Posterior parietal cortex represents sensory history and mediates its effects on behaviour

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Prior stimulus statistics significantly impact working memory and perception.
• Neural mechanisms underlying the use of prior sensory experience remain largely unknown.

Purpose of the Study:

• To identify the neural regions responsible for representing and utilizing prior stimulus information.
• To investigate the role of the posterior parietal cortex (PPC) in processing sensory history.

Main Methods:

• Rats were trained on an auditory parametric working memory task.
• Optogenetic silencing of the PPC was employed to assess its causal role.
• Electrophysiological recordings were conducted to analyze neural activity.

Main Results:

• Silencing the PPC unexpectedly improved performance by reducing the influence of prior sensory stimuli.
• PPC neurons showed greater information about previous trials than the current trial.
• A correlation was found between PPC's representation of stimulus history and behavioral effects.

Conclusions:

• The PPC is critical for processing sensory-stimulus history, not for working memory function.
• The PPC's role in utilizing prior information offers new avenues for studying perception and memory.