Which component of the response time process is
affected by red stimuli?
- Specific colours can form associations found to be important in
basic psychological functions (Moller et al., 2009).
- Red stimuli were found to be associated with failure,
whereas other colours, such as green, were associated
with success when used as the stimulus.
- Brandtstadter et al. (2003) found that stimuli associated
with negativity enhanced perceptual sensitivity.
- The colour red has a has both an evolutionary and social
significance as a ‘signal function’ and a potential ‘threat-cue’ (Elliot
& Aarts, 2011).
- Studies have shown that valid threat-cues can improve
reaction times (Koster et al., 2006).
- Red stimuli have been found to enhance basic motor functioning in
terms of both velocity and force in reaction tests (Elliot & Aarts,
2011).
- Little evaluation of the potential effect of certain colours,
specifically those of a red hue, on reaction time, and the
underlying cognitive processes, has been made.
Introduction:
Hypotheses: 1. When colour is deemed irrelevant,
reaction times will be faster to red
stimuli than to black stimuli in a two-
choice reaction time task.
2. If stimulus colour needs to be relevant
to the task in order to impact upon
reaction time, red stimuli should only
affect reaction time when stimulus
colour is the key task component.
3. Red stimuli will induce a reduction in
the response-caution process of
reaction time in both experiments.
Project: Jack Fantham
Supervisor: Jim Grange
Method:
Research Questions: 1. Can red stimuli affect results in a
two-choice reaction time task?
2. Does colour need to be identified as
relevant to a task in order to prove
influential on reaction time?
Upon signing a consent
form, participants will
allocated to one of two
experiments.
Experiment 1
Experiment 2
Colour deemed irrelevant.
Participants must react as
quickly and accurately as
possible to shape being
‘square’ or ‘circle’.
Colour deemed relevant.
Participants must react as
quickly and accurately as
possible to a shape being
‘red’ or ‘black’.
e.g:
e.g:
or
or
or
Reaction times will
be recorded for
data analysis.
Participants: - 64 undergraduate students total
selected through opportunity sampling.
Apparatus: - QWERTY keyboard. One key
allocated to each option in both
experiments.
- Monitor. Reaction time tasks will rely on
reaction to visual stimuli presented via
computer screen.
Ethical considerations: - Participants will be told that they can choose to
halt the experiment at any time without being
required to justify their decision.
Controls & Measures: - Reaction times will be
recorded in milliseconds.
- Response times shorter
than 100 milliseconds
will be discounted in data
analysis.
Procedure:
Data Analysis: In both experiments, it must first be determined whether or not red stimuli
induce a faster response time than black stimuli. Therefore, a t-test will be
applied to the two reaction time means of each experiment. In turn, the first
and second hypotheses can be evaluated and the research question can be
answered.
Secondly, the Ratcliff Diffusion Model (Ratcliff, 1978) (see Figure 1)
parameters of drift rate, boundary separation, and starting point will be
applied to the results . T-tests will again be used to evaluate the final
hypothesis and determine whether response caution is reduced in reactions
to a red stimulus.
The Ratcliff Diffusion Model &
reaction time process overview
Figure 1 – The parameters of the Ratcliff Diffusion Model
z = starting point/response bias.
v = drift rate/evidence accumulation.
a = boundary separation/caution. A motor response (known as don-decision time) completes
the process.
Response selected
References: Brandtstadter, J.; Voss, A. & Rothermund, K. (2003). Perception of danger signals: The role of control. Experimental Psychology 51(1), p24-32).
Elliot, A.J. & Aarts, H. (2011). Perception of the colour red enhances the force and velocity of motor output. Emotion, 11(2), p445-449.
Koster, E.H.W.; Crombez, G.; Verschuere, B.; Van Damme, S. & Wiersema, J.R. (2006). Components of attentional bias to threat in high trait anxiety: Facilitation engagement, impaired disengagement, and attentional avoidance. Behaviour Research and Therapy, 44, p1757-1771.
Moller, A.C.; Elliot, A.J. & Maier, M.A. (2009). Basic hue-meaning associations. Emotion, 9(6), p898-902.
Ratcliff, R. (1978). A theory of memory retrieval. Psychological Review, 85, p59-108.
Implications: Future research into the effects of colour on reaction time could benefit from this study.
Should red be found to have a significant effect on reaction time, attention can then be
paid to the potential significance of other colours in reaction time and reaction time
processes. Is red the only colour to have an effect on reaction time? If others do have
significant effects, will the dependent component of the reaction time process vary?
or