Experimental Assessments of the Importance of Controlling for Contingency Factors in Human Classical Differential Electrodermal and Plethysmographic Conditioning

The importance of contingency factors implies the contingency prediction: that if CS+:CS- discrimination is obtained in a two-groups design where the control CS- stimulus for the two groups, respectively, is arranged to have a negative (nCS-) CS-US contingency (so-called “explicitly-unpaired” CS) and a zero (zCS-) CS-US contingency (so-called “truly-random” CS), then discrimination in the nCS- group will exceed that in the zCS- group. This implication was tested and disconfirmed for the electrodermal skin resistance response in three 5-sec delay-conditioning experiments (N = 48, 32, and 16, respectively), and for plethysmographic digital pulse-volume change in an 8-sec delay-conditioning experiment (N = 48). Since both the discrimination manipulation (CS+ vs CS-) and, in one experiment, a distraction manipulation (presence vs absence of a distraction task) were shown to be effective, while the contingency manipulation (nCS- vs zCS-) had no autonomic effects in any of the experiments, it was concluded that while contingency factors as represented by the difference between nCS- and zCS- have an obvious logical significance, in human autonomic conditioning, the nCS-:CS- difference is of negligible empirical importance.     

Electrocardiographic T-wave changes are more pronounced in type A than in type B men during mental work

Phasic changes in heart rate (HR) and electrocardiographic T-wave amplitude (TWA) were monitored in healthy Type A (coronary-prone) and Type B (non-coronary-prone) men during the performance of a difficult arithmetic task. Type As showed significantly greater reductions in TWA as compared to Type Bs, though no group differences were present in HR change. This pattern of results, wherein a significant Type A-B difference was observed in a phasic measure of ventricular performance (TWA), but not in one of supraventricular performance (HR), suggests that Type As experience excessive neurally mediated sympathetic stimulation of the myocardium during mental work.     

On Approaches to Explaining Cardiovascular Reactivity: Toward Explanations that Explain

The control-system mode of analysis proposed by Pavloski for cardiovascular reactivity phenomena is a purposive or teleological form of explanation, because the explicans has purpose as the central term. The problem with such explanations is that they are circular and empty, providing only a rhetorical feeling of understanding, and absence of strong-inference research. The S-O-R approach, which Pavlovski opposes, provides at least the potential for non-circular explanations, provided that the O-related explanatory constructs are specified in normal cause-effect terms so that, in another context, the explicans can also serve as an explicandum, and vice-versa. Pavloski may be right in suggesting that the evidence requires a feedback, "control-system" construct to account for cardiovascular reactivity phenomena (although he is far from having proved this in his paper), but such a view would need to be supplemented by (non-purposive) control-system explanations that really explain in the logical rather than the merely rhetorical sense of that term.     

Sharing a common language about conditioning requires accurate characterizations of each others' positions: reply to Shanks

Shanks' characterizations of the positions taken in papers that he comments on are inaccurate on a number of basic counts. For example, the papers were concerned with human autonomic Pavlovian conditioning, whereas Shanks refers to no autonomic evidence in his reply. Again, the two papers more specifically targeted by Shanks (Furedy, 1988b; Furedy & Riley, 1987) do not deny "that cognitive processes have any relevance for conditioning", but rather advocate that both cognitive and non-cognitive factors play roles that need to be empirically determined for different preparations and conditions. And the characterization of cognitive factors in those papers, contrary to Shanks, is not a teleological, intentional one, no matter how fashionable such teleological forms of cognitive psychology may be among many current philosophers and psychologists. We can proceed towards an empirical resolution of disagreements about the role of cognitive factors in human Pavlovian autonomic conditioning only if we both refer to the relevant autonomic conditioning evidence, and also characterize each others' positions with some accuracy.     

Intersession interval affects performance in the Morris Water Maze

We have recently reported an effect that shows a sexually dimorphic difference in cognitive style rather than ability. The preparation for potentially producing this proximal perceptual style effect is one where rats are first given 4-trial daily acquisition sessions for 12 days with the platform always in the same position, but sometimes visible (perceptual, "look-out" condition) and sometimes hidden (conceptual, "navigational" condition). On the first, probe trial of the 13th day, the platform's position is shifted to a point very close (proximal) to the rat's starting position, and made visible. The proximal perceptual style (PPS) effect has emerged sexually dimorphically in that only females swam straight to the newly positioned proximal platform. Other studies have shown that the PPS effect is eliminated (with females behaving like males) by nicotine and prepubertal ovariectomy, and does not occur in prepubertal females. Also, as no sex-related effects emerged during acquisition during these studies, the PPS effect appears to be a function of cognitive style rather than ability. The present study varied age, and, in an effort to economize on time, shortened acquisition to 6 days by having morning and afternoon sessions each day. To our surprise, this relatively subtle psychological manipulation eliminated the PPS effect, and also yielded some sex- and age-related effects during acquisition: A male advantage was observed and prepubertal rats had longer escape latencies; there was no significant interaction between sex and age.     

Phasic T-Wave Amplitude and Heart Rate Changes as Indices of Mental Effort and Task Incentive

The sensitivities of T-wave amplitude (TWA) and heart rate (HR) to manipulations of the mental effort (ME) and incentive associated with performance of the backward digit span task were investigated. The experimental task was so chosen because it could be administered without requiring subjects to speak during its performance, thus minimizing the intrusion of respiratory and motor artifacts. The ME required during task performance was manipulated by varying the number of digits presented, creating Hard and Easy trials. The incentive for subjects to perform well was varied by the threat of the delivery of a noxious noise stimulus, which was ostensibly contingent upon adequate performance on some (Test) but not other (Practice) trials. TWA attenuation and HR acceleration were greater on the Hard as compared to the Easy Trials, and on the Test as compared to the Practice trials. No interactions between the ME and Incentive factors emerged for either cardiac variable. These results suggest that the effort and the incentive of subjects during mental work may be indexed reliably by phasic changes in TWA and HR. The conjoint use of these two cardiac measures may also elucidate the involvement of the two autonomic branches during task performance.