Eye movements reveal age differences in how arousal modulates saliency priority but not attention processing speed

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Arousal-biased competition theory suggests arousal enhances attention to salient stimuli.
• Older adults often show different attentional responses to arousal compared to younger adults.
• Neural mechanisms underlying age-related differences in arousal modulation of attention are not fully understood.

Approach:

• Investigated how threat of shock (arousal) affects attentional control in young and older adults using eye movements.
• Employed singleton and feature search tasks to assess attentional priority and processing speed.
• Measured pupil dilation as an indicator of arousal and its correlation with oculomotor function.

Key Points:

• Arousal did not modulate attentional priority for any stimulus in older adults.
• Arousal did not affect the speed of attention processing in either young or older adults.
• Arousal modulated pupil sizes, with a correlation found between pupil responses and oculomotor function.

Conclusions:

• Findings suggest age-related differences in the interaction between the locus coeruleus-noradrenaline system and attention/oculomotor networks.
• Arousal's impact on selective attention differs significantly between young and older adults.
• The locus coeruleus-noradrenaline system may play a distinct role in modulating attention and eye movements across the lifespan.