Decision making and reaction time

By: David NippardHkin 416Presented to: Dr. Martell

Overview

•Decision making

•Reaction time

•How to develop faster reaction time

•Gaze (Quiet Eye)**

What is decision making ?

•The process of making choices among possible alternatives.

▫Example: During a game of hockey there is a 2 on 1 opportunity, do you pass to your teammate? Or do you shoot on the goaltender?

*Note: The number of stimulus effects the decision.

• 2 on 1 options

What about the goalie?•Will the player shoot, pass or deke?

Reaction time is critical

What is reaction time?

•The time between stimulus and response: ”the interval of time between the application of a stimulus and the first indication of a response”

•Senses (eyes, ears)---Brain (formulate response)---Motor Units (nerves)---Action (muscle)

•Athlete’s ability to react to the information that is processed through the nervous system.

Benefits of reaction time• Faster reaction time= advantage

• Athletes with faster reaction time have the ability to monitor movements for longer periods of time.

• Ability to recognize cues in the environment, or even begin the movement earlier.

• E.g., Returning a tennis serve, saving a goal kick, hitting a baseball etc.

• http://www.youtube.com/watch?v=0kTxTWwkY6k

3 types of reaction time• Simple Reaction time: Only 1 stimulus and 1

response. (e.g. 100m race)

• Choice Reaction Time: More than 1 stimulus, but each stimulus has a designated response. (what shot to choose in a game of badminton. Forehand, backhand, smash, drop-shot).

• Discriminate Reaction time: Multiple stimuli but 1 response. (determining which colour is brighter by hitting an appropriate button)

Movement Time•The time it takes to complete the

movements of a particular action, from the initiation, to the termination.

Influences on Reaction time and decision making

• Age (Older = slower reaction time)

• Intensity of stimulus (Bigger, Louder, Brighter stimuli= faster reaction time)

• Anticipation (If prepared, reaction time may decrease)

• Gender (females show a slower reaction time compared to men)

• Previous experience of stimuli (faster reaction time when exposed to stimuli repeatedly)

Influences on Reaction time and decision making .con’t•Number of Stimulus response alternatives

▫Hick’s Law Relationship between reaction time and the

number of stimuli presented. The more stimuli available, the longer the reaction time.

-This occurs to a certain point, where the response time remains constant despite the increase of stimulus.

Is it possible to develop faster reaction time?

•Practice- with the same stimulus/response, where the outcome is the same response each time=faster reaction time. The response becomes Automatic.

•Anticipation- the action in predicting or expecting something. ▫E.g. Anticipating where the goal kick is

going to be placed.

Two kinds of anticipation

• Spatial anticipation: ability to predict what will happen in the environment.▫ E.g., predict a badminton player’s type of shot (drop-

shot vs smash)

• Temporal anticipation: ability to predict when an environmental event will occur▫ E.g., predict when the referee will drop the puck, or

when the referee will toss the basketball for a jump-ball• Temporal Occlusion (how much information is needed to make an accurate

judgment)

More information= better anticipatory judgments

Successfully anticipate…. Speed of puck

(impossible to track entire flight)

Dynamic Nature of the game (always changing, adapt accordingly))

Eye movement in SportsRecognizing the cues

• -Eye movements are used to pick up the most important visual cues.

• -Eyes sometimes shift in the area of the saccade (fixation point)

• -Longer fixations to more important areas, and the cognitive processing needed to interpret the information.

What is Quiet Eye? (Gaze)

The final fixation on the target prior to the initiation of movement.

Discovering the “Quiet Eye”

Joan Vickers

What is happening in the brain?

Prospective Control*•Searches to determine how particular

optical information is used to control a movement.

•focuses on movement as it unfolds to the point of interception.▫(Elite Baseball players recognize salient cues

early in the pitch)

▫*linking eye movements and Attention (peripheral)