Relationship of extinction to perceptual thresholds for single stimuli

Neurology
K J MeadorD W Loring

Abstract

To demonstrate the effects of target stimulus intensity on extinction to double simultaneous stimuli. Attentional deficits contribute to extinction in patients with brain lesions, but extinction (i.e., masking) can also be produced in healthy subjects. The relationship of extinction to perceptual thresholds for single stimuli remains uncertain. Brief electrical pulses were applied simultaneously to the left and right index fingers of 16 healthy volunteers (8 young and 8 elderly adults) and 4 patients with right brain stroke (RBS). The stimulus to be perceived (i.e., target stimulus) was given at the lowest perceptual threshold to perceive any single stimulus (i.e., Minimal) and at the threshold to perceive 100% of single stimuli. The mask stimulus (i.e., stimulus given to block the target) was applied to the contralateral hand at intensities just below discomfort. Extinction was less for target stimuli at 100% than Minimal threshold for healthy subjects. Extinction of left targets was greater in patients with RBS than elderly control subjects. Left targets were extinguished less than right in healthy subjects. In contrast, the majority of left targets were extinguished in patients with RBS even when right mask intensity was red...Continue Reading

Citations

Apr 25, 2006·Psychophysiology·Ruth SchubertGabriel Curio
Mar 10, 2010·Psychophysiology·Anja WühleChristoph Braun

❮ Previous
Next ❯

Related Concepts

Related Feeds

Brain Ischemia

Brain ischemia is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. Discover the latest research on brain ischemia here.