Complex visual hallucinations and attentional performance in eye disease and dementia: a test of the Perception and Attention Deficit model

Makin, Selina M; Redman, Julie; Mosimann, Urs Peter; Dudley, Robert; Clarke, Michael; Colbourn, Christopher J.; Collerton, Daniel

doi:10.1002/gps.3947

Cited by 12 publications

(9 citation statements)

References 18 publications

(33 reference statements)

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“…Furthermore, default mode network over-activity [41] and dissociation with cognitive control regions [42] have also been reported in patients with schizophrenia. Intriguingly, hallucinations in disorders classically associated with primary retinal impairment, such as Charles Bonnet Syndrome, are also associated with visual attentional impairments [32,33], suggesting a common neural mechanism for hallucinations across all disorders [2,43]. Future studies should thus be designed to delineate the precise combination of deficits across attentional and perceptual domains that lead to the manifestation of visual hallucinatory symptoms across the broad range of neuropsychiatric disorders.…”

Section: Discussionmentioning

confidence: 99%

Imagine that: elevated sensory strength of mental imagery in individuals with Parkinson's disease and visual hallucinations

et al. 2015

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Visual hallucinations occur when our conscious experience does not accurately reflect external reality. However, these dissociations also regularly occur when we imagine the world around us in the absence of visual stimulation. We used two novel behavioural paradigms to objectively measure visual hallucinations and voluntary mental imagery in 19 individuals with Parkinson's disease (ten with visual hallucinations; nine without) and ten healthy, age-matched controls. We then used this behavioural overlap to interrogate the connectivity both within and between the major attentional control networks using restingstate functional magnetic resonance imaging. Patients with visual hallucinations had elevated mental imagery strength compared with patients without hallucinations and controls. Specifically, the sensory strength of imagery predicted the frequency of visual hallucinations. Together, hallucinations and mental imagery predicted multiple abnormalities in functional connectivity both within and between the attentional control networks, as measured with resting-state functional magnetic resonance imaging. However, the two phenomena were also dissociable at the neural level, with both mental imagery and visual misperceptions associated with specific abnormalities in attentional network connectivity. Our results provide the first evidence of both the shared and unique neural correlates of these two similar, yet distinct phenomena.

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Section: Discussionmentioning

confidence: 99%

Imagine that: elevated sensory strength of mental imagery in individuals with Parkinson's disease and visual hallucinations

et al. 2015

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“…The control groups which included friends/relatives (2,8) or spouses of patients, (2,3,5,8) volunteers recruited via advertisement in the Newcastle Elders magazine(4) and in a local church (3,4) and healthy controls from the research database held at the Institute for Ageing, Newcastle University (3,5) comprise the comparison group in this study. Diagnostic criteria were met using the revised International Consensus Guidelines from the third report of the DLB consortium for DLB, the Movement Disorder Committee, United Kingdom.…”

Section: Study Selection and Data Collectionmentioning

confidence: 99%

Visual Hallucinations in Eye Disease and Lewy Body Disease

Urwyler

Nef

Müri

et al. 2016

The American Journal of Geriatric Psychiatry

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Objective: Visual hallucinations (VH) most commonly occur in eye disease (ED), Parkinson's disease (PD), and Lewy body dementia (LBD). The phenomenology of VH is likely to carry important information about the brain areas within the visual system generating them. Methods: Data from five controlled cross-sectional VH studies (164 controls, 135 ED, 156 PD, 79 (PDD 48 + DLB 31) LBD) were combined and analysed. The prevalence, phenomenology, frequency, duration, and contents of VH were compared across diseases and gender. Results: Simple VH were most common in ED patients (ED 65% METHODS Study Selection and Data CollectionThere have been several studies(2-5, 8, 24) using NEVHI(3) since its original publication in 2008. Only controlled cross-sectional NEVHI studies with ED, PD, PDD, and DLB samples using similar methodology were included in this study. Three(3, 4, 8) of them had two sample groups (patients, controls), while the other two had three sample groups (controls, ED, DLB;(2) controls, PD, PDD (5) Committee, United Kingdom. All procedures related to the study were explained to the participants and a written informed consent was obtained prior to participation. All data were merged into a single database including 164 individuals in the comparison group and 383 patients (135 ED, 156 PD, 48 PDD, 31 DLB, 13 with combination of ED/PD/PDD/DLB). The latter 13 patients were excluded from further analysis. A sub-analysis of VH phenomenology did not reveal any differences between DLB and PDD patients, which were subsequently considered as one LBD group. PD and LBD patients were only included if they had no visual field defects on neurological examination. AssessmentsAn interview was used to gather demographic data in all studies. Best near visual acuity was examined 6 members/children), "body parts", "animals/insects", "machines", and "letters/numbers/musical notes".(7, 13, 15) Prevalence, phenomenology, frequency, duration and severity of VH were compared between the (i) comparison group and patients and (ii) different patient groups (ED, PD, LBD). The phenomenology of Complex VH was also compared between gender. Statistical analysisStatistical analysis was undertaken using the Statistical Package for Social Sciences (SPSS Version 20).Normal distribution of data was examined using the Shapiro-Wilk test. Means and standard deviations (SD) were calculated. Data were analysed using parametric tests (one-way analysis of variance (ANOVA)). Multiple comparisons were assessed with Post-hoc Bonferroni tests. Frequencies were compared using the chi-square (χ 2 ) test and Fisher's exact test when expected frequency in either group was < 5. The effect of gender, disease and interaction of gender × disease on contents of complex VH was tested using a two-way ANOVA (Effect sizes are reported using partial η 2 ), whilst logistic regression was used to ascertain whether the VH phenomenology could significantly predict the disease. The homogeneity of variance of the interaction model was tested using Levene's test, while go...

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“…9 Thus, all 3 suggest that the primary cause of hallucinations is that a combination of reduced top-down factors and bottom-up visual processing leads to a lack of perception of a correct image which, in turn, allows the intrusion, or release, of an incorrect image. Such models have received empirical support with attentional, [10][11][12][13][14][15] perceptual, 1,13,14 and combined 16,17 impairments on tasks measuring these abilities all being associated with VH.…”

Section: Introductionmentioning

confidence: 99%

Visual Priming and Visual Hallucinations in Parkinson’s Disease. Evidence for Normal Top-Down Processes

Straughan

Collerton

Bruce

2015

J Geriatr Psychiatry Neurol

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Background: Visual hallucinations (VH) are common in Parkinson's disease (PD) and are associated with increased morbidity and mortality. Current explanations for VH in PD suggest combined impairments in top-down attentional and bottom-up perceptual processes, which allow the passive ''release'' of stored images. Alternative models in other disorders have suggested that top-down factors may actively encourage hallucinations. In order to explore the interaction between top-down and bottom-up visual processing in PDVH, we developed novel experimental priming tasks in which top-down verbal cues were used to prime the bottom-up recognition of partial or ambiguous pictures. Method: Two groups of PD participants with (PD þ VH, n ¼ 16), and without VH (PD -VH, n ¼ 20) were compared to a group of healthy older adults (NC, n ¼ 20) on 3 novel measures of visual priming. Results: All tasks showed significant priming effects. The PD þ VH group was more impaired at accurately identifying silhouette and fragmented images compared to the PD -VH group. There were no differences in priming between the 2 PD groups. Conclusions: The study showed that VH in PD are not associated with relatively greater top-down activation, and that the interaction between top-down and bottom-up processes is intact.

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Complex visual hallucinations and attentional performance in eye disease and dementia: a test of the Perception and Attention Deficit model

Cited by 12 publications

References 18 publications

Imagine that: elevated sensory strength of mental imagery in individuals with Parkinson's disease and visual hallucinations

Imagine that: elevated sensory strength of mental imagery in individuals with Parkinson's disease and visual hallucinations

Visual Hallucinations in Eye Disease and Lewy Body Disease

Visual Priming and Visual Hallucinations in Parkinson’s Disease. Evidence for Normal Top-Down Processes

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