Preconditioning of reinforcing properties to an exteroceptive feedback stimulus

Three groups of rats were given Pavlovian preconditioning by means of a yoking procedure and subsequently trained to avoid. One group received a light stimulus during preconditioning at the same times as the master avoiding animals received an exteroceptive feedback stimulus. During the subsequent avoidance training, this group was then given the same light stimulus as a feedback stimulus on successful avoidance trials. The group learned two-way avoidance in about the same number of trials as one-way avoidance is typically learned and substantially faster than two other control groups. These data indicate that feedback stimuli develop reinforcing properties by a Pavlovian mechanism. The data of the control groups indicate that feedback stimuli do not provide “information” about responding in the present situation.     

The role of feedback in shaping responses to risky road scenarios: Evidence from electrodermal activity

When faced with hazardous driving situations, rapid and effective risk perception and decision-making processes are of crucial importance for avoiding crashes. In these cases, the processes are accompanied and influenced by underlying psychophysiological mechanisms such as electrodermal activity (EDA) modulations. The present work aims to assess the psychophysiological mechanisms underlying participants’ risk perception and decision-making when facing risky road scenarios, as correlated to the feedback role in modulating participants’ behavior. Study 1 (n = 32) explores the behavioral effects of administering a contingent feedback in a decision (decision-making) and an evaluation (risk perception) task in response to a set of risky and not risky images. The behavioral data reveal an effect on the participants’ probability of response, independently from the type of image presented, when the feedback was administered. In the decision task, the effect is accompanied by a change in the amplitude and percentage of the skin conductance responses (SCRs), which are moderated by block of trials. Study 2 (n = 44) better assesses the role of task and block on participants’ physiological activation, as measured by EDA signal. The results show an increase in psychophysiological activation when the feedback is delivered, in the first part of the tasks, both in terms of SCRs amplitude and percentage to the presented road scenarios, followed by a decrease in the second part of the tasks. Moreover, this effect is more evident in the decision task than the evaluation task. These findings suggest that the role exerted by feedback when facing risky traffic images may be described as based on an associative process that, once the correct response has been learned, tends to be reduced as it becomes automatic. Overall, the results of the two studies represent an important step toward the development of training programs aimed at promoting safer behaviors in risky driving contexts.     

Reduced electrodermal activity in psychopathy-prone adolescents

This study tests the hypothesis that psychopathy-prone adolescents show reduced anticipatory skin conductance responding. Electrodermal activity was recorded while participants anticipated and responded to a 105 dB signaled or unsignaled white-noise burst. Using an extreme groups design, the authors used Child Psychopathy Scale (D. R. Lynam, 1997) scores from a community sample of 335 male adolescents (age 16) to form control (n = 65) and psychopathy-prone (n = 65) groups. Significantly more psychopathy-prone participants were nonresponders in the signaled anticipatory (p = .014), signaled responsivity (p = .037), and unsignaled responsivity (p = .003) conditions compared with controls. Anticipatory hyporesponsivity of psychopathy-prone adolescents similar to the electrodermal hyporesponsivity found in psychopathic adults suggests that this autonomic impairment is present by adolescence and may predispose individuals to adult psychopathy.     

Bilateral electrodermal activity in waking man

Skin conductance responses were examined bilaterally in a group of 14 normal subjects. Twelve of them were right-handed and two were left-handed. All right-handed subjects exhibited asymmetry in skin conductance level and in skin conductance response during verbal-numerical and visual-imagery tasks. With the visual activity, larger responses were found in the left hand, while during the verbal task, larger responses were recorded from the right hand. The results were interpreted as evidence of hemispheric asymmetry of the electrodermal activity orienting response control mechanisms. More ipsilateral control for the right hand is predicted.     

Pre-extinction of sensory preconditioned electrodermal activity

In the present study, sensory preconditioning of human electrodermal activity was demonstrated. In the first phase of the experiment, two pairs of neutral pictures of human faces were presented (A/B and C/D) sequentially. In the second phase, one picture of one pair was immediately followed by an electrocutaneous stimulus (B+), and one picture of the other pair was not (D-). In the third phase the other picture of each pair (A and C) was tested. The effect of A and C alone presentations (pre-extinction) between the first and the second phase was investigated. When only those participants that showed reliable B+/D- differentiation were considered, the extinction group did not show stronger conditioned electrodermal activity to A than to C, whereas the control group did. These findings suggest that sensory preconditioning of anticipatory/preparatory responding only occurs when the pre-conditioned stimulus (A) actually predicts the conditioned stimulus (B).     

An investigation of bilateral asymmetries in electrodermal activity

Research in cerebral laterality supports the idea that functional differences between the left and right hemispheres exist with respect to cognitive style and perceptual ability. Related research, which has examined autonomic nervous system (ANS) correlates of cerebral laterality, suggests that a component of the ANS, electrodermal activity (EDA), is also lateralized. Some findings in the literature report the occurrence of bilateral asymmetries in phasic and tonic EDA as a function of a left or right hemisphere preference for information processing. This experiment used normal male subjects who were either left or right movers in a test of Conjugate Lateral Eye Movement (CLEM). This selection procedure served to maximize a subject’s preference for either a right or left hemisphere mode of information processing. Bilateral EDA was recorded continuously while subjects performed a visual recognition task using word (left hemisphere) and shape (right hemisphere) stimuli. The data do not support the contention that performance on a procedure chosen to selectively activate a given hemisphere elicits asymmetric tonic and/or phasic EDA. The results show no significant difference in the frequency of elicited skin conductance responses under either of the experimental conditions. Bilateral tonic EDA rose continuously over time and did not vary in either hand as a function of task. The present results fail to offer support for either of the hypotheses which argue for I) increased contralateralexcitation with selective hemispheric activation, or 2) increased contralateralinhibition of the EDR with hemispheric arousal.     

Effects of attention state on electrodermal activity during auditory stimulation of children.

During passive and active listening tasks electrodermal activity of 49 healthy school children was studied. The procedure included baseline recording, a passive listening task, instructions, and simple and discriminative active-listening tasks. On the passive task from Trials 1 to 10, habituation of the amplitude of the skin conductance response (SCR) occurred. Habituation of SCR amplitude did not occur during the active tasks. The children seemed to pay more attention during the active tasks than during the passive task, since the need to press the key is apt to require and may even increase general attention. As for temporal variables of SCR, the frequency of spontaneous SCRs showed a significant negative correlation with SCR latency and rise time. Reaction time exhibited a significant negative correlation with age. An increase in reaction time was found during the discriminative active-listening task over that for the simple active-listening task during the course of 10 trials. The younger children (6-8 yr.) seemed to require longer to pay attention than the older ones (10-12 yr.). Children seemed to pay more attention during the discriminative than during the simple active-listening task, since the need to press the key for discrimination should require and is likely to increase general attention.     

Extraversion and neuroticism: Investigation of resting electrodermal activity

In 1967 Eysenck published his biological account of extraversion and neuroticism. In the same year Claridge identified several problems with this theory. More recently Robinson has detailed a promising modification to Eysenck's theory which addresses many of the issues raised by Claridge. Drawing on Robinson's theory it was hypothesised that differences in resting electrodermal activity (EDA) would contrast extraverted‐neurotics (low arousal) and introverted‐neurotics (high arousal). The Eysenck Personality Questionnaire (EPQ) was used to identify four extreme groups of female participants: extraverted‐stable (n = 16), extraverted‐neurotic (n = 15), introverted‐stable (n = 8) and introverted‐neurotic (n = 16). EDA measures of skin conductance level (SCL) and non‐specific skin conductance response (NS‐SCR) were collected during two rest periods. Planned contrasts between the extraverted‐neurotic and introverted‐neurotic groups provided support for Robinson's theory on SCL but not NS‐SCR. It was argued that the results for NS‐SCR frequency could be accommodated by Robinson's theory if NS‐SCR was conceptualised as a measure of cortical reactivity to unspecified stimuli rather than as a measure of tonic arousal.     

Individual differences in electrodermal activity as a function of subjects' anxiety

The present study examines the relationships between electrodermal activity (EDA) and anxiety in an attention demanding task, by looking at the neuropsychology of individual differences. 261 normal volunteer female students completed the Cattell anxiety form, and only subjects with extreme anxiety scores (deciles 0, 1 and 2 on the one hand, N = 22; deciles 9 and 10 on the other hand, N = 24) were retained. Subjects were presented a set of 16 stimuli (8 neutral and 8 emotional slides) in a randomized order (different for each subject), of 35 msec and 1 sec duration and a randomized inter-stimuli time of average 45 sec. Skin conductance levels (SCLs), interstimuli spontaneous fluctuations (SSCRs), skin conductance response (SCR) amplitudes and electrodermal latencies were recorded, as well as skin temperature (ST). Highly anxious subjects showed significantly lower SCLs, lower SCR amplitudes, fewer interstimuli SSCRs and longer latencies than subjects with low anxiety, whereas ST did not differ between groups. These results, showing that in normal subjects there are individual electrodermal differences as a function of trait-anxiety scores, are discussed both in terms of individual differences in self-regulatory neural processes and in reference to Gray's anxiety theory.     

Attention of preschool children: electrodermal activity during auditory stimulation

Electrodermal activity during passive and active listening tasks of 43 healthy preschool children (aged 4 yr., 8 mo. to 6 yr., 5 mo.) was studied. The procedure included the following phases: baseline recording (3 min.), a passive listening task, instructions, and an active listening task. An increase in mean amplitude of skin conductance response (SCR) was found during the active listening task over the level for the passive listening task over 10 trials. On the passive listening task from Trial 1 to Trial 10, habituation of mean SCR amplitude occurred. The younger children, moreover, exhibited significantly greater habituation than the older children. Habituation of mean SCR amplitude did not occur during the active listening task. No significant difference was found in mean SCR amplitude during the active listening task for the two age groups. The children seemed to pay more attention during the active listening task than during the passive listening task. The younger children, moreover, are believed to have shorter attention spans.     

Hemispheric asymmetry and electrodermal activity in orienting and pavlovian conditioning paradigms

Three experiments on lateralization of electrodermal orienting and conditioned behavior are reported. The basic findings show effects of hemispheric asymmetry on initial magnitude and rate of habituation of phasic stimulus-elicited electrodermal responses. In summary, responses to verbal stimuli repeatedly flashed to the right visual half-field are larger than corresponding responses in the left half-field. Similarily, spatially relevant stimuli initially presented to the left half-field result in larger responses than when the same stimuli are repeatedly presented in the right half-field. In the auditory modality, data show asymmetrical control of responding to verbal material in a dichotic conditioning paradigm with greater resistance to extinction when the conditioned stimulus is initially fed only to the left hemisphere as compared to when it is fed only to the right hemisphere. It is argued that the present approach taps on basic mechanisms for the lateralization of attentional and associative functions.     

Extraversion and arousal: Effects of attentional conditions on electrodermal activity

Recent work has demonstrated that introverts show arousal decrements with increasing caffeine dosages under nonsignal conditions, but reverse this pattern under signal conditions. Other work, particularly in the areas of vigilance and memory, has pointed to greater attentiveness in introverts than extraverts. It was therefore hypothesized that the two groups would respond differentially under signal and nonsignal conditions as a function of attentional variations. The present study tested introverts and extraverts in a habituation paradigm involving systematic manipulation of signal and attentional conditions. Half of each personality group was randomly assigned to a distraction condition, the other half to an attending condition. Each S received two blocks of 19 habituation trials, a test stimulus and a dishabituation stimulus. In one of the two trial blocks, each stimulus was preceded by an auditory preparatory signal. Results showed that introverts gave larger SCRs, had higher SCLs, and showed greater dishabituation than extraverts. The signal reduced responding significantly more in introverts than in extraverts, and introverts were less affected by the distraction condition than were extraverts. Finally, extraverts showed more rapid habituation under nonsignal conditions and the signal produced a greater increase in habituation rate for introverts than for extraverts. Results were basically supportive of hypotheses derived from the Eysenck theory.     

Error detection and error memory in spatial navigation as reflected by electrodermal activity

The study investigated spatial navigation by means of electrodermal activity (EDA). Two groups of healthy subjects (group 1, age <38; group 2, age ≥38) were recorded during navigation through two 3-D virtual mazes differing in difficulty, that is, Maze Simple (MazeS) and Maze Complex (MazeC). Our results show (1) an effect of difficulty, that is, larger skin conductance responses (SCRs) and slower velocity profiles while navigating through MazeC as compared to MazeS. (2) An effect of age, that is, larger SCRs and faster velocity profiles in younger subjects (group 1) compared to older subjects (group 2). (3) An effect of maze region, that is, SCRs increased when subjects entered dead ends with group 1 (young group) decreasing in velocity, whereas group 2 (old group) increased in velocity. (4) And an error memory effect, that is, subjects who remembered an error at a given decision point (crossroads preceding dead ends in MazeC) from previous trials, and then if they did not repeat that error, elicited decreased SCRs as compared to subjects who did not remember and subsequently repeated an error. The latter aspect is the most impactful as it shows that EDA is able to reflect error detection and memory during spatial navigation. Our data designate EDA as suitable monitoring tool for identification and differentiation of the affective correlates underlying spatial navigation, which has recently attracted researchers’ attention due to its increased use in 3-D virtual environments.     

Common fears: a comparison of adolescents' self-generated and fear survey schedule generated fears.

Investigations into normative fear in adolescence have indicated that the most common fears are consistently death-related and danger-related. Assessments have most commonly been made from self-reports on fear survey schedules. The aim of the present study, therefore, was to determine whether adolescents would provide responses comparable to those generated through the use of a fear survey schedule when asked to list their 3 greatest fears. A total of 439 adolescents aged 11 to 18 years (237 girls, 201 boys, 1 sex not reported) listed their greatest fears; then they completed the 78-item Fear Survey Schedule for Children-II (E. Gullone & N. J. King, 1992). Consistent with past research, the 10 most common fears generated via the fear schedule related to death and danger. However, on the whole, the self-generated fears deviated from the death and danger theme, also including fear of failure, fear of animals, and fear of the unknown. A tendency toward global responses in self-generated fears appeared to encompass the majority of specific death-related fears included in the fear schedule, thus allowing for other predominant fears to be listed among the 3 most common.     

Smoking,personality, and imagery preference in Relation to spontaneous bilateral electrodermal activity

Effects of smoking on spontaneous bilateral skin conductance were studied as a consequence of interactions with set and setting. Bilateral skin conductance was recorded in six men and six women who smoked and an equal number of nonsmokers on two different days. On the first day, spontaneous electrodermal activity was recorded before and after a 10-minute rest period during which half the smokers smoked a cigarette. On the second day, one week later, spontaneous activity was again recorded before and after a 10-minute rest period during which the remaining smokers smoked a cigarette. Nonsmokers did not smoke at any time. Following smoking there was a significant negative correlation between a preference for visual over nonvisual imagery and spontaneous skin conductance responsivity in the left as compared to the right hand. Correlations were significantly different in smokers and nonsmokers. Smokers showed significantly greater preferences for either visual or nonvisual imagery than nonsmokers. Nonresponding nonsmokers were higher on the psychoticism (P) scale of the Eysenck Personality Questionnaire (EPQ) than responding nonsmokers. Smokers scored higher on P than nonsmokers. Interactions between personality, cognitive style, and the experimental situation, set, and setting were discussed in relation to the arousing effects of nicotine.