Biomedical subjects

Magdalena Ietswaart

Publications and source records attributed to Magdalena Ietswaart.

5 recordsLinked to original sources

PubMed2006

Recovery of hand function through mental practice: a study protocol.

BACKGROUND: The study aims to assess the therapeutic benefits of motor imagery training in stroke patients with persistent motor weakness. There is evidence to suggest that mental rehearsal of movement can produce effects normally attributed to practising the actual movements. Imagining hand movements could stimulate the redistribution of brain activity, which accompanies recovery of hand function, thus resulting in a reduced motor deficit. METHODS/DESIGN: A multi-centre randomised controlled trial recruiting individuals between one and six months post-stroke (n = 135). Patients are assessed before and after a four-week evaluation period. In this trial, 45 patients daily mentally rehearse movements with their affected arm under close supervision. Their recovery is compared to 45 patients who perform closely supervised non-motor mental rehearsal, and 45 patients who are not engaged in a training program. Motor imagery training effectiveness is evaluated using outcome measures of motor function, psychological processes, and level of disability. DISCUSSION: The idea of enhancing motor recovery through the use of motor imagery rehabilitation techniques is important with potential implications for clinical practice. The techniques evaluated as part of this randomised controlled trial are informed by the current understanding in cognitive neuroscience and the trial is both of scientific and applied interest.

Hand↗

PubMed2006

Theory of mind following traumatic brain injury: the role of emotion recognition and executive dysfunction.

A number of studies have now documented that traumatic brain injury (TBI) is associated with deficits in the recognition of basic emotions, the capacity to infer mental states of others (theory of mind), as well as executive functioning. However, no study to date has investigated the relationship between these three constructs in the context of TBI. In the current study TBI participants (N=16) were compared with demographically matched healthy controls (N=17). It was found that TBI participants' recognition of basic emotions, as well as their capacity for mental state attribution, was significantly reduced relative to controls. Performance on both of these measures was strongly correlated in the healthy control, but not in the TBI sample. In contrast, in the TBI (but not the control) sample, theory of mind was substantially correlated with performance on phonemic fluency, a measure of executive functioning considered to impose particular demands upon cognitive flexibility and self-regulation. These results are consistent with other evidence indicating that deficits in some aspects of executive functioning may at least partially underlie deficits in social cognition following TBI, and thus help explain the prevalence of social dysfunction in TBI.

Adult↗

PubMed2006

Impairments in theory of mind shortly after traumatic brain injury and at 1-year follow-up.

Most studies into acquired theory of mind (ToM) deficits assessed patients once, long after the onset of brain injury. As a result, the time course of acquired ToM impairments is largely unknown. The present study examined whether ToM impairments following traumatic brain injury (TBI) recover, remain stable, or worsen over time. Because of the alleged association between ToM and social communication, ToM impairments may deteriorate because of changes in patients' social environment following injury. ToM ability and executive functioning were assessed shortly after injury and at 1-year follow-up. Compared with the orthopedic control group, the TBI group was impaired on ToM and executive functioning tasks at both assessments. Furthermore, the ToM impairments in the TBI group remained stable over time.

Adult↗

PubMed2005

Tapping, grasping and aiming in ideomotor apraxia.

Very few studies have investigated sensorimotor control in apraxia using tasks that differ in movement complexity. Nevertheless, there is some evidence to suggest that spontaneous behaviour, although relatively preserved, can be rather clumsy or awkward, and that patients with ideomotor apraxia may have subtle kinematic abnormalities in movements made in the laboratory. It remains unclear whether patients with ideomotor apraxia perform normally on movements such as visually guided aiming, that may not depend on higher-order, more cognitive, processes and that are relatively unguided by overlearned contexts. In this study, three different sensorimotor tasks were given to the same sample of patients with quantified apraxic disturbance. Finger tapping, goal-directed grasping and aiming with and without visual feedback were examined in these patients. A clear dissociation was found between grossly impaired gesture imitation and intact motor programming of goal-directed movements with visual feedback. Apraxic patients were, however, impaired on aiming movements without visual feedback, suggesting that apraxia is associated with an increased reliance on integration of online visual information with feedforward/feedback somatosensory and motor signals. Furthermore, patients were impaired on single finger tapping which was a surprisingly good predictor of apraxia severity.

Aged↗

PubMed2002

Neuropsychological perspectives on eye-hand coordination in visually-guided reaching.

Substantial progress has been made in understanding the neural control of movement in the past 30 years. Lower cost technology for tracking movements of the eyes and the hands has increased our understanding of these two systems and their interactions in both neurologically intact individuals and non-human primates. Nevertheless the neuropsychology of eye-hand coordination during visually-guided tasks such as reaching and grasping remains relatively understudied. This chapter reviews some of the relevant neurophysiology and neuropsychology of eye-hand coordination during visually-guided reaching. Current models emphasising coordinate transformations are discussed in light of new patient data showing a particular type of failure of eye-hand coordination during reaching.

Animals↗