Gender influence on emotional responses to primary tastes.

Several studies have examined the gender differences in the area of emotion, but few data are available in the field of gustation. Yet, such differences are observed in clinical manifestations of nutritional disorders, such as a greater incidence of carbohydrate cravings in women. The aim of this study was consequently to examine the influence of gender on emotional responses to taste, by comparing autonomic responses and basic emotions associated with primary tastes between men and women. Thirty-four subjects (17 males, 17 females, mean age=28) participated in the experiment. Taste stimuli were solutions of 0.3 M sucrose (sweet), 0.15 M NaCl (salty), 0.02 M citric acid (sour) and 0.00015 M quinine sulfate (bitter). Evian mineral water served as the diluent and control (neutral taste). Five autonomic parameters [skin potential (SP) and resistance (SR), skin blood flow (SBF) and temperature (ST), instantaneous heart rate (IHR)] were simultaneously and continuously recorded when subjects tasted the five solutions. The patterns of autonomic responses, obtained for each primary taste and each subject, were transcribed into one of the six basic emotions defined by Ekman (happiness, surprise, sadness, fear, anger and disgust), according to a previously described method for odorants. Results evidenced that the mean variations of each autonomic parameter did not significantly differ between men and women, even if skin resistance and cardiac responses were stronger in men than in women. Concerning the basic emotions associated with each primary taste, a similar distribution for men and women was obtained for sweet, bitter and control solutions, whereas more differences were observed for salt (P=.02) and sour solutions.

Autonomic nervous system responses associated with primary tastes.

The hedonic dimension of the taste sensation plays a crucial role in the control of many taste-mediated responses related to food ingestion or rejection. The purpose of this study was to evaluate the emotional reactivity associated with each primary taste (sweet, salty, sour and bitter) through analysis of the variations of autonomic nervous system (ANS) parameters. Thirty-four healthy non-smoker volunteer subjects (17 males and 17 females, mean age = 28 years) participated in the experiment. Taste stimuli were solutions of 0.3 M sucrose (sweet), 0.15 M NaCl (salty), 0.02 M citric acid (sour) and 0.00015 M quinine sulfate (bitter). Evian mineral water was used as the diluent and control (neutral taste). Throughout the test, five ANS parameters (skin potential and skin resistance, skin blood flow and skin temperature, and instantaneous heart rate) were simultaneously and continuously recorded. Results of the ANOVA evidenced a significant effect of primary taste on skin resistance amplitude (P: < 0.001) and duration (P: < 0.0001), skin temperature amplitude (P: < 0.001), skin blood flow amplitude (vasoconstriction) (P: < 0.0001) and instantaneous heart rate increase (P: < 0.0001). Skin resistance and cardiac responses were the most relevant ANS parameters to distinguish among the taste solutions. The four primary tastes could be associated with significantly different ANS responses in relation to their hedonic valence: the pleasantly connoted and innate-accepted sweet taste induced the weakest ANS responses whereas the unpleasant connoted tastes (salty, sour and bitter) induced stronger ANS responses, the innate-rejected bitter taste inducing the strongest ones. Such a neurovegetative characterization of each primary taste could provide references for the hedonic analysis of the more complex gustative sensation attached to foods.

Autonomic nervous system activity associated with postural disturbances in patients with perilymphatic fistula: sympathetic or vagal origin?

The study focused on patients suffering from perilymphatic fistula (PLF), whether they had undergone surgery or not. Vestibular disturbances can be harmless but are associated with varying symptoms, demonstrating disorders within the autonomic nervous system (ANS). The aim was to test whether the orthosympathetic is involved as the vagal part is often suspected of eliciting a feeling of sickness. Non-invasive and uninterrupted recording of ANS activity represents an objectivation technique to evidence such disturbances. Electrodermal activity, thermovascular variables, instantaneous cardiac rate and blood pressure were recorded. Discomfort was triggered experimentally by applying various stimulations successively to the intact ear then to the PLF (or operated) side. Twelve subjects took part in the experiment. Two types of ANS activity were distinguished: (1) phasic responses during stimulation and (2) tonic evolution thereafter. Results show strong activation in orthosympathetic variables when the PLF side was stimulated. No further significant difference between the two sides was to be observed following surgery. After stimulation, a sudden increase in skin resistance was observed, associated with slight bradycardia. No vagal signs having been evidenced, actual nausea may result from brief inhibition of sympathetic activation resulting, in turn from primary over-activation of this system.

Programming or inhibiting action: evidence for differential autonomic nervous system response patterns.

In the general context of decision-making analysis, the aim of this study was to investigate autonomic nervous system activity when movement execution is inhibited just before onset. Using a 'Go/NoGo' paradigm, 16 subjects (nine males and seven females) had to intercept green table-tennis balls thrown by a robot, with the inner side of their hand and by arm extension. Conversely, they had to inhibit movement programming when a red ball was thrown. Results were displayed in terms of success or failure in view of the aim of each trial. Electrodermal, thermo-vascular and cardio-respiratory parameters were continuously recorded from the non-dominant hand. Results showed that the duration of autonomic responses was significantly longer in action than in inhibition. Temperature responses were negative but significantly more marked in action. Instantaneous respiratory frequency amplitude responses were positive in both action and inhibition conditions, but higher in action. Instantaneous heart rate responses confirmed that inhibition elicits cardiac deceleration. Autonomic responses were shown capable of distinguishing action from inhibition, thus reflecting central nervous system functioning. Results are discussed in terms of autonomic response specificity.

Basic emotions evoked by eugenol odor differ according to the dental experience. A neurovegetative analysis.

Subjective individual experiences seem to indicate that odors may form strong connections with memories, especially those charged with emotional significance. In the dental field, this could be the case with the odorant eugenol, responsible for the typical clinging odor impregnating the dental office. The odor of eugenol could evoke memories of unpleasant dental experiences and, therefore, negative feelings such as anxiety and fear, since eugenates (cements containing eugenol) are used in potentially painful restorative dentistry. This hypothesis was tested by evaluating the emotional impact of the odor of eugenol through autonomic nervous system (ANS) analysis. The simultaneous variations of six ANS parameters (two electrodermal, two thermovascular and two cardiorespiratory), induced by the inhalation of this odorant, were recorded on volunteer subjects. Vanillin (a pleasant odorant) and propionic acid (an unpleasant one) served as controls. After the experiment, subjects were asked to rate the pleasantness versus unpleasantness of each odorant on an 11-point hedonic scale. The patterns of autonomic responses, obtained for each odorant and each subject, were transcribed into one of the six basic emotions defined by Ekman et al. (happiness, surprise, sadness, fear, anger and disgust). Results were compared between two groups of subjects divided according to their dental experience (fearful and non-fearful dental care subjects) and showed significant differences only for eugenol. This odorant was rated as pleasant by non-fearful dental subjects but unpleasant by fearful dental subjects. The evoked autonomic responses were mainly associated with positive basic emotions (happiness and surprise) in non-fearful dental subjects and with negative basic emotions (fear, anger, disgust) in fearful dental subjects. These results suggest that eugenol can be responsible for different emotional states depending on the subjects' dental experience, which seems to confirm the potential role of odors as elicitors of emotional memories. This study also supports the possible influence of the ambient odor impregnating the dental office, strengthening a negative conditioning toward dental care in some anxious patients.

The mother rat's vomeronasal organ is involved in detection of dodecyl propionate, the pup's preputial gland pheromone.

The aim of the present study was to analyze the respective roles of main and accessory olfactory systems in a particular pattern of Wistar rat maternal behavior: specific licking of pup's anogenital areas, a behavioral pattern crucial to pup survival--nonlicked pups cannot defecate, and die. Dodecyl propionate (DP), a chemical agent from rat pup's preputial glands was found to direct and regulate pup's anogenital licking. Primiparous dams underwent one of the following treatments: surgical removal of the vomeronasal organ (hereafter VNX), irrigation of nasal cavities with 5% ZnSO4 solution (ZN), both these treatments (VNX + ZN), surgical control (SC), saline irrigation control (SA), both these treatments (SC + SA), and normal control (N). Fewer pups (only 75%) of VNX dams survived to 15 days of age compared to controls or to females rendered anosmic by zinc-sulfate irrigation of the nasal cavity (>95% survival). Furthermore, pup growth (mass increase over time) was impaired by VNX and/or ZN treatment. Greater than normal amounts of time were spent licking pups' anogenital area by VNX females, although these dams did not spend as much time as normal females in close contact with either pups heads or filter papers anointed with dodecyl propionate. The experiments reported herein suggest that the chemosensory receptors in the vomeronasal organ of dams mediate MAGL responses to pup pheromone, dodecyl propionate, a pheromone from pups' preputial glands secretion, sustaining pups' anogenital licking by dams.

Autonomic nervous system responses as performance indicators among volleyball players.

Complex motor skills require planning and programming before execution. The autonomic nervous system (ANS) is thought to transcribe these central operations at the peripheral level: a motor act is thought to be simultaneously programmed by central and autonomic nervous structures. The aim of this study was to verify that autonomic responses reflect the quality of central motor programming leading to successful or failed performance when subjects are required to perform a complex motor skill. The specificity of the ANS response has already been demonstrated through direct recording from sympathetic fibres. It has also been demonstrated through several mental tasks and closed motor skills such as shooting: ANS responses have been shown to be capable of distinguishing success from failure. The aim of this experiment was to test whether ANS responses are capable of distinguishing two levels of achievement during the performance of a skill involving uncertainty (open skill). The subjects had to intercept a ball on a volleyball court, using the forearm receive and pass technique, in order to pass it on to a moving human target. The results were displayed in terms of accuracy: accurate passes were successful and inaccurate passes missed the target. Six autonomic variables were recorded simultaneously during the task: skin resistance and potential, skin blood flow and temperature, instantaneous heart rate and respiratory frequency. Results showed that autonomic variables were capable of distinguishing success from failure in 22 subjects out of 24. This made it possible to build up autonomic patterns characterising subjects' performances, and to confirm that autonomic functioning may reveal information processing in the central nervous system. Thus, the study of autonomic responses may constitute an inferential model of central nervous system functioning. Such a method could be used as an index for the control of mental preparation.

Imagery quality estimated by autonomic response is correlated to sporting performance enhancement.

It is now well established that mental imagery practice improves motor skills, but performance efficiency depends on many factors: the main one being individual differences. The aim of this study is to evaluate performance improvement with imagery quality estimated during ANS recording. Volleyball training ("receiving serve") afforded us the experimental paradigm. Subjects were required to pass an opponent's serve to a given team mate. The receiver's performance was evaluated from the accuracy of his pass to the targeted team mate. From these first test results, subjects were divided into two equivalent groups: imagers and controls. After mental practice the two groups were submitted to a posttest similar to the first one. During the pretest, posttest actual practice as well as the last session of corresponding mental rehearsal, six autonomic parameters were continuously recorded. Furthermore, and for the first time, a grade obtained from four different aspects of this response permits qualitative evaluation of each subject's mental imagery. This estimation, based on the well-established link between performance and autonomic response, is validated by the fact that good correlation was obtained between this grade and the performance improvement of each of the "imager" group subjects.

Basic emotions induced by odorants: a new approach based on autonomic pattern results.

The aim of this study was to link the effects of odorants with the emotional process, through autonomic nervous system (ANS) responses. Taking Ekman's data and our previous results into account, we tried to verify a possible evocation by odorants of some basic emotions, i.e. anger, fear, sadness, surprise, disgust and happiness. The question investigated was: would it be possible to associate any of these emotions with a pattern of autonomic responses? A total of 15 subjects inhaled five odorants: lavender, ethyl aceto acetate, camphor, acetic acid and butyric acid acting as olfactory stimuli. After inhaling the odorant, subjects were requested to fill out an 11-point hedonic scale to rate its 'pleasantness' vs. 'unpleasantness'. ANS parameters monitored were skin potential and resistance, skin blood flow and temperature, instantaneous respiratory frequency and instantaneous heart rate. Simultaneous recording of these six autonomic parameters permitted the analysis of phasic responses through specific ANS patterns. An analysis of variance made it possible to differentiate among the five odorants. Two-by-two odorant comparisons for autonomic responses using Tukey's HSD multiple comparison test only permitted differentiation between 'pleasant' and 'unpleasant' odors. Camphor was differentiated from both types. For instance, long duration responses were associated with 'unpleasant' odors whereas camphor elicited intermediate responses. Taking into account each subject's preferential channel, it was possible to associate each ANS pattern with a basic emotion by means of a decision tree. The computation of subjects' responses made it possible to associate an odorant with a basic emotion, over the whole group: lavender elicited mostly 'happiness', as did, to a lesser degree ethyl aceto acetate; camphor induced either 'happiness', 'surprise' or 'sadness' according to subjects' past histories; butyric and acetic acids mainly induced negative emotions: 'anger' and 'disgust'. A high correlation was evidenced between subjects' hedonic evaluation and autonomic estimation of basic emotions. These results obtained from 15 subjects were compared to those observed in two similar experiments. These approaches showed comparable results. Thus, more than 60 subjects showed similar autonomic responses which can be transcribed into basic emotions. Thus, a multiparametric autonomic analysis allows the identification of the quality of the response, i.e. the type of basic emotion in addition to the intensity.

Neuroanatomical correlates of visually evoked sexual arousal in human males.

Brain areas activated in human male sexual behavior have not been characterized precisely. For the first time, positron emission tomography (PET) was used to identify the brain areas activated in healthy males experiencing visually evoked sexual arousal. Eight male subjects underwent six measurements of regional brain activity following the administration of [15O]H2O as they viewed three categories of film clips: sexually explicit clips, emotionally neutral control clips, and humorous control clips inducing positive but nonsexual emotions. Statistical Parametric Mapping was used to identify brain regions demonstrating an increased activity associated with the sexual response to the visual stimulus. Visually evoked sexual arousal was characterized by a threefold pattern of activation: the bilateral activation of the inferior temporal cortex, a visual association area; the activation of the right insula and right inferior frontal cortex, which are two paralimbic areas relating highly processed sensory information with motivational states; and the activation of the left anterior cingulate cortex, another paralimbic area known to control autonomic and neuroendocrine functions. Activation of some of these areas was positively correlated with plasma testosterone levels. Although this study should be considered preliminary, it identified brain regions whose activation was correlated with visually evoked sexual arousal in males.

Autonomic nervous system responses correlate with mental rehearsal in volleyball training.

The aim of this study was to assess objectively the processes of mental rehearsing (imagery) by measuring variations of the autonomic nervous system (or ANS responses) during an open-ended complex motor skill in two actual experiments (volleyball) and during mental rehearsing taking place between them. Comparison between pre- and post-test (volleyball) scores related to imagining and non-imagining performances revealed significant improvement in the former (chi2 = 20.9, P < 0.00001) while in the latter chi2 = 27, P < 0.9, NS. The ANS parameters (skin potential and resistance, skin temperature and heat clearance, instantaneous heart rate and respiratory frequency) were quantified by original techniques and indices. Results from a principal component analysis showed a strong correlation between the responses in actual tasks (pre- and post-test volleyball) and during mental imagery, since the same preferential variables appeared on the main axis in 87% of cases. Thus the same autonomic channels seemed to be used during the actual activity and during the mental imagery of this activity. So far as phasic results were concerned, the main finding was a differing development of skill between imagining and non-imagining volleyball players. No clear difference was seen between pre- and post-tests in non-imaginers, except an increase in the median of the duration of the response observed in heat clearance, m1 and m2 respectively [m1 = 5.8 (SD 4.1) s, m2 = 7.6 (SD 3.9) s, P < 0.001]. Conversely, for other ANS parameters, a significant decrease was seen in the post-test responses compared to pre-test responses in the imagining group [for instance, the median of the duration of the resistance responses decreased from m1 = 12.6 (SD 4.3) s, and m2 = 7.8 (SD 4.5) s, P < 0.0001 in imaginers, while no change was observed in non-imaginers: 9.6 (SD 6.0) s vs 9.5 (SD 6.1) s, NS] except in the duration of the heat clearance response where an increase was seen [m1 = 7.3 (SD 5.0) s vs m2 = 7.6 (SD 3.1) s, NS]. Compared to the non-imagining group, the latter result may also have been associated with a response decrease in the imagining group. Thus mental rehearsing induced a specific pattern of autonomic response: decreased amplitude, shorter duration and negative skin potentials compared to the control group. As this pattern was associated with better performance in the tests it can be suggested that in the case of open-ended motor activity, mental rehearsing may help in the construction of schema which can be reproduced, without thinking, in actual practice. Thus a neural information process might develop in the central nervous system changing from a parallel into a serial treatment.

Emotional responses evoked by dental odors: an evaluation from autonomic parameters.

Among the factors which could explain avoidance behavior toward dental care, the typical clinging odor of the dental office, due to eugenol, is investigated in this study. The hypothesis is supported by the well-known effects of odorants which may influence cognition, emotion, and behavior. The association between the odor of eugenol and dental fear and anxiety could be explained by the fact that eugenates (eugenol-containing cements) are often used in potentially painful restorative dentistry on vital teeth. The emotional impact of the odors of eugenol and two other dental products (menthol and methyl methacrylate) was evaluated on volunteer subjects through autonomic nervous system (ANS) analysis by recording the variations of six ANS parameters (two electrodermal, two thermovascular, and two cardiorespiratory) induced by the inhalation of the odorants. After the experiment, subjects were asked to fill out an 11-point hedonic scale to rate the pleasantness vs. unpleasantness for each odorant. Results were compared between two groups of subjects divided according to their own dental experience (fearful and non-fearful dental-care subjects). These showed that, in both groups, menthol was rated as pleasant and methyl methacrylate as very unpleasant, whereas eugenol was judged pleasant by non-fearful subjects but unpleasant by fearful subjects. Concerning autonomic analysis, only eugenol induced significantly different patterns of ANS responses between the two groups, with stronger variations for dentally fearful subjects, mainly observed through the electrodermal channel. These results suggest that eugenol can be responsible for different emotional states, depending on the unpleasantness of the subjects' dental experience. This seems to confirm the role of odors as elicitors of emotional memories and to support the possible influence of eugenol odor on the avoidance behavior of some subjects toward dental care.

Basic emotions evoked by odorants: comparison between autonomic responses and self-evaluation.

The present study was designed to analyze the relationship between self-report and physiological expression of basic emotions (happiness, surprise, fear, sadness, disgust and anger) in response to odorants. 44 subjects inhaled five odorants: vanillin, menthol, eugenol, methyl methacrylate, and propionic acid. Six autonomic nervous systems (ANS) parameters were simultaneously recorded in real time and without interference: Skin Potential (SP), Skin Resistance (SR), Skin Temperature (ST), Skin Blood Flow (SBF), Instantaneous Respiratory Frequency (IRF) and Instantaneous Heart Rate (IHR). At the end of the recording, subjects were instructed i) to identify the odorants roughly II) to situate them on an 11-point hedonic scale from highly pleasant (0) to highly unpleasant (10); and iii) to define what type of basic emotion was evoked by each odorant. In this study, the expected affects were aroused in the subjects. Vanillin and menthol were rated pleasant, while methyl methacrylate and propionic acid were judged unpleasant. Eugenol was median in hedonic estimation. ANS evaluation (each autonomic pattern induced by an odorant was transcripted into a basic emotion) shows that pleasantly connoted odorants evoked mainly happiness and surprise, but that unpleasant ones induced mainly disgust and anger. Eugenol was associated with positive and negative affects. Comparison between conscious (verbal) and unconscious (ANS) emotions, reveals that these two estimations 1) were not significantly different as far as the two pleasant odorants were concerned, 2) showed a tendency to be significantly different for eugenol odorant which was variably scored on the hedonic axis, and 3) exhibited a significant difference for the two unpleasant odorants, for which the corresponding "verbal emotion" was mainly "disgust", while the most frequent ANS emotion was "anger". In conclusion, these results show quite a good correlation between verbal and ANS estimated basic emotions. The main difference concerns anger: while there is a high occurrence of this emotion revealed by the analysis of ANS responses, it does not appear to be easily expressed through the verbal channel.

Odor hedonics: connection with emotional response estimated by autonomic parameters.

The aim of this paper is to analyse the relationship between self-report hedonic evaluations and the physiological expression of emotion in response to odorants. We try to solve the following questions: (1) Is it possible to find any experimental evidence that the sense of smell is linked with emotion? (2) What kind of odorants can be distinguished by autonomic analysis? (3) Is there a link between hedonics and autonomic information? The effects of odorants on the emotional process were estimated, in terms of autonomic nervous system (ANS) activity. Fifteen subjects inhaled five odorants as olfactory stimuli: lavender (LAV), ethyl acetoacetate (EAA), camphor (CAM), acetic acid (AA) and butyric acid (BA). After inhaling the odorant, subjects were requested to fill out an 11-point hedonic scale to rate its pleasantness versus unpleasantness. ANS parameters were as follows: two electrodermal responses, skin potential (SP) and resistance (SR); two thermovascular parameters, skin blood flow (SBF) and skin temperature (ST); and two cardiorespiratory parameters; instantaneous respiratory frequency (IRF) and instantaneous heart rate (IHR). Simultaneous recording of six parameters showed that specific autonomic patterns were associated with each odorant. An analysis of variance made it possible to differentiate among the five odorants. Two-by-two odorant comparisons for autonomic responses using Tukey's HSD multiple comparison test only permitted differentiation between pleasant odorants (LAV and EAA) and unpleasant (AA and BA) ones, but camphor was differentiated from both pleasant and unpleasant odorants. Each odorant elicited responses in the different parameters, yet subjects responded through their preferential channels; an average of two channels was used by each subject. These results when compared with those obtained with other senses (visual and auditory), did not evidence the postulated preferential link between olfaction and emotion. A strong link between hedonics and ANS response could be demonstrated when considering each subject and mainly through his/her preferential channel(s); conversely a weak correlation (SR duration excepted) was obtained between inter-subjects' hedonic evaluation. It seems that for a given population the autonomic response reflect the odor valence only through some parameters related to the main preferential channel(s) and thus the global autonomic pattern has to be considered.

Autonomic nervous system response patterns specificity to basic emotions.

The aim of this study was to test the assumption that the autonomic nervous system responses to emotional stimuli are specific. A series of six slides was randomly presented to the subjects while six autonomic nervous system (ANS) parameters were recorded: skin conductance, skin potential, skin resistance, skin blood flow, skin temperature and instantaneous respiratory frequency. Each slide induced a basic emotion: happiness, surprise, anger, fear, sadness and disgust. Results have been first considered with reference to electrodermal responses (EDR) and secondly through thermo-vascular and respiratory variations. Classical as well as original indices were used to quantify autonomic responses. The six basic emotions were distinguished by Friedman variance analysis. Thus, ANS values corresponding to each emotion were compared two-by-two. EDR distinguished 13 emotion-pairs out of 15. 10 emotion-pairs were separated by skin resistance as well as skin conductance ohmic perturbation duration indices whereas conductance amplitude was only capable of distinguishing 7 emotion-pairs. Skin potential responses distinguished surprise and fear from sadness, and fear from disgust, according to their elementary pattern analysis in form and sign. Two-by-two comparisons of skin temperature, skin blood flow (estimated by the new non-oscillary duration index) and instantaneous respiratory frequency, enabled the distinction of 14 emotion-pairs out of 15. 9 emotion-pairs were distinguished by the non-oscillatory duration index values. Skin temperature was demonstrated to be different i.e. positive versus negative in response to anger and fear. The instantaneous respiratory frequency perturbation duration index was the only one capable of separating sadness from disgust. From the six ANS parameters study, different autonomic patterns were identified, each characterizing one of the six basic emotion used as inducing signals. No index alone, nor group of parameters (EDR and thermovascular for instance) were capable of distinguishing each emotion from another. However, electrodermal, thermo-vascular and respiratory responses taken as a whole, redundantly separated each emotion thus demonstrating the specificity of autonomic patterns.

Relationships between performance and skin resistance evolution involving various motor skills.

The aim of this article was to question the classical inverted-U curve relationship between activation and performance. It was hypothesized that changes in performance were related to both activation and the degree of skill difficulty, suggesting a more complex relation. Fifty-one subjects took part in one of three experiments requiring sensory and motor anticipation abilities. They were divided into three different groups, each performing one particular anticipation task. Skin resistance was continuously recorded during task performance. This autonomic variable is well known to be a reliable index in predicting activation variations. The first task, carried out in a seated position, was to intercept a moving spot on a computer screen by pressing the space bar on the keyboard. The second task, performed standing, required subjects to intercept a moving table tennis ball with palm of the hand, by extending the forearm and the arm. The third task, executed in movement was performed on a volley-ball ground. The aim was to hit a ball to reach a moving human target, using the forearm-blow technique. Results showed that 90.9% of subjects'performance in Experiment 1 was related to skin resistance tonic level variations, thus establishing a strong relationship between performance and arousal. Subjects' performance (43.8%) in Experiment 2 was related to skin resistance tonic level variations, whereas only 12.5% of performance was related to this variable in Experiment 3. In conclusion, tonic level variations can only account for success or failure in the first experiment. Conversely, success or failure were dependent upon information processing, decision making, and motor execution in the third experiment. The second experiment, requiring intermediate abilities, was found to show intermediate results. The role of skin resistance tonic level fluctuations and their use in the study of sporting performance are discussed, suggesting that arousal/performance relationships do not correspond to a simple inverted-U curve in complex motor skills requiring a steady level of arousal.

Increased activation as a limiting factor of performance in sharp shooters.

The measurement of autonomic nervous system (ANS) activity was performed on 10 male and five female sharp shooters (rifle) during competitions. Electrodermal, thermovascular, cardiorespiratory variables and two indices of performance were recorded simultaneously. When the subjects fired shots that hit the target, they had a higher number of negative skin potential responses than when they missed. The responses had lower amplitude but lasted longer than when the shots missed the target. Good performance seemed to depend on high levels of motivation (increase in negative potential response), better mastery of the emotional reactivity (low amplitude response), and greater concentration time (increased duration of response).

The ohmic perturbation duration, an original temporal index to quantify electrodermal responses.

The reactivity of the autonomic nervous system was (D.C.) recorded using six parameters simultaneously. Such a device permitted to describe a new index of skin resistance response (SRR). The ohmic perturbation duration (O.P.D. index) was defined as the period during which the subject is effectively responding to the stimulation. O.P.D. index was easily quantified because the specific part of the response, showing many fluctuations at a low resistance level, can be distinguished from the recovery part without fluctuations or with smaller microevents of different kinds. Moreover, the slope of this fluctuation is identical to that observed just before the stimulation. The comparison between the values of the O.P.D. index and classically used SRR durations enabled us to calculate the identity percentages from five other neurovegetative parameters. Results showed high values for the skin potential (91%) and skin blood flow (82.5%). These values were smaller as far as skin superficial temperature (50.5%), heart (40.8%) and respiratory (46.5%) variations were concerned. Nonetheless these last three percentages were still higher than those usually obtained with the values of the correlation coefficients from different, simultaneously recorded parameters. O.P.D. index comparison with four other classical used temporal indices (recovery time, 1/3, 1/2 and 2/3 of the recovery time) show a high significant concordance in O.P.D. index opposed to aleatory one obtained with these four other durations. Thus, the O.P.D. index could be an appropriate measure of electrodermal response (EDA) allowing any stimulus to be temporarily quantified towards sympathetic activation induced response.

Bioelectric and microcirculation cutaneous sensors for the study of vigilance and emotional response during tasks and tests.

Bioelectronic phenomena related to the activity of the Autonomic Nervous System (ANS) activity mainly take place in the deep part of the brain where they are difficult to record. The hand skin, being richly innervated by sympathetic efferent fibres, offers an interface from which relevant ANS-related signals can be recorded. Two non-invasive bioelectronic measurements (skin resistance and potential) reflecting the activity of the ANS were performed at the skin surface. These measurements were complemented by thermovascular (skin microcirculation and skin temperature) and cardiorespiratory (instantaneous heart rate and instantaneous respiratory frequency) measurements. The bioelectric measurements were performed using noninvasive Ag/AgCl electrodes. Non-metallic NASICON (Na Super Ionic Conductor) electrodes were tested and compared with traditional electrodes for the optimization of bioelectric measurements. Signal analysis and data processing was accomplished by means of original indices on a specially designed PC-based software. The methodology was used to evaluate vigilance level, mental workload, and emotional response during tasks (sporting activity, mental calculation, olfactive stimuli) and in critical situations (car crash avoidance).

Autonomic responses correlate to motor anticipation.

New findings have stated that autonomic nervous system (ANS) functioning may reflect some cognitive processes observed in real time analysis. Four ANS variables plus instantaneous heart rate and respiratory frequency were quantified by original techniques and indices on 11 subjects during a coincidence-anticipation task, performed on a computer screen under six different, randomly-presented modalities (3 modalities describing the spot moving along a parabola at 2 speeds). Tonic levels and phasic responses corresponding to each trial were recorded continuously. Results showed that skin resistance tonic level evolution gave evidence of vigilance changes. Thus, performance can be related to subjects' vigilance. An autonomic response was always observed during performance of an anticipation task. The six task modalities were distinguished by performance values. Simultaneously recorded ANS responses fully differentiated these same modalities for 10 subjects out of 11. These ANS responses were furthermore related to performance. Ten subjects out of 11 possess at least one Autonomic variable which can differentiate the six task modalities, confirming Lacey's hypothesis on ANS preferential response, and suggesting ANS specificity. ANS functioning may reveal some brain functions through a specific autonomic channel, characterizing each subject. The behavioral output of an individual may thus be reflected by such a functioning.