Functional Magnetic Resonance Imaging Analysis of Attention to One’s Heartbeat

Address correspondence and reprint requests to: Joseph Tracy, PhD, E-mail: joseph.i.tracy{at}jefferson.edu.

	Abstract

Objectives: The convergence of a neural system for monitoring external stimuli with mechanisms that process somatic information leads to the hypothesis that the anterior parietal cortex may mediate attention to a specific internal visceral signal. Methods: We measured regional brain activity through functional magnetic resonance imaging and directed subjects (6 men and 11 women) to attend to their own heartbeat, and to a heartbeat played on an external tape. Results: Statistical parametric brain mapping revealed the importance of right (nondominant) parietal cortex to directing attention internally to one’s visceral state and focusing on a specific body signal. Conclusions: The parietal activation may be taking advantage of monitoring skills typically utilized for vigilance to the external environment, in addition to working as a higher-level recognition system for signals emerging from the viscera. The finding suggests that the parietal cortex plays a central role in an interoceptive attention system that monitors bodily states.

Key Words: attention, interoceptive processing, visceral processing, somatic processing