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The article presents a case study of a 37-year-old man who was admitted to the hospital with complaints of progressive gait disorder followed by cognitive difficulties. His structural magnetic resonance imaging (MRI) scan revealed posterior cortical atrophy on T1 sequence. His thorough analysis revealed a higher bilateral hippocampal AV45 uptake in patient than in patients with Alzheimer's disease.

We report the case of a 62-year-old asymptomatic carrier of AβPP gene duplication. He was investigated by MRI and the amyloid ligand 18F-AV45, and compared to Alzheimer's disease patients (n = 11) and healthy controls (n = 11). The neuropsychological examination was normal. Cortical thickness and AV45 retention were comparable to Alzheimer's disease patients. AβPP duplication was diagnosed because cerebral amyloid angiopathy and Alzheimer's disease pathology were found on the neuropathological examination of his youngest brother, who died at 42 from intracerebral hemorrhage. This is the first description of a pre-symptomatic AβPP duplication carrier over 60, despite widespread cerebral amyloid angiopathy, 'Alzheimer's like' atrophy, and amyloid deposition. [ABSTRACT FROM AUTHOR]

There is an ongoing debate regarding the respective role of anterior subhippocampal structures and the hippocampus in recognition memory. Here, we report a double anatomo-functional dissociation observed in two brain-damaged patients, FRG and JMG. They both suffered from complete destruction of left MTL structures. In the right hemisphere however, FRG sustained extensive lesions to the hippocampus sparing anterior subhippocampal structures, while JMG suffered from the reversed pattern of lesion, i.e., extensive damage to anterior subhippocampal structures but preserved hippocampus. FRG was severely amnesic and failed all recall tasks involving visual material, but exhibited normal performance at a large battery of visual recognition memory tasks. JMG was not amnesic and showed the opposite pattern of performance. These results strongly support the view that right anterior subhippocampal structures are a critical relay for visual recognition memory in the human. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Most of what we know about the human frontal eye field (FEF) is extrapolated from studies in animals. There is ample evidence that this region is crucial for eye movements. However, evidence is accumulating that this region also plays a role in sensory processing and that it belongs to a "fast brain" system. We set out to investigate these issues in humans, using intracerebral recordings in patients with drug-refractory epilepsy. Event-related potential recordings were obtained from 11 epileptic patients from within the FEF region while they passed a series of visual and auditory perceptual tests. No eye movement was required. Ultra-rapid responses were observed, with mean onset latencies at 24 ms after stimulus to auditory stimuli and 45 ms to visual stimuli. Such early responses were compatible with cortical routes as assessed with simultaneous recordings in primary auditory and visual cortices. Components were modulated very early by the sensory characteristics of the stimuli, in the 30-60 ms period for auditory stimuli and in the 45- 60 ms period for visual stimuli. Although the frontal lobes in humans are generally viewed as being involved in high-level cognitive processes, these results indicate that the human FEF is a remarkably quickly activated multimodal region that belongs to a network of low-level neocortical sensory areas. [ABSTRACT FROM AUTHOR]

Despite highlighting the role of the attribution system and proposing a coherent large-scale architecture of declarative memory, the integrative memory model would be more "integrative" if the temporal dynamics of the interactions between its components was clarified. This is necessary to make predictions in patients with brain injury and hypothesize dissociations.

The rapid recognition of familiar faces is crucial for social interactions. However the actual speed with which recognition can be achieved remains largely unknown as most studies have been carried out without any speed constraints. Different paradigms have been used, leading to conflicting results, and although many authors suggest that face recognition is fast, the speed of face recognition has not been directly compared to "fast" visual tasks. In this study, we sought to overcome these limitations. Subjects performed three tasks, a familiarity categorization task (famous faces among unknown faces), a superordinate categorization task (human faces among animal ones), and a gender categorization task. All tasks were performed under speed constraints. The results show that, despite the use of speed constraints, subjects were slow when they had to categorize famous faces: minimum reaction time was 467 ms, which is 180 ms more than during superordinate categorization and 160 ms more than in the gender condition. Our results are compatible with a hierarchy of face processing from the superordinate level to the familiarity level. The processes taking place between detection and recognition need to be investigated in detail.