Feature-based attention in primate visual cortex
Mechanisms and limitations of color- and motionselection as assessed by neurophysiology, psychophysics and computational modeling
Feature-based attention in primate visual cortex
by Philipp Schwedhelm
Date of Examination:2015-09-09
Date of issue:2016-07-06
Advisor:Prof. Dr. Stefan Treue
Referee:Prof. Dr. Hansjörg Scherberger
Referee:Prof. Dr. Melanie Wilke
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Abstract
English
The scope of this thesis, after a brief summary of the core ideas of top-down attentional control is given (Chapter 2.1), is to shed some light on the cortical control circuit underlying the deployment of feature-based attention. A first study (Chapter 2.2) deduces from human psychophysical performance how an attentional signal acts on a local sensory population of motion-selective neurons. A second empirical study (Chapter 2.3) attempts to identify and characterize resource limitations for the deployment of feature-based attention in macaque monkeys. In particular, the aim of the study was to compare neuronal modulations of motion-selective neurons in three different cases of feature-based modulation. In summary, this work provides novel insights into the properties of the feature-based attention system of monkeys and humans. I describe a stimulus-independent influence of attention on neuronal normalization and a potential resource limitation of feature-based attentional deployment. Both results will guide further research aiming at characterizing the brain networks subserving the deployment of top-down feature-based attention.
Keywords: attention; features; motion; area MT; macaque