# Temporal visual processing deficits in post concussion syndrome

## TL;DR

This study finds that people with post-concussion syndrome have altered visual processing, possibly due to increased perceptual noise affecting motion sensitivity.

## Contribution

The study introduces evidence that perceptual noise, rather than fixed visual deficits, may underlie motion hypersensitivity in post-concussion syndrome.

## Key findings

- PCS patients showed heightened CFF thresholds influenced more by variability compared to controls.
- Visual temporal sensitivity in PCS is modulated by perceptual noise and visual-field eccentricity.
- Days since injury correlate with reduced variability, suggesting partial stabilization over time.

## Abstract

Post-concussive (PCS) motion hypersensitivity represents a common sequela of mild traumatic brain injury. This study investigated whether PCS alters visual temporal resolution thresholds in psychophysical measures that sustain motion detection. Fifteen PCS patients and fifteen age-matched controls underwent critical flicker fusion (CFF) threshold assessments across visual-field eccentricities. A Generalized linear mixed model tested group differences in CFF thresholds, treating eccentricity as a repeated factor and including CFF variability as a covariate. Pupil measurements and catch trials controlled for fatigue and alertness. Nonparametric correlations assessed relationships among time from injury, symptom severity, and CFF measures. Results showed CFF variability heightening CFF thresholds in the PCS group to a significantly larger extent compared to controls. Absence of significant CFF variability differences between groups, and modulation by eccentricity, suggests perceptual noise more strongly influences the overall visual temporal sensitivity in PCS. Days since injury negatively correlated with variability, indicating compensatory stabilization of temporal sensitivity over time. Symptom severity did not correlate with CFF measures. In conclusion, PCS motion hypersensitivity may reflect disturbances in visual temporal processing parameters, potentially involving altered internal neural noise. Although some recalibration occurs post-injury, persistent abnormalities underscore the need for further research into early, clinical interventions targeting perceptual noise.

The online version contains supplementary material available at 10.1038/s41598-025-24029-0.