Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Kinesiology

Faculty/School

Faculty of Science

First Advisor

Dr. Pam Bryden

Advisor Role

Supervisor

Advisor Role

Supervisor

Abstract

The objective of the present study was to examine the different kind of switch costs among a varied population using a modified bimanual serial reaction time task. Alternating between responses produce a cost of increased response time, which is termed a switch cost. However, not all switch costs are equal, and its effect on response time is dependent on what previous hand and digit combination was utilized. A detachable touchscreen tablet PC running a custom built JavaScript based software prompted participants to press down with their digits (2nd-5th) to corresponding buttons which would light up in a serial fashion. Response times for inter- to intra- hand, homologous to non-homologous digits, ‘left-to-right’ and right-to-left’ switches were then recorded once the button was pressed. An example of a homologous switch would be the response time of the 3rd digit on the left hand if it followed the 3rd digit on the right hand. Left-handed (n=18) and right-handed (n=91) individuals, aged 5-58 years, M = 21.65 years, SD = 11.97 years, 65 females participated. Past research on bimanual digit movement within and between hands has not been congruous, suggesting either faster response times when a following digit movement is made on the same versus opposite hand, and vice versa. This incongruity is furthered by response time differences in homologous and non-homologous movement of the digits. This inconsistency exists because of differing objectives in past work, which are not focused on isolating response times when alternating between hands or digits. In this study, stimulus-response effects were minimized by using a personalized hand and digit orientation, with buttons customized to the width of the hands for each participant, and visual responses directly under the digits, still visible in a seated position. The effects of gender and handedness were insignificant. Quantitative results determined that age had the most significant effect on all types of response time, with the youngest ages (5-13 years) being the slowest, adolescents to middle adults (14-25 years) being the fastest, and a slight decline in middle to older adults’ (26-58 years) response times. Additionally, errors played a significant role explaining these differences in response time. Differences in errors for the same and opposite hand reflected the same trend found in response time for age. Furthermore, a greater number of errors were encountered progressing from the 2nd to 5th digit. Overall, this study highlights the impact of age on bimanual response time, and the lesser impact of gender and handedness, which should still be controlled for. Moreover, there may be implications for research on bimanual movements by considering the impact of errors, which may be a means to further the understanding of bimanual movement and coordination in the future.

Comments

In partial fulfillment of the requirements for Master of Science in Kinesiology at Wilfrid Laurier University

Convocation Year

2015

Included in

Motor Control Commons

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