Jonathan G. Hakun

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Public service announcements (PSAs) are non-commercial broadcast ads that are an important part of televised public health campaigns. "Message sensation value" (MSV), a measure of sensory intensity of audio, visual, and content features of an ad, is an important factor in PSA impact. Some communication theories propose that higher message sensation value(More)
Task performance often improves when tasks can be prepared in advance. However, the mechanisms that support advance preparation are highly debated. Proceeding under the hypothesis that switch-specific neural activation during advance preparation is the hallmark of controlled processing, this study investigates the behavioral and neural effects of component(More)
Cross-sectional research has shown that older adults tend to have different frontal cortex activation patterns, poorer brain structure, and lower task performance than younger adults. However, relationships between longitudinal changes in brain function, brain structure, and cognitive performance in older adults are less well understood. Here we present the(More)
The ability to maintain information in visual working memory (VWM) in the presence of ongoing visual input allows for flexible goal-directed behavior. Previous evidence suggests that categorical overlap between visual distractors and the contents of VWM is associated with both the degree to which distractors disrupt VWM performance and activation among(More)
A growing body of evidence indicates that cardiorespiratory fitness attenuates some age-related cerebral declines. However, little is known about the role that myocardial function plays in this relationship. Brain regions with high resting metabolic rates, such as the default mode network (DMN), may be especially vulnerable to age-related declines in(More)
Older adults often show different functional activation patterns than younger adults in prefrontal cortex (PFC) when performing cognitive control tasks. These differences include age-related increases in PFC activation magnitude and reorganized PFC functional connectivity (fC) patterns. However, it remains unclear whether age-related alterations in brain(More)
Task-induced deactivations within the brain's default mode network (DMN) are thought to reflect suppression of endogenous thought processes to support exogenous goal-directed task processes. Older adults are known to show reductions in deactivation of the DMN compared to younger adults. However, little is understood about the mechanisms contributing to(More)
BACKGROUND Clinically depressed patients without substance use disorders, compared to controls, exhibit significantly lower resting regional cerebral blood flow (rCBF) in the prefrontal cortex (PFC). In this study, we examined the link between resting rCBF in the PFC and current depressive symptoms in methadone-maintained opiate-dependent (MM) patients with(More)
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