Visual imagery and spectrum symptoms of depression and hypomania differentially modulate brain responses during...

Depressive (DD) and bipolar (BD) disorders are characterized by biases in anticipating and encoding emotional information. This study examined how lifetime dimensional symptoms of depression and hypomania interact with the vividness of visual imagery to modulate brain activation during the anticipation and encoding of happy and sad faces.

A total of 155 participants, including individuals with DD, BD, and healthy controls (HC), completed an fMRI task that involved processing cues predicting happy or sad faces and encoding the faces by judging them as pleasant or unpleasant. Lifetime dimensional symptoms of depression and hypomania, vividness of visual imagery, and brain activation during face anticipation and encoding were assessed. Analyses focused on symptom-by-imagery interactions within task-specific brain regions.

Higher spectrum hypomania scores were associated with greater imagery vividness, lower activation for happy versus sad faces in the precentral gyrus during anticipation, and greater activation for happy versus sad faces in the occipital cortex during encoding. Depressive symptoms interacted with imagery vividness within default mode network regions. Specifically, higher spectrum depression scores combined with lower imagery vividness were associated with greater activation for happy versus sad faces in the frontopolar cortex during anticipation and lower activation in the angular gyrus during encoding.

These findings suggest that imagery-related mechanisms may contribute to negative expectancy and encoding biases associated with depressive traits, while hypomanic traits influence emotional processing through distinct perceptual and sensorimotor pathways. Distinguishing these trait-specific neural mechanisms may help inform targeted interventions aimed at modifying emotional biases across the mood spectrum.