Pupil dilation as a marker of attention/effort in aging and mild cognitive impairment.

Pupil dilation responses to salient oddball stimuli were observed across all three groups (younger adults, older adults, and MCI patients).

• The study included younger adults (YAs), older adults (OAs), and patients with mild cognitive impairment (MCI).
• An oddball task was used to investigate attentional allocation via pupil dilation responses.
• Elevated PD to salient stimuli was observed, suggesting attentional processing across all participant groups.

MCI patients with better attentional control showed elevated pupil dilation responses to salient stimuli.

• Within the MCI group, individuals with better attentional control demonstrated greater pupil dilation to salient stimuli.
• This pattern suggests that pupil dilation can differentiate cognitive functioning within MCI patients.
• The finding supports PD as a marker of attentional capacity even within a cognitively impaired population.

A Simon task was used to assess cognitive effort in addition to the oddball task for attentional allocation.

• The Simon task allows investigation of cognitive effort by introducing response conflict.
• Two tasks were administered: an oddball task and a Simon task.
• The Simon task provided an additional dimension of cognitive assessment beyond attention alone.

Pupil dilation holds promise as an easy-to-administer cognitive marker for individuals with restricted abilities to respond in standard cognitive assessments.

• PD can be easily measured and reflects responses to subjectively salient or cognitively demanding events.
• The authors note particular relevance for individuals with MCI or other neurodegenerative conditions.
• Measurement of PD may serve as an easy-to-administer measure to assess changes in cognitive function in healthy aging and MCI.

Pupil dilation reflected cognitive effort during the Simon task across participant groups including younger adults, older adults, and MCI patients.

• The Simon task additionally allows for investigating cognitive effort beyond attentional allocation.
• The study compared PD responses across YAs, OAs, and MCI patients during cognitively demanding conditions.
• Results support pupil dilation as a marker of cognitive effort in aging populations.