Depression, recognition-memory and hedonic tone a signal detection analysis.

A signal detection analysis was used in a recognition memory task involving material of varying hedonic tone. Major differences were found between the control and depressed states. Although overall recognition rates were the same, pleasant material was recognised less and unpleasant material more easily by depressives. Neutral material was recognised equally well by both groups. In the depressed state, response biases were altered such that unpleasant material was handled in a preferential way to neutral or pleasant material.