Early effects of previous experience on conscious perception

Area of Science:

• Cognitive Neuroscience
• Neuroscience of Perception

Background:

• Constructive theories, like predictive coding, suggest prior knowledge rapidly shapes our perception.
• The precise timing of prior knowledge's neural impact on conscious experience remains unclear.

Purpose of the Study:

• To investigate the temporal dynamics of prior knowledge influencing conscious perception.
• To determine how quickly prior knowledge affects neural processes underlying conscious experience.

Main Methods:

• Utilized an experimental paradigm to enhance perception using prior knowledge.
• Employed magnetoencephalography (MEG) to measure neural activity and its timing.
• Correlated perceptual benefits with specific MEG activity patterns.

Main Results:

• Prior knowledge significantly impacted neural activity between 80-95 milliseconds post-stimulus onset.
• This early neural effect was linked to the observed perceptual benefits.
• Neural sources of this effect were identified in occipital and posterior parietal brain regions.

Conclusions:

• Prior knowledge exerts an early influence on conscious perception, supporting predictive coding models.
• Neural mechanisms for integrating prior knowledge into perception occur rapidly.
• Findings highlight the swift interaction between expectation and sensory processing in the brain.