Affective cognition and its disruption in mood disorders

Abstract

In this review, we consider affective cognition, responses to emotional stimuli occurring in the context of cognitive evaluation. In particular, we discuss emotion categorization, biasing of memory and attention, as well as social/moral emotion. We discuss limited neuropsychological evidence suggesting that affective cognition depends critically on the amygdala, ventromedial frontal cortex, and the connections between them. We then consider neuroimaging studies of affective cognition in healthy volunteers, which have led to the development of more sophisticated neural models of these processes. Disturbances of affective cognition are a core and specific feature of mood disorders, and we discuss the evidence supporting this claim, both from behavioral and neuroimaging perspectives. Serotonin is considered to be a key neurotransmitter involved in depression, and there is a considerable body of research exploring whether serotonin may mediate disturbances of affective cognition. The final section presents an overview of this literature and considers implications for understanding the pathophysiology of mood disorder as well as developing and evaluating new treatment strategies.

Figure 1

Tasks used to assess attentional bias. This figure shows an emotional Stroop (panel a), affective Go/No-Go (panel b), and dot-probe task (panel c). Bias is indicated by facilitation of reaction time by emotional valence (as indicated).

Figure 2

Key connections of the amygdala that may be differentially probed by affective cognition paradigms. It must be noted that this figure is a schematic only and does not purport to display all amygdala connections or the interconnections between any other components.

Figure 3

The affective Go/No-Go task in depression. The three panels show behavioral responses to the task (adapted from Erickson et al, 2005) and the ventral ACC focus mediating mood-congruent bias, with enhanced response to happy targets in controls and sad targets in patients (adapted from Elliott et al, 2002).

Figure 4

Mayberg's network model of depression. va=ventral anterior, dp=dorsal posterior. Regions within each grouping (‘compartment') are heavily interconnected and connections between compartments are indicated by black errors. Figure adapted from Mayberg (2009), which also proposes that different therapeutic interventions may differentially target particular compartments and connections.