Brain activation during ideomotor praxis: imitation and movements executed by verbal command

Abstract

Background: Ideomotor apraxia is a disorder of both imitation movements and movements executed by verbal command. Lesion studies have identified the left parietal lobe as the neural correlate for ideomotor praxis (IP), although there are opposing views. Objectives: To localise the neural substrates for IP using functional magnetic resonance imaging. Brain regions activated by both imitation and verbal command movements were tested against a simple self paced movement. Methods: Twenty two young, right handed, healthy subjects were examined. Functional and anatomical data were acquired. The experiment comprised three motor conditions (imitation, movements executed by verbal command, and finger bending/unbending) and a rest condition. All motor tasks were performed using the left hand. Eighteen drawings of left hand postures were presented for the imitation condition. Identical postures were instructed verbally for the verbal command condition. The finger bending/ unbending movement was self paced. Blood oxygenation level dependent (BOLD) signal increases were compared during two kinds of IP (imitation and verbal command movements) and during finger bending/ unbending movements. Results: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei were activated during both imitation and verbal command movements. The difference in BOLD signal between imitation and verbal command movements was localised in the dorsal and ventral occipital areas. BOLD signal differences for movements executed by verbal command against imitation were observed in the superior temporal areas. Conclusions: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei are the neural substrates for IP.

A parietal–temporal sensory–motor integration area for the human vocal tract: Evidence from an fMRI study of skilled musicians

“…Consistent with previous functional imaging studies on the production of manual gestures including piano-playing and gesture imitation (Meister et al, 2004;Peigneux et al, 2004;Makuuchi et al, 2005), the present study found a region in the left aIPS which showed an effector bias in the opposite direction, responding significantly more during the covert play than covert hum condition. This finding is consistent with the idea that the aIPS contains a system that functions as a sensory-motor interface for the manual effectors (Colby & Goldberg, 1999;Culham & Kanwisher, 2001).…”

“…All seven subjects had significant activations in this region. Based on previous studies showing that production of manual movements (e.g., gesture copying) activated posterior parietal areas (Makuuchi et al, 2005;Muhlau et al, 2005), we also defined a parietal ROI using the covert play regressor: a region within the left aIPS was activated in all seven subjects. The top 4 activated contiguous voxels in this ROI, in each subject, were selected for further analysis.…”

“…As a secondary hypothesis, we postulated that the use of manual effectors in covertly playing the melody will activate PPC, as this region has been implicated in several manual tasks including visually-guided reaching, apraxic assessments, and piano-playing (Burnod et al, 1999;Haslinger et al, 2005;Makuuchi, Kaminaga, & Sugishita, 2005;Meister et al, 2004).…”

Swallowing Disturbance Pattern Relates to Brain Lesion Location in Acute Stroke Patients

“…1 Our results concur with left-hemispheric dominance in the early stage of volitional swallowing, 9 and key role of left parietal cortex in ideomotor apraxia. 10 The found association of PTI (on any side) with attention deficit underscores significance of bilateral parietal cortex in control of attention, even in tasks involving neither spatial nor visual cognition. 11 Confirming earlier findings, 6 all patients with lateral medullary infarction had pharyngeal dysfunction which, however, was also frequent and more severe in hemispheric infarctions.…”

“…Dysphagia was considered present at inability to swallow, food stuck in mouth/throat, cough after swallowing, impaired voice, or abnormal oximetry result on water swallowing test. 2 Applying consensus criteria, 2 pneumonia within 21 days after stroke was diagnosed (nϭ39; median latency, 3 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] days). Decision on gastrostomy (nϭ17) was based on FEES.…”