Identification of a novel link between adiposity and visuospatial perception

Area of Science:

• Neuroscience
• Ophthalmology
• Human Physiology

Background:

• Previous studies suggest a link between Body Mass Index (BMI) and visual task performance.
• The reliability and specific mechanisms of this association require further investigation.

Purpose of the Study:

• To assess visual function in individuals with healthy weight (HW) versus overweight/obesity (OW/OB).
• To determine the impact of adiposity on line orientation perception and underlying neural activity.

Main Methods:

• A case-control study involving 80 participants (40 HW, 40 OW/OB) measuring visual acuity, contrast, line orientation task performance, and visuospatial function.
• Assessment of adiposity, metabolic factors, diet, physical activity, and heart rate variability.
• Functional magnetic resonance imaging (fMRI) in a subgroup (n=27) to examine brain activity during visual tasks.

Main Results:

• Individuals with OW/OB exhibited poorer performance on line orientation judgment compared to HW individuals.
• The observed deficit was mediated by body fat percentage and not related to other metabolic or lifestyle factors.
• fMRI revealed a negative association between BMI and activity in the primary visual cortex (V1) during the task, while performance correlated with activity in higher-order visual areas.

Conclusions:

• Adiposity is associated with a selective deficit in line orientation perception.
• Blunted V1 activation in individuals with OW/OB is linked to adiposity, independent of visual acuity.
• The findings suggest that increased adiposity impacts specific visual processing pathways beyond basic visual acuity.