IMPAIRED TRACE EYEBLINK CONDITIONING IN BILATERAL, MEDIAL-TEMPORAL LOBE AMNESIA

Trace eyeblink classical conditioning was assessed in patients with bi lateral medial-temporal amnesia and matched control participants who h ad previously shown equivalent delay eyeblink conditioning (J. D. E. G abrieli et al., 1995). The silent trace interval varied for durations of 500, 750, or 1,000 ms in successive sessions separated by at least 2 weeks; extinction trials followed each session. Patients with amnesi a produced significantly fewer conditioned responses (CRs) than did co ntrol participants at all trace intervals. Both groups produced fewer CRs as the trace interval lengthened. Thus, the temporal lobe memory s ystem in humans makes an essential contribution to normal acquisition in trace, but not delay, classical eyeblink conditioning.