Affiliation:
1. School of Psychology, University of St. Andrews, St. Andrews, Fife KY16 9JU, United Kingdom
2. Istituto di Fisiologia Umana, Università di Parma, 43100 Parma, Italy
Abstract
The inferotemporal (IT) cortex of the monkey lies at the head of the ventral visual pathway and is known to mediate object recognition and discrimination. It is often assumed that color plays a minor role in the recognition of objects and faces because discrimination remains highly accurate with black-and-white images. Furthermore it has been suggested that for rapid presentation and reaction tasks, object classification may be based on a first wave of feedforward visual information, which is coarse and achromatic. The fine detail and color information follows later, allowing similar stimuli to be discriminated. To allow these theories to be tested, this study investigates whether the presence of color affects the response of IT neurons to complex stimuli, such as faces, and whether color information is delayed with respect to information about stimulus form in these cells. Color, achromatic, and false-color versions of effective stimuli were presented using a rapid serial visual presentation paradigm, and responses recorded from single cells in IT of the adult monkey. Achromatic images were found to evoke significantly reduced responses compared with color images in the majority of neurons (70%) tested. Differential activity for achromatic and colored stimuli was evident from response onset with no evidence to support the hypothesis that information about object color is delayed with respect to object form. A negative correlation ( P < 0.01) was found between cell latency and color sensitivity, with the most color-sensitive cells tending to respond earliest. The results of this study suggest a strong role for color in familiar object recognition and provide no evidence to support the idea of a first wave of form processing in the ventral stream based on purely achromatic information.
Publisher
American Physiological Society
Subject
Physiology,General Neuroscience
Cited by
63 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献