Effect of Unpaired UCS Presentations on Performance in Eyelid Conditioning

Abstract

The facilitative effect of unpaired UCS presentations in eyelid conditioning was studied by varying the number of prior paired CS-UCS presentations (associative factor) and the intensity of the UCS (motivational factor). Results showed that, when a strong UCS was used on paired CS-UCS trials, performance following unpaired UCS presentations was significantly poorer than performance of a control group which had received continued CS-UCS pairings. When a weak UCS was used, unpaired UCS presentations led to an increase in CRs but no more than would have been expected following an equal number of prior paired CS-UCS trials. Performance was not related to the intensity of the UCS on unpaired trials. Results are interpreted as leaving the issue unresolved.