Looming animate and inanimate threats: The response of the amygdala and periaqueductal gray

Abstract

Looming stimuli are processed as threatening and activate basic neural defense systems. However, it is unclear how animacy information modulates this response. Participants (N = 25) viewed threatening or neutral images that were either animate (animals) or inanimate (objects) and which either approached (loomed) or receded from the participant. The amygdala was responsive to emotional, animacy, and looming information (particularly to looming threats and looming animate stimuli). Periaqueductal gray was also sensitive to emotional information and particularly responsive to looming threats. The data are interpreted within category-specific models of the amygdala and temporal cortex.

Keywords:

• Amygdala
• Animacy
• Threat
• Looming
• Periaqueductal gray

The authors report no competing interests.

This work was supported by the Intramural Research Program of the National Institute of Mental Health, National Institutes of Health [grant no. 1-ZIA-MH002860-08]. Ethical approval for this study was granted by the National Institutes of Health Combined Neuroscience Review Board under protocol 93-M-0170.