Neural activity in human visual cortex is transformed by learning real world size.

Area of Science:

• Neuroscience
• Cognitive Science
• Visual Perception

Background:

• Visual processing is shaped by experience and plasticity in the visual cortex.
• Humans can acquire visual knowledge through instruction, a unique capability.
• Experience-dependent plasticity influences how the brain interprets visual stimuli.

Purpose of the Study:

• To investigate how instructed learning of real-world size and functional motion affects visual cortex activity.
• To determine if learning size information influences neural representations in the ventral visual stream.
• To explore the relationship between learning new object properties and activity in semantic and spatial cognition hubs.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan human participants.
• Machine learning compared brain activity patterns before and after learning.
• Participants were taught the real-world size of unfamiliar animals and the functional motion of novel tools.

Main Results:

• Learning object size led to more confusable activity patterns in early visual cortex, but not ventral temporal cortex.
• Acquired size information influenced posterior, but not anterior, components of the ventral stream.
• Learning functional motion of tools did not yield similar changes in visual activity patterns.
• Early visual cortex changes related to size learning correlated with increased activation in the right angular gyrus.

Conclusions:

• Acquiring real-world size information via instruction impacts visual cortex activity.
• Learned size knowledge influences posterior visual processing regions and semantic/spatial hubs like the angular gyrus.
• The brain's response to visual stimuli is modulated by learned semantic properties, such as object size.