Hippocampal lesions and active avoidance

Rats with lesions of the hlppocampus were impaired relative to normal rats in the acquisition and retention of a one-way active avoidance task, but were superior to normal and partially neodecorticate rats in the acquisition of a two-way active avoidance task. The deficit of rats with hippocampal damage in the one-way task was accentuated when "no shock trials " (CS only) preceded acquisition or reacqulsition training. Neocortically lesioned animals howed a shght deficit on both response and latency measures of performance. It is suggested that hippocampectomized rats are deficient in the ability to associate noxious events with cues indicating spatial ocation. Acquisition Active avoidance Hlppocampal lesions Neocortlcal lesions Retention A SIGNIFICANT advance in the experimental study of the relationship between brain lesions and avoidance condi-tioning was the distinction between active and passive avoidance tasks [15]. Subsequent experimentation has indicated that an equally important differentiation must be made between one-way and two-way active avoidance problems [20]. It is now clear that passive avoidance tasks, one-way and two-way active avoidance problems tap differen