Action Preparation

began the research that demonstrated the need for time for the motor control system to prepare to produce an intended action RT (reaction time) is the commonly used index of the preparation time required to produce action Based on findings showing that RT is influenced by many performance situation and performer characteristics

1. Number of responses2. Predictability of the correct response chioce3. Influence of the probablity of pre cue correctness4. Stimulus- response compatibilty5. Foreperiod length regularity6. Movement comlexity7. Movement Accuracy8. Reptition of a movement9. Time between different responses to different signals

Hick's law: RT increases logarithmically as the number of stimulus-response choices increases

If a number of possible responses exist, and one alternative is more predictable than others RT decreases as the predictability of the correct response choice increases

Precue = an advance indication that a specific upcoming event will require a response Faster RT if probability of precue correctness is higher than if probabilities of possible choices are equally possible Cost – benefit trade-off for biasing

RT will be faster as the relationship between the stimulus characteristics and their required response becomes more compatible

PINK PINK GREEN GREEN

e.g., Stove top example –

The time between Go and RT .. RT increases/decreases as a function of the length and the regularity of the length of the RT foreperiod

RT increases as amount of complexity of the action increases First demonstrated by classic experiment by Henry and Rogers (1960

RT increases as movement accuracy demands of the action increase First demonstrated by evaluating RT results for Fitts’ tapping tasks with different Indexes of Difficulty (i.e. as MT increased, RT also increased)

Reaction time increases with repition

Relate to a situation in sports involving a “fake” movement followed by the intended movement as the 2 stimuli and the other player’s responses as the 2 responses Delay of response to 2nd stimulus (signal) is called the psychological refractory period (PRP)

Alertness of the performerAttention focused on the signal vs. the movement

Warning signal effect- Foreperiod length effect- Optimal length 1-4 sec Vigilance effects- Always impairs alertness longer than 4 sec