'Le regard des autres': the experience of walking in social environments as a person with Parkinson's disease.

Objective: To examine the experience of people with Parkinson's disease when walking in different social situations, and improve understanding of how this affects participation in meaningful activity.

Methods: A convenience sample of fourteen people with Parkinson's disease and a history of gait dysfunction was recruited. In-depth interviews and direct observations were conducted in the participants' home environments.

"The whole perimeter is difficult": Parkinson's disease and the conscious experience of walking in everyday environments.

This study sought to characterize the way patients with Parkinson's disease consciously perceive and respond to their surroundings while walking in everyday situations. A qualitative research program designed around an ecological data collection protocol was employed. A convenience sample of 14 patients with a diagnosis of Parkinson's disease and a history of gait difficulties were recruited.

Patterns of bidirectional communication between cortex and basal ganglia during movement in patients with Parkinson disease.

Cortico-basal ganglia networks are considered to comprise several parallel and mostly segregated loops, where segregation is achieved in space through topographic connectivity. Recently, it has been suggested that functional segregation may also be achieved in the frequency domain, by selective coupling of related activities at different frequencies. So far, however, any coupling across frequency in the human has only been modeled in terms of unidirectional influences, a misplaced assumption given the looped architecture of the basal ganglia, and has been considered in static terms.

Phasic increases in cortical beta activity are associated with alterations in sensory processing in the human.

Oscillatory activity in the beta (beta)-frequency band (13-35 Hz) can be recorded over the sensorimotor cortex in humans. It is coherent with electromyographic activity (EMG) during tonic contraction, but whether the cortical beta-oscillations are primarily motor or sensorimotor in function remains unclear. We tested the hypothesis that cortical beta-activity is associated with an up-regulation of sensory inputs that may be relevant to the organization of the motor response.

Existing motor state is favored at the expense of new movement during 13-35 Hz oscillatory synchrony in the human corticospinal system.

Oscillations in local field potentials in the beta-frequency band (13-35 Hz) are a pervasive feature of human and nonhuman primate motor cortical areas. However, the function of such synchronous activity across populations of neurons remains unknown. Here, we test the hypothesis that beta activity may promote existing motor set and posture while compromising processing related to new movements.

Late event-related potentials and movement complexity in young adults with Down syndrome.

Objectives: Through event-related potential (ERP) recording, to better understand the perceptive-motor slowness in adults with Down syndrome (DS); in particular, to assess whether motor preparation influences the speed of allocation of perceptual attention as reflected by the P3 latency.

Patients And Methods: ERPs were obtained in adults with and without DS through an auditory oddball paradigm under a passive and two active (simple vs. complex motor response) conditions.