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Biomedical subjects

G L Ahern

Publications and source records attributed to G L Ahern.

25 records · Page 2Linked to original sources

Dissociated neglect behavior following sequential strokes in the right hemisphere.

A 42-year-old woman suffered two focal right hemisphere strokes, sequentially damaging different components of a proposed cerebral network for the spatial distribution of attention. Her first stroke was centered in the right frontal lobe and resulted in left hemi-spatial neglect but only for tasks that emphasize exploratory-motor components of directed attention. A second stroke occurred 20 days later in the parietal lobe and led to the emergence of perceptual-sensory aspects of neglect. This case strongly supports the existence of a distributed anatomic-functional network subserving directed attention.

Adult↗

Differential lateralization for positive and negative emotion in the human brain: EEG spectral analysis.

The present experiment utilized EEG spectral analysis to investigate lateralization for emotional processes in the human brain. In frontal zones, a differential lateralization for positive and negative emotion was observed, with relative left-hemispheric activation (as measured by decreases in alpha abundance) for positive emotions and relative right-hemispheric activation for negative emotions. In parietal zones, a differential lateralization for verbal and spatial processes was observed, with relative left-hemispheric activation for verbal questions and relative right-hemispheric activation for spatial questions. Examination of EEG bands other than alpha (i.e. delta, theta, beta, and total power) suggested that emotional and cognitive processes are further distinguished by different EEG spectral patterns.

Adolescent↗

Escape from deficits in sodium intake after thalamic lesions as a function of preoperative experience.

Saline and water intakes in response to treatments with a natriuretic agent and a mineralocorticoid were studied in intact rats and in rats with lesions centered in the taste delay of the thalamus. Intact rats responded to the treatments by increasing both saline and water intake. Rats with thalamic lesions that had never drunk saline prior to induction of the lesions generally did not increase their saline intake in response to the treatments but showed normal increases in water intake. In contrast, rats with thalamic lesions that had drunk saline prior to induction of the lesions showed normal increases in both saline and water intake. Preoperative experience of sodium need did not protect rats against the lesion-induced deficit.

Animals↗

Posttraumatic pilomotor seizures: a case report.

Pilomotor epilepsy is a rare phenomenon. A 35-year-old man suffered a traumatic contusion of the right temporal lobe and subsequently developed spells characterized by diffuse piloerection and sweating. We believe this to be the first reported association between pilomotor epilepsy and posttraumatic head injury. Although pilomotor seizures may result from diverse etiologies, they appear to have a common involvement of temporolimbic structures.

Adult↗