Insula mediates heartbeat related effects on visual consciousness

Area of Science:

• Neuroscience
• Cognitive Science
• Psychology

Background:

• Interoceptive signals, like heartbeats, are processed in the insular cortex.
• These signals influence perception, cognition, and visual awareness.
• Previous studies link cardiac synchrony to visual awareness and insular activation.

Purpose of the Study:

• To investigate the causal role of the anterior insular cortex in integrating interoceptive and exteroceptive signals for visual awareness.
• To determine if anterior insular lesions abolish the cardio-visual suppression effect.

Main Methods:

• Investigated two patients with anterior insular lesions.
• Included four patients with non-insular lesions and healthy controls for comparison.
• Assessed the impact of cardiac synchrony on visual awareness.

Main Results:

• Lesions of the anterior insular cortex abolished the cardio-visual suppression effect.
• This effect was not abolished by lesions in other brain regions.
• Anterior insular activation correlated with the suppression effect.

Conclusions:

• The anterior insula plays a causal role in integrating interoceptive and exteroceptive signals.
• This integration is crucial for visual awareness.
• The anterior insula may suppress sensory consequences of cardiac signals to facilitate visual consciousness.