Chlordiazepoxide-induced disruption of discrimination behaviour: a signal detection analysis.

To assess the effects of chlordiazepoxide (CDP) on a stable discrimination performance, eight rats were trained on a simple brightness discrimination and injected with three dosages (0, 5, and 10 mg/kg) once performance was stable. Signal detection analysis of the results was used to differentiate sensory from motor/responsivity effects of the drug. At 5 mg/kg, CDP increased general responsiveness which is consistent with the hypothesis that CDP disinhibits responding. At 10 mg/kg, however, this effect on responsivity was reversed and there was also a suppression of stimulus sensitivity.