scholarly journals Cerebral Organization of Motor Imagery: Contralateral Control of Grip Selection in Mentally Represented Prehension

1998 ◽  
Vol 9 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Scott H. Johnson
Keyword(s):  
Motor Imagery ◽  
Cerebral Hemisphere ◽  
Human Subjects ◽  
Object Oriented ◽  
Movement Planning ◽  
Right Visual Field ◽  
Motor Systems ◽  
Response Hand ◽  
Grip Selection ◽  
Contralateral Hand

The principle of contralateral organization of the visual and motor systems was exploited to investigate contributions of the cerebral hemispheres to the mental representation of prehension in healthy, right-handed human subjects. Graphically rendered dowels were presented to either the left or right visual field in a variety of different orientations, and times to determine whether an underhand or overhand grip would be preferred for engaging these stimuli were measured. Although no actual reaching movements were performed, a significant advantage in grip-selection time was found when information was presented to the cerebral hemisphere contralateral to the designated response hand. Results are consistent with the position that motor imagery recruits neurocognitive mechanisms involved in movement planning. More precisely, these findings indicate that processes within each cerebral hemisphere participate in mentally representing object-oriented actions of the contralateral hand.

scholarly journals Bimanual coupling effect during a proprioceptive stimulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Biggio ◽  
A. Bisio ◽  
F. Garbarini ◽  
Marco Bove
Keyword(s):  
Motor Imagery ◽  
Coupling Effect ◽  
Line Drawing ◽  
Proprioceptive Information ◽  
Muscle Vibration ◽  
Imagery Condition ◽  
Left Hand ◽  
Contralateral Hand ◽  
Bimanual Coupling ◽  
The Right

AbstractCircle-line drawing paradigm is used to study bimanual coupling. In the standard paradigm, subjects are asked to draw circles with one hand and lines with the other hand; the influence of the concomitant tasks results in two “elliptical” figures. Here we tested whether proprioceptive information evoked by muscle vibration inducing a proprioceptive illusion (PI) of movement at central level, was able to affect the contralateral hand drawing circles or lines. A multisite 80 Hz-muscle vibration paradigm was used to induce the illusion of circle- and line-drawing on the right hand of 15 healthy participants. During muscle vibration, subjects had to draw a congruent or an incongruent figure with the left hand. The ovalization induced by PI was compared with Real and Motor Imagery conditions, which already have proved to induce bimanual coupling. We showed that the ovalization of a perceived circle over a line drawing during PI was comparable to that observed in Real and Motor Imagery condition. This finding indicates that PI can induce bimanual coupling, and proprioceptive information can influence the motor programs of the contralateral hand.

Experimentally Confirmed Mathematical Model for Human Control of a Non-Rigid Object

2004 ◽  
Vol 91 (3) ◽  
pp. 1158-1170 ◽  
Author(s):  
Jonathan B. Dingwell ◽  
Christopher D. Mah ◽  
Ferdinando A. Mussa-Ivaldi
Keyword(s):  
Mathematical Model ◽  
Human Subjects ◽  
Movement Planning ◽  
Relative Speed ◽  
Rigid Object ◽  
Hand Motion ◽  
Human Control ◽  
Rigid Objects ◽  
Minimum Jerk ◽  
Neuroscience Research

Determining the principles used to plan and execute movements is a fundamental question in neuroscience research. When humans reach to a target with their hand, they exhibit stereotypical movements that closely follow an optimally smooth trajectory. Even when faced with various perceptual or mechanical perturbations, subjects readily adapt their motor output to preserve this stereotypical trajectory. When humans manipulate non-rigid objects, however, they must control the movements of the object as well as the hand. Such tasks impose a fundamentally different control problem than that of moving one's arm alone. Here, we developed a mathematical model for transporting a mass-on-a-spring to a target in an optimally smooth way. We demonstrate that the well-known “minimum-jerk” model for smooth reaching movements cannot accomplish this task. Our model extends the concept of smoothness to allow for the control of non-rigid objects. Although our model makes some predictions that are similar to minimum jerk, it predicts distinctly different optimal trajectories in several specific cases. In particular, when the relative speed of the movement becomes fast enough or when the object stiffness becomes small enough, the model predicts that subjects will transition from a uni-phasic hand motion to a bi-phasic hand motion. We directly tested these predictions in human subjects. Our subjects adopted trajectories that were well-predicted by our model, including all of the predicted transitions between uni- and bi-phasic hand motions. These findings suggest that smoothness of motion is a general principle of movement planning that extends beyond the control of hand trajectories.

The representing brain: Neural correlates of motor intention and imagery

1994 ◽  
Vol 17 (2) ◽  
pp. 187-202 ◽  
Author(s):  
M. Jeannerod
Keyword(s):  
Motor Imagery ◽  
Object Oriented ◽  
Action Planning ◽  
Motor Preparation ◽  
Neural Pathways ◽  
Positive Effects ◽  
Motor Intention ◽  
Posterior Parietal ◽  
Motor Actions ◽  
Motor Representations

AbstractThis paper concerns how motor actions are neurally represented and coded. Action planning and motor preparation can be studied using a specific type of representational activity, motor imagery. A close functional equivalence between motor imagery and motor preparation is suggested by the positive effects of imagining movements on motor learning, the similarity between the neural structures involved, and the similar physiological correlates observed in both imaging and preparing. The content of motor representations can be inferred from motor images at a macroscopic level, based on global aspects of the action (the duration and amount of effort involved) and the motor rules and constraints which predict the spatial path and kinematics of movements. A more microscopic neural account calls for a representation of object-oriented action. Object attributes are processed in different neural pathways depending on the kind of task the subject is performing. During object-oriented action, a pragmatic representation is activated in which object affordances are transformed into specific motor schemas (independently of other tasks such as object recognition). Animal as well as human clinical data implicate the posterior parietal and premotor cortical areas in schema instantiation. A mechanism is proposed that is able to encode the desired goal of the action and is applicable to different levels of representational organization.

Lateralized Visual-Field Inattention in Schizophrenia

1994 ◽  
Vol 79 (1) ◽  
pp. 699-702 ◽  
Author(s):  
Daniel S. Lobel ◽  
Rex M. Swanda ◽  
Miklos F. Losonczy
Keyword(s):  
Visual Field ◽  
Cerebral Hemisphere ◽  
Right Visual Field ◽  
Verbal Processing ◽  
Cognitive Research ◽  
Schizophrenic Patients ◽  
Hemispheric Functioning ◽  
Left And Right ◽  
Verbal Functioning ◽  
The Right

Numerous studies have shown impaired verbal functioning in schizophrenic patients as compared with normals. The verbal deficits are generally attributed to damage of the left cerebral hemisphere. This attribution is based on literature which suggests that verbal processing is primarily mediated by the left hemisphere in right-handed humans. This study explored left-hemispheric integrity directly by assessing sustained attention in both the left and right hemispheres of 40 schizophrenic patients with the Weintraub Cancellation Tasks. Patients made significantly more errors of omission on the right visual field than on the left. These results are consistent with cognitive research in schizophrenia by demonstrating selective left-hemispheric impairment relative to right-hemispheric functioning.

Changes of intracortical inhibition during motor imagery in human subjects

1999 ◽  
Vol 263 (2-3) ◽  
pp. 113-116 ◽  
Author(s):  
G Abbruzzese ◽  
A Assini ◽  
A Buccolieri ◽  
R Marchese ◽  
C Trompetto
Keyword(s):  
Motor Imagery ◽  
Human Subjects ◽  
Intracortical Inhibition

Relations between Attentional and Intentional Neural Systems

1995 ◽  
Vol 81 (3) ◽  
pp. 947-951 ◽  
Author(s):  
Gianpaolo Basso ◽  
Paolo Nichelli
Keyword(s):  
Visual Field ◽  
Cerebral Hemisphere ◽  
Arm Movement ◽  
Neural Systems ◽  
Right Visual Field ◽  
Contralateral Hemisphere ◽  
Lateral Direction ◽  
Response Latencies ◽  
Rightward Movement ◽  
The Right

This study explored whether preparing an arm movement influences detection of a visual stimulus We cued subjects to respond with either a rightward or a leftward movement to the appearance of a stimulus located either in the centre, in the left, or in the right visual field. Programming a movement toward a lateral direction enhanced visual attention at that side. Rightward movements were associated with an attentional cost only for responses to a central location, while leftward movements slowed response latencies to both central and right-sided stimuli. We hypothesized that programming a rightward movement depends on the activation of intentional centers in either cerebral hemisphere. On the contrary, leftward movements might be only driven by the contralateral hemisphere.

Is saccade averaging determined by visual processing or movement planning?

2012 ◽  
Vol 108 (12) ◽  
pp. 3161-3171 ◽  
Author(s):  
Neha Bhutani ◽  
Supriya Ray ◽  
Aditya Murthy
Keyword(s):  
Visual Processing ◽  
Human Subjects ◽  
Movement Planning ◽  
Double Step ◽  
Alternative Hypotheses ◽  
Task Conditions ◽  
Saccade Averaging ◽  
Initial Target

Saccadic averaging that causes subjects' gaze to land between the location of two targets when faced with simultaneously or sequentially presented stimuli has been often used as a probe to investigate the nature of computations that transform sensory representations into an oculomotor plan. Since saccadic movements involve at least two processing stages—a visual stage that selects a target and a movement stage that prepares the response—saccade averaging can either occur due to interference in visual processing or movement planning. By having human subjects perform two versions of a saccadic double-step task, in which the stimuli remained the same, but different instructions were provided (REDIRECT gaze to the later-appearing target vs. FOLLOW the sequence of targets in their order of appearance), we tested two alternative hypotheses. If saccade averaging were due to visual processing alone, the pattern of saccade averaging is expected to remain the same across task conditions. However, whereas subjects produced averaged saccades between two targets in the FOLLOW condition, they produced hypometric saccades in the direction of the initial target in the REDIRECT condition, suggesting that the interaction between competing movement plans produces saccade averaging.

scholarly journals Classification of Motor Imagery Based EEG Signals

2019 ◽  
Vol 8 (9) ◽  
pp. 1012-1020
Keyword(s):  
Motor Imagery ◽  
Learning Algorithm ◽  
Human Subjects ◽  
Brain Activity ◽  
Back Propagation ◽  
Support Vector ◽  
Raw Data ◽  
Left Hand ◽  
Right Hand ◽  
Eeg Data

Brain Computer Interface (BCI) enable the user to interact with system only through brain activity, usually measured by Electroencephalography (EEG). BCI systems additionally offers analysis of Motor Imagery EEG, which may be appeared, is a novel way of communication for the patients who are physically disabled. Motor Imagery based EEG data (left hand, right hand, or foot) movements supplied by BCI Competition IV dataset1. The data signals were band-pass filtered between 0.05 and 200Hz and sampled at 100Hz. The features extracted from the raw data with respect to time and frequency domain of required channels. Motor Imagery based EEG (left hand, right hand or foot) data classified using machine learning algorithm namely Support Vector Machine (SVM) and Back Propagation Neural Network (BPNN) for four normal human subjects (a, b, f, g). Analysis of motor imagery-based EEG data was studied using EEGLAB toolbox. Selected data are presented from raw data in channel data (scroll), representation of channel location in 2D and 3D form, channel spectra and maps and channel properties.

Sidestepping spatial confounds in object-based correspondence effects: The Bimanual Affordance Task (BMAT)

2019 ◽  
Vol 72 (11) ◽  
pp. 2605-2613 ◽  
Author(s):  
Shaheed Azaad ◽  
Simon M Laham
Keyword(s):  
Response Times ◽  
Spatial Compatibility ◽  
Response Type ◽  
Motor Systems ◽  
Response Hand ◽  
Object Affordances ◽  
Object Based ◽  
Correspondence Effects ◽  
Grasp Affordances ◽  
Task Irrelevant

Tucker and Ellis found that when participants made left/right button-presses to indicate whether objects were upright or inverted, responses were faster when the response hand aligned with the task-irrelevant handle orientation of the object. The effect of handle orientation on response times has been interpreted as evidence that individuals perceive grasp affordances when viewing briefly presented objects, which in turn activate grasp-related motor systems. Although the effect of handle alignment has since been replicated, there remains doubt regarding the extent to which the effect is indeed driven by affordance perception. Objects that feature in affordance-compatibility paradigms are asymmetrical and have laterally protruding handles (e.g., mugs) and thus confound spatial and affordance properties. Research has attempted to disentangle spatial compatibility and affordance effects with varying results. In this study, we present a novel paradigm with which to study affordance perception while sidestepping spatial confounds. We use the Bimanual Affordance Task (BMAT) to test whether object affordances in symmetrical objects facilitate response times. Participants ( N = 36) used one of three (left unimanual/right unimanual/bimanual) responses to indicate the colour of presented objects. Objects afforded either a unimanual (e.g., handbag) or a bimanual (e.g., laundry hamper) grasp. Responses were faster when the afforded grasp corresponded with the response type (unimanual vs. bimanual), suggesting that affordance effects exist independent of spatial compatibility.

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