Coralie Creupelandt1, Pierre Maurage1, Quentin Lenoble2, Carine Lambot3, Christophe Geus4, Fabien D'Hondt2,5,6. 1. Louvain Experimental Psychopathology Research Group (UCLEP), Psychological Sciences Research Institute (IPSY), UCLouvain, B-1348, Louvain-la-Neuve, Belgium. 2. Univ. Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, F-59000, Lille, France. 3. Clinique Regina Pacis, Le Beau Vallon, B-5002, Saint-Servais, Belgium. 4. Psychiatry unit, Clinique Saint Pierre Ottignies, B-1340, Ottignies, Belgium. 5. CHU Lille, Clinique de Psychiatrie, CURE, F-59000, Lille, France. 6. Centre National de Ressources et de Résilience Lille-Paris (CN2R), F-59000, Lille, France.
Abstract
BACKGROUND: Severe Alcohol Use Disorder (SAUD) is associated with widespread cognitive impairments, including low-level visual processing deficits persisting even after prolonged abstinence. However, the extent and characteristics of these visual deficits remain largely undetermined, impeding the identification of their underlying mechanisms and influence on higher-order processing. In particular, little work has been conducted to assess the integrity of the magnocellular (MC) and parvocellular (PC) visual pathways, namely the two main visual streams that convey information from the retina up to striate, extra-striate, and ventral/dorsal cerebral regions. METHODS: We investigated achromatic luminance contrast processing mediated by inferred MC and PC pathways in 33 patients with SAUD and 32 matched healthy controls using two psychophysical pedestal contrast discrimination tasks promoting responses of inferred MC or PC pathways. We used a staircase procedure to assess participants' ability to detect small changes in luminance within an array of four grey squares that were either continuously presented (steady pedestal, MC-biased) or briefly flashed (pulsed pedestal, PC-biased). RESULTS: We replicated the expected pattern of MC and PC contrast responses in healthy controls. We found preserved MC and PC contrast signatures dissociation in SAUD but also higher MC-mediated mean contrast discrimination thresholds compared to healthy controls, combined with a steeper PC-mediated contrast discrimination slope. CONCLUSION: These findings indicate altered MC-mediated contrast sensitivity and PC-mediated contrast gain, confirming the presence of early sensory disturbances. Such low-level deficits, while usually overlooked, might influence higher-order abilities (e.g., memory, executive functions) in SAUD by disturbing the "coarse-to-fine" tuning of the visual system, which relies on the distinct functional properties of MC and PC pathways and ensures proper and efficient monitoring of the environment. This article is protected by copyright. All rights reserved.
BACKGROUND: Severe Alcohol Use Disorder (SAUD) is associated with widespread cognitive impairments, including low-level visual processing deficits persisting even after prolonged abstinence. However, the extent and characteristics of these visual deficits remain largely undetermined, impeding the identification of their underlying mechanisms and influence on higher-order processing. In particular, little work has been conducted to assess the integrity of the magnocellular (MC) and parvocellular (PC) visual pathways, namely the two main visual streams that convey information from the retina up to striate, extra-striate, and ventral/dorsal cerebral regions. METHODS: We investigated achromatic luminance contrast processing mediated by inferred MC and PC pathways in 33 patients with SAUD and 32 matched healthy controls using two psychophysical pedestal contrast discrimination tasks promoting responses of inferred MC or PC pathways. We used a staircase procedure to assess participants' ability to detect small changes in luminance within an array of four grey squares that were either continuously presented (steady pedestal, MC-biased) or briefly flashed (pulsed pedestal, PC-biased). RESULTS: We replicated the expected pattern of MC and PC contrast responses in healthy controls. We found preserved MC and PC contrast signatures dissociation in SAUD but also higher MC-mediated mean contrast discrimination thresholds compared to healthy controls, combined with a steeper PC-mediated contrast discrimination slope. CONCLUSION: These findings indicate altered MC-mediated contrast sensitivity and PC-mediated contrast gain, confirming the presence of early sensory disturbances. Such low-level deficits, while usually overlooked, might influence higher-order abilities (e.g., memory, executive functions) in SAUD by disturbing the "coarse-to-fine" tuning of the visual system, which relies on the distinct functional properties of MC and PC pathways and ensures proper and efficient monitoring of the environment. This article is protected by copyright. All rights reserved.
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Keywords:
Alcohol use disorder; magnocellular; parvocellular; vision; visual pathways