Pupil size changes signal hippocampus-related memory functions

Abstract

A major task of episodic memory is to create unique, distinguishable representations of highly overlapping perceptual inputs. Several studies on this basic function have shown that it is based on the intact functioning of certain subregions of the hippocampus and is among the most sensitive behavioral indicators of mild cognitive impairment (MCI) and dementia. Here we assessed pupil dilation associated with performance in a widely used recognition paradigm that aims to uncover the intactness of fine-graded mnemonic discrimination. A sample of healthy undergraduate students was used. First, we showed that the correct discrimination between highly similar lure items and target items elicit larger pupil response than correct target identification. Second, we found that mnemonic discrimination is associated with larger pupil response in general as compared to target identification, regardless of whether the response was correct or not. These results suggest the pupil changes differentiate mnemonic discrimination and memory identification processes in recognition performance.

A Pilot Study to Improve Cognitive Performance and Pupil Responses in Mild Cognitive Impaired Patients Using Gaze-Controlled Gaming

“…Both pupil and vergence responses are manifestations of cognitive processing. Pupil dilation reflects the allocation of top-down attentional resources [ 48 ] and has been linked to various cognitive processes, including perception [ 49 ], cognitive effort [ 50 ], memory [ 51 , 52 ], prediction error [ 53 ], and decision-making [ 33 , 54 , 55 ]. Similarly, vergence responses are associated with attention and memory [ 40 , 56 , 57 ], and may trigger pupil responses [ 49 ].…”

A Pilot Study to Improve Cognitive Performance and Pupil Responses in MCI Patients Using Gaze-Controlled Gaming

“…Both pupil and vergence responses are manifestations of cognitive processing. Pupil dilation reflects the allocation of top-down attentional resources (Lisi et al, 2015) and has been linked to various cognitive processes, including perception (Sole Puig et al, 2021), cognitive effort (van der Wel & van Steenbergen, 2018), memory (Papesh et al, 2012;Pajkossy et al, 2020), prediction error (Koenig et al, 2018) and decision-making (Urai et al, 2017, Van Slooten et al, 2018Strauch et al, 2020). Similarly, vergence responses are associated with attention and memory (Sole Puig et al, 2013;.…”

Effect of cognitive reserve on physiological measures of cognitive workload in older adults with cognitive impairments

“…Whereas higher cognitive reserve affects P3 amplitude and latency with respect to task demand in healthy older adults, no such relationship has been observed in MCI [17]. Changes in pupillary size have also shown to correlate with cognitive workload in older adults with and without cognitive impairments,[18-20] but no studies have evaluated the effect of cognitive reserve on pupillary response in people with cognitive impairments.…”