Limb and hemispatial hypometria

In a previous study, we demonstrated that unilateral cerebral lesions produce hypometric limb movements of the contralateral arm and hemispatial (i.e., directional) hypometria for movements towards contralateral hemispace. In the present study, we investigated 10 patients with right cerebral lesions and 25 healthy controls using a task to uncouple deficits in sensory perceptual systems and motor-action output systems on directional hypometria. This task required participants, with their eyes closed, to reproduce lateral and medial horizontal displacements (15–27 cm) with each arm. Each participant was seated at a waist high table and had their hand placed at an origin point aligned with the axillary fold on the same side. Their hand was moved by the investigator from the origin point to a target point and brought back to the point of origin (input displacement). The participant was then asked to return their hand to either the same target point or to an equidistant target point in the opposite direction. Healthy dextral participants were significantly more hypometric with their right arm, but patients with right cerebral lesions exhibited an opposite pattern with overall left arm hypometria. In addition, patients were significantly more hypometric for movements when output displacements were toward left hemispace. No effect was found for direction of sensory input. The results suggest that the directional hypometria is predominantly produced by hemispatial output deficits. (JINS, 2000, 6, 71–75.)

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Sensory Modulation and Participation in Daily Occupations in Stroke Survivors

Canadian Journal of Occupational Therapy ◽

10.1177/00084174211047372 ◽

2021 ◽

pp. 000841742110473

Author(s):

Avivit Fuks Sharony ◽

Batya Engel-Yeger

Keyword(s):

Sensory Input ◽

Occupational Therapists ◽

Sensory Profile ◽

Stroke Survivors ◽

Healthy Controls ◽

Social Activities ◽

Sensory Modulation ◽

Card Sort ◽

The Relationship

Background. Stroke may alter sensory modulation and restrict participation in daily occupations. Although studies highlight the relationship between altered sensory modulation and reduced participation, this relationship in stroke survivors has not been studied enough. Purpose. To examine the prevalence of altered sensory modulation among stroke survivors; to compare sensory modulation and participation between stroke survivors and healthy controls; to estimate the relationship between sensory modulation and participation among stroke survivors. Method. Thirty stroke survivors and 30 healthy controls, aged 18–70, completed the MoCA, the Adolescent-Adult Sensory Profile and the Activity Card Sort. Findings. Altered sensory modulation was more prevalent among stroke survivors. Their participation was significantly restricted as compared to healthy controls. Lower tendency to seek sensory input predicted lower participation in social activities. Implications. Occupational therapists should screen for altered sensory modulation in stroke survivors and understand their impacts on participation, in order to improve intervention outcomes.

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A Pilot Study Investigating a Novel Non-Linear Measure of Eyes Open versus Eyes Closed EEG Synchronization in People with Alzheimer’s Disease and Healthy Controls

Brain Sciences ◽

10.3390/brainsci8070134 ◽

2018 ◽

Vol 8 (7) ◽

pp. 134 ◽

Cited By ~ 6

Author(s):

Daniel Blackburn ◽

Yifan Zhao ◽

Matteo De Marco ◽

Simon Bell ◽

Fei He ◽

...

Keyword(s):

Pilot Study ◽

Resting State ◽

Low Cost ◽

Linear Measure ◽

Ageing Population ◽

Healthy Controls ◽

Causality Test ◽

Non Invasive ◽

Eyes Closed ◽

Eyes Open

Background: The incidence of Alzheimer disease (AD) is increasing with the ageing population. The development of low cost non-invasive diagnostic aids for AD is a research priority. This pilot study investigated whether an approach based on a novel dynamic quantitative parametric EEG method could detect abnormalities in people with AD. Methods: 20 patients with probable AD, 20 matched healthy controls (HC) and 4 patients with probable fronto temporal dementia (FTD) were included. All had detailed neuropsychology along with structural, resting state fMRI and EEG. EEG data were analyzed using the Error Reduction Ratio-causality (ERR-causality) test that can capture both linear and nonlinear interactions between different EEG recording areas. The 95% confidence intervals of EEG levels of bi-centroparietal synchronization were estimated for eyes open (EO) and eyes closed (EC) states. Results: In the EC state, AD patients and HC had very similar levels of bi-centro parietal synchronization; but in the EO resting state, patients with AD had significantly higher levels of synchronization (AD = 0.44; interquartile range (IQR) 0.41 vs. HC = 0.15; IQR 0.17, p < 0.0001). The EO/EC synchronization ratio, a measure of the dynamic changes between the two states, also showed significant differences between these two groups (AD ratio 0.78 versus HC ratio 0.37 p < 0.0001). EO synchronization was also significantly different between AD and FTD (FTD = 0.075; IQR 0.03, p < 0.0001). However, the EO/EC ratio was not informative in the FTD group due to very low levels of synchronization in both states (EO and EC). Conclusion: In this pilot work, resting state quantitative EEG shows significant differences between healthy controls and patients with AD. This approach has the potential to develop into a useful non-invasive and economical diagnostic aid in AD.

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The role of action intentionality and effector in the subjective expansion of temporal duration after saccadic eye movements

Scientific Reports ◽

10.1038/s41598-020-73830-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

David Melcher ◽

Devpriya Kumar ◽

Narayanan Srinivasan

Keyword(s):

Eye Movements ◽

Visual Processing ◽

Saccadic Eye Movements ◽

Intentional Binding ◽

Opposite Pattern ◽

Motor Action ◽

Saccade Onset ◽

Backward Shift ◽

The Moment

Abstract Visual perception is based on periods of stable fixation separated by saccadic eye movements. Although naive perception seems stable (in space) and continuous (in time), laboratory studies have demonstrated that events presented around the time of saccades are misperceived spatially and temporally. Saccadic chronostasis, the “stopped clock illusion”, represents one such temporal distortion in which the movement of the clock hand after the saccade is perceived as lasting longer than usual. Multiple explanations for chronostasis have been proposed including action-backdating, temporal binding of the action towards the moment of its effect (“intentional binding”) and post-saccadic temporal dilation. The current study aimed to resolve this debate by using different types of action (keypress vs saccade) and varying the intentionality of the action. We measured both perceived onset of the motor action and perceived onset of an auditory tone presented at different delays after the keypress/saccade. The results showed intentional binding for the keypress action, with perceived motor onset shifted forwards in time and the time of the tone shifted backwards. Saccades resulted in the opposite pattern, showing temporal expansion rather than compression, especially with cued saccades. The temporal illusion was modulated by intentionality of the movement. Our findings suggest that saccadic chronostasis is not solely dependent on a backward shift in perceived saccade onset, but instead reflects a temporal dilation. This percept of an effectively “longer” period at the beginning of a new fixation may reflect the pattern of suppressed, and then enhanced, visual processing around the time of saccades.

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Resting EEG Measures of Brain Arousal in a Multisite Study of Major Depression

Clinical EEG and Neuroscience ◽

10.1177/1550059418795578 ◽

2018 ◽

Vol 50 (1) ◽

pp. 3-12 ◽

Cited By ~ 11

Author(s):

Christine Ulke ◽

Craig E. Tenke ◽

Jürgen Kayser ◽

Christian Sander ◽

Daniel Böttger ◽

...

Keyword(s):

Low Voltage ◽

Clinical Care ◽

The United States ◽

Alpha Activity ◽

Healthy Controls ◽

Significant Group ◽

Depressed Patients ◽

Eyes Closed ◽

Eeg Recordings ◽

Brain Arousal

Several studies have found upregulated brain arousal during 15-minute EEG recordings at rest in depressed patients. However, studies based on shorter EEG recording intervals are lacking. Here we aimed to compare measures of brain arousal obtained from 2-minute EEGs at rest under eyes-closed condition in depressed patients and healthy controls in a multisite project—Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care (EMBARC). We expected that depressed patients would show stable and elevated brain arousal relative to controls. Eighty-seven depressed patients and 36 healthy controls from four research sites in the United States were included in the analyses. The Vigilance Algorithm Leipzig (VIGALL) was used for the fully automatic classification of EEG-vigilance stages (indicating arousal states) of 1-second EEG segments; VIGALL-derived measures of brain arousal were calculated. We found that depressed patients scored higher on arousal stability ( Z = −2.163, P = .015) and A stages (dominant alpha activity; P = .027) but lower on B1 stages (low-voltage non-alpha activity, P = .008) compared with healthy controls. No significant group differences were observed in Stage B2/3. In summary, we were able to demonstrate stable and elevated brain arousal during brief 2-minute recordings at rest in depressed patients. Results set the stage for examining the value of these measures for predicting clinical response to antidepressants in the entire EMBARC sample and evaluating whether an upregulated brain arousal is particularly characteristic for responders to antidepressants.

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T142. SELF-OTHER DISTINCTION IN SCHIZOPHRENIA: ABNORMALITIES IN THE PREDICTION OF THE SENSORY CONSEQUENCES OF ONE’S OWN ACTIONS

Schizophrenia Bulletin ◽

10.1093/schbul/sbaa029.702 ◽

2020 ◽

Vol 46 (Supplement_1) ◽

pp. S285-S285

Author(s):

Lukas Uhlmann ◽

Mareike Pazen ◽

Bianca M van Kemenade ◽

Tilo Kircher ◽

Benjamin Straube

Keyword(s):

Posterior Parietal Cortex ◽

Sensory Input ◽

Body Part ◽

Predictive Processing ◽

Hand Movements ◽

Healthy Controls ◽

Schizophrenia Spectrum Disorders ◽

Action Execution ◽

Suppression Effect ◽

Suppression Effects

Abstract Background Core symptoms of schizophrenia include disturbances in the distinction between the self and the external world. It has been suggested that self-other distinction is governed by predictive processing: Copies of an action’s motor command are used to generate forward models that predict upcoming sensory input. These predictions are compared with actual sensory input, thereby enabling the brain to discard the processing of sensory input arising from one’s own actions. This is reflected in a decreased perception of and reduced BOLD signal for actively versus passively generated sensory input (suppression effect). Here, we investigated whether BOLD suppression effects for the processing of action feedback involving active and passive hand movements differ between patients with schizophrenia and healthy control participants. Since the identity of one’s body also contributes to self-other distinction, we additionally investigated if differences in BOLD suppression effects between patients and healthy controls are further modulated by whether participants see their own or someone else’s hand moving in accordance with their action. Methods 17 patients with schizophrenia spectrum disorders and 13 healthy controls (matched for age, sex, and educational degree) performed active and passive hand movements while lying in the MRI scanner. During movement execution (active and passive), participants saw either a real-time video of their current movement (“self”) or someone else’s hand moving in accordance with their action (“other”). This manipulation allowed disentangling the effects of movement characteristics (e.g., who is triggering the movement) from visual identity characteristics (whose hand is moving), which both contribute to self-other distinction. Variable delays were inserted between the movement and the images (“self” and “other”), which had to be detected by the participants. Results Preliminary results of behavioral performance showed an interaction between group (patients vs. healthy controls) and action execution (active vs. passive): Healthy controls detected less delays in the active condition than in the passive condition, whereas this difference was reduced in patients. In line with this, active vs. passive trials revealed larger BOLD suppression effects in healthy controls than in patients with schizophrenia in multiple brain areas (e.g., lingual gyrus, middle and superior occipital gyrus, posterior parietal cortex, cerebellum). Finally, an interaction effect was found in the thalamus, such that in healthy controls, but not in patients with schizophrenia, this area showed a BOLD suppression effect for active vs. passive movements specific for feedback of one’s own hand. Discussion Weaker behavioral and neural suppression effects in patients with schizophrenia (compared to healthy controls) show that actively generated sensory input is not as effectively discarded from further processing, suggesting that efference copy-based predictive mechanisms are impaired in patients with schizophrenia. Furthermore, BOLD suppression in the thalamus was not modulated by hand identity in patients with schizophrenia, indicating that predictive processing in schizophrenia might not take the identity of the seen body part into account.

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Neurovascular coupling and cerebral autoregulation in atrial fibrillation

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x19870770 ◽

2019 ◽

Vol 40 (8) ◽

pp. 1647-1657 ◽

Cited By ~ 4

Author(s):

Rehan T Junejo ◽

Igor D Braz ◽

Samuel JE Lucas ◽

Johannes J van Lieshout ◽

Aaron A Phillips ◽

...

Keyword(s):

Atrial Fibrillation ◽

Cerebral Artery ◽

Cerebral Autoregulation ◽

Visual Stimulation ◽

Function Analysis ◽

Neurovascular Coupling ◽

Healthy Controls ◽

Eyes Closed ◽

Increased Risk ◽

Transfer Function Analysis

The risk of cognitive decline and stroke is increased by atrial fibrillation (AF). We sought to determine whether neurovascular coupling and cerebral autoregulation are blunted in people with AF in comparison with age-matched, patients with hypertension and healthy controls. Neurovascular coupling was assessed using five cycles of visual stimulation for 30 s followed by 30 s with both eyes-closed. Cerebral autoregulation was examined using a sit–stand test, and a repeated squat-to-stand (0.1 Hz) manoeuvre with transfer function analysis of mean arterial pressure (MAP; input) and middle cerebral artery mean blood flow velocity (MCA Vm; output) relationships at 0.1 Hz. Visual stimulation increased posterior cerebral artery conductance, but the magnitude of the response was blunted in patients with AF (18 [8] %; mean [SD]) and hypertension (17 [8] %), in comparison with healthy controls (26 [9] %) ( P < 0.05). In contrast, transmission of MAP to MCA Vm was greater in AF patients compared to hypertension and healthy controls, indicating diminished cerebral autoregulation. We have shown for the first time that AF patients have impaired neurovascular coupling responses to visual stimulation and diminished cerebral autoregulation. Such deficits in cerebrovascular regulation may contribute to the increased risk of cerebral dysfunction in people with AF.

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Laterality of visuo-spatial attention in acute and chronic schizophrenia, major depression and in healthy controls

Psychological Medicine ◽

10.1017/s0033291700037582 ◽

1995 ◽

Vol 25 (5) ◽

pp. 1091-1095 ◽

Cited By ~ 5

Author(s):

R. E. O'Carroll ◽

A. Rogers ◽

S. M. Lawrie ◽

C. Murray ◽

M. Van Beck ◽

...

Keyword(s):

Major Depression ◽

Spatial Attention ◽

Chronic Schizophrenia ◽

Healthy Controls ◽

Opposite Pattern ◽

Chronic Schizophrenic ◽

Schizophrenic Patients ◽

Schizophrenic Group ◽

Two Measures

SYNOPSISPrevious studies have suggested that schizophrenia is characterized by an asymmetry of visuo-spatial attention, in particular that acute unmedicated schizophrenics demonstrate relative inattention to right hemispace, whereas chronically medicated patients demonstrate the opposite pattern. In the present study, 30 unmedicated schizophrenic patients, 32 chronically medicated schizophrenic patients, 30 patients suffering from major depression and 60 healthy controls were assessed using two measures of hemispatial attentional neglect, namely letter and star cancellation. The results demonstrated that the chronic schizophrenic group made more total omissions for star cancellation (in both right and left hemispace), but that there was no difference between the groups in terms of omission asymmetry for either letter or star cancellation.

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PHYSIOLOGICAL SIGNAL ANALYSIS FOR COGNITIVE STATE ESTIMATION

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237212002950 ◽

2012 ◽

Vol 24 (01) ◽

pp. 57-69 ◽

Cited By ~ 10

Author(s):

Mohiuddin Ahmad ◽

Atiqul Islam ◽

T. T. Khan Munia ◽

M. A. Rashid ◽

T. M. N. Tunku Mansur

Keyword(s):

Signal Analysis ◽

Occipital Lobe ◽

Physiological Signals ◽

Cognitive State ◽

Specific Sequence ◽

Motor Action ◽

Physiological Signal ◽

Eyes Closed ◽

Cognitive States ◽

Emg Signal

The purpose of this paper is to identify inconsistency in human physiological signals based on cognitive states by measuring and analyzing bio-signals. In this paper, the cognitive states are estimated using physiological signal analysis. The parameters are electrocardiogram (ECG), electromyogram (EMG), electroencephalogram (EEG) and blood pressure (BP). The signals have been collected using BIOPAC system in which the subjects were induced to undergo the specific sequence of the cognitive state. For getting physiological signals during different conditions, we utilized power point slide show, video clips and question answer method which elicits mental reactions from the subjects. Data is taken before and after four tasks that encompassed the motor action (MA), thought (TH), memory related (MR) and emotion (EM). These measured values are analyzed using BIOPAC Acknowledge software. It was found that the motor action and thought states have effects on BP while MR and EM state mainly affect the ECG measurement. The decibel value and frequency found for EM state in ECG are minimum compared to relaxed state (RS) condition. Similarly, the maximum frequency and dB value is found for MR state. No significant variation was seen for MA and TH states. Thus it was decided that the MR and EM states mainly affect the ECG measurement. For BP the value increases in MA state and decreases in TH state. The MA state mainly affects the EMG signal while other states have no significant changes. The EEG mainly detects the signal of task performed by the specific brain region where the electrodes are placed. In EEG analysis, the electrodes are placed in occipital lobe region which gives mainly the variation in alpha amplitude of EEG with eyes closed and eyes opened. Alpha wave amplitudes vary with the subjects attention to mental tasks performed with eyes closed.

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Sensory Processing Patterns affect Headache Severity among Adolescents with Migraine

10.21203/rs.3.rs-16925/v1 ◽

2020 ◽

Author(s):

Jacob Genizi ◽

Ayelet Halevy ◽

Mitchell Schertz ◽

Khaled Osman ◽

Nurit Assaf ◽

...

Keyword(s):

Sensory Processing ◽

Sensory Input ◽

Pain Catastrophizing ◽

Episodic Migraine ◽

Healthy Controls ◽

Sensory Sensitivity ◽

Headache Severity ◽

Sensory Processing Patterns ◽

The Relationship ◽

Disability Level

Abstract Objective : To evaluate the relationship between pain catastrophizing level, sensory processing patterns, and headache severity among adolescents with episodic migraine. Background : Catastrophizing about pain is a critical variable in how we understand adjustment to pain and has a unique contribution in predicting pain intensity. Recent reports found that migraine is also related to enhanced sensory sensitivity. However, the relationship between pain severity, pain catastrophizing level and sensory sensitivity requires greater study especially among adolescents. Methods : Participants were 92 adolescents aged 13-18 years, 40 with episodic migraine and 52 healthy controls. The migraine patients were prospectively recruited from outpatient pediatric neurology clinics. All participants completed the Short Sensory Profile (SSP), and the Pain Catastrophizing Scale for children (PCS-ch). The migraine groups also completed the PedMIDAS, which measures Headache related disability. Results : Adolescents with migraine had significantly lower tendency to seek sensory input than healthy controls. Elevated rumination and helplessness correlated with higher migraine pain severity. Tendency to avoid sensory input predicted the migraine related disability level. They also significantly higher pain catastrophizing level than healthy controls, as seen in enhanced rumination (p ≤ 0.001) and helplessness (p ≤ 0.05). Conclusions : Sensory processing difficulties are common among adolescents with episodic migraine. Sensory avoidance may be related to pain experience, and pain catastrophizing and disability level.

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AN ASSOCIATION BETWEEN POSTURAL STABILITY AND SACROILIAC JOINT PAIN — A CASE CONTROL STUDY

Journal of Musculoskeletal Research ◽

10.1142/s0218957713500176 ◽

2013 ◽

Vol 16 (04) ◽

pp. 1350017 ◽

Cited By ~ 1

Author(s):

Snigdha Baruah ◽

Charu Eapen ◽

Katpadi Ramachandra Kamath

Keyword(s):

Joint Pain ◽

Postural Stability ◽

Healthy Controls ◽

Balance Test ◽

Exact Test ◽

Fisher's Exact Test ◽

Eyes Closed ◽

Fisher’S Exact Test ◽

Healthy Participants ◽

Control Study

Purpose: To evaluate and to find an association between postural stability amongst the subjects with sacroiliac iliac joint pain (SIJP) and compare it with healthy subjects. Methods: Single leg standing balance test with eyes closed (SLSBT-EC) was performed in 30 SIJP subjects without any visual, vestibular or other neuromusculoskeletal conditions and in 46 healthy controls aged 18-59 years. SLSBT-EC holding duration was measured for both the groups. "t"-test was done to compare the SLSBT (EC) holding duration between the groups and Fisher's exact test to find an association between postural stability and SIJP group. Results: SLSBT (EC) duration was significantly decreased (95% CI: t = 10.34, p = < 0.001) amongst the cases (15.56 s ± 4.73 s) as compared to healthy participants (26.06 s ± 4.05 s) and Fisher's exact test value for association between postural stability and SIJP was found to be statistically significant (F = 0.54, p = < 0.001). Conclusion: Subjects with SIJP exhibited diminished SLSBT (EC) holding duration compared to healthy controls suggesting proprioceptive deficits.

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