Functional aspects of colour processing within the human brain
Date
2006-04-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Masters
Abstract
In a seminal work, Ungerleider and Mishkin (1982) offered substantial evidence that two separate visual pathways – coding what/where-- exist within the primate brain. Recently, human evidence has resulted in the “what/where” pathways being reconsidered in terms of ventral stream (vision for perception) and dorsal stream (vision for action; Goodale & Milner, 1992). Consistently, many studies have demonstrated that there is an overrepresentation of magnocellular (luminance) information within the dorsal stream; parvocellular input (colour, shape, consistancy) represents the primary source of information for the ventral stream. Although luminance contrast is important in perceiving moving objects, colour discrepancies help the visual system to identify the detailed characteristics of the environment and, subsequently, to prepare the motor system for action. This thesis endeavors to determine the role played by colour, in contrast with luminance, in influencing the programming and control movement production. Using a grasping paradigm and two different luminance conditions (iso-luminance vs. heteroluminance) within two separate experiments (experiment 1 – programming; experiment 2 – online control), we show that chromatic information can be successfully be used by motor circuits to complete the grasping task faultlessly. Although significant temporal delays in terms of reaction time and movement time between colour and luminance processing are identified, the human visual system seems able to fully integrate colour features for action with no significant spatial error cost.
Description
Keywords
colour, vision, perception, luminance, action, grasping
Citation
Degree
Master of Science (M.Sc.)
Department
College of Kinesiology
Program
College of Kinesiology