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Full-Text Articles in Medicine and Health Sciences
Dual-Task Interference: The Effects Of Verbal Cognitive Tasks On Upright Postural Stability In Parkinson's Disease, J. Holmes, M. Jenkins, Andrew Johnson, S. Adams, S. Spaulding
Dual-Task Interference: The Effects Of Verbal Cognitive Tasks On Upright Postural Stability In Parkinson's Disease, J. Holmes, M. Jenkins, Andrew Johnson, S. Adams, S. Spaulding
Andrew M. Johnson
Although dual-task interference has previously been demonstrated to have a significant effect on postural control among individuals with Parkinson's disease, the impact of speech complexity on postural control has not been demonstrated using quantitative biomechanical measures. The postural stability of twelve participants with idiopathic Parkinson's disease and twelve healthy age-matched controls was evaluated under three conditions: (1) without a secondary task, (2) performing a rote repetition task and (3) generating a monologue. Results suggested a significant effect of cognitive load on biomechanical parameters of postural stability. Although both groups increased their postural excursion, individuals with Parkinson's disease demonstrated significantly reduced …
Dual Task Performance In A Healthy Young Adult Population: Results From A Symmetric Manipulation Of Task Complexity And Articulation, Albert Armieri, Jeffrey Holmes, Sandi Spaulding, Mary Jenkins, Andrew Johnson
Dual Task Performance In A Healthy Young Adult Population: Results From A Symmetric Manipulation Of Task Complexity And Articulation, Albert Armieri, Jeffrey Holmes, Sandi Spaulding, Mary Jenkins, Andrew Johnson
Andrew M. Johnson
The ability to execute and maintain gait while performing simultaneous cognitive, verbal, or motor tasks ('dual-tasking') is beneficial in many ways. It is well-documented, however, that dual-tasking can result in cognitive or motoric interference that results in diminished gait performance, and impaired secondary task performance. When manipulating cognitive load, it is common to have participants respond verbally to stimuli. While this is an ecologically valid way to measure the effects of cognitive load on gait, it ignores the additional demands inherent in the verbal aspect of the task. In the present study, we manipulated complexity and articulation within a single …
Brain Nerve Conduction Velocity Is A Valid And Useful Construct For Studying Human Cognitive Abilities: A Reply To Saint-Amour Et Al, Andrew Johnson, T. Reed, Philip Vernon
Brain Nerve Conduction Velocity Is A Valid And Useful Construct For Studying Human Cognitive Abilities: A Reply To Saint-Amour Et Al, Andrew Johnson, T. Reed, Philip Vernon
Andrew M. Johnson
No abstract provided.
Visual Inspection Time In Parkinson's Disease: Deficits In Early Stages Of Cognitive Processing, Andrew Johnson, Quincy Almeida, Con Stough, James Thompson, Rene Singarayer, Mandar Jog
Visual Inspection Time In Parkinson's Disease: Deficits In Early Stages Of Cognitive Processing, Andrew Johnson, Quincy Almeida, Con Stough, James Thompson, Rene Singarayer, Mandar Jog
Andrew M. Johnson
Inspection time (IT) is a simple information processing paradigm dependent on a participant's ability to identify physical properties of a stimulus presented for a specified time interval. In contrast with reaction time (RT) studies, the dependent variable of interest in IT is not related to the motoric speed with which the individual is able to respond, but rather the minimum presentation time necessary for participants to reliably identify physical properties of the stimulus. It is well documented that individuals with Parkinson's disease (PD) experience significant impairment on tests of simple RT, but it is unclear whether such deficits can be …
A Role Of The Basal Ganglia In Movement: The Effect Of Precues On Discrete Bi-Directional Movements In Parkinson's Disease, Andrew Johnson, Philip Vernon, Quincy Almeida, Linda Grantier, Mandar Jog
A Role Of The Basal Ganglia In Movement: The Effect Of Precues On Discrete Bi-Directional Movements In Parkinson's Disease, Andrew Johnson, Philip Vernon, Quincy Almeida, Linda Grantier, Mandar Jog
Andrew M. Johnson
The effect of a precue on improving movement initiation (i.e., reaction time; RT) is well understood, whereas its influence on movement execution (i.e., movement time; MT) has rarely been examined. The current study investigated the influence of a directional precue (i.e., left vs. right) on the RT and MT of simple and discrete bi-directional movements in a large sample of Parkinson's disease patients and healthy control participants. Both patients and controls were tested twice, with testing sessions separated by 2 hours. Patients were tested first following an overnight levodopa withdrawal and again after they had taken their medication. Both patients …