The Amygdala & The Anterior Cingulate System

Amygdala

• 2 Almond shaped groups of nervous tissue located in the temporal lobes• Research proposes that the amygdala plays a primary role in process of memory,

decision making and emotional reactions• The amygdala sends projections to:

the hypothalamus, the dorsomedial thalamus, the thalamic reticular nucleus, the nuclei of the trigeminal nerve and the facial nerve, the ventral tegmental area, the locus coeruleus, and the laterodorsal tegmental nucleus

• Responsible for the perception of emotions (eg. Anger, sadness, fear)• Controlling aggression

Amygdala & its Functions

• Two-factor theory of emotion by Schachter and Singer (1962)• Proposes that when humans experience a sense of physiological arousal we

use the immidiate environmental to search for emotional cues to label the physiological arrousal.

• Amygdala pathways by Joseph E. LeDoux• Proposes that there are two amygdala pathways that he calls the ”high road”

and the ”low road” that work simultaneously to provide both fear-response and perceptual feedback.

Psychological Studies on the Amygdala

• Massive reduction of fear and aggression – Tested on monkeys• Impaired ability to interpret emotional aspects in facial expressions• Linked to autism

Amygdala Dysfunction

Anterior Cingulate System

• The frontal part of the cingulate cortex• Resembles a "collar" form around the “corpus callosum”• The fibrous bundle that relays neural signals between the right and left

cerebral hemispheres of the brain• play a role in a wide variety of autonomic functions• Regulating blood pressure and heart rate. As well as specific functions such as

error detection, anticipation of tasks, attention, motivation, and modulation of emotional responses to the ACC.[

The Anterior Cingulate System & its Functions

• Stroop task (Pardo et al., 1990)• which involves naming the color ink of words that are either congruent (RED

written in red) or incongruent (RED written in blue).

Psychological Stud on the ACS

• Reduction in error detections• Attention, motivation and modulation of emotional responses to the ACC.

ACS Dysfunction