Prominent models of human long-term memory distinguish between memory systems on the basis of whether learning and retrieval occur consciously or unconsciously. Episodic memory formation requires the rapid encoding of associations between different aspects of an event which, according to these models, depends on the hippocampus and on consciousness. However, recent evidence indicates that the hippocampus mediates rapid associative learning with and without consciousness in humans and animals, for long-term and short-term retention. Consciousness seems to be a poor criterion for (...) differentiating between declarative (or explicit) and nondeclarative (or implicit) types of memory. A new model is therefore required in which memory systems are distinguished based on the processing operations involved rather than by consciousness. (shrink)

This study investigates the performance of psychopathic individuals on tasks believed to be sensitive to dorsolateral prefrontal and orbitofrontal cortex (OFC) functioning. Psychopathic and non-psychopathic individuals, as defined by the Hare psychopathy checklist revised (PCL-R) [Hare, The Hare psychopathy checklist revised, Toronto, Ontario: Multi-Health Systems, 1991] completed a gambling task [Cognition 50 (1994) 7] and the intradimensional/extradimensional (ID/ED) shift task [Nature 380 (1996) 69]. On the gambling task, psychopathic participants showed a global tendency to choose disadvantageously. Specifically, they showed an (...) impaired ability to show learning over the course of the task. On the ID/ED task, the performance of psychopathic individuals was not significantly different from incarcerated controls on attentional set-shifting, but significant impairments were found on response reversal. These results are interpreted with reference to an OFC and amygdala dysfunction explanation of psychopathy. (shrink)

Previous work has inconsistently reported difficulties with response reversal/extinction in children with psychopathic tendencies. Method: We tested the hypothesis that the degree of impairment seen in children with psychopathic tendencies is a function of the salience of contingency change. We investigated the performance of children with psychopathic tendencies on a novel prob- abilistic response reversal task involving four conditions with gradated reward–punishment contin- gencies (100–0, 90–10, 80–20 and 70–30; i.e., for the 100–0 contingency, responding to one object is always rewarded (...) while responding to the other is always punished). Results: In line with predictions, the impairment seen in the children with psychopathic tendencies was an inverse function of the salience of the contingency change. Conclusions: We suggest that this data is consistent with suggestions of subtle orbital frontal cortex impairment in children with psychopathic tendencies. (shrink)