Preliminary studies from our laboratory suggest that Parkinson patients may demonstrate a significantly diminished emotional reactivity to fear-inducing emotional materials compared to their healthy counterparts. This may be related to the fact that the amygdala has been shown to exhibit pathology in Parkinson's disease (PD), and is a neural structure that plays a key role in processing and interpreting signals of threat in the environment. As such, the proposed study will test the following hypotheses: a) Parkinson patients will demonstrate reduced emotional reactivity, as indexed by emotional modulation of startle, to both verbal and nonverbal fear-inducing stimuli; b) emotional reactivity to fear inducing materials will correlate with amygdala volume; and c) reduced emotional reactivity will correlate with an increased propensity for families to inaccurately view their Parkinson family member as depressed and unmotivated. These hypotheses will be tested through a method that is not confounded by deficits of overt expression in PD: emotional modulation of the startle eyeblink reflex. Increased understanding of emotional changes accompanying PD may prove to be clinically useful by reducing problems such as healthcare worker and family member misattributions that the Parkinson patient is """"""""uninterested"""""""" or depressed due to lack of reaction. This proposal will also examine 1 potential neural mechanism for reduced emotional reactivity in PD, decreased amygdala volume, with the aim of increasing knowledge of neuropathological changes that may lead to emotional reactivity deficits in PD.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31NS053403-01
Application #
6993762
Study Section
Special Emphasis Panel (ZRG1-F12B (20))
Program Officer
Babcock, Debra J
Project Start
2005-07-01
Project End
2007-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
1
Fiscal Year
2005
Total Cost
$29,771
Indirect Cost
Name
University of Florida
Department
Other Health Professions
Type
Schools of Public Health
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Miller, K M; Okun, M S; Marsiske, M et al. (2009) Startle reflex hyporeactivity in Parkinson's disease: an emotion-specific or arousal-modulated deficit? Neuropsychologia 47:1917-27
Miller, Kimberly M; Okun, Michael S; Fernandez, Hubert F et al. (2007) Depression symptoms in movement disorders: comparing Parkinson's disease, dystonia, and essential tremor. Mov Disord 22:666-72