Covert Spatial Attention, Arousal, and Visual Perception: A Behavioural and fNIRS Investigation

Sammanfattning

Covert spatial attention, the ability of focusing attention to a location in the visual field without overt eye movement, has been shown to modulate visual processing and behavioural task performance while arousal, a physiological and psychological state of alertness and responsiveness, has been associated with changes in cognitive performance and perceptual processing. The present study investigated whether arousal modulates the effects of covert spatial attention on perceived contrast, discrimination performance, and visual cortical activity. Ten participants (eight female, two male) completed a two-by-two alternative forced choice task in which attentional cues and auditory white noise were systematically manipulated to investigate the independent and interactive effects of attention and arousal on visual perception and discrimination task performance. Along with behavioural measures, functional nearinfrared spectroscopy (fNIRS) was used to measure haemodynamic responses in occipital cortex regions associated with visual processing. Results showed that covert spatial attention enhanced behavioural performance and increased perceived contrast. Furthermore, arousal improved discrimination task accuracy while reducing the magnitude of attentional effects on perceived contrast. Although, no significant differences in visual cortex activity were observed between conditions. These findings suggest that arousal modulates the relationship between attention and perception by attenuating subjective attentional enhancement while improving objective task performance. However, the absence of corresponding neural effects indicates that these influences may primarily reflect behavioural or decision-level processes rather than changes in occipital cortical activity. Further research is required to clarify the mechanisms underlying interactions between attention, arousal, and visual cortex activity.