Neural mechanisms of attention: Distinctions and overlaps between voluntary and automatic activation.

BACKGROUND: Visuospatial attention involves neural activity that prioritizes certain regions of space over others and can be categorized into two types: automatic and voluntary attention. Although both forms of attention engage overlapping brain areas, some studies suggest distinct additional areas of activation by each type. OBJECTIVE: This study aimed to explore the differences and similarities in the brain activation patterns associated with voluntary and automatic attention, using event-related Functional Magnetic Resonance Imaging (fMRI). METHODS: Twenty young adults performed two attention tasks, outside and inside a 3T MRI scanner, both coupled to an eye-tracking system. Each trial began with a central fixation point and two marked rings, one positioned on each side of the screen. After the appearance of a preceding stimulus, a target stimulus appeared inside one of the rings. The experimental design includes valid, neutral, and invalid conditions for both the automatic and voluntary attention tasks. RESULTS: Reaction times were faster under valid conditions than under invalid ones. Distinct patterns of brain activity were identified for automatic and voluntary attention. Automatic attention predominantly activated the right and medial posterior brain regions, while voluntary attention engaged the medial superior frontal and lateral parietal regions. However, both types of attention shared common activation in the frontoparietal network, including the dorsolateral prefrontal cortex, frontal eye fields, intraparietal sulcus, temporoparietal junction, precuneus, and cingulate regions. CONCLUSION: These findings deepen our understanding of attentional neural mechanisms in healthy young adults and provide a normative framework for future studies investigating clinical conditions associated with impaired attention.