Perceptual learning across saccades: Feature but not location specific

Area of Science:

• Visual perception
• Neuroscience
• Cognitive psychology

Background:

• Perceptual learning enhances perception through practice, typically showing high specificity for trained locations and features.
• Traditional studies focused on static stimuli, neglecting the role of eye movements in real-world visual exploration.
• Eye movements create successive stimulus projections on different retinal locations, posing a challenge for location-specific learning.

Purpose of the Study:

• To investigate perceptual learning of orientation discrimination across saccades (transsaccadic perceptual learning - TPL).
• To determine if TPL exhibits location specificity or generalizes across different visual field locations.
• To explore the reference frame encoding and flexibility within TPL.

Main Methods:

• Observers trained to saccade to a peripheral grating and discriminate orientation changes during the saccade.
• Tested generalization of TPL to untrained orientations and untrained locations.
• Conducted control experiments without saccades and an untrained fixation task.

Main Results:

• Training induced TPL with performance improvements that did not generalize to untrained orientations.
• Complete transfer of TPL to an untrained location in the opposite hemifield for the trained orientation was observed.
• Location transfer was contingent upon eye movements, as control experiments without saccades showed no such transfer.
• Performance improved at the trained location in an untrained fixation task, but not at the untrained location.

Conclusions:

• TPL demonstrates a unique flexibility in reference frame encoding, allowing generalization across visual field locations.
• The observed location generalization is critically dependent on the saccade itself.
• TPL comprises both a location-specific component (pre-saccade) and a saccade-related component (involving location generalization).