Sugar ingestion and dichotic listening: Increased perceptual capacity
is more than motivation |
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Authors: | Matthew H Scheel Aimee L Ambrose |
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Institution: | Department of Psychology, Carroll University, Wisconsin,
USA |
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Abstract: | Participants ingested a sugar drink or a sugar-free drink and then engaged in a
pair of dichotic listening tasks. Tasks presented category labels then played a
series of word pairs, one in the left ear and one in the right. Participants
attempted to identify pairs containing a target category member. Target category
words were homonyms. For example, arms appeared as a target in
the “body parts” category. Nontargets that played along with targets were
related to a category-appropriate version of the target (e.g.,
sleeves), a category-inappropriate version (e.g.,
weapons), or were unrelated to either version of the target
(e.g., plant). Hence, an effect of nontarget type on number of
targets missed was evidence that participants processed nontargets for meaning.
In the divided attention task, participants monitored both ears. In the focused
attention task, participants monitored the left ear. Half the participants in
each group had the divided attention task before the focused attention task; the
other half had the focused attention task before the divided attention task. We
set task lengths to about 12 min so working on the first task would give
sufficient time for metabolizing sugar from the drink before the start of the
second task. Nontarget word type significantly affected targets missed in both
tasks. Drink type affected performance in the divided attention task only after
sufficient time for converting sugar into blood glucose. The result supports an
energy model for the effect of sugar ingestion on perceptual tasks rather than a
motivational model. |
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Keywords: | perceptual load selective attention glucose dichotic listening |
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