1989 — 1992 |
Wolford, George [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Masking, Integration, and Practice Effects
The goal of this project is to examine the malleability of the visual system, in particular, its ability to resolve stimuli over time. Previous research has shown that people improve over time dramatically in some visual tasks but not in others. Tasks that involve the ability to resolve stimuli quickly consistently exhibit improvement with practice. One such task is backward masking, in which a visual target, a display to be identified or recognized, is followed closely in time by a visual mask, a display that lights up all the places on the screen where parts of targets could possibly appear. One hypothesis is that practice effects in these tasks are the result of learning to process the information more quickly or over smaller time frames. Several real-world tasks, such as landing a plane and hitting a baseball, profit from such rapid visual processing. There are other activities, however, that require one to integrate information over time, for example, watching television and computer screens and using fluorescent lights (this research will use a task that simulates these examples in a controlled and sensitive fashion). If improvement on backward masking is the result of learning to process information in smaller time frames, then performance on tasks that require integration over longer time frames should be impaired. The experiments will test for this impairment by training people either on tasks that require rapid processing or on tasks that require integration and looking for the effect of improvement on the trained task on performance on tasks requiring the opposite skills. The experiments will also examine individual differences in performance on these tasks. Some people are quite good at backward masking from the very beginning and others are quite bad. Will those people who are good at backward masking be bad at integration tasks and vice versa? Performance on backward masking decreases with age. Does performance on integration tasks improve with age? Are these individual differences reversible (i.e., the result of prior training and experience) or the result of physiological differences and changes in the visual system? The experiments will help resolve these various issues.
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0.915 |
1999 — 2000 |
Wolford, George L [⬀] |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Assessing Hiv Risk in Severely Mentally Ill People
Information from patients with severe mental illness (SMI) is essential for accurate diagnosis, effective monitoring, and research to improve services. Despite reports of elevated risk for HIV and other sexually transmitted diseases (STDs) in this population, risk and disease status are inadequately assessed. Self-report data are crucial for this assessment. Studies by our group and others have shown that substance use disorders and posttraumatic stress disorder (PTSD), contribute to HIV risk, are prevalent in people with SMI, but are rarely noted on admission. Similarly, HIV and other STDs often go undetected in mental health services settings. Current research by our consortium has underlined the problems of assessment of risk behavior for HIV/AIDS and other STDs including interviewer reluctance and patient underreporting. Systematic assessment of risk status and co-morbid conditions is needed for effective intervention. Computerization is proceeding in the field, but patient input continues to be collected in an expensive, time-consuming manner. Service providers and researchers often use trained interviewers to collect data from patients. They believe that interviewers are essential for overcoming potential literacy problems, translating ambiguous language, and using nonverbal information to facilitate data collection. These reasons have rarely been subjected to investigation. There are liabilities to the use of trained interviewers: interviewer reluctance, high cost, lack of uniformity, inhibition in answering sensitive questions, and possible subjectivity. We propose a study comparing trained interviewers and computer- assisted interviews (CAI) for obtaining self-report on HIV risk and co-morbid conditions from patients with SMI. The CAI includes speech and uses the internet. We will collect data on gender, age, and number of recent hospitalizations and on several scales: the AIDS Risk Inventory (ARI), the Dartmouth Assessment of Lifestyle Instrument (DALI, a substance abuse screen), the PTSD Checklist (PCL), and a questionnaire on patient preferences. These scales were chosen because they stress different aspects of self report and because they are related to the prevalence of HIV and other STDs in this population. We plan to measure patient attitudes, reliability, intercorrelations, completion rates, and amount of information divulged. We have criterion measures of substance abuse for the DALI and hospital utilization, allowing us to compute criterion validity for those measures. The data will supplement two ongoing research projects investigating HIV/AIDS and risky behaviors in people with SMI.
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1 |
1999 — 2002 |
Wolford, George L [⬀] |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Neural Correlates of Strategic Thinking
Almost every task used in studying human behavior demands that subjects make categorical responses int eh face of ambiguous or incomplete information. This requirement introduces a decision-making component into many experiments that are designed to measure other aspects of perception or cognition. The strategies subjects adopt to cope with this decision-making component can dramatically and misleadingly influence experimental outcomes if they are not explicitly considered by the investigator. The aim of this proposal is to investigate the role of strategic thinking in behavioral tasks and to investigate specific neural mechanisms associated with decision making and strategic though processes. We propose a series of experiments to investigate the role of the left hemisphere and the prefrontal cortex in hypothesis formation. We believe that subjects have a strong tendency to look for and to posit causal relationships even when none exist. There is evidence that this tendency is supported by structures in the left hemisphere in most individuals. This type of thought process is of real benefit when there is a logical relationship among events but is potentially detrimental if there is no casual relationship exists. We propose a series of studies testing normal subjects, callosotomy patients, and lesion patients that vary the nature of the relationship among elements of the task and examine the presence and nature of hypothesis that are formed. Data from the patient populations will serve to identify cortical regions fundamental to these tasks. We believe that these two sets of studies will have a significant impact on the way that imaging studies and patient studies are evaluated, and will further our understanding of how the brain makes a decision.
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1 |