Kate Arrington
Research Interests
General
Interests
The functioning of
the mind and the neural systems that underly these mental processes are
"vast and intricate beyond the imagination" (with thanks to J.R.R.
Tolkien
for this phrase.) My wonder at the workings of the mind is
equalled
in my appreciation for the art of scientific investigation. I
have
a broad range of research interests that generally fall under the
headings
of cognitive psychology and cognitive neuroscience.
Task Switching
Projects
I am currently engaged
in several lines of research
addressing
questions concerning mechanisms of executive control. The
coordination
of perceptual input, encoding and retrieval of memories, and motor
responses
involved in complex task situations demands a high degree of
control.
I am examining issues of executive control within task switching
paradigms.
The somewhat ironic thing about most task switching
experiments is
that researchers are studying cognitive control in a highly controlled
environment in which the participant actually has very little choice in
and
control over how they are going to behave.
In collaboration with Gordon Logan,
I developed a modified version of the task switching paradigm where
participants
actually make choices about which task to perform (Arrington &
Logan, 2004;
2005). In this voluntary task switching
(VTS)
procedure, subjects are instructed to perform each of the possible
tasks equally
often and to perform the tasks in a random order. The
instructions to perform the tasks in a
random order are intended to encourage subjects to actively choose the
task to
perform on every trial and to discourage subjects from selecting a
strategy
where they perform one task for a large number of trials and then
switch to the
other task or where they strictly alternate from one task to another. This key difference between VTS and other
task switching paradigms results in subjects having control over the
task to be
performed. Removing some of the external
support and placing control with the participant rather than the
experimenter
results in a more ecologically valid task switching environment than is
found
in other task switching paradigms.
In my lab currently, we are examining how internal and external factors influence task
performance in such environments, in particular the choice to perform
one task
versus another. Internal factors include
the representation of specific tasks and the larger multitask
environment, the
executive processes involved in preparing the cognitive system to
optimally
perform a given task, and the control processes engaged in selecting a
task
from among multiple available behavioral pathways.
External factors include the availability and
salience of external stimuli appropriate for a given task.
Theories of task switching that attribute the cost of
switching tasks to the time necessary to reconfigure task set have paid
little attention to the question of how tasks are represented. I
believe that a better understanding of the effects
of various task
characteristics
may provide some valuable constraints on theories of task
representation
and executive control. In particular, I am using manipulations of
task similarity to address questions of how tasks are represented
within
a larger domain of multiple potential stimulus-response contingencies
or
task sets. For example, tasks involving discrimination of the hue
or the luminance of a stimulus are more similar to each other than
either
of these tasks is to a discrimination of size. Careful
manipulation
of task similarity on dimensions of stimulus characteristics,
operations
to be performed, or mode of response will allow us to pry apart the
components
of task set reconfiguration. In collaboration with Tom
Carr, I am currently undertaking a series
of studies aimed at understanding the nature of this task similarity
effect
and how it can be used to probe processes of executive control.
Other Projects
- Object-Based
Visual Attention
Orienting of
visual
attention is fundamental for the selection of information entering the
cognitive system. Control of the focus of attention can be either
stimulus driven by salient environmental cues (exogenous) or goal
directed
under voluntary control of the perceiver (endogenous). The modal
model of visual orienting has been the spotlight model (Posner, 1980)
that
emphasizes the spatial representation of the visual field and the
movement
of attention within this spatial domain. Recently however
extensive
evidence has demonstrated the importance of objects in guiding the
deployment
of attention (i.e. not only can attention be allocated to a particular
location in space, but also to a particular object even as it moves
from
one location to another.) With empirical results showing that
both
space-based and object-based allocation of attention do occur, a key
question
in the field becomes: Under what circumstances do these two
different
kinds of representations serve as the basis for attentional
allocation?
My research has addressed that question by examining whether the
mechanism
of attentional orienting, exogenous or endogenous, will determine
whether
attention is deployed in a space-based or object-based fashion. I
began this research while working on my Master's degree at Wake
Forest University with Dale
Dagenbach. My research in this area has included both
behavioral
mental chronometry studies and functional neuroimaging work conducted
in
collaboration with Steve
Rao at the Medical College of
Wisconsin.
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Last updated 3/10/06