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Abstract:
An important general hypothesis about the effects of CHI on
cognitive function is the coping hypothesis. CHI is assumed to slow
processing but to have few specific effects on brain systems. In
order to compensate for this slowed processing individuals who have
sustained a CHI are said to engage in more effortful processing. It
is hypothesised that this, in association with increased
distractibility, leads to rapid fatigue and reduced capacity to
deal with complex tasks. In this research the following attention
mechanisms were assumed: 1) Early or peripheral enhancement or
suppression of particular input streams. 2) A central or late
selection of competing responses. 3) A mechanism for reorienting
individuals to unexpected or salient stimuli. Our recent findings
using ERP measures of auditory selective attention, the Stroop
task, the paired auditory serial arithmetic task (PASAT) and
responses to novel stimuli suggest, when considered in the context
of other recent studies: 1) Impairment of allocation of early or
peripheral stimulus enhancement mechanisms. 2) Enhancement of late
central response control mechanisms. 3) Distractibility is enhanced
but the magnitude of this effect is influenced by perceptual load
and working memory load.
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