a critical target. Task demands were a major determinant of vigilance performance. Cognitive vigilance was more resistant to decrement over time than sensory vigilance. On the other hand, the cognitive task was more adversely affected by high event rate than the sensory task. Older subjects had lower hit rates than young and middle-aged subjects on the cognitive task, particularly at the high event rate. Subjective workload results suggested that the increased mental demands required of the cognitive task at the high event rate were associated with performance differences between sensory and cognitive tasks. However, the results also revealed an apparent dissociation between performance and subjective workload measures. Implications of the results for display design and assessment of individual differences in monitoring capability are discussed.
To a psychiatrist like myself, practising in Redditch, Worcestershire, the need for an effective stress-relieving therapy is only too apparent. Redditch is a new town, still unsettled, a place where anxiety and stress-related difficulties are common. Traditional advice offered to sufferers from such problems has been to ‘get away from it all — take a relaxing holiday by the seaside’. For my patients this advice is not easy to follow since the town is about as far away from the sea as you can get in the UK.
Forty-five male subjects performed a simulated air traffic control radar task for 1 hour. Subjects were equally divided into three time-of-day groups and tested at 1000, 1300, and 1530. The subject's task was to respond as rapidly as possible to infrequent changes in alphanumeric symbols. Physiological recordings of blood pressure, oral temperature, skin conductance, body movement, heart rate and heart-rate variability, and performance measures of mean response latency and variability of response latencies were obtained. In addition, subjects rated their levels of boredom, monotony, irritation, attentiveness, fatigue, and strain at the beginning and end of the session. There were no differences between any of the time-of-day groups except in oral temperature, which was significantly higher in the afternoon than in the morning. Two extreme groups of eight subjects each were formed on the basis of their rated boredom and monotony and compared with respect to changes in each of the measures during the task period. The two groups differed significantly on several measures, with the high boredom-monotony group showing greater increases in 'long response times,' heart-rate variability, and strain along with a greater decrease in attentiveness. The nature of the pattern associated with boredom and monotony suggests a pattern more closely related to attentional processes than to 'arousal.' The extreme groups did not differ on the Eysenck Extraversion Scale or the Zuckerman General Sensation Seeking and Boredom Susceptibility Scales. Possible reasons for the lack of relationship with these scales are discussed.
workload measurement techniques vary with respect to certain properties that determine the utility of a technique for individual applications two particularly critical properties are the sensitivity and intrusiveness of a technique present theory and supporting evidence suggest that these properties can be influenced by a number of factors, including the level and type of information processing demands that are imposed on an operator such factors emphasize the need for more extensive comparative information regarding the sensitivity and intrusiveness of the major classes of techniques this chapter discusses theoretical bases of these properties, and reviews some current data that address the sensitivity and intrusiveness of several techniques the development of a standard evaluation methodology which is designed to provide the required comparative data and refine present workload metric application guidelines is also discussed (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Tested 60 undergraduates who scored on the extremes of the introversion-extraversion dimension of the Eysenck Personality Inventory on a vigilance task under either a drug (caffeine), placebo, or no drug condition. The prediction that extraverts in the no drug condition would show a significant decrement in performance between the 1st and last 3rd of the task was supported. The introverts as predicted showed no decrement. As hypothesized, the drug produced differential effects on the 2 groups relative to their performance without the drug: the extraverts and introverts who were given caffeine showed no increment or decrement between the 1st and last 3rd of the task. (22 ref.) (PsycINFO Database Record (c) 2012 APA, all rights reserved)