Conditioned task set competition: Neural mechanisms of emotional interference in depression
Depression has been associated with increased response times at the incongruent neutral and negative word trials of the classical and emotional Stroop tasks (Epp et al. Clinical Psychology Review, 32, 316 328, 2012) Response time slowdown effects at incongruent and negative word trials of the Stroop tasks were reported to correlate with depressive severity, indicating strong relevance of the effects to the symptomatology. This study proposes a novel integrative computational model of neural mechanisms of both the classical and emotional Stroop effects, drawing on the previous prominent theoretical explanations of performance at the classical Stroop task (Cohen, Dunbar, McClelland, Psychological Review, 97, 332 361, 1990; Herd, Banich, O'Reilly, Journal of Cognitive Neuroscience, 18, 22 32, 2006) and in addition suggesting that negative emotional words represent conditioned stimuli for future negative outcomes. The model is shown to explain the classical Stroop effect and the slow (between trial) emotional Stroop effect with biologically plausible mechanisms, providing an advantage over the previous theoretical accounts (Matthews Harley, Cognition Emotion, 10, 561 600, 1996; Wyble, Sharma, Bowman, Cognition Emotion, 22, 1019 1051, 2008) Simulation results suggested a candidate mechanism responsible for the pattern of depressive performance at the classical and the emotional Stroop tasks. Hyperactivity of the amygdala, together with increased inhibitory influence of the amygdala over dopaminergic neurotransmission, could be at the origin of the performance deficits.
Cognitive, affective behavioral neuroscience