Related Experiment Videos
Topographical representations of mental images in primary visual cortex
S M Kosslyn1, W L Thompson, I J Kim
1Department of Psychology, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|November 30, 1995
Summary
Visualizing objects activates the primary visual cortex, as shown by positron emission tomography (PET). This brain activity supports depictive representations in visual mental imagery, not just descriptions.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Neuroimaging
Background:
- The activation of early visual cortex during visual mental imagery has been a subject of debate.
- Understanding the neural basis of imagery is crucial for cognitive science.
Purpose of the Study:
- To investigate whether the primary visual cortex is activated during visual mental imagery.
- To determine the nature of representations involved in visual mental imagery.
Main Methods:
- Positron emission tomography (PET) was used to measure brain activity.
- Subjects visualized objects with eyes closed.
- Imagery conditions were compared to a controlled non-imagery auditory baseline and a resting baseline.
Main Results:
- The primary visual cortex showed significant activation during visual mental imagery.
- Activation size correlated with the location of maximal activity, reflecting retinotopic organization.
- Imagery-specific activation was only observed when compared to a controlled non-imagery baseline.
Conclusions:
- Visual mental imagery activates early visual cortex, supporting 'depictive' representations.
- Stored visual information can influence processing in early visual areas, biasing perception.
- Findings resolve a long-standing debate in the neuroscience literature.