RePer-AGE: Reorganization of Visuo-cognitive Functions Based on Peripheral Vision With Aging

Visual recognition depends on the complementary contribution of central and peripheral vision. Central vision provides high spatial resolution and supports the detailed analysis required for object identification, whereas peripheral vision rapidly extracts coarse visual information that provides a global representation of the surrounding environment. According to predictive models of visual processing, this early peripheral information is used to generate predictions that facilitate the subsequent processing of detailed visual inputs.

The RePer-AGE project is based on the hypothesis that peripheral vision plays a key role in predictive visual processing and that this contribution changes during normal aging. Although aging is associated with well-documented declines in visual acuity and contrast sensitivity, particularly for high spatial frequencies, several findings suggest that the processing of coarse visual information conveyed by peripheral vision may be relatively preserved. This preserved processing may contribute to compensatory mechanisms supporting visual recognition in older adults.

RePer-AGE is a prospective, monocentric interventional study conducted at Grenoble Alpes University Hospital (CHU Grenoble Alpes) and the Laboratoire de Psychologie et NeuroCognition (LPNC, CNRS, Université Grenoble Alpes). The study will recruit 160 healthy volunteers divided into two age groups: young adults (18-30 years) and older adults (60-85 years). Participants will undergo an ophthalmological examination to ensure normal or corrected-to-normal vision and the absence of ocular disease likely to affect visual performance. Older participants will also complete a brief cognitive screening assessment.

The project combines complementary behavioral, ophthalmological, and neuroimaging approaches to investigate the respective contributions of central and peripheral vision to visual recognition.

The first research axis combines psychophysical experiments with ophthalmological assessments. Participants perform computerized visual recognition tasks specifically designed to evaluate the relative contribution of central and peripheral vision. Additional ophthalmological examinations include automated static perimetry to assess retinal sensitivity across the visual field and low-luminance visual acuity testing. These measurements will allow the relationship between retinal function and visual recognition performance to be investigated.

The second research axis combines psychophysical experiments with functional magnetic resonance imaging (fMRI). During MRI acquisition, participants perform visual recognition tasks while blood oxygen level-dependent (BOLD) activity is recorded. These data will be used to identify the cortical networks supporting predictive visual processing and to determine how these neural mechanisms are modified during normal aging.

The psychophysical paradigms are derived from previous studies conducted by the research team and investigate two complementary aspects of visual recognition. One paradigm evaluates the respective contribution of central and peripheral vision to scene categorization, whereas the second examines how semantic information extracted from peripheral vision influences the recognition of centrally presented visual stimuli through predictive mechanisms.

The primary objective of the study is to determine how central and peripheral vision differentially contribute to visual recognition and how these mechanisms are reorganized with aging. Secondary objectives include characterizing age-related changes in retinal sensitivity, examining the relationship between retinal function and behavioral performance, and identifying the neural correlates of predictive visual processing using functional MRI.

The results of RePer-AGE are expected to improve the understanding of the mechanisms underlying normal visual aging. They will provide normative reference data for future studies investigating pathological aging and visual disorders affecting central vision, and may ultimately contribute to the development of new approaches for visual assessment and rehabilitation.

Inclusion criteria

• Healthy young adults aged 18 to 30 years or healthy older adults aged 60 to 85 years.
• Normal or corrected-to-normal visual acuity.
• No ophthalmological disease affecting visual function.
• For participants aged 60 years or older: Mini-Mental State Examination (MMSE) score ≥23.
• Affiliated with a national health insurance system.
• Written informed consent.

Non inclusion Criteria:

• Individuals protected under French regulations governing research involving human participants.
• Employees or individuals under the direct authority of the investigators.
• History of neurological or psychiatric disorders likely to affect visual or cognitive functions.
• Current treatment likely to alter visual function or vigilance.
• MRI contraindications (metallic implants, pacemaker, severe claustrophobia, or other MRI safety contraindications) for participation in the MRI arm only.