Peter F. Lovibond’s research while affiliated with University of South Wales and other places

Two experiments investigated phasic and tonic electrodermal responding to long, variable-duration stimuli in aversive conditioning procedures. Experiment 1 demonstrated reliable differential conditioning on both phasic (first interval response, FIR) and tonic (change in skin conductance level, δSCL; spontaneous fluctuations) measures, using 10–40-s slides as conditioned stimuli (CSs) and electric shock as the unconditioned stimulus (UCS). Experiment 2 examined the sensitivity of phasic and tonic measures to UCS aversiveness. Both FIR and δSCL were greater to a conditioned stimulus paired with shock than one paired with an innocuous reaction-time warning tone. Responding was reversed when the reinforcement contingencies were reversed. It was suggested that, with long duration CSs and an aversive UCS, phasic measures to stimulus onset, such as FIR, may reflect both stimulus significance and threat appraisal, whereas tonic measures reflect primarily arousal or anxiety arising from anticipation of the aversive unconditioned stimulus.

Expresses concern that H. D. Kimmel and H. Lachnit (see record 1990-00403-001), both in their original article on extending the Rescorla-Wagner theory to account for transswitching and in their reply to P. F. Lovibond's (see record 1990-00212-001) comments on that article, are debating issues that are out of date in the animal-learning literature and do not acknowledge the directions that debate has taken. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Safety signal learning in human subjects was investigated using a conditioned inhibition procedure with a shock unconditioned stimulus (US). The conditioned stimulus (CS) duration, and thus the CS-US interval, varied randomly from 20 to 50 s. Conditioning was assessed by change in tonic skin conductance level (SCL). Experiment 1 demonstrated reliable learning of a conditioned inhibition (A+/AB-) discrimination, in terms of both self-reported shock expectancy and change in SCL, in subjects who were able to report correctly the stimulus contingency. There was, however, no evidence of transfer of inhibitory properties from the safety signal B to a separately trained excitor. Experiment 2 compared two groups in which the safety signal was either fear-relevant (picture of snake or spider) or fear-irrelevant (flower or mushroom). As in previous research, there was no effect of fear-relevance on safety-signal learning. The results are discussed in terms of preparedness theory and excitatory conditioning with fear-relevant stimuli.

Four experiments investigated the role of information value, or stimulus validity, in human electrodermal conditioning. Conditioned stimuli (CSs) were long, variable duration (10-50-sec) slides or sounds, the unconditioned stimulus (US) was shock, and the primary measures were change in tonic skin conductance level and self-report expectancy of shock. In Experiment 1 electrodermal responding to a target stimulus was marginally lower in a blocking group than in a superconditioning group. This difference failed to occur in Experiment 2, despite increased sensitivity of the electrodermal measure. Explicit instructions to pay attention to the relationship between each stimulus and shock improved learning, but did not lead to group differences (Experiment 3). In Experiment 4 expectancy ratings in a blocking group were lower than in an overshadowing group, but no electrodermal differences occurred. The results were interpreted in terms of non-additive learning processes such as occasion-setting, in addition to a general lack of transfer of learning about a stimulus from one context to another (element to compound or vice versa). It was suggested that sensitivity to stimulus validity might be observed if conditioning were embedded in a causally familiar task, as in contingency judgement research.

This paper first reviews the research on predictive validity in animal conditioning, and the informational theories deriving from this research. The major section of the paper examines the role of predictive validity, and thus the applicability of informational theories, in two major human learning paradigms: causal judgement and Pavlovian conditioning. There is more empirical support for informational theories in the causal judgement literature than in the conditioning literature. It is argued that judgement of predictive or causal relationships in humans is governed by processes similar to those governing conditioning in animals, and that the question of whether the same processes operate in human conditioning has not yet been adequately tested. Such a test would require joint measurement of predictive judgements and conditioned responding in a design which manipulates predictive validity independently of contiguity; it may also require a task which explicitly or implicitly restricts predictive judgements to the experimentally designated stimuli.

The present experiment (W=72) employed a differential conditioning procedure to investigate the effects of fear-relevance of the conditioned stimulus (CS) and postacquisition exposure to the unconditioned stimulus (US) on the retention of human autonomic conditioning and relational learning. The CSs were pictures of snakes and spiders (fear-relevant) for half the subjects, and pictures of flowers and mushrooms (fear-irrelevant) for the other half. A delay conditioning procedure was employed with a GS-US onset interval of 8 sec. Following the acquisition phase, one group was exposed to 30 presentations of US-alone, another was exposed to 30 presentations of white noise, and a third group received no stimulation. The dependent variables were the skin conductance response (SCR) and a continuous measure of US expectancy. The results indicated that fear-relevant CSs elicited larger responses during the adaptation phase and resulted in greater first- and second-interval SCR conditioning than did fear-irrelevant CSs. However, the test phase data revealed that electrodermal conditioning was not influenced by postacquisition exposure to the US. Expectancy of the US increased in the presence of CS+ during acquisition and expectancy of no-US increased in the presence of CS-. Moreover, postacquisition exposure to the US attenuated US expectancy in the test phase. The results are discussed in terms of general-process theories of conditioning and in terms of the concept of preparedness.

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it is proposed that all anxiety reactions are based on a common appraisal mechanism which generates anxiety via the activation of expectancy of harm several experiments are reported which make use of conditioning and instructional procedures to investigate anxiety reactions in the laboratory self-report, psychophysiological and indirect (attentional) measures were employed to evaluate possible biases in threat appraisal in trait anxious subjects anxiety was strongly related to expectancy of an aversive event, whether expectancy was measured by self-report or manipulated by instruction trait anxious subjects appeared to demonstrate a bias in threat appraisal under conditions of ambiguous threat / the results also highlighted the distinction between uncertainty and ambiguity in threat appraisal (PsycINFO Database Record (c) 2012 APA, all rights reserved)