scholarly journals Ocular fixations and presaccadic potentials to explain pareidolias in Parkinson’s disease

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Gajanan S Revankar ◽  
Noriaki Hattori ◽  
Yuta Kajiyama ◽  
Tomohito Nakano ◽  
Masahito Mihara ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Tracking ◽  
Eye Movement ◽  
Visual Processing ◽  
Top Down ◽  
Scalp Eeg ◽  
Wide Range ◽  
Saccade Size ◽  
Global And Local

Abstract In Parkinson’s disease, a precursor phenomenon to visual hallucinations presents as ‘pareidolias’ which make ambiguous forms appear meaningful. To evoke and detect pareidolias in patients, a noise pareidolia test was recently developed, although its task-dependent mechanisms are yet to be revealed. When subjected to this test, we hypothesized that patients exhibiting pareidolias would show altered top-down influence of visual processing allowing us to demonstrate the influence of pareidolic illusionary behaviour in Parkinson’s disease patients. To that end, we evaluated eye-movement strategies and fixation-related presaccadic activity on scalp EEG when participants performed the test. Twelve healthy controls and 21 Parkinson’s disease patients, evaluated for cognitive, visuo-spatial and executive functions, took a modified computer-based version of the noise pareidolia test in a free-viewing EEG eye-tracking experiment. Eye-tracking metrics (fixation-related durations and counts) documented the eye movement behaviour employed in correct responses (face/noise) and misperceptions (pareidolia/missed) during early and late visual search conditions. Simultaneously, EEG recorded the presaccadic activity in frontal and parietal areas of the brain. Based on the noise pareidolia test scores, we found certain Parkinson’s disease patients exhibited pareidolias whereas others did not. ANOVA on eye-tracking data showed that patients dwelled significantly longer to detect faces and pareidolias which affected both global and local search dynamics depending on their visuo-perceptual status. Presaccadic activity in parietal electrodes for the groups was positive for faces and pareidolias, and negative for noise, though these results depended mainly on saccade size. However, patients sensitive to pareidolias showed a significantly higher presaccadic potential on frontal electrodes independent of saccade sizes, suggesting a stronger frontal activation for pareidolic stimuli. We concluded with the following interpretations (i) the noise pareidolia test specifically characterizes visuo-perceptual inadequacies in patients despite their wide range of cognitive scores, (ii) Parkinson’s disease patients dwell longer to converge attention to pareidolic stimuli due to abnormal saccade generation proportional to their visuo-perceptual deficit during early search, and during late search, due to time-independent alteration of visual attentional network and (iii) patients with pareidolias show increased frontal activation reflecting the allocation of attention to irrelevant targets that express the pareidolic phenomenon. While the disease per se alters the visuo-perceptual and oculomotor dynamics, pareidolias occur in Parkinson’s disease due to an abnormal top-down modulation of visual processing that affects visual attention and guidance to ambiguous stimuli.

scholarly journals Abnormal Vision-Based Displacement Perception in Parkinson’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Matthew Bernardinis ◽  
S. Farokh Atashzar ◽  
Rajni V. Patel ◽  
Mandar S. Jog
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Visual Processing ◽  
De Novo ◽  
Early Stage ◽  
Absolute Measurement ◽  
Motor Disorder ◽  
Independent Manner ◽  
Graphical Tool ◽  
Wide Range

In this work, we investigate the effect of Parkinson’s disease (PD), and common corresponding therapies on vision-based perception of motion, a critical perceptual ability required for performing a wide range of activities of daily livings. While PD has been recognized as mainly a motor disorder, sensory manifestation of PD can also play a major role in the resulting disability. In this paper, for the first time, the effect of disease duration and common therapies on vision-based perception of displacement were investigated. The study is conducted in a movement-independent manner, to reject the shadowing effects and isolate the targeted perceptual disorder to the maximum possible extent. Data was collected using a computerized graphical tool on 37 PD patients [6 early-stage de novo, 25 mid-stage using levodopa therapy, six later-stage using deep brain stimulation (DBS)] and 15 control participants. Besides the absolute measurement of perception through a psychometric analysis on two tested position reference magnitudes, we also investigated the linearity in perception using Weber’s fraction. The results showed that individuals with PD displayed significant perceptual impairments compared to controls, though early-stage patients were not impaired. Mid-stage patients displayed impairments at the greater of the two tested reference magnitudes, while late-stage patients were impaired at both reference magnitudes. Levodopa and DBS use did not cause statistically significant differences in absolute displacement perception. The findings suggest abnormal visual processing in PD increasing with disease development, perhaps contributing to sensory-based impairments of PD such as bradykinesia, visuospatial deficits, and abnormal object recognition.

scholarly journals Pre-stimulus low-alpha frontal networks characterize pareidolias in Parkinson’s disease

2020 ◽  
Author(s):  
Gajanan S. Revankar ◽  
Yuta Kajiyama ◽  
Noriaki Hattori ◽  
Tetsuya Shimokawa ◽  
Tomohito Nakano ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Visual Processing ◽  
Small World ◽  
Stimulus Presentation ◽  
Clustering Coefficient ◽  
Centrality Measures ◽  
Top Down ◽  
Frontal Activity ◽  
External Stimuli

AbstractBackgroundParkinson’s disease (PD) patients susceptible to visual hallucinations experience perceptual deficits in the form of pareidolias. While pareidolias necessitate top-down modulation of visual processing, the cortical dynamics of internally generated perceptual priors on pareidolic misperceptions is unknown.ObjectivesTo study pre-stimulus related EEG spectral and network abnormalities in PD patients experiencing pareidolias.Methods21 PD in-patients and 10 age-matched healthy controls were evaluated. Neuropsychological assessments included tests for cognition, attention and executive functions. To evoke and quantify pareidolias, participants performed the noise pareidolia test (NPT) with simultaneous EEG recording. PD patients were sub-divided into two groups - those with high pareidolia counts (N=10) and those without (N=11). EEG was analyzed 1000ms before stimulus presentation in the spectral domain (theta, low-alpha and high-alpha frequencies) with corresponding graph networks that evaluated small-world properties, efficiency and centrality measures. Statistical analysis included ANCOVA and multiple regression to evaluate the differences.ResultsPD group with high pareidolias were older with lower scores on neuropsychological tests. Their pre-stimulus EEG low-alpha band showed a tendency towards higher frontal activity (p=0.06). Graph networks showed increased normalized clustering coefficient (p=0.05), higher local parietal cortex efficiency (p=0.049) and lower frontal degree centrality (p=0.005). These network indices correlated positively to patients’ pareidolia scores.ConclusionPareidolias in PD are a consequence of an abnormal top-down modulation of visual processing which are defined by their frontal low-alpha spectral and network alterations in the pre-stimulus phase due to a dissonance between patients’ internally generated mental-processing with external stimuli.

scholarly journals Fixation Duration and Pupil Size as Diagnostic Tools in Parkinson’s Disease

2021 ◽  
pp. 1-11
Author(s):  
Panagiota Tsitsi ◽  
Mattias Nilsson Benfatto ◽  
Gustaf Öqvist Seimyr ◽  
Olof Larsson ◽  
Prof Per Svenningsson ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Movements ◽  
Eye Tracking ◽  
Eye Movement ◽  
Pupil Size ◽  
Clinical Investigation ◽  
Sampling Rate ◽  
Diagnostic Tools ◽  
Eye Tracker

Background: Visual and oculomotor problems are very common in Parkinson’s disease (PD) and by using eye-tracking such problems could be characterized in more detail. However, eye-tracking is not part of the routine clinical investigation of parkinsonism. Objective: To evaluate gaze stability and pupil size in stable light conditions, as well as eye movements during sustained fixation in a population of PD patients and healthy controls (HC). Methods: In total, 50 PD patients (66% males) with unilateral to mild-to-moderate disease (Hoehn & Yahr 1– 3, Schwab and England 70– 90% ) and 43 HC (37% males) were included in the study. Eye movements were recorded with Tobii Pro Spectrum, a screen-based eye tracker with a sampling rate of 1200 Hz. Logistic regression analysis was applied to investigate the strength of association of eye-movement measures with diagnosis. Results: Median pupil size (OR 0.811; 95% CI 0.666– 0.987; p = 0.037) and longest fixation period (OR 0.798; 95% CI 0.691-0.921; p = 0.002), were the eye-movement parameters that were independently associated with diagnosis, after adjustment for sex (OR 4.35; 95% CI 1.516– 12.483; p = 0.006) and visuospatial/executive score in Montreal Cognitive Assessment (OR 0.422; 95% CI 0.233– 0.764; p = 0.004). The area under the ROC curve was determined to 0.817; 95% (CI) 0.732– 0.901. Conclusion: Eye-tracking based measurements of gaze fixation and pupil reaction may be useful biomarkers of PD diagnosis. However, larger studies of eye-tracking parameters integrated into the screening of patients with suspected PD are necessary, to further investigate and confirm their diagnostic value.

scholarly journals Hispanic Perspectives on Parkinson’s Disease Care and Research Participation

2021 ◽  
pp. 1-11
Author(s):  
Lisa Damron ◽  
Irene Litvan ◽  
Ece Bayram ◽  
Sarah Berk ◽  
Bernadette Siddiqi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Native Language ◽  
Research Participation ◽  
Ongoing Research ◽  
Research Recruitment ◽  
Research Opportunities ◽  
Research Engagement ◽  
Wide Range ◽  
Tertiary Center

Background: Hispanics are under-represented in Parkinson’s disease (PD) research despite the importance of diversity for results to apply to a wide range of patients. Objective: To investigate the perspective of Hispanic persons with Parkinson disease (PWP) regarding awareness, interest, and barriers to participation in research. Methods: We developed and administered a survey and qualitative interview in English and Spanish. For the survey, 62 Hispanic and 38 non-Hispanic PWP linked to a tertiary center were recruited in Arizona. For interviews, 20 Hispanic PWP, 20 caregivers, and six physicians providing service to Hispanic PWP in the community were recruited in California. Survey responses of Hispanic and non-Hispanic PWP were compared. Major survey themes were identified by applying grounded theory and open coding. Results: The survey found roughly half (Q1 54%, Q2 55%) of Hispanic PWP linked to a tertiary center knew about research; there was unawareness among community Hispanic PWP. Most preferred having physician recommendations for research participation and were willing to participate. Hispanics preferred teams who speak their native language and include family. Research engagement, PD knowledge, role of family, living with PD, PD care, pre-diagnosis/diagnosis emerged as themes from the interview. Conclusion: Barriers exist for participation of Hispanic PWP in research, primarily lack of awareness of PD research opportunities. Educating physicians of the need to encourage research participation of Hispanic PWP can address this. Physicians need to be aware of ongoing research and should not assume PWP disinterest. Including family members and providing research opportunities in their native language can increase research recruitment.

Parkinson’s Disease Genetic Loci in Rapid Eye Movement Sleep Behavior Disorder

2015 ◽  
Vol 56 (3) ◽  
pp. 617-622 ◽  
Author(s):  
Z. Gan-Or ◽  
S. L. Girard ◽  
A. Noreau ◽  
C. S. Leblond ◽  
J. F. Gagnon ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Movement ◽  
Behavior Disorder ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Genetic Loci ◽  
Sleep Behavior

Impulse control disorder and rapid eye movement sleep behavior disorder in Parkinson's disease

2014 ◽  
Vol 20 (12) ◽  
pp. 1411-1414 ◽  
Author(s):  
Sophie Bayard ◽  
Yves Dauvilliers ◽  
Huan Yu ◽  
Muriel Croisier-Langenier ◽  
Alexia Rossignol ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Movement ◽  
Impulse Control ◽  
Behavior Disorder ◽  
Impulse Control Disorder ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Sleep Behavior

scholarly journals Top–Down Attentional Control in Parkinson's Disease: Salient Considerations

2010 ◽  
Vol 22 (5) ◽  
pp. 848-859 ◽  
Author(s):  
Roshan Cools ◽  
Robert Rogers ◽  
Roger A. Barker ◽  
Trevor W. Robbins
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Attentional Control ◽  
Direct Evidence ◽  
Control Mechanisms ◽  
Set Shifting ◽  
Top Down ◽  
Bottom Up ◽  
Salient Dimension ◽  
Dimensional Salience

Cognitive dysfunction in Parkinson's disease (PD) has been hypothesized to reflect a failure of cortical control. In keeping with this hypothesis, some of the cognitive deficits in PD resemble those seen in patients with lesions in the lateral pFC, which has been associated with top–down attentional control. However, there is no direct evidence for a failure of top–down control mechanisms in PD. Here we fill this gap by demonstrating disproportionate control by bottom–up attention to dimensional salience during attentional set shifting. Patients needed significantly more trials to criterion than did controls when shifting to a low-salient dimension while, remarkably, needing significantly fewer trials to criterion than did controls when shifting to a high-salient dimension. Thus, attention was captured by bottom–up attention to salient information to a greater extent in patients than in controls. The results provide a striking reinterpretation of prior set-shifting data and provide the first direct evidence for a failure of top–down attentional control, resembling that seen after catecholamine depletion in the pFC.

Dissociating cognitive deficits involved in voluntary eye movement dysfunctions in Parkinson's disease patients

2006 ◽  
Vol 44 (8) ◽  
pp. 1475-1482 ◽  
Author(s):  
S AMADOR ◽  
A HOOD ◽  
M SCHIESS ◽  
R IZOR ◽  
A SERENO
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Movement ◽  
Cognitive Deficits

Rapid eye movement behavior disorder in drug-naïve patients with Parkinson’s disease

2019 ◽  
Vol 59 ◽  
pp. 254-258 ◽  
Author(s):  
Hui Liu ◽  
Ruwei Ou ◽  
Qianqian Wei ◽  
Yanbing Hou ◽  
Bei Cao ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Eye Movement ◽  
Behavior Disorder ◽  
Movement Behavior ◽  
Rapid Eye Movement ◽  
Drug Naïve
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