Hypnotic modulation of resting state fMRI default mode and extrinsic network connectivity

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• Resting state functional magnetic resonance imaging (fMRI) reveals two key brain networks: the default mode network (DMN) for self-related processes and an anticorrelated extrinsic system for external stimuli.
• Understanding the interplay between these networks is crucial for elucidating the neural basis of conscious awareness.

Purpose of the Study:

• To investigate how hypnosis transiently modulates the relationship between the DMN and the extrinsic system.
• To explore the functional contribution of these networks to conscious awareness.

Main Methods:

• Utilized independent component analysis (ICA) on resting state fMRI data.
• Acquired fMRI data during normal wakefulness, hypnotic state, and autobiographical mental imagery (control condition).

Main Results:

• Hypnosis reduced connectivity in the lateral frontoparietal extrinsic system, suggesting decreased sensory awareness.
• The DMN showed increased connectivity in specific regions (angular and middle frontal gyri) but decreased connectivity in others (posterior midline, parahippocampal structures), potentially linked to altered self-awareness and amnesia.

Conclusions:

• Hypnosis dynamically alters intrinsic brain networks associated with consciousness.
• Further fMRI studies on various states (sleep, anesthesia, coma) modulating these networks will enhance understanding of subjective awareness's neural correlates.