Inhibitory Control of Saccadic Eye Movements and Cognitive Impairment in Mild Cognitive Impairment

Julius Opwonya; Changwon Wang; Kyoung-Mi Jang; Kunho Lee; Joong Il Kim; Jaeuk U Kim

doi:10.3389/fnagi.2022.871432

Inhibitory Control of Saccadic Eye Movements and Cognitive Impairment in Mild Cognitive Impairment

Front Aging Neurosci. 2022 Apr 11:14:871432. doi: 10.3389/fnagi.2022.871432. eCollection 2022.

Authors

Julius Opwonya^{1

2}, Changwon Wang¹, Kyoung-Mi Jang³, Kunho Lee^{4

5

6}, Joong Il Kim¹, Jaeuk U Kim^{1

2}

Affiliations

¹ Digital Health Research Division, Korea Institute of Oriental Medicine, Daejeon, South Korea.
² KM Convergence Science, University of Science and Technology, Daejeon, South Korea.
³ Medical Data Precision Measurement Team, Korea Research Institute of Standards and Science, Daejeon, South Korea.
⁴ Gwangju Alzheimer's Disease and Related Dementias (GARD) Cohort Research Center, Chosun University, Gwangju, South Korea.
⁵ Department of Biomedical Science, Chosun University, Gwangju, South Korea.
⁶ Dementia Research Group, Korea Brain Research Institute, Daegu, South Korea.

Abstract

Background: Mild cognitive impairment (MCI) may occur due to several forms of neurodegenerative diseases and non-degenerative conditions and is associated with cognitive impairment that does not affect everyday activities. For a timely diagnosis of MCI to prevent progression to dementia, a screening tool of fast, low-cost and easy access is needed. Recent research on eye movement hints it a potential application for the MCI screening. However, the precise extent of cognitive function decline and eye-movement control alterations in patients with MCI is still unclear.

Objective: This study examined executive control deficits and saccade behavioral changes in patients with MCI using comprehensive neuropsychological assessment and interleaved saccade paradigms.

Methods: Patients with MCI (n = 79) and age-matched cognitively healthy controls (HC) (n = 170) completed four saccadic eye-movement paradigms: prosaccade (PS)/antisaccade (AS), Go/No-go, and a battery of neuropsychological tests.

Results: The findings revealed significantly longer latency in patients with MCI than in HC during the PS task. Additionally, patients with MCI had a lower proportion of correct responses and a marked increase in inhibition errors for both PS/AS and Go/No-go tasks. Furthermore, when patients with MCI made errors, they failed to self-correct many of these inhibition errors. In addition to the increase in inhibition errors and uncorrected inhibition errors, patients with MCI demonstrated a trend toward increased correction latencies. We also showed a relationship between neuropsychological scores and correct and error saccade responses.

Conclusion: Our results demonstrate that, similar to patients with Alzheimer's dementia (AD), patients with MCI generate a high proportion of erroneous saccades toward the prepotent target and fail to self-correct many of these errors, which is consistent with an impairment of inhibitory control and error monitoring.

Significance: The interleaved PS/AS and Go/No-go paradigms are sensitive and objective at detecting subtle cognitive deficits and saccade changes in MCI, indicating that these saccadic eye movement paradigms have clinical potential as a screening tool for MCI.

Keywords: Go/No-go; frontal/executive function; inhibitory control; mild cognitive impairment; prosaccade/antisaccade; self-monitoring.