5/16/2023 0 Comments Cev hallucination![]() ![]() This preservation of neuroplasticity suggests that visual training methods designed to improve visual performance based on eye occlusion should maintain effectiveness into older age. The older visual system maintains the ability to rapidly adjust to changes in perceptual experience induced by eye occlusion. The effect of occlusion on all features of binocular rivalry did not significantly differ between groups. Post-patching, perceptual dominance of the non-patched eye decreased ( p < .001) in both age groups. Binocular rivalry features were measured before and after 2 h of occlusion. Thirty younger (18–35 years) and 30 older adults (60–81 years) participated. Here we measure whether the strength and general features of neuroplasticity revealed by monocular patching are maintained in older adults. This ocular dominance shift demonstrates homeostatic neuroplasticity within the visual system and has been explored in detail in younger adults. ![]() Specifically, occluding one eye shifts the balance of ocular dominance to favour the recently deprived eye, which can be measured using binocular rivalry. Occluding one eye for several hours alters visual experience. The views expressed are those of the author and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care. TL is in receipt of a PhD studentship funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust (SLaM BRC) and Kings College London. The authors declare no competing financial interests. However, although consistent Declaration of competing interest Section snippets Why cerebellum not cortex?Īs discussed in our original paper (Lawn & ffytche, 2021) and supported by Zorzi et al., the cerebellar subfields altered in hallucinators have been linked to attentional mechanisms, adding support to aetiological theories of hallucinations based on dysfunctional relationships between the dorsal attentional network (DAN), ventral attentional network (VAN), and default mode network (DMN) (Collerton, Perry, & McKeith, 2005 Shine et al., 2011 Shine et al., 2014). As such, cerebellar subfield differences may offer value as candidate prognostic and predictive biomarkers as well as targets for neuromodulatory treatment across a range of clinical conditions. Additionally, we contend that the relatively neuroanatomically localised nature of the cerebellum makes it particularly suited to identifying changes affecting distributed cortical networks using imaging techniques. The combined structural and functional evidence is consistent with two models of cerebellar contribution to hallucination which differ in their implied direction of cause, effect and temporal sequence. Here, we review evidence for cerebellar involvement in hallucinations across multiple clinical conditions and sensory modalities as well as examine its wider clinical and mechanistic implications. provided additional evidence of functional cerebellar changes in Dementia with Lewy bodies. Our recent neuroimaging study identified structural differences in cerebellar subfields linked to cortical attentional networks in patients with eye disease or Parkinson’s disease who experience visual hallucinations and a commentary on the study by Zorzi et al.
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