The Initiation of Visual Corrections Within The Acceleration and Deceleration Phases of a Movement

Two experiments were conducted to examine changes in the kinetic parameters as corrections were introduced into the movement. It was postulated that the amount of peak force produced by a group of muscles (peak acceleration and deceleration) and time of activation (time of peak values and duration of the acceleration phase) would differ according to the type of correction initiated. In the present set of experiments subjects modified movements by either extending the distance of the response or reversing the direction of the ongoing movement. The signal for subjects to modify their movement was visual and could occur at six different locations in the movement. In the first experiment reversing and continuing corrections were examined across three different distance/movement time combinations. Continuing signals caused an increase in the duration of the acceleration phase and/or the creation of a second acceleration phase. Reversing signals affected peak deceleration and/or time of peak deceleration. The location of both continuing and reversing stimuli, acceleration rate, and movement time appeared to determine which kinematic parameters were adjusted for a specific correction. The second experiment was designed to compare how continuing and reversing corrections were initiated when a choice had to be made between similar and opposing response corrections, and when a choice was not involved. One of the most interesting differences between continuing and reversing corrections was that when a choice had to be made between similar continuing changes the continuing corrections were still initiated in the same manner as in a simple amendment paradigm. However, when a choice had to be made between similar reversing corrections the processing was increased to the level that reversing corrections could not affect the movement as soon as in a simple amendment paradigm. These findings support the general premise that continuing corrections require less processing than reversing corrections.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physical Education

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Falkenberg, Lori Ellen

• Education, Physical

Identifier

(UMI)AAI8209566

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71859