2009 |
Liu, Xun |
M01Activity Code Description: An award made to an institution solely for the support of a General Clinical Research Center where scientists conduct studies on a wide range of human diseases using the full spectrum of the biomedical sciences. Costs underwritten by these grants include those for renovation, for operational expenses such as staff salaries, equipment, and supplies, and for hospitalization. A General Clinical Research Center is a discrete unit of research beds separated from the general care wards. |
Neural Basis of a Unified Framework of Attentional Control-Dimensional Overlap @ Icahn School of Medicine At Mount Sinai
This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 1/14/2008 Recent progress in neuroimaging techniques has greatly advanced our understanding of attention and its neural network. A variety of theoretical frameworks have been proposed to illustrate the mental and neural mechanisms of attention and its role in cognitive and affective controls. However, several critical issues remain unsolved and call for further investigation. This application, combining advanced functional magnetic resonance imaging techniques and wellconceived theory-driven behavioral paradigms, will provide a foundation for generating refined hypotheses about the neural mechanism of attentional control. The unique approach of this proposal is to examine and account for different effects of attention and executive control under a unified framework of attentional control, dimensional overlap. According to this framework, compatibility of the stimulus and response sets can be categorized based on the dimensional overlap across the stimulus and response domains between the task-relevant and task-irrelevant dimensions. We hypothesize that the dimensional overlap across the stimulus and response domains between the task-relevant and taskirrelevant dimensions is the common driving force underlying various effects of attention in orienting and executive control. We propose the following two specific aims. Specific Aims: (1) To examine common and distinct neural substrates underlying conflict resolution of stimulusstimulus (S-S) and stimulus-response (S-R) incompatibility. We expect that the frontoparietal network will be commonly activated for both S-S and S-R incompatibility effects, whereas distinct brain areas in the inferior frontal cortex, inferior temporal cortex, and anterior cingulated cortex, will be responsible for the unique effects of S-S and S-R incompatibility. (2) To examine common and distinct neural substrates underlying attentional control of endogenous and exogenous orienting. We expect that the similar frontoparietal network will modulate people?s attention whereas endogenous and exogenous orienting of attention will rely on distinct brain regions reflecting top-down selection and bottom-up capture respectively. Specifically, top-down selection will recruit more dorsal regions such as the inferior parietal cortex and frontal eye field whereas bottom-up capture will selectively activate more ventral areas such as the temporal parietal junction and inferior frontal cortex. Significance. These studies will provide insight into the neural mechanism of attentional control and help researchers design better behavioral and therapeutic prevention and interventions to effectively target at-risk individuals, who suffer from attention-related deficits due to either neuropsychological insults or natural degradation of aging.
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2009 |
Liu, Xun |
M01Activity Code Description: An award made to an institution solely for the support of a General Clinical Research Center where scientists conduct studies on a wide range of human diseases using the full spectrum of the biomedical sciences. Costs underwritten by these grants include those for renovation, for operational expenses such as staff salaries, equipment, and supplies, and for hospitalization. A General Clinical Research Center is a discrete unit of research beds separated from the general care wards. |
Neural Mechanisms of Reward Processing &Executive Control in Sensation Seeking @ Icahn School of Medicine At Mount Sinai
This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Previous studies have indicated a strong relationship between sensation seeking and substance use and abuse. Sensation seeking has been defined as a personality trait that is marked by a tendency to seek out and engage in novel and varied experiences to maintain an optimal level of arousal - even if those experiences involve significant risk. Among a number of well-established personality dimensions of sensation seeking, two are especially related to susceptibility to drug use and abuse: novelty and reward seeking, and lack of control and impulsivity. Although biochemical and biological markers have long been proposed and studied extensively for sensation seeking, these models are either based on animal studies or peripheral physiological measures in humans. This application, by combining advanced functional magnetic resonance imaging (fMRI) techniques and well-established behavioral paradigms, will provide a foundation for generating hypotheses about the neurobiological markers for sensation seeking in humans. We hypothesize that as compared to low sensation seeking (LSS) individuals, high sensation seeking (HSS) individuals show greater sensitivity and stronger neural responses to positive reward, which may result in their susceptibility to initial substance use and abuse. In contrast, HSS individuals show less sensitivity to negative outcomes and reduced control to goal-irrelevant external cues in both reward and executive control tasks, which may account for their impulsivity and lack of control to resist substance abuse. We propose to achieve the following specific aims. Specific Aims: (1) To examine individual differences in neural mechanisms of reward-related decision making between the HSS and LSS groups. We predict that the delicate balance between the neural circuitries of reward seeking and sensitivity, and emotional evaluation and cognitive control of behavior - which is crucial to defend people against addictive behaviors - may be compromised in the HSS individuals. (2) To examine individual differences in neural mechanisms of attentional and executive control between the HSS and LSS groups. We predict that HSS individuals will show less efficiency of executive control network in the frontal and parietal regions, which may account for their high impulsivity and reduced ability of executive control to resist cues that induce drug use and abuse.
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