Sensory encoding and memory retrieval are coordinated with propagating waves in the human brain

Area of Science:

• Neuroscience
• Cognitive Science
• Human Brain Imaging

Background:

• Complex behavior requires balancing external sensory input with internal memory.
• Previous research in mice demonstrated cyclical shifts between outward and inward cognitive modes.
• These shifts in mice are associated with specific patterns of neuronal activity.

Purpose of the Study:

• To investigate if a similar cognitive mode switching mechanism exists in the human brain.
• To analyze functional magnetic resonance imaging (fMRI) data for evidence of brain-wide cyclical activity.
• To understand the relationship between these brain dynamics, sensory encoding, and memory retrieval.

Main Methods:

• Analysis of large-scale human fMRI datasets.
• Identification of propagating brain activity waves.
• Correlation of wave activity with sensory information processing and memory recall.

Main Results:

• Human brain activity exhibits cyclical patterns, with waves propagating from sensorimotor to default mode networks every few seconds.
• These brain waves are linked to enhanced encoding of sensory information.
• The waves also correlate with improved retrieval of internal memories.

Conclusions:

• A conserved mammalian brain mechanism for alternating cognitive modes was identified in humans.
• This brain physiology facilitates the integration of sensory information and memory during behavior.
• The findings offer insights into the neural basis of complex cognitive functions.