An investigation of electrodermal and electrocortical indices of preparatory set

A classical differential conditioning paradigm involving the implementation of a long, 6.4 second, inter-stimulus-interval was utilized in an investigation of the conditionability of multiple response, electrodermal FIR and SIR, electrocortical VER, and hypothesized contingent negative variation 0 and E wave components in addition to their inter-relationship in motor and non-motor preparatory intervals. A total of twelve human subjects was used; each receiving all four CS conditions. In all, there were 20 trials of each of the visual CS cue conditions. Of the four visual cues, two were CS+'s and the other two were CS-'s. All CS cues were followed by a tone (S2) approximately 6.4 seconds later. Further, two CS's signaled to~ that he/she would be required to perform a motor response whereas the other two visual CS cues indicated that no motor response was to be performed to the second stimulus. Additionally, CS+ visual cues signified that an aversive UCS noise (S 3) having a 70% probability of occurrence might follow S2 on some trials. However, the S3 noise never followed S2 onset for CStrials. Also, Ss were instructed to indicate their judgment concerning s3 probability of occurrence (e.g., 0-33%, 33-67%, and 67-100%) by pressing one of three buttons concomitant with S2 onset. The results indicated only minimal evidence of EDR or EEG conditioning across the four CS conditions. No significant differentiation was obtained for CS+ or CS- elicited visual evoked response component magnitudes for either motor or non-motor preparatory conditions. Moreover, electrodermal FIR/SIR and electrocortical CNV O/E wave response magnitudes appeared to exhibit some response differentiation with CS motor conditions producing generally larger response component magnitudes, however, these differences were not significant. Finally, a number of significant electrodermal and electrocortical component correlations was obtained, but these results were not in the hypothesized direction nor do they appear amenable to interpretation.