Cortical Activation

Emctional Behavior:


Emctional Behavior:

Subjective Emotional Steta Replierai/Autonomic Arousal

Figure 2.8. Schematic illustration of a model of limbic-cortical interactions: During the emotion suppression phase, when the subjective affective state wears off or is actively suppressed, the neocortex is activated again and the limbic-subcortical targets of emotion are switched off.

emotional response and the subjective state reach a critical threshold in the more subcortical regions of the engaged pathway, the limbic efferent targets become activated and the connected cortical regions become deactivated (Fig. 2.7), resulting in a "flip-flop" inversion of the functional relationship between cortical and subcortical systems (Mayberg et al., 1999; Reiman, 1997). State changes in emotion-cognition interactions would resemble those present during waking and dreaming sleep, where limbic system arousal is accompanied by sustained deactivation of certain frontal cortical zones (see Solms, 2002, for a review). During most waking activity, the cortex tends to suppress limbic activities (Fig. 2.8), helping create a dynamic "unconscious" that is always potentially conscious during environmental events that tend to arouse emotions.

This model of limbic-cortical function has the advantage of explaining both top-down influences (such as psychotherapy in affective disorders) and bottom-up influences (such as emotional arousal produced by CO2 or pharmacological agents) on emotion regulation. Furthermore, it also provides a mechanism to explain neuropsy-chological deficits in affective disorders and other intense emotional states. During sad moods and depression, there is selective deactivation of the brain substrates of sustained attention/vigilance (right DLPFC, right inferior parietal), with reaction time performance improving with increased activity in right DLPFC during recovery from depression (Liotti and Mayberg, 2001). Also, sad mood selectively deactivates dorsal anterior cingulate, a substrate of selective attention (Liotti et al., 2000b). In other words, cortical deactivations during emotional states can provide clues into specific cognitive functions impaired during those states.

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