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Biomedical subjects

L Mercier

Publications and source records attributed to L Mercier.

58 records · Page 4Linked to original sources

Attention deficits: is there a right hemisphere specialization for simple reaction time, sustained attention, and phasic alertness?

Impairments of attentional focus often are claimed to be associated with lesions of the right hemisphere. Although some studies comparing right- and left-brain-damaged patients have supported this idea, others have not found differences between these patients in various attention tasks. The present study was carried out in order to further investigate the putative role of the right hemisphere in a simple reaction time task, a sustained attention task, and a phasic alertness task. Subjects were 46 patients with right-hemisphere lesions and 37 patients with left-hemisphere lesions. Results showed no difference between right- and left-brain-damaged patients in simple reaction time, in speed of response over time (sustained attention), and in the capacity to prepare to an uncoming stimulus (phasic alertness). Future studies will have to use a more precise categorization of lesions than only right-versus left-brain damage.

Adult↗

Impact of elbow position on grip strength of elderly men.

Grip strength is frequently measured in rehabilitation settings in order to monitor patient progress. Many factors influence grip strength measurements, including body segment positions and particularly elbow position. The objective of this study was to compare grip strength measurements obtained with two different elbow positions: full extension and 90 degrees of flexion. Forty-nine healthy right-handed men aged 60 to 84 years were tested with a Jamar dynamometer. Results indicated that left grip strength was significantly higher when the elbow was flexed to 90 degrees compared with when it was fully extended. No statistical difference between the two elbow positions was found for the dominant hand.

Aged↗