The many directions of time

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Temporal Processing

Background:

• Sensory adaptation influences perceived duration of visual events.
• The neural origin (cortical vs. pre-cortical) of these temporal distortions is debated.

Purpose of the Study:

• To investigate the neural basis of spatially localized duration compression.
• To determine if duration compression is direction-contingent and its cortical localization.

Main Methods:

• Experiment 1: Assessed duration compression using spatially localized visual adaptation with direction-matched and direction-mismatched stimuli.
• Experiment 2: Localized adaptation processes using stimuli presented at or beyond human cortical area MT+.

Main Results:

• Spatially localized duration compression was direction-contingent, occurring only when adapting and test stimuli moved in the same direction.
• This direction-specificity suggests a cortical origin for the observed duration compression.
• Adaptation processes occurred at or beyond the motion-sensitive human cortical area MT+.

Conclusions:

• Direction-specific temporal adaptation mechanisms, likely cortical, contribute to subsecond duration encoding.
• Visual event duration perception involves multiple processing levels, including pre-cortical and cortical areas.
• Cortical area MT+ is implicated in motion-based temporal adaptation influencing duration perception.