Biomedical subjects

A L Chasteen

Publications and source records attributed to A L Chasteen.

5 recordsLinked to original sources

PubMed2001

Implementation intentions and facilitation of prospective memory.

Forming detailed implementation intentions for a future behavior can increase the probability that the behavior is actually completed. We investigated whether this intention effect could be used to improve prospective memory in older adults. As expected, participants who formed an implementation intention were more than twice as likely to self-initiate the intended behavior (writing down the day of the week on every sheet of paper received during the experiment) compared with participants who either were merely instructed to do so or actively rehearsed the instruction. Forming an implementation intention, however did not improve performance on a task that required a response to salient cues. We conclude that detailed implementation intentions facilitate prospective memory on tasks that lack salient cues and require self-initiation.

Aged↗

PubMed1999

The effect of age-related stereotypes on response initiation and execution.

In 2 experiments, the authors investigated the effects of positive and negative stereotypes of older adults on response initiation and execution. College students were first primed with the word young or the word old, and then produced an aimed hand movement in response to a positive or negative trait. Results of the 1st experiment indicated that the participants produced the fastest and most forceful movements when the word "old" primed negative traits; they produced the slowest and least forceful responses when the word old primed positive traits. In a 2nd experiment, the authors replicated these effects by using only the prime old. The results suggest that ageist responses extend beyond reaction time in a social judgment task.

Adult↗

PubMed1998

Aging and movement: variability of force pulses for saccadic eye movements.

Age-related differences in the trajectories of saccadic eye movements were examined. Younger and older adult subjects produced saccades to predictable target locations. Detailed features of the movements were examined such as the time of peak acceleration and the variability in the magnitude of the peak velocity. These and other measures reveal important details of the force pulses underlying the eye movements and the mental mechanisms that control them. Although minor differences were apparent between the eye movements of younger and older adults, the general patterns were the same across age groups. These results suggest that fundamental details of the brain mechanisms involved in the control of movement are the same for younger and older adults.

Adult↗

PubMed1997

Initiation and inhibition of saccadic eye movements in younger and older adults: an analysis of the gap effect.

Previous research with young adults has shown that the latency to initiate a saccadic eye movement is typically reduced when the visual fixation stimulus is removed prior to the appearance of a peripheral target stimulus (the "gap effect"). The present study sought to determine whether such fixation offsets would produce similar reductions in reaction time in both younger and older adults. The results indicated that older adults have longer overall latencies to initiate saccadic eye movements and that they exhibit the gap effect. However, the reduction in reaction time due to the fixation offset was approximately equal between younger and older adults relative to the overall saccadic latencies. These findings, along with some other recent evidence, suggest that some of the mechanisms involved in the production of saccadic eye movements may not reveal the changes often found in the skeletal motor system with increasing age. The implications of the findings to age-related differences in inhibitory function are discussed.

Acoustic Stimulation↗

PubMed1994

Rapid aimed limb movements: age differences and practice effects in component submovements.

Two experiments are reported in which younger and older adults practiced rapid aimed limb movements toward a visible target region. Ss were instructed to make the movements as rapidly and as accurately as possible. Kinematic details of the movements were examined to assess the differences in component submovements between the 2 groups and to identify changes in the movements due to practice. The results revealed that older Ss produced initial ballistic submovements that had the same duration but traveled less far than those of younger Ss. Additionally, older Ss produced corrective secondary submovements that were longer in both duration and distance than those of the younger subjects. With practice, younger Ss modified their submovements, but older Ss did not modify theirs even after extensive practice on the task. The results show that the mechanisms underlying movements of older adults are qualitatively different from those in younger adults.

Acceleration↗