Computational model of visual hallucination in dementia with Lewy bodies

Tsukada, Hiromichi; Fujii, Hiroshi; Aihara, Kazuyuki; Tsuda, Ichiro

doi:10.1016/j.neunet.2014.09.001

Cited by 13 publications

(13 citation statements)

References 48 publications

(83 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although we found that differences in MD and FA were not specifically related to visual hallucinations, nevertheless, it is possible that the presence of the white matter alterations may have contributed to the formation of hallucinations in the group, as suggested by the disconnection models of visual hallucinations. 3 , 4 …”

Section: Discussionmentioning

confidence: 99%

“…Visual hallucinations are common in Parkinson disease (PD), 1 particularly as the disease advances, and range from relatively simple flashes of light or color to more complex hallucinations that are typically well-formed images. 2 A number of models 3 , 4 have been proposed to explain the origin of complex recurrent visual hallucinations. Unifying elements across the models include breakdown in communication between cortical regions involved in visual processing, and alteration in the weighting of internal vs external input.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Reduced occipital GABA in Parkinson disease with visual hallucinations

et al. 2018

View full text Add to dashboard Cite

ObjectiveTo investigate the relationship between visual hallucinations in Parkinson disease (PD) and levels of γ-aminobutyric acid (GABA) in the primary visual cortex.MethodsWe utilized magnetic resonance spectroscopy to investigate occipital GABA levels in 36 participants with PD, 19 with and 17 without complex visual hallucinations, together with 20 healthy controls without hallucinations. In addition, we acquired T1-weighted MRI, whole-brain fMRI during a visual task, and diffusion tensor imaging.ResultsWe found lower GABA+/creatine in PD with visual hallucinations (0.091 ± 0.010) vs those without (0.101 ± 0.010) and controls (0.099 ± 0.010) (F2,49 = 4.5; p = 0.016). Reduced gray matter in the hallucinations group was also observed in the anterior temporal lobe. Although there were widespread reductions in white matter integrity in the visual hallucinations group, this was no longer significant after controlling for cognitive function.ConclusionsThe data suggest that reduced levels of GABA are associated with visual hallucinations in PD and implicate changes to the ventral visual stream in the genesis of visual hallucinations. Modulation of visual cortical excitability through, for example, pharmacologic intervention, may be a promising treatment avenue to explore.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Reduced occipital GABA in Parkinson disease with visual hallucinations

et al. 2018

View full text Add to dashboard Cite

show abstract

“…CBS patients can experience complex VH ( Urwyler et al, 2016 ) similar to those frequently experienced by people with Parkinson’s disease or cognitive impairment with Lewy bodies. A number of hypotheses have been suggested for these VH, involving dysfunctional communication of visual pathways, including the frontal lobe and thalamic radiation, as well as occipital tracts ( Esmaeeli et al, 2019 , Tsukada et al, 2015 , Shine et al, 2011 ). An fMRI study of CBS experiencing hallucinations ( ffytche et al, 1998 ) found increased activity in regions of extrastriate cortex relevant for the percept (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…Hypotheses regarding the etiology of VH in neurodegenerative disease involve altered connections between visual regions ( Esmaeeli et al, 2019 , Tsukada et al, 2015 , Shine et al, 2011 ). Supporting these hypotheses, alterations in white matter tracts, including the inferior and superior longitudinal fasciculus (which connect parieto-occipital cortex with anterior temporal and frontal cortices respectively) have been reported in Lewy body dementia patients with complex VH ( Zorzi et al, 2021 , Zarkali et al, 2020 , Yuki et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Investigation of structural brain changes in Charles Bonnet Syndrome

Firbank

Morgan

Collerton

et al. 2022

NeuroImage: Clinical

View full text Add to dashboard Cite

“…As this model would predict, treatment with cholinesterase inhibitors increases occipital blood flow, while attenuating visual hallucinations (Mori et al, 2006 ). A complementary, and more biophysically detailed, perspective on this is formulated in terms of impaired conductance (Tsukada et al, 2015 ) in the synapses between visual cortical neurons, and those in the ventral visual stream.…”

Section: Computational Neuropathologymentioning

confidence: 99%

Precision and False Perceptual Inference

Parr

Benrimoh

Vincent

et al. 2018

Front. Integr. Neurosci.

View full text Add to dashboard Cite

Accurate perceptual inference fundamentally depends upon accurate beliefs about the reliability of sensory data. In this paper, we describe a Bayes optimal and biologically plausible scheme that refines these beliefs through a gradient descent on variational free energy. To illustrate this, we simulate belief updating during visual foraging and show that changes in estimated sensory precision (i.e., confidence in visual data) are highly sensitive to prior beliefs about the contents of a visual scene. In brief, confident prior beliefs induce an increase in estimated precision when consistent with sensory evidence, but a decrease when they conflict. Prior beliefs held with low confidence are rapidly updated to posterior beliefs, determined by sensory data. These induce much smaller changes in beliefs about sensory precision. We argue that pathologies of scene construction may be due to abnormal priors, and show that these can induce a reduction in estimated sensory precision. Having previously associated this precision with cholinergic signaling, we note that several neurodegenerative conditions are associated with visual disturbances and cholinergic deficits; notably, the synucleinopathies. On relating the message passing in our model to the functional anatomy of the ventral visual stream, we find that simulated neuronal loss in temporal lobe regions induces confident, inaccurate, empirical prior beliefs at lower levels in the visual hierarchy. This provides a plausible, if speculative, computational mechanism for the loss of cholinergic signaling and the visual disturbances associated with temporal lobe Lewy body pathology. This may be seen as an illustration of the sorts of hypotheses that may be expressed within this computational framework.

show abstract

Computational model of visual hallucination in dementia with Lewy bodies

Cited by 13 publications

References 48 publications

Reduced occipital GABA in Parkinson disease with visual hallucinations

Reduced occipital GABA in Parkinson disease with visual hallucinations

Investigation of structural brain changes in Charles Bonnet Syndrome

Precision and False Perceptual Inference

Contact Info

Product

Resources

About