System and Cognitive unit

Sang-Hun Lee, PhD, Dept. of Psychology, SNU HP

2009

* Asymmetric interaction between motion and stereopsis 23 revealed by concurrent adaptation.
[Article (PDF)]
Although contingent aftereffects between motion and stereopsis have been referred to as behavioral evidence for the joint processing of the two features, the reciprocal nature of encoding the two features has not been systematically studied. Using a novel form of concurrent adaptation, we probed the perception of direction- and disparity-de!ned coherent surfaces in parallel before and after adaptation to a stimulus that moved in a single direction at a particular binocular disparity. Contrary to earlier !ndings, we found a strong asymmetry between motion and stereopsis: the detection of disparity signal after adaptation was more impaired when the test stimulus was moving in the adapted direction than in the non-adapted direction, whereas the test disparity hardly affected the detection of coherent motion. However, motion adaptation became dependent on disparity when we added another surface that was moving in the opposite direction at the opposite sign of disparity to those of the original adaptor, as in previous studies of contingent aftereffects. The observed asymmetric contingency between motion and disparity adaptation urges the reinterpretation of previously reported contingent aftereffects and suggests a corresponding asymmetry between neural mechanisms devoted to processing of motion and stereopsis in human visual cortex.

2007

* Hierarchy of cortical responses underlying binocular rivalry.
[>Article (PDF)]
During binocular rivalry, physical stimulation is dissociated from conscious visual awareness. Human brain imaging reveals a tight linkage between the neural events in human primary visual cortex (V1) and the dynamics of perceptual waves during transitions in dominance during binocular rivalry. Here, we report results from experiments in which observers’ attention was diverted from the rival stimuli, implying that: competition between two rival stimuli involves neural circuits in V1, and attention is crucial for the consequences of this neural competition to advance to higher visual areas and promote perceptual waves.

2005

* Traveling waves of activity in primary visual cortex during binocular rivalry.
[Article (PDF)]
http://bcs.snu.ac.kr/mediawiki/uploads/e/ee/Lee_NatureNeuro2005.pdf
When the two eyes view large, dissimilar patterns that induce binocular rivalry, alternating waves of visibility arre experienced as one pattern sweeps the other out of conscious awaerness. Here we combine psychophysics with functional magnetic resonance imaging to show tight linkage between dynamics of perceptual waves during ribalry and neural events in human primary wisual cortex (V1).

Randolph Blake, PhD, Dept. of Psychology, Vanderbilt University HP

2010

[Publication list]

2009

* Periodic perturbations producing phase-locked fluctuations in visual perception. Journal of Vision, 9, 1 -12.
[Related articles]

* Spatial spread of interocular suppression is guided by stimulus configuration. Perception, 38, 215-231.
[PubMed]

Inah Lee, PhD, Dept. of Psychology, U of Iowa HP

2010

* Hippocampus is necessary for spatial discrimination using distal cue-configuration. Hippocampus.
[Article (PDF)]

* Dentate gyrus is necessary for disambiguating similar object-place representations.
[Related articles] [PDF]

*Perirhinal cortex is necessary for acquiring, but not for retrieving, object-place paired association.
[Related articles] [PDF]

Marcus Kaiser, PhD, Complex Neural Systems, Newcastle Univ. HP

2010

* Optimal hierarchical modular topologies for producing limited sustained activation of neural networks.
[Article (PDF)]

* A nonsynaptic mechanism underlying interictal discharges in human epileptic neocortex.
[Article (PDF)]

* Reducing influenza spreading over the airline network.
[Article (PDF)]

* Parallel calculation of multi-electrode array correlation networks.
[Article (PDF)]

* Random outgrowth and spatial competition generate realistic connection length distributions and filling fractions.
[Article (PDF)]

* Beyond the average: detecting global singular nodes from local features in complex networks.
[Article (PDF)]