2012 Summer Symposium Program - Middlebury College

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Patrick Hebble ‘13
Major: NSCI
NIH AREA Grant (R15
MH081276)
Hugh Randall ‘14
Major: PSYC at UVM
NIH AREA Grant (R15
MH081276)
Matthew Kimble
Associate Professor of
Psychology
Middlebury Summer Research Symposium 2012
the sloA promoter to a cat reporter gene within the bacterial chromosome. Future
experiments will assess the putative effect(s) of these mutations on SloR binding
to the promoter-proximal SRE at the sloABC locus. Residues identified as being
important to the SloR-SRE interaction could be potential therapeutic targets.
Treatments could be developed that would interfere with or enhance this interaction
with the aim of controlling S. mutans virulence and cariogenicity.
Attentional Biases to Trauma Relevant Stimuli in
Motor Vehicle Accident Survivors and Veterans of
the Iraq War: An Eye Tracking Study
Patrick Hebble, Hugh Randall, and Matthew Kimble
Department of Psychology, Middlebury College, Middlebury VT 05753
Attentional impairment is one of the symptoms most often associated with posttraumatic
stress disorder (PTSD). Yet, the manifestation of these impairments is
complex and still not completely understood. The DSM-IV lists that both avoidance
of stimuli associated with trauma and hyper-arousal/vigilance are symptoms of
PTSD (APA, 2000). While many studies have used event related potentials to study
these attentional biases in PTSD, relatively few have used eye tracking technology
to do the same. Our research is a follow up to one such study (Kimble et. al., 2010).
In this study a group of veterans of the Iraq war (n=19) were presented with a
series of 20 slides containing two images: one negatively valenced picture and one
neutral. Negatively valenced pictures varied in terms of trauma relevance [Iraq War
vs. Motor Vehicle Accident (MVA) images]. Participants were told to look at the
images as they interested them while their eye movements were being tracked. The
study found that veterans with comparatively higher levels of PTSD symptomology
spent more time looking at the negatively valenced imaged (regardless of trauma
relevance) than participants who reported lower levels of PTSD symptoms. In
addition, the veterans reporting higher levels of PTSD symptoms also tended to look
towards Iraq images first, suggesting that PSTD is associated with hyper-vigilance
rather than avoidant behavior when processing trauma relevant stimuli. In this study,
we collected data from MVA survivors (n=17) using Kimble et al.’s (2010) methods
and compared it to their combat veteran sample. All subjects tended to look first and
longest at negatively valenced images. However, regardless of PTSD levels, veterans
looked at the negative images significantly longer than the MVA survivors. Veterans
also looked at the negative images first significantly more than the MVA survivors
regardless of PTSD symptoms. Finally, while not statistically significant, veterans
looked at trauma relevant images longer than MVA survivors. These findings suggest
that trauma type plays a key role in post-traumatic pathology, and that the levels of
vigilance and avoidance in persons with PTSD may be dependent on the type of
trauma one experienced.