Persistent activity in human parietal cortex mediates perceptual choice repetition bias

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Making

Background:

• Humans and animals often exhibit choice biases, repeating or alternating previous decisions despite random stimuli.
• The neural mechanisms underlying these idiosyncratic behavioral biases in sensory, associative, and motor cortical circuits remain unclear.

Purpose of the Study:

• To investigate the neural dynamics underlying choice history biases in human visual perception.
• To differentiate the roles of sensory, associative, and motor cortical circuits in generating these biases.

Main Methods:

• Combined behavioral modeling of visual perceptual decisions with magnetoencephalographic (MEG) analyses of neural dynamics.
• Examined neural activity across multiple regions of the human cerebral cortex.

Main Results:

• Identified distinct history-dependent neural signals in motor and posterior parietal cortex.
• Sustained gamma-band activity in parietal cortex tracked previous choices, biasing evidence accumulation toward repetition.
• Sustained beta-band activity in motor cortex reflected previous actions, biasing accumulation toward alternation.

Conclusions:

• Parietal cortical signals, not motor signals, mediated the impact of previous choices on current decisions.
• Parietal signals reflected individual differences in choice repetition, suggesting a key role in shaping choice sequences.