We
cordially invite you to the next lecture of the BME cognitive
seminar series:
Date
& Time: November 22, Tuesday, 16:00-17:00
Location: BME, XI., Egry József utca 1., T. ép 515.
Wolfgang
Klimesch
The
meaning of alpha synchronization and inhibition for memory
Abstract
Convergent
evidence suggests
that an increase in alpha amplitudes reflects inhibition. As an
example, alpha
is increased over the ipsilateral hemisphere in a variety of
spatial attention-
and working memory tasks with hemifield presentations of visual
stimuli. But
alpha obviously also reflects an ‘active’ process that can
hardly be
interpreted in terms of ‘pure’ inhibition that simply blocks
information processing.
As an example, an increase in evoked alpha and inter-areal phase
synchronisation can be observed during access to stored
memories. It is
suggested that inhibition – associated with alpha - might
operate in at least
two different ways. In
task irrelevant and potentially competing/interfering networks, an increase in inhibition
may indeed reflect
the actual blocking of information processing. In task relevant neural networks, however, an
increase in inhibition may
improve the signal to noise ratio by silencing neurons with a
comparatively low
level of excitation. A
variety of recent
findings – including evoked traveling alpha waves – will be
discussed that are
well in line with the suggested interpretation.
-- Attila Keresztes Junior Research Fellow Budapest University of Technology and Economics Dept. of Cognitive Science, Egry József u. 1, Budapest 1111, Hungary Tel: +36 1 4633525