Structural Brain Predictors of Visual Attention Gradient Modulated by Trait Anxiety
Dynamic allocation of attention across the visual field, quantified as a visuospatial attention gradient, is essential for maintaining perceptual breadth. Disruptions to this flexibility may contribute to altered spatial attentional bias and may be influenced by trait anxiety. We investigated whether individual differences in structural brain morphology predict spatial attentional deployment as a function of trait anxiety. Sixty participants, recruited based on an a priori sample size calculation, completed a visuospatial attention gradient task incorporating brief partial facial emotion cues. Although discrete emotional cues did not significantly modulate attention gradients, structural neuroimaging analyses revealed that greater grey matter volume in bilateral cerebellar lobule VI and increased cortical thickness in the left precentral gyrus and paracentral lobule were associated with reduced interaction between the magnitude of the spatial attention gradient (averaged across emotions) and trait anxiety. Machine-learning models further predicted individual attention-anxiety profiles from these neuroanatomical features. These findings suggest that greater structural integrity in cerebellar and sensorimotor regions is associated with more flexible spatial attentional deployment in individuals with lower trait anxiety. Together, the results highlight the contribution of cerebellar and sensorimotor regions, beyond their traditional motor functions, to individual differences in visual spatial attention and cognitive-affective interactions, while demonstrating the predictive utility of structural brain markers.