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Attention versus consciousness
Attention versus consciousness
Attention
versus consciousness
Valerie Hardcastle
In: Neural Basis of Consciousness
– John Benjamins (2003)
The author suggests that definite images in the mind
are surrounded by a peripheral consciousness that gives value and significance
to the definite image. She argues that attention is something different from
consciousness, and that what we pay attention to does not comprise the whole of
conscious experience, but is supplemented by background material. This appears
to depart from the views of many other writers.
Vision works on the bases
saccades that fixate on object for about 20 ms and then move on. Our visual
world is based on a series of inputs separated by gaps. With written text
(western style) our conscious perception extends about 15 characters to the
right and four characters to the left. Using gappy inputs, the brain constructs
an overall picture of the visual scene based on various assumptions. This
accounts for change blindness, which is the failure to notice sometimes
dramatic changes in a visual scene.
Initially this would seem to suggest
that attention was the same as consciousness, with even dramatic changes in peripheral
areas going unnoticed, but the author argues that the relationship is more
complicated than it initially seems. She also raises the issue of the
connection between the ability to report things and conscious awareness.
Research
by G. Sperling and E. Averbach in the 1960s
is taken as establishing that subjects are conscious of more than they
report. This research was partly initiated by subjects’ own claims that they
could perceive more than they had reported. Later studies seem to support this view that
we can perceive a certain amount independently of attention. The explanation
looks to be that unreported items are available in memory for a few hundred
milliseconds, and during this time can potentially be retrieved and brought
into consciousness.
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