Habituation Of Skin Conductance Response Research Articles

Fear conditioning depends on the nature of the unconditional stimulus and may be related to hair levels of endocannabinoids.

The replicability of fear conditioning research has come under recent scrutiny, with increasing acknowledgment that the use of differing materials and methods may lead to incongruent results. Direct comparisons between the main two unconditional stimuli used in fear conditioning - an electric shock or a loud scream-are scarce, and yet these stimuli are usually used interchangeably. In the present study, we tested whether a scream, a shock, or an unpredictable combination of the two affected fear acquisition, extinction, and return of fear amongst healthy participants (N=109, 81 female). We also collected hair samples and tested the relationship between fear conditioning and hair endocannabinoid levels. Our findings suggest that, although subjective ratings of pleasantness, arousal, and anxiety were similar regardless of the unconditional stimuli used, skin conductance responses were significantly lower for stimuli paired with the scream compared to a shock alone. Further, reducing the predictability of the unconditional stimulus reduced habituation of skin conductance responses during acquisition and reacquisition, but did not produce stronger conditioning compared to shock alone. Exploratory analyses suggested that hair endocannabinoids were associated with overall physiological arousal during fear conditioning, as well as higher return of fear to the threat cue, but not to the safety cue. These findings have multiple implications for the design and replicability of fear conditioning research and provide the first evidence for an association between hair levels of endocannabinoids and human fear conditioning.

Multimodal analysis of startle type responses

Background and objectiveThis article presents a multimodal analysis of startle type responses using a variety of physiological, facial, and speech features. These multimodal components of the startle type response reflect complex brain–body reactions to a sudden and intense stimulus. Additionally, the proposed multimodal evaluation of reflexive and emotional reactions associated with the startle eliciting stimuli and underlying neural networks and pathways could be applied in diagnostics of different psychiatric and neurological diseases. Different startle type stimuli can be compared in the strength of their elicitation of startle responses, i.e. their potential to activate stress-related neural pathways, underlying biomarkers and corresponding behavioral reactions. MethodsAn innovative method for measuring startle type responses using multimodal stimuli and multimodal feature analysis has been introduced. Individual's multimodal reflexive and emotional expressions during startle type elicitation have been assessed by corresponding physiological, speech and facial features on ten female students of psychology. Different startle eliciting stimuli like noise and airblast probes, as well as a variety of visual and auditory stimuli of different valence and arousal levels, based on International Affective Picture System (IAPS) images and/or sounds from International Affective Digitized Sounds (IADS) database, have been designed and tested. Combined together into more complex startle type stimuli, such composite stimuli can potentiate the evoked response of underlying neural networks, and corresponding neurotransmitters and neuromodulators as well; this is referred to as increased power of response elicitation. The intensity and magnitude of multimodal responses to selected startle type stimuli have been analyzed using effect sizes and medians of dominant multimodal features, i.e. skin conductance, eye blink, head movement, speech fundamental frequency and energy. The significance of the observed effects and comparisons between paradigms were evaluated using one-tailed t-tests and ANOVA methods, respectively. Skin conductance response habituation was analyzed using ANOVA and post hoc multiple comparison tests with the Dunn–Šidák correction. ResultsThe results revealed specific physiological, facial and vocal reflexive and emotional responses on selected five stimuli paradigms which included: (1) acoustic startle probes, (2) airblasts, (3) IAPS images, (4) IADS sounds, and (5) image-sound-airblast composite stimuli. Overall, composite and airblast paradigms resulted in the largest responses across all analyzed features, followed by sound and acoustic startle paradigms, while paradigm using images consistently elicited the smallest responses. In this context, power of response elicitation of the selected stimuli paradigms can be described according to the aggregated magnitude of the participants’ multimodal responses. We also observed a habituation effect only in skin conductance response to acoustic startle, airblast and sound paradigms. ConclusionsThis study developed a system for paradigm design and stimuli generation, as well as real-time multimodal signal processing and feature calculation. Experimental paradigms for monitoring individual responses to stressful startle type stimuli were designed in order to compare the response elicitation power across various stimuli. The developed system, applied paradigms and obtained results might be useful in further research for evaluation of individuals’ multimodal responses when they are faced with a variety of aversive emotional distractors and stressful situations.

One night of partial sleep deprivation affects habituation of hypothalamus and skin conductance responses

Sleep disturbances are prevalent in clinical anxiety, but it remains unclear whether they are cause and/or consequence of this condition. Fear conditioning constitutes a valid laboratory model for the acquisition of normal and pathological anxiety. To explore the relationship between disturbed sleep and anxiety in more detail, the present study evaluated the effect of partial sleep deprivation (SD) on fear conditioning in healthy individuals. The neural correlates of 1) nonassociative learning and physiological processing and 2) associative learning (differential fear conditioning) were addressed. Measurements entailed simultaneous functional MRI, EEG, skin conductance response (SCR), and pulse recordings. Regarding nonassociative learning, partial SD resulted in a generalized failure to habituate during fear conditioning, as evidenced by reduced habituation of SCR and hypothalamus responses to all stimuli. Furthermore, SCR and hypothalamus activity were correlated, supporting their functional relationship. Regarding associative learning, effects of partial SD on the acquisition of conditioned fear were weaker and did not reach statistical significance. The hypothalamus plays an integral role in the regulation of sleep and autonomic arousal. Thus sleep disturbances may play a causal role in the development of normal and possibly pathological fear by increasing the susceptibility of the sympathetic nervous system to stressful experiences.

Interactions of time of day and sleep with between-session habituation and extinction memory in young adult males.

Within-session habituation and extinction learning co-occur as do subsequent consolidation of habituation (i.e., between-session habituation) and extinction memory. We sought to determine whether, as we predicted: (1) between-session habituation is greater across a night of sleep versus a day awake; (2) time-of-day accounts for differences; (3) between-session habituation predicts consolidation of extinction memory; (4) sleep predicts between-session habituation and/or extinction memory. Participants (N = 28) completed 4-5 sessions alternating between mornings and evenings over 3 successive days (2 nights) with session 1 in either the morning (N = 13) or evening (N = 15). Twelve participants underwent laboratory polysomnography. During 4 sessions, participants completed a loud-tone habituation protocol, while skin conductance response (SCR), blink startle electromyography (EMG), heart-rate acceleration and heart-rate deceleration (HRD) were recorded. For sessions 1 and 2, between-session habituation of EMG, SCR and HRD was greater across sleep. SCR and HRD were generally lower in the morning. Between-session habituation of SCR for sessions 1 and 2 was positively related to intervening (first night) slow wave sleep. In the evening before night 2, participants also underwent fear conditioning and extinction learning phases of a second protocol. Extinction recall was tested the following morning. Extinction recall was predicted only by between-session habituation of SCR across the same night (second night) and by intervening REM. We conclude that: (1) sleep augments between-session habituation, as does morning testing; (2) extinction recall is predicted by concurrent between-session habituation; and (3) both phenomena may be influenced by sleep.

Napping promotes inter-session habituation to emotional stimuli

The effects of a daytime nap on inter-session habituation to aversive visual stimuli were investigated. Healthy young adult volunteers viewed repeated presentations of highly negative and emotionally neutral (but equally arousing) International Affective Picture System (IAPS) photographs during two afternoon sessions separated by 2.5 h. Half of the photographs were shown at both sessions (Repeated Sets) and half differed between sessions (Novel Sets). For each stimulus presentation, evoked skin conductance response (SCR), heart-rate deceleration (HRD) and corrugator supercilii EMG response (EMG), were computed and range corrected using respective maximum session-1 responses. Following each presentation, subjects rated each photograph on dimensions of pleasantness and arousability. During the inter-session interval, Nap subjects had a 120-min polysomnographically monitored sleep opportunity, whereas Wake subjects watched a non-stimulating video. Nap and Wake subjects did not differ in their subjective ratings of photographs. However, for Repeated-Set photographs, Nap subjects demonstrated greater inter-session habituation in SCR and EMG but a trend toward lesser inter-session habituation in HRD. These group differences were absent for Novel-Set photographs. Group differences across all measures were greater for negative stimuli. Occurrence of SWS during the nap was associated with greater inter-session habituation of EMG whereas occurrence of REM was associated with lesser inter-session habituation of SCR to negative stimuli. Sleep may therefore promote emotional adjustment at the level of somatic responses. Physiological but not subjective inter-session habituation to aversive images was enhanced by a daytime nap.

Acute dissociation predicts rapid habituation of skin conductance responses to aversive auditory probes

The present study examined how acute dissociation, trait-like dissociative symptoms, and physiological reactivity relate to each other. Sixty-nine undergraduate students were exposed to 14 aversive auditory probes, while their skin conductance responses were measured. A combination of self-reported anxiety and trait-like dissociation was found to predict variability in peritraumatic dissociation levels induced by the aversive probes. Furthermore, high levels of acute dissociation were associated with faster habituation of skin conductance responding, while trait-like dissociation was unrelated to habituation. Interestingly, individuals who reported childhood trauma displayed elevated skin conductance responses. Our findings contribute to the growing body of evidence indicating that subjective feelings of acute dissociation have their objective concomitants, notably fast habituation of physiologic responses.

Pain perception, somatosensory event-related potentials and skin conductance responses to painful stimuli in high, mid, and low hypnotizable subjects: effects of differential pain reduction strategies

In this study, pain perception, somatosensory event-related potential (SERP) and skin conductance response (SCR) changes during hypnotic suggestions of Deep Relaxation, Dissociated Imagery, Focused Analgesia, and Placebo, compared with a Waking baseline condition, were investigated. SERPs were recorded from frontal, temporal, central, and parietal scalp sites. Ten high, 9 mid, and 10 low hypnotizable right-handed women participated in the experiment. The following measures were obtained: (1) pain and distress tolerance ratings; (2) sensory and pain thresholds to biphasic electrical stimulation delivered to the right wrist; (3) reaction time and number of omitted responses; (4) N2 (280±11 ms) and P3 (405±19 ms) peak amplitudes of SERPs to target stimuli delivered using an odd-ball paradigm; (5) number of evoked SCRs and SCR amplitudes as a function of stimulus repetition. Results showed, high, mid and low hypnotizables exhibited significant reductions of reported pain and distress ratings during conditions of Deep Relaxation/Suggestion of Analgesia, Dissociated Imagery and Focused Analgesia. High hypnotizable subjects displayed significant reductions in pain and distress levels compared to mid and low hypnotizables during Dissociated Imagery, Focused Analgesia and, to a lesser degree, during Deep Relaxation. Placebo condition did not display significant differences among hypnotizability groups. High hypnotizables, compared to mid and low hypnotizables, also showed significant increases in sensory and pain thresholds during Dissociated Imagery and Focused Analgesia. High, mid, and low groups showed significant reductions in P3 peak amplitudes across all hypnosis conditions and, to a lesser degree, during Placebo. The temporal cortical region was the most sensitive in differentiating SERP responses among hypnotizability groups. On this recording area the subjects highly susceptible to hypnosis displayed significantly smaller P3 and greater N2 peaks during Focused Analgesia than did the other hypnotizable groups. In this condition highly susceptible subjects also reported the highest number of omitted responses and the shortest Reaction Times. These subjects also showed faster habituation of SCRs when compared with mid and low hypnotizables. During Dissociated Imagery and Focused Analgesia, highly hypnotizable subjects also disclosed a smaller total number of evoked SCRs than did mid and low hypnotizable subjects. The results are discussed considering possible common and different mechanisms to account for the effects of different hypnotic suggestions.

Physiologic responses to loud tones in Israeli patients with posttraumatic stress disorder.

Orbicularis oculi (eye blink) electromyogram, skin conductance, and heart rate responses to 15 consecutive 95-dB, 500-millisecond, 1000-Hz tones with 0-millisecond rise and fall times were measured in 14 patients with posttraumatic stress disorder, 14 patients with other anxiety disorders, 15 mentally healthy subjects with past traumatic experiences, and 19 mentally healthy subjects with no trauma history. The patients with posttraumatic stress disorder showed significantly larger skin conductance and heart rate responses and a trend toward larger electromyogram responses to the tones than every other group. These effects were not explained by subjective anxiety, resting physiologic arousal, physiologic arousal preceding the tone trials, or initial physiologic responsivity. The group with posttraumatic stress disorder was the only one that failed to show habituation of skin conductance responses.

Evaluation of a psychophysiological model of classical fear conditioning in anxious patients

Skin conductance variables have been compared in 30 anxious patients and 30 controls to investigate the extent to which anxiety is associated with increased autonomic arousal, reduced habituation or enhanced aversive conditioning. Skin conductance level, variability (spontaneous fluctuations) and response amplitudes to tones were significantly greater in patients than controls. Habituation of skin conductance responses to a series of ten innocuous tones (80 dB, 1 s) did not differ between the groups. Aversively conditioned skin conductance responses were measured to a further series of ten tones after a conditioning trial in which a loud white noise (100 dB) followed tone 11. All subjects showed enhanced (conditioned) responses to the tones after the conditioning trial, but patients did not show greater conditioning than controls. The results indicate that anxious neurotic out-patients have greater sweat gland activity and reactivity than controls but fail to demonstrate differences in central mechanisms of habituation or conditioning.

Psychophysiological reactions in methadone maintenance patients do not correlate with methadone plasma levels

In methadone maintenance therapy methadone plasma concentrations of 400 ng/ml are necessary to suppress any further opiate action and to provide stabilized maintenance. In a controlled study we have searched for a differentiation in autonomous activation between patients having low and high methadone plasma levels, using static and dynamic pupillometry and habituation of skin conductance response. Results show that there is no difference in psychophysiological response between patients with high (greater than 400 ng/ml) or low (less than 400 ng/ml) plasma levels of methadone. This indicates that there is no reduction in behavioral arousal in patients with high plasma methadone levels. On the basis of these findings, there is no rationale to maintain patients on plasma levels below 400 ng/ml.

健常幼児と多動幼児の注意聴覚刺激による皮膚電気活動

Attention of 43 healthy and 4 hyperactive preschool children was studied by electrodermal activity on 10 passive and active tone listening tasks. On the passive task from Trial 1 to Trial 10, habituation of skin conductance response (SCR) amplitude occurred in the healthy and 2 of 4 hyperactive subjects. The healthy younger subjects, however, should have exhibited significantly greater habituation than the healthy older subjects. The younger children were believed to have a lower attention span. In the remaining 2 hyperactive subjects no SCR was observed on Trials 2 to 10. Habituation of SCR amplitude did not occur during the active task in the healthy and 1 of the hyperactive subjects. The healthy children seemed to have paid more attention during the active task than during the passive task. In 1 of the hyperactive subjects no SCR was observed during the 10 Trials. For the remaining 2 hyperactive subjects, during Trials 1 to 10, a decrease was observed, but none for the healthy subjects. Hyperactive children were believed to have shorter attention spans.

Skin conductance responding in Schizophrenic patients with abnormal involuntary movements

The present study tested the hypothesis that neuroleptic treatment modifies the skin conductance response (SCR) to loud tones. Schizophrenic patients with and without drug-induced abnormal involuntary movements were tested before and after drug withdrawal. During the on-drugs session, habituation of SCR correlated with the daily neuroleptic dose, and patients with tardive dyskinesia (TD) showed the fastest habituation of SCR. These findings were interpreted as indicating that SCR is attenuated by neuroleptics present during the examination and that TD patients demonstrate a preferential susceptibility to this effect. Withdrawal of medication resulted in slowing of SCR habituation only in TD patients, following which the entire sample showed a similar rate of habituation. These findings suggest that accelerated SCR habituation is not a stable trait of TD patients.

Habituation of skin conductance response in a methadone population

By measurement of the habituation to the skin conductance response (SCR) no reduction of activation could be observed between stable patients in methadone maintenance therapy and healthy normal subjects, but significant differences were obtained between the well-performing group and poly-drug users treated with methadone. The findings are discussed within the context of previous research on outcome of methadone maintenance. Measurement of habituation to SCR is a useful instrument for detecting polydrug addicts in methadone maintenance programmes.

Electrodermal activity in menstrual cycle phases: a comparison of within- and between-subjects designs

Electrodermal activity (EDA) changes in menstrual cycle were studied in two experiments. In both experiments subjects were presented with 16 80-dB tones; 15 tones were 4 s, 1000 Hz, and the last one - change trial - was a 6-s, 3000-Hz tone. In Expt. 1, a within-subjects design was employed, and 15 women were studied throughout a complete menstrual cycle. No significant changes in EDA associated with menstrual cycle phases were found, but significant decreases in electrodermal responsiveness during experimental sessions in EDA parameters were observed. In Expt. 2, with a between-subjects design, 56 women were divided in menstrual ( n=10), follicular ( n=12), ovulatory ( n=14), luteal ( n=13) and premenstrual ( n=7) groups, according to the cycle phase in which the subject was at the time of recording. At the ovulatory phase there were significant increases in skin conductance response (SCR) magnitude, skin conductance level, SCR habituation rate, and SCR amplitude to stimulus change, in relation to menstrual, luteal, and premenstrual phases. The discrepancies in the EDA data coming from the two experiments may be explained by practice effects appearing in Expt. 1.

The effects of selective inattention upon the electrodermal orienting reflex: A test of information-processing theory

Information-processing theories of the orienting reflex (OR) predict that disruptions of attention which impede the registration of a stimulus in memory should retard habituation of the OR. Studies examining effects of selective inattention upon rate of habituation of skin conductance responses (SCRs) to concurrently presented stimuli have yielded inconsistent results. We employed a dichotic vigilance task calling for selective attention to either male-voice or female-voice words. Comparisons between previously attended versus nonattended stimuli were subsequently conducted for habituation of SCR, as well as for a direct measure of recognition memory. Although there were unequivocal differences in long-term memory between attended and non-attended material, there was no clear evidence for corresponding differences in either initial magnitude or rate of habituation of SCR. These data, which replicated results from an earlier study, failed to demonstrate an effect of memory on the OR as predicted by information-processing theories.

Effects of hyperventilation on skin conductance response habituation

Effects of hyperventilation on skin conductance response habituation

Generalization of habituation of skin conductance responses to multidimensional sequences of stimuli.

ABSTRACTThis study presents a generalized approach to the problem of habituation to complex sequences of stimuli. Ninety‐five subjects were requested to choose one of four cards, showing a blue triangle (BT), a blue square (BS), a red triangle (RT), or a red square (RS). Subjects then heard a prerecorded sequence of the stimulus elements blue (B), red (R), triangle (T), and square (S), in various predetermined orders. Skin conductance responses were recorded during stimulus presentations. Four theoretical models were formulated, and compared for their abilities to describe the habituation process in the present experiment. The models differ in how they define the stimulus categories within which habituation generalizes. The model which defines the stimulus categories by “chosen” versus “non chosen” elements gave the best fit to the data.

The effects of electrodermal lability and stimulus intensity on skin conductance habituation: A preliminary report

A between-subjects design (N=60) was used to investigate the effects of electrodermal lability and auditory stimulus intensity on habituation of the skin conductance response (SCR). Subjects were subdivided into “labile” and “stabile” groups on the basis of frequency of nonspecific electrodermal responses during the prestimulation period. They received 20 presentations of a 1,000-Hz tone of 15, 35, 55, 75, 95, or 110 dB. There were significant effects of stimulus intensity on all three habituation measures (number of trials to habituation, reciprocal of SCR frequency to the first 10 stimuli, slope of the regression of SCR amplitude on log stimulus number). Additionally, significant effects of lability on the number of trials to habituation and the slope scores were found. Conclusions about the direction of influence of lability and intensity on SCR habituation, however, differed, depending on the habituation measure used.

Effects of stimulus intensity on electrodermal activity.

ABSTRACTThe present experiment employed a between‐subjects design (N=75) to investigate the effects of auditory stimulus intensity on a number of aspects of the skin conductance response (SCR) and the skin potential response (SPR). The primary predictions were that the electrodermal orienting response (OR) would be characterized by SCRs with relatively fast recovery times and positive SPRs, while the defense response (DR) would consist of SCRs with relatively slow recovery times and negative SPRs; SCR habituation differences as a function of stimulus intensity were also expected. Subjects received 12 presentations of a 1000 Hz tone of 45, 60, 75, 90 or 105 dB. Stimulus rise time was 30 msec and the duration 2 sec. The results provided no evidence for the differentiation of electrodermal ORs and DRs, and the effects of stimulus intensity were confined largely to differences in SCR magnitude; all groups displayed SCR habituation. The data from the first trial were examined using several multivariate procedures, and these results are discussed in terms of Sokolov's (1963) distinctions between ORs and DRs and in terms of Edelberg's (1973) model of electrodermal activity.

The effect of task and stimulus variability on habituation of electrodermal and vasomotor reactions

The effects of reaction time (RT) task and stimulus variability upon the habituation of skin conductance responses (SCR) and vasomotor responses (VMR) were studied in two experiments. In Experiment 1, subjects who performed an RT response to stimulus onset or who received stimuli which varied in frequency required more trials to reach an SCR habituation criterion than subjects who did not perform the task or receive frequency variability. While the overall VMR magnitude was affected by RT task and frequency variability, no VMR habituation itself was observed. In Experiment 2, the effects of RT task to stimulus offset and stimulus-duration variability were investigated. RT task again produced retardation of SCR habituation. This indicated that the task effect was not simply due to contraction-elicited SCRs, since the task reactions occurred well after the onset-elicited SCRs. Stimulus-duration variability reduced the overall effect of task, and it was hypothesized that manipulations which tend to increase postonset SCR reactivity have a negative effect on the persistence of onset reactivity.