Intact emotion-induced recognition bias in neuropsychological patients with executive control deficits

In recognition memory tasks, emotionally negative words are judged more often as "old" relative to emotionally neutral words, suggesting a shift in response bias. We wondered whether this bias shift was due to the flexible regulation of executive control during memory retrieval. To address this question, we investigated individuals with high variability in executive control functions. As expected, we observed that emotional word meaning did indeed have a strong influence on the bias toward responding "old," independent of recognition accuracy and overall response bias. However, these effects were uncorrelated with executive control, as measured by the Trail Making Test, and were fully intact, even in a sample of hospitalized neurological patients with severe executive dysfunctions, some of whom had marked damage in fronto-thalamo-striatal networks. Having concluded that the emotion-induced bias must develop on different grounds, we went on to discuss alternative explanations.