This work explores the cerebral structures involved in the appreciation of music. We studied six young healthy subjects (right handed, French, without musical talent), using a high resolution PET device (CTI 953B) and 15O-labelled water. In three tasks, we studied the effects of selective attention to pitch, timbre and rhythm; a final task studied semantic familiarity with tunes (considered as divided attention for pitch and rhythm). These four tasks were performed on the same material (a tape consisting of 30 randomly arranged sequences of notes). We selected a paradigm, without a reference task, to compare the activations produced by attention to different parameters of the same stimulus. We expected that the activations recorded during each task would differ according to the differences in cognitive operations. We found activations preferentially in the left hemisphere for familiarity, pitch tasks and rhythm, and in the right hemisphere for the timbre task. The familiarity task activated the left inferior frontal gyrus, Brodmann area (BA) 47, and superior temporal gyrus (in its anterior part, BA 22). These activations presumably represent lexico-semantic access to melodic representations. In the pitch task, activations were observed in the left cuneus/precuneus (BA 18/19). These results were unexpected and we interpret them as reflecting a visual mental imagery strategy employed to carry out this task. The rhythm task activated left inferior Broca's area (BA 44/6), with extention into the neighbouring insula, suggesting a role for this cerebral region in the processing of sequential sounds.

These findings contribute to the overall evidence suggesting that aircraft noise exposure at night-time may increase the risk of hypertension in men. Hypertension is a well-known and established risk factor for cardiovascular disease. The association reported in the present study between aircraft noise and hypertension implies that aircraft noise might be a risk factor also for cardiovascular disease.

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Two cancellation tests, Albert's Test and a new test with distractors, the Bells Test, which are both used for the evaluation of unilateral visuospatial neglect, were applied to 40 neurologically normal adults and 47 right CVA patients, 4-12 weeks after stroke. Norms are proposed for both tests. Results show that the Bells Test has greater discrimination power than Albert's Test. In both tasks, a left-to-right gradient of neglect is found in patients who show neglect.

Background and Purpose-Follow-up neuroimaging studies of aphasia never addressed a comparison between aphasic and healthy subjects. Investigation of changes over time in healthy subjects during language tasks seems a prerequisite before interpretation of longitudinal changes in aphasic patients. Methods-Six healthy subjects and 8 aphasic patients were PET scanned twice (PET1 and PET2) at a 1-year interval during a word generation task. Using SPM99, language-rest main effect was compared at PET1 and PET2 in each group, whereas group effect was assessed at each session. Correlations were analyzed in each group between performance indexes and changes in regional cerebral flood flow (rCBF) between the 2 sessions. Results-Language performances were improved in both groups. rCBF decreased from PET1 to PET2 in the healthy group and increased in the aphasic group in perisylvian regions bilaterally. Correlations between performance and rCBF changes across sessions were similar in the 2 groups; positive correlations involved superior temporal cortexes bilaterally, and negative correlations concerned superior frontal and medial temporal regions. Conclusions-Increased

A dissociation in the central processes of spelling, with preferentially lexical over phonological impairment, frequently affects patients with early Alzheimer's disease. The aim of this work was to test whether dissociations in the language domain in Alzheimer's disease can be exploited with PET to assess the neural basis of cognition. To this end, we studied the functional neuroanatomy of writing impairment in Alzheimer's disease by means of PET measurements of the local cerebral glucose utilization and neuropsychological tests specially designed to assess the phonological and lexical components of writing. We analysed the performance in written spelling of irregular words and non-words of 11 right-handed patients with mild-to-moderate Alzheimer's disease. For each patient, we calculated a residual phonological score and a residual lexical score, based on a cognitive interpretation of the errors according to the item category. In each of these 11 patients, using PET, we measured the resting-state utilization of glucose in the left supramarginal gyrus and the left angular gyrus, two cortical regions selected a priori because of their presumed role in the central processes for spelling, and identified on CT scans obtained according to stereotaxic references and coregistered with PET. To assess the relationships between the neuropsychological scores and the metabolic data, we used the 'ratio paradigm', the sensitivity of which has been previously documented in cognitive-metabolic correlative PET studies of Alzheimer's disease that were less focused than the present study in both cognitive and anatomical terms. We found a highly significant positive correlation between phonological score:lexical score neuropsychological ratios and corresponding supramarginal gyrus:angular gyrus metabolic ratios. These findings further support the role of these two left-sided temporo-parietal regions in the central processes of writing and show that the neuropsychological dissociations in early Alzheimer's diseases can be exploited to further our understanding of the functional neuroanatomy of cognitive operations. The role of focal, as compared with more diffuse, brain damage in the development of impaired written language of central origin in Alzheimer's disease is also discussed.

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The impact of aircraft noise on health is of growing concern. We investigated the relationship between this exposure and mortality from cardiovascular disease, coronary heart disease, myocardial infarction, and stroke. We performed an ecological study on 161 communes (commune being the smallest administrative unit in France) close to the following three major French airports: Paris-Charles de Gaulle, Lyon Saint-Exupéry, and Toulouse-Blagnac. The mortality data were provided by the French Center on Medical Causes of Death for the period 2007-2010. Based on the data provided by the French Civil Aviation Authority, a weighted average exposure to aircraft noise (Lden AEI) was computed at the commune level. A Poisson regression model with commune-specific random intercepts, adjusted for potential confounding factors including air pollution, was used to investigate the association between mortality rates and Lden AEI. Positive associations were observed between Lden AEI and mortality from cardiovascular disease [adjusted mortality rate ratio (MRR) per 10 dB(A) increase in Lden AEI = 1.18; 95% confidence interval (CI): 1.11-1.25], coronary heart disease [MRR = 1.24 (1.12-1.36)], and myocardial infarction [MRR = 1.28 (1.11-1.46]. Stroke mortality was more weakly associated with Lden AEI [MRR = 1.08 (0.97-1.21]. These significant associations were not attenuated after the adjustment for air pollution. The present ecological study supports the hypothesis of an association between aircraft noise exposure and mortality from cardiovascular disease, coronary heart disease, and myocardial infarction. However, the potential for ecological bias and the possibility that this association could be due to residual confounding cannot be excluded.