Biomedical subjects

Jacqueline C Shin

Publications and source records attributed to Jacqueline C Shin.

4 recordsLinked to original sources

PubMed2004

Multidimensional sequence learning in patients with focal basal ganglia lesions.

Parkinson's patients have been found to be impaired in learning movement sequences. In the current study, patients with unilateral basal ganglia lesions due to stroke were tested on a serial reaction time task in which responses were based on the spatial location of each stimulus. The spatial locations either followed a fixed sequence or were selected at random, with learning operationalized as the difference in reaction time between these two conditions. In addition, three response-to-stimulus intervals were used, and these either followed a fixed sequence or were randomized. Compared to control participants, the patients showed normal learning of the spatial and temporal sequences, as well as normal cross-dimensional learning. This was true for performance with either the contralesional or ipsilesional hand. Sequence learning was not correlated with maximum tapping rate, a simple measure of motor impairment. These results raise questions concerning the use of Parkinson's disease as a model for studying basal ganglia dysfunction.

Aged↗

PubMed2003

Spatial and temporal sequence learning in patients with Parkinson's disease or cerebellar lesions.

The functional role of different subcortical areas in sequence learning is not clear. In the current study, Parkinson's patients, patients with cerebellar damage, and age-matched control participants performed a serial reaction time task in which a spatial sequence and a temporal sequence were presented simultaneously. The responses were based on the spatial sequence, and the temporal sequence was incidental to the task. The two sequences were of the same length, and the phase relationship between them was held constant throughout training. Sequence learning was assessed comparing performance when both sequences were present versus when the dimension of interest was randomized. In addition, sequence integration was assessed by introducing phase-shift blocks. A functional dissociation was found between the two patient groups. Whereas the Parkinson's patients learned the spatial and temporal sequences individually, they did not learn the relationship between the two sequences, suggesting the basal ganglia play a functional role in sequence integration. In contrast, the cerebellar patients did not show any evidence of sequence learning at all, suggesting the cerebellum might play a general role in forming sequential associations.

Aged↗

PubMed2002

Reaching while calculating: scheduling of cognitive and perceptual-motor processes.

To address the neglected question of how cognitive and perceptual-motor processes are coordinated, the authors asked participants to move a cursor from one target to another to reveal operators and operands for a running arithmetic task. In Experiment I performance on this task was compared with performance on tasks requiring only aiming or only arithmetic. Aiming was faster in the aiming-only task than in the combined task. More importantly, times for steps requiring calculation were equivalent in the combined and arithmetic-only tasks. The results from this and a second experiment suggest that participants slowed their aiming to allow calculations to be completed before subsequent targets were entered. As a whole, the results suggest that cognitive and perceptual-motor processes are coordinated through scheduling.

Cognition↗

PubMed2002

Concurrent learning of temporal and spatial sequences.

In a serial reaction time task, stimulus events simultaneously defined spatial and temporal sequences. Responses were based on the spatial dimension. The temporal sequence was incidental to the task, defined by the response-to-stimulus intervals in Experiment 1 and stimulus onset asynchronies in Experiment 2. The two sequences were either of equal length and correlated or of unequal length. In both experiments, spatial learning occurred regardless of sequence length condition. In contrast, temporal learning occurred only in the correlated condition. These results suggest that timing is an integrated part of action representations and that incidental learning for a temporal pattern does not occur independently from the action. Interestingly, sequence learning was enhanced in the correlated condition, reflecting the integration of spatial-temporal information.

Analysis of Variance↗