HEART RATE RESPONSES OF THE CURARIZED RAT

Heart rate of curarized and non-curarized rats was recorded while both groups were exposed to classical conditioning procedures with tone as the conditional stimulus (CS) and shock as the unconditional stimulus (UCS). The unconditional HR response of curarized animals to the tone was significantly greater than that of the non-curarized animals, while the HR response to shock of the curarized animals was significantly less than that of the non-curarized group. Both groups showed evidence of conditioning over 30 conditioning trials.     

INSTRUMENTAL MODIFICATION OF THE GSR

Four experiments investigated the effects of instructions, response-contingent shock, and the latency of the critical response on the GSR. Using a discrimination procedure, in which responding in the presence of one stimulus avoided shock while responding in the presence of another led to shock, it was found that relative to non-instructed, yoked-noncontingent conditions, instructed subjects responded at higher levels to the respond stimuli and at lower levels to inhibit stimuli. The effects of instructions appeared stronger than the effects of the shock contingencies. Only when the “contingent” GSR was of the “anticipatory” latency were differential effects obtained, however. No effects were observed in the absence of cognitive mediation.     

CLASSICAL CONDITIONING OF THE ELECTRODERMAL RESPONSE WITH NOVEL STIMULI

Most attempts to classically condition the electrodermal response (GSR) have used aversive stimuli. A series of 20 novel slides were used as unconditional stimuli in a delayed differential conditioning paradigm involving reinforced and unreinforced conditional stimuli. Thirty female Ss were given 10 habituation trials, 40 conditioning trials of which half were reinforced, and 10 extinction trials. Orienting response, anticipatory response, and post-conditional stimulus response components were analyzed separately for the different series. Differential conditioning was obtained for two of the responses during the conditioning and extinction series. The results indicate that a relatively mild novel stimulus can also effectively condition the GSR.     

Effects of Exteroceptive Feedback and Instructions on Control of Spontaneous Galvanic Skin Responses

To more fully explore the possibility of control of the autonomic nervous system (ANS) in the human S, this study investigated the effects of instructions and exteroeeptive feedback on the control of spontaneous galvanic skin responsivity (GSR). Two sets of instructions (“Relax” and “Think”) were alternately presented to Ss under four types of meter feedback: accurate, positive, negative, and control. In addition to GSR activity, respiration and cardiac rate were recorded. The results indicated that Ss receiving accurate feedback were significantly better able to comply with the “Relax”-“Think” instructions; next most effective was positive feedback, while negative and control feedback were least effective. No within-subject relationships were found between control of spontaneous GSRs and respiration or cardiac activity. The results suggest that Ss are responsive to the consequences of their antonomic behavior in much the same manner as they are responsive to the consequences of other learned behaviors.     

RATE OF HABITUATION AND THE LAW OF INITIAL VALUES

The galvanic skin response (GSR) data of two experiments were analyzed in an attempt to determine the effects of tonic shifts in baseline conductance on apparent rate of habituation. The results of the first experiment indicated that rate of habituation is exaggerated when response measures which are not base-independent are employed. The positive correlation found between habituation slope and an index of base-level change in conductance was significantly reduced when autonomic lability scores (ALSs) were used. Thus, base-corrected responses produced less steep habituation functions. The second experiment demonstrated that a tonic increase in conductance occurs to an intense auditory stimulus and that rate of habituation is consequently over-estimated in comparison to that associated with repeated presentation of a mild stimulus.     

THE USE OF ELECTRO-OCULOGRAPHY FOR IDENTIFYING PHASES OF COGNITIVE PROCESS

The present investigators were partly concerned with possible uses of electro-oculography for studying the cognitive process in decision-making situations involving nonneutral visual stimuli. S was faced with receiving an electric shock if on critical trials he correctly reported (manually) the identity of the visual stimulus, or with escaping shock by incorrect reporting. Electrooculogram responses were ascertained to identify eye movements. The first study employed slit geometric figures as critical stimuli and nonslit figures as noncritical stimuli. The second study differed only in using blanks as critical and nonblanks (figures) as noncritical stimuli. The 80 males in the first study showed longer ocular latency, then greater ocular avoidance (narrower excursions) but longer stimulus viewing, then longer poststimulus viewing on critical compared to noncritical trials. The 25 males in the second study showed relatively greater ocular latency, then greater ocular avoidance and briefer stimulus viewing, then briefer poststimulus viewing on critical trials. Discrepancies between the two studies were discussed. The results clearly indicate the applicability of electrooculography for identifying phases of cognitive process.     

GALVANIC SKIN RESPONSE DURING AVOIDANCE LEARNING

Relations between galvanic skin response (GSR) and other variables during learning of a shock-avoidance task were observed. Ss operated a four-position switch as cued by visual stimuli: one always shocked, one never shocked, and two associated with switch positions which avoided the shock. Forty-eight Ss formed successive subgroups which exhibited: (1) progressively better avoidance learning with increased awareness instruction and (2) significantly decreased GSR when the correct avoidance had been learned. Analyses were made to differentiate autonomic responding due to reinforcement (i.e. number of shocks received) from that due to expectancy (anticipation of avoidance).     

SELECTIVE ATTENTION AND INSTRUMENTAL MODIFICATION OF THE GSR

A series of experiments were conducted on instrumental modification of the Galvanic Skin Response (GSR) in a discrimination procedure where preparatory signals indicated which discriminative stimulus was to occur. When shock avoidance was contingent upon the presence of a response the GSR was enhanced; when shock avoidance was contingent upon the inhibition of a response there was a decrement in reactivity. Heart rate acceleration occurred to Respond stimuli while deceleration occurred to Inhibit stimuli. Various types of cognitive strategies were reported by the subjects from attempts to control attention by attending less to stimuli associated with inhibition to attempts to arouse a response by thinking of exciting events and to inhibit by thinking of calming events. Postexperimental recognition of words tended to be negatively related to magnitude of response. When the verbal stimuli served directly as discriminative stimuli, however, these relationships tended to be reversed.     

CLASSICAL CONDITIONING OF THE GALVANIC SKIN RESPONSE IN IMMOBILIZED CATS

Ten cats were immobilized with Flaxedil and given either paired conditioning trials or unpaired presentations of the CS and UCS in a study of classical GSR conditioning. The paired group received 5 adaptation trials followed by 40 paired tone-shock acquisition trials and 10 extinction trials. A pseudo-conditioning control group received unpaired trials with tone and shock, to control for pseudoconditioning and sensitization. It was found that the group receiving paired conditioning trials responded at a significantly higher magnitude than did control Ss, thus demonstrating classical conditioning in this preparation. Electromyograms were recorded for all Ss during the experimental sessions to monitor skeletal movements. The level of immobilization was such that no movements were seen in response to the CS. Analysis of the baseline skin resistance data revealed no significant differences which could have contributed to group differences in GSR magnitudes. It is concluded that skeletal movement was not a necessary concomitant of classical conditioning of the GSR.     

SELECTIVE HABITUATION OF GALVANIC SKIN RESPONSE COMPONENT OF THE ORIENTATION REACTION TO AN AUDITORY STIMULUS

The prediction from Sokolov's (1960) theory that, following OR habituation, size of OR return is proportional to the amount of difference between the new stimulus and the habituating stimulus was tested using an auditory stimulus varying in frequency and intensity. Five Ss were allocated to each of 16 conditions, three conditions involving changes in frequency, three involving changes in intensity, nine involving changes in both frequency and intensity, with one control condition involving a repetition of the habituating stimulus. Following habituation of the GSR component of the OR to a criterion of response failure for three successive trials, magnitude of GSR under the 16 conditions was measured. Contrary to Sokolov's theory, only increase in intensity had a significantly different effect on OR return. More importantly, it was found that Ss habituating rapidly to the initial stimulus were less likely to show OR return to stimulus change. It was concluded that individual differences in habituation rate may be more important than stimulus difference effects in selective habituation.     

COUNTERCONDITIONING: FEAR AND RELAXATION

Counterconditioning of autonomic responses was evaluated by means of a compound stimulus transfer paradigm. During three sessions on different days Ss were conditioned to give a GSR to a visual stimulus (colored light) and further trained to relax on presentation of a visually projected stimulus word. After training on both experiences had progressed, test trials were introduced to assess the magnitude of response to the fear cue alone and to the compound stimulus created by simultaneous presentation of both cues (the word superimposed on the colored light background). Significant inhibitory transfer effects were observed with the GSR. On the last test trials the digital pulse volume showed less constriction to the compound of fear and relaxation stimuli than to the fear stimulus alone.     

SEX DIFFERENCES IN SKIN CONDUCTANCE MEASURES AS A FUNCTION OF SHOCK THREAT

Investigations of sex differences in various electrodermal measures have yielded inconsistent results. The present investigation attempted to examine sex differences primarily as a function of varied conditions of threat (stated probability of receiving electric shock). Thirty males and 30 females were randomly assigned to three conditions: High Threat Probability (HTP), Moderate Threat Probability (MTP), or No Threat Probability (NTP). All Ss heard, under assigned threat instructions, 2 sets of 11 tones, preceded by a nonstimulation period and followed by 11 tones with shock threat removed. Results indicated that the threat conditions did affect electrodermal measures as expected. In addition, males exhibited higher tonic (basal conductance) levels throughout, while females displayed greater phasic reactivity (GSR magnitude) and a larger number of nonspecific GSRs. In addition, nonspecific frequency was affected by the interaction of sex with treatment (threat), such that females displayed higher frequencies under moderate threat, while males increased linearly with increased threat. Degree of stress or threat, the possibility of differential perceptions, and a theory of differential hormonal functioning were applied in interpreting results.     

PERSONALITY AND AROUSAL CORRELATES OF SPECIFIC GALVANIC SKIN RESPONSES

Basal skin resistance (BSR) and galvanic skin responses (GSR) to five intensities of sound and light were recorded on four occasions in 32 student subjects (Ss). These occasions were assumed to include unfamiliarity and basal and real life stress conditions. All Ss completed the MMPI, California Personality Inventory, Wechsler Adult Intelligence Scale, Clyde Mood Scale and Examination Anxiety Scale. GSR amplitude was greater under conditions of unfamiliarity, alertness (by electroencephalographic criteria), and higher intensities of stimulation in both stimulus modalities. It was not greater during the presumed stress period. High ego strength-high Barrier score Ss showed a greater GSR amplitude than low ego strength-low Barrier Ss. Test indices of anxiety generally were not related to GSR amplitude, nor were other personality and mood variables.     

AVOIDANCE CONDITIONING OE SKIN POTENTIAL RESPONSES

Avoidance of electric shock was used to manipulate skin potential changes elicited by a simple visual stimulus. Experimental and control Ss were matched on habituation trials and yoked for 40 acquisition and 10 extinction trials. During acquisition the avoidance Ss differentiated between stimulus and non-stimulus periods more reliably than the controls. During extinction the avoidance group produced significantly more criterion electrodermal responses, with greater magnitude of positive wave components, than the control group. Some of the problems of appropriate control procedures inherent in this design are examined in relation to these results.     

Measurement of the cardiac response in schizophrenic and normal children

In a previous study (Bernal & Miller, 1970), striking differences were found between schizophrenic and normal children in the magnitude of their galvanic skin responses (GSRs) to simple sensory stimuli. However, the Lang and Hnatiow (1962) measure of cardiac response failed to demonstrate these GSR group differences. The present paper is a followup of the Bernal and Miller study and its purpose was to evaluate the use of various measures of heart rate (HR) in discriminating between clinical and normal groups of children. The cardiac data were converted to measures that were (1) independent of and dependent upon prestimulus HR level, and (2) based upon individually and group derived decelerative trough in HR. The main results of the analyses of variance for repeated measurements were: (1) no single HR measure was found to delineate the cardiac response reliably across stimulus conditions or between groups of Ss, and (2) individually-determined HR deceleration, especially when corrected via covariance analysis for prestimulus level, was superior to a group-determined decelerative HR measure in demonstrating both habituation and group effects.     

Heart Rate Changes During a Fixed Reaction Time Task in Normal and Retarded Adult Males

The relationship between heart rate (HR) changes and fixed reaction time (RT) performance was studied in groups of normal and mentally retarded male Ss. Each 5 received blocks of 15 RT trials during 4-, 7-, and 13-sec preparatory intervals. Heart rate was continuously monitored. The results revealed that retarded Ss had significantly slower RT scores, significantly lower basal HR, and lower magnitude HR decelerations prior to reaction signal onset when compared to normal Ss. These group differences were apparent in all three preparatory interval conditions and were interpreted to indicate less accurate covert timing of PI length in retarded 5s. Correlations between HR deceleration (measured during the sec in which the reaction signal occurred) and RI scores lent support to the notion that significant HR deceleration accompanies fast RT responding in all but the 13-sec PI condition for retarded Ss. In this condition, HR acceleration was related to fast RT performance in retarded Ss. It was suggested that in the 13-sec PI, retarded Ss exhibited a dissociation between somatic and autonomic response systems which might he related to an information processing deficit in tasks of extended duration.     

Preception: Autonomic Response to Shock as a Function of Predictability in Time and Locus

Signals were used to manipulate S's ability to predict when and where (i.e., on which limb) he would receive each of 48 painful shocks. Two groups of 24 Ss received 12 shocks in each of four predictability conditions. Heart rate and palmar SC were monitored throughout. Both HR and SC responses to shock were consistently reduced when shock was preceded by a warning signal; predictability of locus had no effect on HRR and a weak effect on SCR. More anxious Ss showed greater post-shock HR acceleration under all conditions; less anxious Ss showed greater anticipatory HR acceleration. In a separate experiment, 9 Ss in whom the later components of the vertex AER increased systematically with shock intensity showed a decrease in these same components when shock was made predictable in time.     

Some Limits on the Cognitive Control of Conditioned Autonomic Behavior

Because certain recently adopted doctrinaire cognitivist positions are just as undesirable as the doctrinaire behaviorist positions of the fifties, evidence is presented to indicate that there are some instances where cognitive factors do not appear to control autonomic conditioning. The first aspect of that evidence deals with tests of the applicability of the contingency position to Pavlovian autonomic conditioning, and the data indicate that conditioned autonomic responses like the GSR do not act like “contingency analysers” over CS-US intervals ranging from .75 to 8.0 sec. Moreover, measures of cognitive subjective contingency (SC), which could not be taken in the animal studies used previously to support the contingency analysis of Pavlovian conditioning, indicate that the human Ss are aware of the contingency differences considered important for autonomic conditioning by the contingency position. This lack of correspondence between the autonomic and cognitive dependent variables is also relevant to another form of the cognitive-control position, that knowledge of CS-US contingencies is related to autonomic conditioning. Such relations were not, in fact, observed between the extents of autonomic and cognitive (SC) discrimination. Finally, a more sensitive and continuous measure of SC is proposed which should yield more precise answers to the empirical and complex question of the limits of cognitive control of conditioned autonomic behavior.     

Effects of Feedback in a Forced-Choice GSR Detection Task

Previous studies of the detection of internal events have failed to assess adequately the effects of external feedback on detection and identification of internal events. The purpose of the present study was to make use of a signal detection paradigm in an evaluation of feedback effects on the detection and identification of galvanic skin responses (GSRs). GSR detection was measured by the absolute difference between the areas above and below the receiver operating characteristic (ROC) curve, and reflected the extent to which subjects were able to differentiate between GSR and no-GSR trials. GSR identification was measured by the area below the ROC curve and reflected the labeling strategy (accurate or reversed) chosen by the subjects. It was found that external feedback as to the presence or absence and relative magnitude of GSRs was not necessary for differentiation of GSR and no-GSR trials, and that such feedback was detrimental to increased differentiation over sessions. External feedback may, however, have been useful in directing the attachment of identifying responses to the differentiated internal events. The similarity of these findings to findings reported in the schematic concept formation (SCF) literature was discussed. It was concluded that internal event detection tasks such as that used in the present study may be seen as examples of SCF involving internal stimulus events.     

INSTRUMENTAL MODIFICATION OF ELICITED AUTONOMIC RESPONSES

Discrete trials methodology was used to study the instrumental modification of elicited palmar SPRs in humans. Simple auditory stimuli defined the trials for a number of different reinforcement conditions. The data indicate that autonomic responses elicited by discrete stimuli can be facilitated by operant reinforcement, but there is no evidence for an inhibitory or suppressive effect. The specific contingency of reinforcement and response appears necessary to show the effect.