New staff member Dr Don van Ravenzwaaij talks about his recent research:
In everyday life, we are constantly
confronted with situations that require a quick and accurate action or
decision. Examples include mundane tasks such as doing the dishes (we do not
want to break china, but we also do not want to spend the next hour polishing),
but also more serious activities, such as performing a test. For these actions,
there exists a tradeoff, such that more speed comes at the expense of more
errors. This phenomenon is called the speed-accuracy tradeoff.
In psychology, we study the speed-accuracy
tradeoff by having participants repeatedly make a decision between two
alternatives as quickly and accurately as possible. Conclusions from the data
of these tasks are often based on the mean response time and the percentage of
correct responses. These measures, however, do not speak directly to underlying
psychological processes.
In order to draw conclusions about these
unobserved processes, one should use a mathematical process model, such as the
drift diffusion model (DDM; see Figure 1). The DDM decomposes response time
distributions into their constituent components, such as the speed of information
processing, response caution, and time needed for non-decision processes (i.e.,
response execution).
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| Figure 1 |
In my research, I have used the DDM to
demonstrate that the effects of alcohol on response times lead to a
deterioration in cognitive performance before motor processes are impaired (van
Ravenzwaaij, Dutilh, & Wagenmakers, 2012). I have applied the DDM to the
Implicit Association Test, designed to measure racial prejudice, and concluded
that the effect measured by this test is in fact not driven by racial
prejudice, but by ingroup/outgroup status (van Ravenzwaaij, van der Maas, &
Wagenmakers, 2011, see Psychology
Today for coverage in the popular media). Using the DDM, I have
also demonstrated that playing action video games does not lead to faster
information processing, despite claims to the contrary in the popular media
(van Ravenzwaaij et al., 2013).
For more information on these and other
research projects, please visit my website: www.donvanravenzwaaij.com or
contact me at don.vanravenzwaaij@newcastle.edu.au
