de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Report

The Dynamics of Visual Pattern Masking in Natural Scene processing: A MEG-Study

MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons84172

Rieger,  JW
Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons83926

Braun C, Gegenfurtner,  KR
Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons83839

Bülthoff,  HH
Department Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Rieger, J., Braun C, Gegenfurtner, K., & Bülthoff, H.(2002). The Dynamics of Visual Pattern Masking in Natural Scene processing: A MEG-Study (103).


Cite as: http://hdl.handle.net/11858/00-001M-0000-0013-DEEF-F
Abstract
We investigated the mechanisms of pattern masking in a scene recognition task by recording simultaneously psychophysical performance and magnetic brain activity using magnetoencephalography (MEG). Photographs of natural scenes were displayed for various durations and then immediately followed by a pattern mask. We were able to identify the transient brain activation caused by the switching from scene to mask. The latency of this mask-transient signals the earliest cortical interaction between target and mask. The scenes alone elicited a transient occipital activation starting 70ms after stimulus onset, peaking at 110ms and reaching a minimum at 160ms. By comparing psychophysical performance with the latency of the mask transient and the dynamics of the undistorted processing of the scene at various SOAs we found that the initial occipital activation peak reflects processes vulnerable to pattern masking. The additional activation from the mask falling within this target-processing activity significantly reduces recognition performance. We found no measurable impact of mask activation later than 160ms after target onset. Our results indicate that the information necessary for the reliable recognition of a scene among a set of distracters can be extracted within about 90ms of cortical processing. Our data support the view, that the effect of the pattern backward mask occurs by overwriting a visual buffer in which the scene is stored during analysis.