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We report the case of a patient with sensorimotor conversion that improved transiently during post-anoxic medial temporal ischemia inducing anterograde and retrograde amnesia. Symptoms reappeared in parallel with mnesic recovery. This case raises a hypothesis concerning the role of hippocampi and amygdalae, which are involved in emotionally-associated memory. The amnesia may have modified the patient's "self," giving her a "distant" point of view. Another hypothesis is that cerebral anoxic stress may have "reset" the cerebral network that controls behavior. These findings give clues about the mechanisms of somatoform disorder and highlight the possibility of specific therapeutic strategies to induce cognitive reappraisal of emotionally-associated experiences.

We explored potential contributing psychological factors in a patient ('XF') with focal retrograde amnesia, within the framework proposed by Kopelman (2000, Cognitive Neuropsychology, 17, 585). In particular, we investigated the psychological trait of self-enhancement. We constructed a self-report questionnaire measure of self-enhancement and compared XF's score on this measure with the scores of 61 control participants. XF was found to have a significantly greater level of self-enhancement than the entire control group, and also than a smaller sample of age- and sex-matched controls. We propose that heightened self-enhancement may reflect a premorbid tendency that potentially predisposes individuals to develop retrograde amnesia.

We studied a case of psychogenic amnesia by means of a functional magnetic resonance imaging (fMRI) experiment involving the retrieval of autobiographical memories. The 38-year-old patient was unable to access most of her autobiographical memories from her childhood up to 16 years of age. Compared with the forgotten period, evocation of the normally retrieved memories elicited increased activity in medial temporal and dorso-lateral frontal regions. Evocation of the preserved scattered recollections was associated with bilaterally distributed temporo-parieto-occipital loci of activations. These functional changes seem to support the idea of common mechanisms involved in both organic and psychogenic amnesias.

Recent case studies of amnesic patients have yielded patterns of impairment that challenge Tulving's (1972) division of retrograde memory into two categories (namely, episodic and semantic memory). Here we describe a patient (JG) who developed partially blocked access to previously stored knowledge following the onset of a medial thalamic infarction. Having previously demonstrated that JG has a dense, pervasive amnesia for autobiographical material, famous people and famous events (Miller et al. , 2001), in this study, we show that he is unable to access information about unique entities across a range of domains. In contrast, his memory for more general semantic knowledge (such as word meanings) is intact. JG's memory impairment is discussed in the context of a model of neural functioning put forward by Damasio (1990), in which it was proposed that recall of unique entities depends on many cortical regions being activated in synchrony. This activity, thought to be triggered and coordinated by anterior temporal and frontal lobe regions is, in turn, modulated by projections from the thalamus. We propose that JG's thalamic lesion has disrupted the coordination of the diffuse cortical networks necessary to generate highly specific memories from the past, be they episodic or semantic.

In current functional models of person recognition it is proposed that there exists a single common body of semantic information concerning people accessible from all modalities (e.g. names, faces). In this paper, we present evidence that challenges this view. Two experiments are discussed investigating residual autobiographical and public knowledge in a patient suffering from retrograde amnesia. Knowledge about people was investigated in each case by asking a series of questions, ranging from the very general to the very specific. Experiment 1 examined knowledge about famous people. The results showed that the patient accessed more information about famous people when cued with names than when cued with faces. Experiment 2 examined knowledge about people known personally to the patient. Again, the same pattern of results emerged. While the patient responded accurately to all questions posed with name cues, her ability to recall the same information when prompted with face cues was clearly inferior. This modality-based difference in accessing biographical knowledge is discussed in relation to models of person recognition.