Robert W. Christina

Premotor and Motor Reaction Time As a Function of Response Complexity

Abstract Two experiments were conducted to identify the response elements responsible for the complexity effect found by Henry and Rogers (1960). An attempt was made to determine if these elements were affecting the premotor time component of simple reaction time (SRT). If they were, a strong case could be made for the argument that neuromotor programming time was affected because premotor time is a more exact estimate of it than SRT. The results revealed that premotor time was unaffected by a forward change in movement direction, but increased as the number of movement parts increased from one to two and as the demand for movement accuracy increased. Thus, increasing the (1) number of parts and (2) accuracy demands were identified as elements of response complexity which increase programming time and support Henry and Rogers (1960) hypothesis that the time to initiate a response becomes longer as the programming process become more complex.

Simple Reaction Time as a Function of Response Complexity: Christina et al. (1982) Revisited

Abstract Two alternative interpretations to the one proposed by Christina, Fischman, Vercruyssen, and Anson (1982) were investigated. They interpreted the simple reaction time (SRT) increase they found, which was thought to reflect an increase in programming time, to be due to the increase in number of movement parts from one response to another. Experiment 1(N = 15 males) tested the alternative interpretation that the SRT increase was caused by the difference in how the first movement part of the three responses was executed. However, no evidence was found to support this interpretation. Experiment 2 (N = 15 males) tested the alternative interpretation that the SRT increase was due to the increase in the demand for movement accuracy from one response to another. The results revealed that only a very small portion of the SRT increase could be attributed to the increased accuracy demand while the major portion of the increase was due to the increase in number of movement parts.

A Movement Constraint Interpretation of the Response Complexity Effect on Programming Time

This paper reinterprets data from five recently published experiments on response complexity and programming time in which number of movement parts of rapidly executed limb responses was advanced as the principal element influencing length of response programming time. Alternatively it is argued here that programming time, in these experiments, was predominantly a function of the constraints placed upon the output of the motor system by the demand for movement accuracy. The quantification of this accuracy demand is achieved by using the metric of Index of Difficulty (Fitts, 1954). In discrete and straight-line tapping responses to circular targets, response complexity may be conceptualized in terms of the angular constraint imposed on movement initiation at the start key. When responses require changes of direction between movement parts it is proposed that programming time may be a function of the cumulative movement constraints imposed by the task. The discussion focuses on the process by which an increased accuracy demand requires a more constrained motor system output which is brought about by a larger and/or more precise muscle synergy recruitment pattern, resulting in an increase in programming time.

Retention and Transfer of Motor Skills: A Review for the Practitioner

This paper reviews the literature on retention and transfer of motor skills to determine what is currently known about these two topics and to apply this knowledge to sport and physical education environments. Within each topic, eight areas are identified as being particularly useful in bridging the gap between the laboratory and the world of the practitioner. In some of these areas, however, it is acknowledged that the present state of knowledge is less than adequate for making generalizations to applied settings. Therefore, more research is needed that is both theoretically and empirically based and from which practitioners can draw their technology.

Proprioception as a basis for the temporal anticipation of motor responses .

The present study attempted to distinguish between the proprioceptive Decay and proprioceptive Input Hypotheses of motor timing behavior. The hypothesis that an increased level of proprioceptive cues results in more proficient temporal anticipation was also tested. 90 male Ss were required to anticipate (no preview) the coincidence of a moving pointer and a stationary one. The timing response was executed with the right hand while 3 levels of proprioceptive cues were indirectly manipulated in the left arm. While results were unable to distinguish between the hypotheses, support was found for the hypothesis that an increased level of proprioceptive feedback administered during the interval can increase anticipatory response consistency.

A Test of Schmidt's Schema Theory of Discrete Motor Skill Learning

Abstract Schmidts (1975) schema theory was tested with subjects who had to emit a rapid aiming response while wearing prism glasses. The glasses enabled them to view the target, but not their responding limb or the outcome of the movement. The problem was to determine the effect of (a) training with variable target practice, and (b) experiencing visual displacement information of the target, prior to training, on performance in transfer to a novel target distance. A 2 × 2 (type of practice × displacement information) factorial design was used, in which four groups of 15 male college subjects performed 60 training trials with verbal knowledge of results. The groups with variable target practice had less error on initial transfer to the novel target and throughout transfer than the groups with nonvariable target practice. No evidence was found to indicate that rate of learning for a novel target distance during transfer in the absence of KR is a positive function of the variability of target practice in tr...

Influence of Enforced Motor and Sensory Sets on Reaction Latency and Movement Speed

Abstract Requiring a performer to consciously attend to the components of a well-learned movement response, rather than to the stimulus which evokes the response is referred to as enforced motor set. The present study tested the prediction that enforced motor set results in longer reaction and movement times than does enforced sensory set (concentrating on the stimulus). Thirty right-handed male college students were randomly assigned to 1 of the 2 enforced sets. Before performing under the influence of either set, each subject was pretested first on the reaction portion of the novel task and then on the movement portion. Following the pretest, each subject performed the reaction-movement time task as a whole in accordance with the set he was randomly assigned to. The ANCOVA revealed that the data supported the prediction being tested for reaction time, but not for movement time.

The effect of movement amplitude and target diameter on reaction time: comments on Siegel (1977).

Siegels (1977) interpretation that his reaction time results were solely a function of response factors (movement amplitude and target diameter) was discussed and criticized. It was argued that Siegels interpretation was inappropriate because stimulus factors (eccentric and visual angle) and response factors were confounded. It was also argued that the surprising U-shaped relation between reaction time and movement amplitude was probably the result of the confounding between stimulus and response factors.

Preview and movement as determiners of timing a discrete motor response.

Preview and voluntary movement in discrete motor response timing was investigated. Subjects lifted the right index finger from a response key when a moving pointer (1.260-sec travel time) passed directly under a stationary pointer. Four groups of 15 male and female college students performed 150 trials of the timing task with knowledge of results after each trial under one of four conditions: (a) preview of the moving pointer and left-arm movement, (b) preview of the moving pointer but no left-arm movement, (c) left-arm movement but no preview, and (d) no preview and no left-arm movement. Preview led to greater timing accuracy and consistency than did either no preview or movement. Movement did not influence timing accuracy, but resulted in greater timing consistency in the absence of preview. When preview and movement were available at the same time, the subject relied on preview to keep time.

Proprioceptive feedback as a mediator in interlimb timing.

Prior findings regarded as evidence for proprioceptive feedback as a mediator in interlimb timing can also be interpreted as evidence for motor outflow because they came from research that had subjects make voluntary movements, and such movements allow for both feedback and outflow to operate. The present study was designed to resolve this controversy by determining if these findings could be replicated with passive movements which allow for feedback, but not outflow, to operate. The interlimb timing task studied was one where subjects made the timing response with their right hand while moving their left arm during the 1.5-sec interval to be timed. Three groups of 16 male college students performed 50 trials of the right-hand response with knowledge of results, under one of three left-arm conditions: (a) passive movement, (b) voluntary movement, and (c) no movement. The results indicated that the findings were replicated with passive movements and this was interpreted as support for the involvement of proprioceptive feedback in interlimb timing.