Changes in primary visual and auditory cortex of blind and sighted adults following 10 weeks of click-based echolocation training

Norman, Liam; Hartley, Tom; Thaler, Lore

Abstract

Recent work suggests that the adult human brain is very adaptable when it comes to sensory processing. In this context, it has also been suggested that structural “blueprints” may fundamentally constrain neuroplastic change, e.g. in response to sensory deprivation. Here, we trained 12 blind participants and 14 sighted participants in echolocation over a 10-week period, and used MRI in a pre–post design to measure functional and structural brain changes. We found that blind participants and sighted participants together showed a training-induced increase in activation in left and right V1 in response to echoes, a finding difficult to reconcile with the view that sensory cortex is strictly organized by modality. Further, blind participants and sighted participants showed a training induced increase in activation in right A1 in response to sounds per se (i.e. not echo-specific), and this was accompanied by an increase in gray matter density in right A1 in blind participants and in adjacent acoustic areas in sighted participants. The similarity in functional results between sighted participants and blind participants is consistent with the idea that reorganization may be governed by similar principles in the two groups, yet our structural analyses also showed differences between the groups suggesting that a more nuanced view may be required.

Citation

Norman, L., Hartley, T., & Thaler, L. (2024). Changes in primary visual and auditory cortex of blind and sighted adults following 10 weeks of click-based echolocation training. Cerebral Cortex, 34(6), Article bhae239. https://doi.org/10.1093/cercor/bhae239

• Journal Article Type: Article
• Acceptance Date: May 29, 2024
• Online Publication Date: Jun 20, 2024
• Publication Date: Jun 4, 2024
• Deposit Date: Jul 3, 2024
• Publicly Available Date: Jul 3, 2024
• Journal: Cerebral Cortex
• Print ISSN: 1047-3211
• Electronic ISSN: 1460-2199
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 34
• Issue: 6
• Article Number: bhae239
• DOI: https://doi.org/10.1093/cercor/bhae239
• Keywords: blindness, audition, Brain Mapping, Echolocation - physiology, Auditory Cortex - diagnostic imaging - physiology - physiopathology, Humans, Young Adult, fMRI, Auditory Perception - physiology, Acoustic Stimulation, Blindness - physiopathology - diagnostic imaging, neuroplasticity, Visual Cortex - diagnostic imaging - physiology, Adult, Magnetic Resonance Imaging, Middle Aged, Neuronal Plasticity - physiology, Male, Female
• Public URL: https://durham-repository.worktribe.com/output/2514799