Working memory signals in early visual cortex are present in weak and strong imagers.

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Visual Perception

Background:

• Visual working memory and imagery are thought to involve early visual cortex.
• A hypothesis suggests these visual cortex signals reflect a combined memory and imagery code.
• This implies reduced imagery vividness should correlate with weaker memory signals.

Purpose of the Study:

• To investigate if early visual cortex working memory signals differ between strong and weak visual imagers.
• To test the prediction that weaker imagery leads to weaker memory representations in visual cortex.

Main Methods:

• Participants were categorized as strong or weak visual imagers.
• fMRI data was collected while participants performed a visual memory task over brief delay periods.
• Machine learning was used to reconstruct memorized visual stimuli from early visual cortex activity.

Main Results:

• Memorized visual stimuli were successfully reconstructed from early visual cortex activity in both groups.
• Reconstruction quality was equally accurate for strong and weak imagers, contrary to the initial prediction.
• Decodable information in visual cortex correlated with behavioral precision across the imagery spectrum.

Conclusions:

• Working memory representations in early visual cortex are present regardless of phenomenal visual imagery vividness.
• These visual cortex signals can support behavioral performance even in individuals with severely limited imagery (aphantasia).
• The findings challenge the notion that vivid imagery is essential for visual working memory encoding in early visual areas.