Bimanual coordination and perceptual grouping in a patient with motor neglect

2005 ◽  
Vol 22 (7) ◽  
pp. 795-815 ◽  
Author(s):  
T. D. Punt ◽  
M. J. Riddoch ◽  
G. W. Humphreys
Keyword(s):  
Perceptual Grouping ◽  
Bimanual Coordination ◽  
Motor Neglect

Shall I Move My Right or My Left Hand?

2003 ◽  
Vol 17 (2) ◽  
pp. 69-86 ◽  
Author(s):  
Claudio Babiloni ◽  
Fabio Babiloni ◽  
Filippo Carducci ◽  
Febo Cincotti ◽  
Claudio Del Percio ◽  
...  
Keyword(s):  
Bimanual Coordination ◽  
Central Area ◽  
Eeg Analysis ◽  
Complementary Information ◽  
Left Hand ◽  
Mirror Movements ◽  
Related Potentials ◽  
Motor Acts ◽  
Abstract Event

Abstract Event-related desynchronization/synchronization (ERD/ERS) at alpha (10Hz), beta (20Hz), and gamma (40Hz) bands and movement-related potentials (MRPs) were investigated in right-handed subjects who were “free” to decide the side of unilateral finger movements (“fixed” side as a control). As a novelty, this “multi-modal” EEG analysis was combined with the evaluation of involuntary mirror movements, taken as an index of “bimanual competition.” A main issue was whether the decision regarding the hand to be moved (“free” movements) could modulate ERD/ERS or MRPs overlying sensorimotor cortical areas typically involved in bimanual tasks. Compared to “fixed” movements, “free” movements induced the following effects: (1) more involuntary mirror movements discarded from EEG analysis; (2) stronger vertex MRPs (right motor acts); (3) a positive correlation between these potentials and the number of involuntary mirror movements; (4) gamma ERS over central areas; and (5) preponderance of postmovement beta ERS over left central area (dominant hemisphere). These results suggest that ERD/ERS and MRPs provide complementary information on the cortical processes belonging to a lateralized motor act. In this context, the results on vertex MRPs would indicate a key role of supplementary/cingulate motor areas not only for bimanual coordination but also for the control of “bimanual competition” and involuntary mirror movements.

scholarly journals Motor neglect

Cortex ◽  
2021 ◽  
Author(s):  
Paolo Bartolomeo
Keyword(s):  
Motor Neglect

Unraveling Interlimb Interactions Underlying Bimanual Coordination

2005 ◽  
Vol 94 (5) ◽  
pp. 3112-3125 ◽  
Author(s):  
Arne Ridderikhoff ◽  
C. (Lieke) E. Peper ◽  
Peter J. Beek
Keyword(s):  
Bimanual Coordination ◽  
Feedforward Control ◽  
Emg Activity ◽  
Minor Role ◽  
Error Corrections ◽  
Flexion Extension ◽  
Contralateral Hand ◽  
Phase Coordination ◽  
The Stability ◽  
Passive Movements

Three sources of interlimb interactions have been postulated to underlie the stability characteristics of bimanual coordination but have never been evaluated in conjunction: integrated timing of feedforward control signals, phase entrainment by contralateral afference, and timing corrections based on the perceived error of relative phase. In this study, the relative contributions of these interactions were discerned through systematic comparisons of five tasks involving rhythmic flexion–extension movements about the wrist, performed bimanually (in-phase and antiphase coordination) or unimanually with or without comparable passive movements of the contralateral hand. The main findings were the following. 1) Contralateral passive movements during unimanual active movements induced phase entrainment to interlimb phasing of either 0° (in-phase) or 180° (antiphase). 2) Entrainment strength increased with the passive movements' amplitude, but was similar for in-phase and antiphase movements. 3) Coordination of unimanual active movements with passive movements of the contralateral hand (kinesthetic tracking) was characterized by similar bilateral EMG activity as observed in active bimanual coordination. 4) During kinesthetic tracking the timing of the movements of the active hand was modulated by afference-based error corrections, which were more pronounced during in-phase coordination. 5) Indications of in-phase coordination being more stable than antiphase coordination were most prominent during active bimanual coordination and marginal during kinesthetic tracking. Together the results indicated that phase entrainment by contralateral afference contributed equally to the stability of in-phase and antiphase coordination, and that differential stability of these patterns depended predominantly on integrated timing of feedforward signals, with only a minor role for afference-based error corrections.

Perceptual grouping of line features in 3-D space: a model-based framework

2004 ◽  
Vol 37 (1) ◽  
pp. 145-159 ◽  
Author(s):  
In Kyu Park ◽  
Kyoung Mu Lee ◽  
Sang Uk Lee
Keyword(s):  
Perceptual Grouping ◽  
Model Based ◽  
Line Features

The Subjective Present and Its Modulation in Clinical Contexts

2013 ◽  
Vol 1 (2) ◽  
pp. 239-259 ◽  
Author(s):  
Wolfgang Tschacher ◽  
Fabian Ramseyer ◽  
Claudia Bergomi
Keyword(s):  
Perceptual Grouping ◽  
Statistical Significance ◽  
Temporal Distribution ◽  
Future Research ◽  
Implicit Processes ◽  
The Social ◽  
Gestalt Perception ◽  
Psychotherapeutic Techniques ◽  
The Mean ◽  
The Individual

Time is a basic dimension in psychology, underlying behavior and experience. Timing and time perception constitute implicit processes that are often inaccessible to the individual person. Research in this field has shown that timing is involved in many areas of clinical significance. In the projects presented here, we combine timing with seemingly different fields of research, such as psychopathology, perceptual grouping, and embodied cognition. Focusing on the time scale of the subjective present, we report findings from three different clinical studies: (1) We studied perceived causality in schizophrenia patients, finding that perceptual grouping (‘binding’, ‘Gestalt formation’), which leads to visual causality perceptions, did not distinguish between patients and healthy controls. Patients however did integrate context (provided by the temporal distribution of auditory context stimuli) less into perceptions, in significant contrast to controls. This is consistent with reports of higher inaccuracy in schizophrenia patients’ temporal processing. (2) In a project on auditory Gestalt perception we investigated auditory perceptual grouping in schizophrenia patients. The mean dwell time was positively related to how much patients were prone to auditory hallucinations. Dwell times of auditory Gestalts may be regarded as operationalizations of the subjective present; findings thus suggested that patients with hallucinations had a shorter present. (3) The movement correlations of interacting individuals were used to study the non-verbal synchrony between therapist and patient in psychotherapy sessions. We operationalized the duration of an embodied ‘social present’ by the statistical significance of such associations, finding a window of roughly 5.7 seconds in conversing dyads. We discuss that temporal scales of nowness may be modifiable, e.g., by mindfulness. This yields promising goals for future research on timing in the clinical context: psychotherapeutic techniques may alter binding processes, hence the subjective present of individuals, and may affect the social present in therapeutic interactions.

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