English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  The role of color in natural images to recognition performance and neural activity in extrastriate and prefrontal cortex

Liebe, S., Logothetis, N., & Rainer, G. (2007). The role of color in natural images to recognition performance and neural activity in extrastriate and prefrontal cortex. Poster presented at 7th Meeting of the German Neuroscience Society, 31st Göttingen Neurobiology Conference, Göttingen, Germany.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/11858/00-001M-0000-0013-CE43-C Version Permalink: http://hdl.handle.net/21.11116/0000-0004-4A96-0
Genre: Poster

Files

show Files

Creators

show
hide
 Creators:
Liebe, S1, 2, Author              
Logothetis, NK1, 2, Author              
Rainer, G1, 2, Author              
Affiliations:
1Department Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497798              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, Spemannstrasse 38, 72076 Tübingen, DE, ou_1497794              

Content

show
hide
Free keywords: -
 Abstract: Although objects can be identified based solely on the information provided by the spatial structure of an image, color adds another perceptual dimension which may facilitate object identification. However, the addition of color in form of colored noise may interfere with object identification. Here we investigate whether color in natural images is associated with changes in visual memory performance. In addition, we examined neural activity in area V4 and dorsolateral prefrontal cortex (PF) and address whether alterations in neural responses are correlated with changes in performance. Additionally we explore whether there is neural evidence of a functional specialization for color processing in natural scenes in either of the two brain areas. We used a procedure based on Fourier analysis to degrade a unique set of four colored and achromatic natural scenes with increasing amounts of four unique achromatic noise patterns. We also degraded achromatic images with chromatic noise patterns. At a given degradation level, the difference between colored and achromatic images was thus provided only by color: the remaining image specific color or the colored noise. In a delayed matching to sample paradigm a sample stimulus (250ms) at various degradation levels was presented, followed by an undegraded probe stimulus (1s) after a delay period (1500ms). A lever press was required if the sample stimulus matched the probe. We have preliminary results from one monkey. The monkey's recognition performance decreased as a function of noise for all conditions. In addition, we found that the recognition performance was best for the 'natural' color condition and worst for the colored noise condition at the same degradation level (paired t-tests, p<0.01). These results suggest that color independent of spatial composition, confers either an advantage or impairment in object identification depending on whether the color is related to the object or not. Single neuron responses were recorded from a total of 84 neurons in V4 and 76 neurons in PF. In V4 73 of visually responsive cells conveyed less information about image identity with increasing amounts of noise (39/53 units, Signtest p<0.0001). In addition, at the same degradation level, the information about image identity was significantly higher for the natural color condition than the colored noise condition (paired ttest, p<0.05). In PF 72 of visually responsive neurons conveyed less information about image identity with increasing amounts of noise (42/58 units, Signtest p<0.001). In PF no significant differences between the achromatic and chromatic stimulus conditions were found. For both areas, the effect of noise on information conveyed by neural activity about image identity is consistent with the effect of noise on behavioral performance. Furthermore, in V4 the elevated information about image identity for image specific color vs. colored noise is correlated with increased recognition performance in the image specific color condition. These results reveal noise and color specific modulations in neural activity at the level of single neurons in area V4 and PF in object identification.

Details

show
hide
Language(s):
 Dates: 2007-02
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: BibTex Citekey: LiebeLR2007
 Degree: -

Event

show
hide
Title: 7th Meeting of the German Neuroscience Society, 31st Göttingen Neurobiology Conference
Place of Event: Göttingen, Germany
Start-/End Date: 2007-03-29 - 2007-04-01

Legal Case

show

Project information

show

Source 1

show
hide
Title: Neuroforum
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 13 (Supplement) Sequence Number: T17-6C Start / End Page: 766 Identifier: ISSN: 0947-0875
CoNE: https://pure.mpg.de/cone/journals/resource/110978984249776