Transcript AS Level - Week 3 Theory

AS Level – Week 23
Theory
Module 1
Information Processing
Reaction Time, Decision
Making and Hicks Law
Reaction Time
A key element in the decision making process for a performer
is the amount of time it takes to receive, interpret and
analyse stimuli to then formulate an appropriate response.
The faster this can be achieved, the more time the performer
is likely to have in order to complete the selected skill
successfully.
We often attempt to confuse our opponents by giving them
false cues, such as a dummy pass.
A performer with a faster reaction time can delay the start of
their movement, giving them a greater opportunity to fully
assess the situation and eliminating the need to guess what
may happen.
The diagram below shows the whole sequence of responding to
a stimulus in the context of a sprint.
Diagram
Response Time = Reaction Time + Movement Time
Reaction Time - the time between the onset of a stimulus and
the initiation of the response. It is the time the information
processing system takes to interpret the situation, formulate a
motor programme and transmit the information to the muscular
system. E.g the time taken when a striker thinks they have the
opportunity to score a goal and the start of the shooting action.
Movement Time - the time between the start of the movement
and its completion. It is the time the performer takes to
physically complete the movement when the muscular system
has received the message from the brain via the effector
system. E.g the time it takes the striker to move their limbs to
strike the ball.
Response Time - the time from the onset of the stimulus to the
completion of the movement. it’s the combination of the
reaction time and the movement time. E.g the overall time the
striker takes to complete the shot from first seeing the ball,
their position and the goal.
Hot Tip -: Make sure you know the definitions of each term, their
relationship and you are able to apply them to practical
examples.
Reaction time is an ability and it varies between individuals.
Many factors can affect the speed of a performers reaction
time.
Age - reaction times improve until the early twenties but then
become slower.
Gender - males generally have faster reaction times but as we
become older, the difference becomes less.
Fatigue - tired performers tend to have slower reaction times.
Intensity of the stimulus - the more intense, the faster the
time, E.g brighter and louder stimulus help increase reaction
time.
Probability of the stimulus occurring - if the stimulus is
expected, there is a reduced element of doubt and anticipation.
E.g an opponent always plays the same shot in a particular
situation.
Presence of a warning signal - this may be a call or gesture. E.g
the starter at the beginning of a race issuing commands or
coloured lights to begin a grand prix.
Personality - introverts tend to have slower reaction times than
extroverts.
Previous experience - the greater the experience the faster the
recall from the long term memory.
Arousal Level - optimum arousal will cause heightened
concentration levels and allow the performer to only focus on
key stimuli.
Stimulus-response compatibility - the reaction time is faster if
the required action is normally linked to the stimulus. E.g bang
of a gun in athletics.
Body Temperature - reaction time is slower if the body is cold.
Limbs used - the further the nerve impulse has to travel, the
slower the reaction time. E.g hand movements tend to be
completed faster than foot movements.
Sense Used to detect stimulus - sight, sound, touch and
kinaesthetic awareness all produce differing reaction times.
Fastest Reaction Time
Kinaesthetic
Hearing
Touch
Vision
Pain
Smell
Slowest Reaction Time
There are two forms of reaction time -:
Simple reaction time -involves one stimulus and one possible
response. E.g the time a sprinter takes to start moving off the
blocks when the gun is fired.
Choice reaction time -involves the performer being presented
with numerous stimuli, each with a different response. This
situation occurs in all open skills, causing the performer to
make decisions largely based on past experiences. E.g
basketball player must decide whether to shoot pas or dribble
and their situation will constantly alter requiring another
decision to be made.
Hicks Law
Hick’s Law suggests that reaction time will increase in a linear
fashion as the amount of information to be processed
increases.
Diagram
If a performer can develop a range of skills and employ them
effectively when faced with a number of different situations,
their opponent will not know what is going to happen and as a
result will have to delay their decision-making until the last
moment. E.g a squash player who is able to play a variety of
shots from differing positions will find it easier to out wit and
deceive an opponent.
The increase in reaction time can be explained using the
Psychological Refractory Period (PRP).
Diagram
The delay is caused by an increase in the information
processing time when the initial stimulus is closely followed by
a second stimulus. The reaction time is slowed because the first
piece of information must be cleared before the second can be
processed, as explained by the single channel hypothesis. This
suggests that the brain can only deal with one piece of
information at a time. When it receives several pieces in rapid
succession a ‘bottleneck’ is formed.
Diagram
Improving Response Time
One of the most effective measures can be the use of
anticipation. Anticipation depends on past experience and
involves the recognition of specific cues.
Spatial anticipation - involves predicting what will happen. E.g
the badminton player detects the slight difference in the shot
action and is expecting the drop shot.
Temporal anticipation - involves predicting when the action will
happen. E.g a football defender tries to guess when the
attacker will actually pass the ball.
Other methods used to improve response time include -:
a) relevant practice responding to specific cues or stimulus.
b) mental rehearsal.
c) concentration on early warning signs.
d) improvement of selective attention.
e) control of arousal levels.
f)
improvement of physical fitness.
g) altering the intensity of the stimulus
h) identification of specific actions/cues used by opponents