Advanced analysis of motor development by Kathleen Haywood

The performer may step forward with either an ipsilateral or a contralateral pattern, and the arm is brought forward in a transverse plane. The motion may resemble a sling rather than a throw due to the extended arm position during the course of the throw. Stage 3 The distinctive characteristic is the ipsilateral arm and leg action. The ball is placed into a throwing position above the shoulder by a vertical and posterior motion of the arm at the time that the ipsilateral leg moves forward. There is little or no rotation of the spine and hips in preparation for the throw.

Hence the notion of programs that control movement, or motor programs. In the late 1960s and the 1970s it was popular to picture more and more elaborate information-processing models. 3). These simple models were often called black box models because all the intervening cognitive processing Perspectives on Perception and Action 37 Input was represented by one box between input and output, without a proposition for the various sequential steps involved in processing. Models became more elaborate as psychologists attempted to explain how perceivers add to the impoverished input to recreate the real world comStimulus prising the environment, its features, and its objects.

The fourth graders were also slower than the adults in movement time, and they again took slightly longer to move in the most complex condition. The kindergartners, as expected, were slower than the other groups, but they were slower in the moderate condition than they were in the most complex condition. In the complex condition the kindergartners took longer to react but moved more quickly to the second response key. They traded off reaction time and movement time depending on the response complexity.