Author Correction: High-resolution record reveals climate-driven environmental and sedimentary changes in an active rift.

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High-resolution record reveals climate-driven environmental and sedimentary changes in an active rift.

Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvironmental changes when a young rift connects to the global oceans. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift show 10s-100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and character of sediment delivered into the rift. During interglacials, when the basin was marine, sedimentation rates were lower (excepting the Holocene), and bioturbation and organic carbon concentration higher. During glacials, the basin was isolated from the ocean, and sedimentation rates were higher (~2-7 times those in interglacials). We infer that reduced vegetation cover during glacials drove higher sediment flux from the rift flanks. These orbital-timescale changes in rate and type of basin infill will likely influence early rift sedimentary and faulting processes, potentially including syn-rift stratigraphy, sediment burial rates, and organic carbon flux and preservation on deep continental margins worldwide.

[Neuropsychological aspects of Alzheimer's disease]. / La neuropsychologie de la maladie d'Alzheimer.

This analysis is centered on the study of cognitive disorders in Alzheimer's Disease (AD), mainly for major neuropsychological functions. We insist on the heterogeneity of the clinical picture especially in the early stages of the illness, when deficits of episodic memory and executive functions are prevalent. We consider that studying early stages of the illness is necessary to delineate the diagnostic signs, to validate the new therapeutic experiments, to predict stages of decline.

Discrimination of facial identity and of emotions in Alzheimer's disease.

OBJECTIVE: To investigate processing of human faces identity and of emotional expressions in patients with Alzheimer's Disease (AD). BACKGROUND: Mechanisms responsible for discriminating facial identity may be dissociated from those involved in discriminating facial expressions. Patients with prosopagnosia often have preserved capacities for processing emotional facial expressions and occasionally, patients with focal lesions may recognize human faces without being able to recognize their facial expression. Such a dissociation has not been clearly shown in groups of AD patients. METHODS: Thirty-one probable AD patients and 14 control subjects were administered tasks of discrimination of faces and of emotions. RESULTS: AD patients were significantly impaired in discriminating facial identities and in naming and pointing to named emotions, but were comparable to controls in discriminating facial expressions of emotion. The deficits of facial discrimination and of identification of emotions were, on the whole, correlated with the MMS and Raven scores. Discrimination of emotions was not correlated to either test, suggesting that this ability is based on cognitive processes different from those underlying the MMS and the PM47. CONCLUSIONS: This dissociation implies two separate systems, one dedicated to discrimination of facial identities and the other to discrimination of emotions. This is compatible with the modular organization of cognitive deficits in AD and may explain the well known experience that nonverbal communication often remains effective even in patients with severe dementia.

Memory and depression in Parkinson's disease.

Disorders of learning and memory are a frequent finding in nondemented Parkinson disease (PD) patients. It is not clear to what extent depression, present in at least half the cases of PD, contributes to these disorders. This paper investigates the possible influence of depression on tests of episodic memory in patients with Parkinson's disease (PD). We studied three groups of 11 subjects each (controls, non-depressed PD, mildly to moderately depressed PD). Neuropsychological tests included tests of short and long-term memory in verbal and non-verbal modalities. The two groups of PD patients performed significantly worse than controls on the memory tests, but there were no differences between the depressed and non-depressed PD patients. This lack of influence of depression on neuropsychological performance is compatible with Starkstein's view that cognitive imnpairment is only found beyond a given threshold of depression severity.Copyright Lippincott-Raven Publishers

Principal component analysis of language performances in Alzheimer's disease.

This report analyzes the performances of a group of 104 mildly to moderately impaired probable Alzheimer's disease patients (Mini Mental Examination 10 to 23) on linguistic tasks exploring written and oral language. A principal component analysis showed a two-factor solution including 14 out of the 15 linguistic tasks. Each factor is characterized by a type of operation required to process language material: "operativeness factor," where verbal material receives a transformation; "transcoding factor," where verbal material is processed without any structural modification. Oral verbal repetition remained isolated from the solution.

[Quantified neuropsychological study in senile dementia of Alzheimer's type]. / Etude neuropsychologique quantifiée dans la démence sénile de type Alzheimer.

Forty six patients affected by senile dementia of the Alzheimer type and 20 control subjects of similar age, sex and educational level have been studied, using a quantified neuropsychological battery (Wechsler memory scale, Raven progressive matrices and quantified tests for aphasia, apraxia and agnosia). There was a significant correlation between the scores of all cognitive functions with one another and with the Mini Mental State. The results show a rather global impairment of cognitive functions in these patients and suggest that intellectual impairment progresses as a continuum in senile dementia of the Alzheimer type.

EEG mapping of left hemisphere dysfunction during motor performance in schizophrenia.

With a newly developed system of brain electrical activity mapping we studied 10 right-handed, neuroleptic-treated schizophrenics (five of the disorganized, five of the paranoid type, corresponding to 295.1 and .3 in DSM-III), compared with 10 normal controls. Increasingly complex motor tasks were used for cortical activation, all functional states being referenced to resting states recorded after a special relaxation program. We found higher delta and theta amplitudes during rest, as noted in previous studies, and lower beta power values. As a major result, however, we found a widespread left hemisphere dysfunction in schizophrenics, predominantly in the left primary sensory and motor areas. Additionally, we found signs of a "compensatory" overactivation in patients in motor tasks, when this hemisphere is not "used" by normal persons. The results support our findings obtained with this method during multisensory motor coordination in schizophrenia. The results in these patients suggest that these are not merely vigilance, attention, or motivation dysfunctions, but rather specific cortical correlates of impaired motor performance.