Cognitive manipulation of GSR extinction: Analogues for conditioning therapies

Cognitive determinants of GSR activity during extinction trials were examined following conditioning. Conditioned GSRs extinguished rapidly when subjects were informed the UCS would not again be administered, compared to subjects not given this information. Of greater interest was the finding that (false) high feedback concerning subjects’ responsivity to the Cs+ during extinction served to maintain GSR activity at a higher level than subjects receiving (false) low feedback. The relationship was observed within both information conditions. Implications are drawn for both aversive conditioning therapy and systematic desensitization.     

Aversive and compensatory classical conditioning with diazepam as conditional stimulus

The purpose of the first experiment was to investigate whether diazepam could acquire anxiogenic properties by signalling an aversive event. Rats were trained in an operant chamber in the pentylenetetrazol (PTZ) model of anxiety. Thereafter the animals were divided into groups that received classical diazepam conditioning (Group 1), and conditioning of diazepam + tone (Group 2). In the test phase diazepam was injected prior to placement in the operant chamber. Group 2 selected the PTZ-appropriate lever more often than the other groups, indicating that the tone induced anxiety, and diazepam did not. Tones and shock may therefore be more easily associated than diazepam and shock. The second experiment investigated this. Rats were trained the same way as in the first experiment. Thereafter the experimental group received injections of a small dose of diazepam prior to a second injection of a large dose of diazepam. The hypothesis was that a compensatory anxiogenic conditional response to diazepam's anxiolytic effect should be elicited by the small dose. There were no differences between the groups in lever selection, indicating that a compensatory anxiogenic response was not elicited.     

Eyelid conditioning and concomitant GSR activity

The purpose of these experiments was to investigate an aspect of autonomic activity (namely, skin resistance) during the course of eyelid conditioning, as a check on those theories which postulate that ‘arousal’ or ‘emotionality’, as measured by autonomic activity, is related to the level of conditioning.

Although many measures of skin resistance were obtained (including both basal levels and responses), the results were with one exception entirely negative in showing no significant correlations between the autonomic variables and eyelid conditioning. The exception was a significant correlation between skin resistance change to a test-trial puff of air (the UCS) and the level of eyelid conditioning reached by the subject; this result supports predictions made by Spence about the role of a hypothetical emotional response in conditioning, but was obtained in only one of the two studies.

The generally non-significant relationship between skin resistance and eyelid conditioning is discussed with respect to response specificity, and also to a postulated specificity in conditioning such that a subject who conditions well in one modality does not necessarily condition well in another modality. This specificity is considered in the light of the physiological mechanisms involved in each response system.     

Heart rate conditioning in young infants using a visual conditional stimulus

Trace heart rate conditioning was evaluated in 16 infants having a mean age of 4.5 months. The Experimental Group received a 3-sec blinking light pattern as the CS, followed by a 3-sec interstimulus interval (ISI), and 3-sec tone as the UCS. The Control Group received an equal number of presentations of the CS and UCS at randomized intervals and in a randomized order. The acquisition of a conditioned deceleration during the period which included the visual CS and the ISI was demonstrated only in the Experimental males. Response differences were also found in the absence of the auditory UCS, with only Experimental females exhibiting a deceleration.     

Manipulation of CS-US conditional probability and of the US-US trace interval on conditioning to the CS and to a background stimulus in a CER situation

Two experiments examined the relationship between conditioning to the CS and background using a novel CER paradigm, in which a long background stimulus played the role of more conventional contextual cues. Experiment 1 manipulated the probability of US occurrence given the CS (p(US/CS)). Conditioning to the background was not a monotonically decreasing function of p(US/CS) at all shock intensities, and conditioning to the CS was remarkably insensitive to the value of p(US/CS) when assessed off the baseline. Experiment 2 manipulated the trace interval between the CS and US. Although conditioning to the CS decreased as the trace interval increased, conditioning to the background was dependent upon whether it served as the interstimulus interval (ISI; interval between the CS and US) or intertrial interval (ITI; interval between CS-US pairs) stimulus. Conditioning to the ISI background decreased as the trace interval increased, but conditioning to the ITI background at first increased, but then decreased as the trace interval was further increased. These results are discussed with respect to the adequacy of contemporary models of conditioning.     

Effects of operant conditioning on the GSR

Each of nine Ss was run for 11 daily sessions. Except for the first (operant level) and last two (extinction) sessions, 500-ohm drops in skin resistance were followed by reinforcement (light). These reinforcement periods lasted 20 min and were preceded by 10-min control periods during which no reinforcement was administered. Although the results showed no evidence for operant conditioning of the GSR, they did indicate that increased emission of GSR's occurred during the reinforcement period. This effect was shown to hold for Ss with low operant levels of GSR's but not for Ss with high operant levels.