The CEU Department of Cognitive Science cordially invites you to its
talk by
Cong Yu (Department of Psychology and Peking-Tsingua Center for Life
Sciences, Peking University, Beijing, China)
Date: Wednesday, September 30, 2015 - 17:00-18:30
Host: Jozsef Fiser, Associate Professor
Location: Department of Cognitive Science, CEU, Oktober 6 street 7,
room 101.
Visual perceptual learning: A new perspective
Abstract: For many years perceptual learning (PL) researchers are
excited by the observations that PL is specific to the trained retinal
location and orientation, and regard these specificities as indications
of neural plasticity in the early visual cortex. However, we have
created a “double training” design to enable complete learning transfer
to untrained conditions, suggesting that PL is mainly a cognitive
learning process beyond the retinotopic visual areas. More recently we
studied why PL is specific in the first place, and what is really
learned in PL. In double training, PL becomes transferable if the
subjects are exposed to the untrained location or orientation through an
irrelevant task, indicating that learning specificity may be to do with
the untrained conditions. We used a continuous flash suppression
technique to create “bottom-up only” or “top-down only” exposure
stimuli. We found that bottom-up exposure of an untrained location or
orientation, or pure top-down influences, can both enable significant
and sometimes complete learning transfer. These results suggest that
learning specificities may result from neural under-activations at the
untrained conditions that receive insufficient bottom-up stimulation
and/or top-down attention during training.In addition, we demonstrated
that PL is a form of concept learning. We studied orientation learning
with orientation features defined by either luminance gratings or
symmetric dot patterns, and motion direction learning with first-order
luminance stimuli and second-order contrast stimuli. Each pair of
stimuli had distinctive physical properties that are encoded by
different neuronal mechanisms. Using a variation of the double training
method, we observed complete mutual transfer of learning between grating
and dot-pattern defined orientations, and between first- and
second-order motion directions. These results indicate that what is
learned in PL is the abstract concept of a trained visual feature, such
as orientation or motion direction.
See more at:
http://cognitivescience.ceu.edu/events/2015-09-30/departmental-colloquium-c…
We are looking forward to see you there (Oktober 6 street 7)!
Cognitive Science Events at CEU:
http://cognitivescience.ceu.hu/events
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