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International audience; Patients with chronic mesial temporal lobe epilepsy have difficulties at identifying familiar faces as well as at explicit old/new face recognition tasks. However, the extent to which these difficulties can be attributed to visual individuation of faces, independently of general explicit learning and semantic memory processes, is unknown. We tested 42 mesial temporal lobe epilepsy patients divided into two groups according to the side of epilepsy (left and right) and 42 matched controls on an extensive series of individuation tasks of unfamiliar faces and control visual stimuli, as well as on face detection, famous face recognition and naming, and face and non-face learning. Overall, both patient groups had difficulties at identifying and naming famous faces, and at explicitly learning face and non-face images. However, there was no group difference in accuracy between patients and controls at the two most widely used neuropsychological tests assessing visual individuation of unfamiliar faces (Benton Facial Recognition Test and Cambridge Face Memory Test). While patients with right mesial temporal lobe epilepsy were slowed down at all tasks, this effect was not specific to faces or even high-level stimuli. Importantly, both groups showed the same profile of response as typical participants across various stimulus manipulations, showing no evidence of qualitative processing impairments. Overall, these results point to largely preserved visual face individuation processes in patients with mesial temporal lobe epilepsy, with semantic and episodic memory difficulties being consistent with the localization of the neural structures involved in their epilepsy (anterior temporal cortex and hippocampus). These observations have implications for the prediction of neuropsychological outcomes in the case of surgery and support the validity of intracranial electroencephalographic recordings performed in this population to understand neural mechanisms of human face individuation, notably through intracranial electrophysiological recordings and stimulations.

In contrast to most memory systems that decline with age, semantic memory tends to remain relatively stable across the life span. However, what exactly is stable remains unclear. Is it the quantity of information available or the organization of semantic memory, i.e., the connections between semantic items? Even less is known about semantic memory for celebrities, a subsystem of semantic memory. In the present study, we studied the organization of person-specific semantic memory and its stability in aging.We designed a word association task based on a previous study, which consisted in providing the first word that came to the mind of the participants (15 participants for each age group 20-30, 40-50 and 60-70 years old) for 144 celebrities. We developed a new taxonomy of associated responses as the responses associated with celebrities name could in principle be very varied.We found that most responses (90%) could be grouped into five categories (subjective; superordinate general; superordinate specific; imagery and activities). The elderly group did not differ from the other two groups in term of errors or reaction time suggesting they performed the task well. However, they also provided associations that were less precise and less based on imagery. In contrast, the middle-age group provided the most precise associations.These results support the idea of a durable person-specific semantic memory in aging but show changes in the type of associations that elders provide. Future work should aim at studying patients with early semantic impairment, as they could be different from the healthy elders on such semantic association task.

Acquired prosopagnosia is primarily defined as a defect in recognizing familiar faces. Nonetheless, for practical and methodological reasons, studies of such rare patients typically use pictures of unfamiliar faces. Here, we report an extensive investigation (17 behavioural tasks grouped in nine experiments) with a homogenous set of personally familiar faces in patient PS (Rossion et al., 2003. A network of occipito-temporal face-sensitive areas besides the right middle fusiform gyrus is necessary for normal face processing.), a well-documented case of acquired prosopagnosia with intact object recognition. PS’s recognition of the face pictures of 3–4-yearold children of her kindergarten is severely impaired—both in terms of accuracy and speed of recognition—and differs qualitatively from her colleagues’ performance. Relative to these typical individuals, PS relies more on external features, colour and local details of faces. She is also specifically impaired at processing the eye region in two-alternative face matching tasks, as well as in a familiar face recognition task performed both with pre-defined isolated parts and with randomly placed apertures revealing selective parts (“Bubbles”, >20.000 trials) of the personally familiar faces. These observations indicate that the same impairment observed previously with unfamiliar faces for PS and other cases of acquired prosopagnosia is associated with a deficient long-term representation of the eye region. Various manipulations that differentially affect the processing of the eye region suggest that this impairment is a consequence of the inability to represent the multiple parts of the eye region, and of the whole familiar face, as a single unit. This impairment in holistic processing is further evidenced here across different paradigms with composite faces, wholes and parts, and configurally distorted faces, mirroring and strengthening previous observations made with unfamiliar faces in PS and other cases of acquired prosopagnosia. Altogether, these observations suggest that prosopagnosia following brain damage affects unfamiliar and familiar face processing in a qualitatively similar way.

Objective: To estimate the prevalence of topographical memory impairment following posterior cerebral artery infarctions (PCAI) and define its anatomical correlations. Methods: We recruited 15 patients (mean duration of 4 months postinfarct). We administered 2 sets of experimental tests to assess topographical memory: one set included 5 computerized tasks (CompT) and the other set consisted of one ecological topographical orientation test (EcolT) that included 4 tasks (i.e., map drawing, picture recognition and ordering, backward path). Fifteen healthy participants served as controls. Patients and controls underwent a volumetric T1 MRI brain scan. Brain lesions in patients were segmented, normalized, and correlated with performance. Results: Topographical memory impairments were evidenced in patients with PCAI using both group and individual analyses (50%), with more severe outcomes in patients with PCAI in the right hemisphere. CompT and EcolT were highly correlated, but the ecological test was more sensitive in revealing topographical memory impairments. Voxel-based lesion-symptom mapping demonstrated that 2 regions located in the cuneus and the calcarine sulcus correlated significantly with behavioral performance. Conclusions: Topographical memory disorders following PCAI are reported in 50% of the patient population. Our results demonstrate the importance of developing and using dedicated batteries of topographical memory tests, in particular real-life tests, to identify such deficits. Neurology®

A B S T R A C T Purpose: The Wada test is still the gold standard procedure to predict language and memory deficits before temporal lobe epilepsy surgery. As amobarbital was no longer available, our aim was to validate propofol as an alternative. Method: We retrospectively studied 47 patients who underwent a bilateral intracarotid procedure, performed with amobarbital (18), or propofol (29), between 2000 and 2010 during the preoperative evaluation of temporal lobe epilepsy. Results: The number of patients experiencing an adverse event (mostly transient disturbance of consciousness or benign ocular symptoms) during both injections did not differ significantly between amobarbital and propofol. Hemispheric dominance was successfully determined in 96.5% patients with propofol vs. 94.4% with amobarbital for language, and in 72.4% under propofol vs. 77.7% under amobarbital for memory with no significant difference between groups. Conclusion: Propofol can be used for the Wada test with an efficacy and safety comparable to amobarbital.

Previous studies have shown that acquired prosopagnosia is characterized by impairment at holistic/configural processing. However, this view is essentially supported by studies performed with patients whose face recognition difficulties are part of a more general visual (integrative) agnosia. Here, we tested the patient PS, a case of acquired prosopagnosia whose face-specific recognition difficulties have been related to the inability to process individual faces holistically (absence of inversion, composite, and whole-part effects with faces). Here, we show that in contrast to this impairment, the patient presents with an entirely normal response profile in a Navon hierarchical letter task: she was as fast as normal controls, faster to identify global than local letters, and her sensitivity to global interference during identification of local letters was at least as large as normal observers. These observations indicate that holistic processing as measured with global/local interference in the Navon paradigm is functionally distinct from the ability to perceive an individual face holistically.