Authors:

Nagrodzki, J., Passamonti, L., Schweizer, SS., STRETTON, J., Knights, E., Wolpe, N., HENSON, R.

Reference:

Year of publication:

In Press

CBU number:

9118

Abstract:

Depressed individuals show significant biases in the processing of emotional stimuli, focussing attention on negative face expressions (termed ‘attentional negativity bias’). Some of these biases persist in previously depressed individuals, but their mechanisms remain largely unknown. Here, in a population-based study in which participants (n=134, 68 females; 21-92 years) were recruited as part of the Cambridge Centre for Ageing and Neuroscience in 2010-2014, we explored: 1) the cognitive process underlying attentional negativity bias; 2) whether this process is associated with self-reported history of depression; 3) the neural corelates of this process. Participants completed an implicit emotion processing task, while functional MRI was acquired. Drift-diffusion modelling was used to calculate each participant’s tendency for sustained task-irrelevant attention on negative (angry) compared to neutral faces. In the cohort, 14% of participants reported a history of depression. Drift-diffusion modelling showed reduced drift rate for angry compared to neutral faces. The magnitude of this reduction was associated with self-reported depression history. Across the whole group, drift rate for angry faces was associated with increased brain activity when processing angry vs. neutral faces in areas of bilateral insula/inferior frontal gyrus and bilateral parietal cortex. Our results suggest that attentional negativity bias is explained by slower task-relevant drift rate for negative (angry) stimuli. This slower drift rate is associated with difference in brain activity when processing these stimuli, possibly reflecting increased emotional engagement. Such altered processing may persist even after a depressive episode, but this finding should be validated in clinical samples.

Data available, click to request