Neurobiology of Category Learning and Attention A major focus of our research is to examine the neurobiological underpinnings of category learning and attentional processes. We achieve this goal through a blending of empirical data collection, cognitive neuroscience, and mathematical modeling.  [ for more details ] Motivational Influences on Human Decision Making In a recent line of work, conducted in collaboration with Dr. Arthur Markman here at UT, we examine the influence of motivational factors on category learning and decision-making. Participants are placed in an approach (perform well and attain a reward) or an avoidance (perform well and avoid losing a previously attained reward) motivational state and are then asked to perform specific tasks. Motivational state is predicted to affect cognitive flexibility and thus performance in systematic ways. We are beginning to examine the relation between motivational state and other states (e.g., positive affect, anxiety, etc), and are working toward the development of a neurobiological model of motivation and cognition.  Human Decision Making When the medical doctor diagnoses a patient, they are making a decision. When the deer determines whether that sound was due to a hunter approaching or a gust of wind, they are making a decision. All organisms make hundreds of these decisions daily and often are remarkably accurate. Accurate decision making requires knowledge of the category structures (e.g., the symptoms associated with each disease category), knowledge of the base-rates (the prevalence of each disease in the general population), and the costs and benefits of correct and incorrect decisions. Our lab studies human decision-making by manipulating category structures, category base-rates, and the costs and benefits of various decisions, and attempts to determine the underlying brain mechanisms.  [ for more details  ]      Relating Identification and Categorization:  Separating Low-Level Perceptual Processes from High-Level Decisional Processes Different goals require different decisions. For example, the forensic scientist might be asked to determine whether a bullet was fired from a specific .357 Magnum found at a crime scene (identification). Alternatively, the scientist might be asked to determine only whether the bullet was fired from some .357 Magnum (categorization). Although the goals of identification and categorization tasks are different, it is likely that the psychological processes, and underlying brain mechanisms are related. [ for more details  ] Miscellaneous We also conduct work examining the relationship between recognition memory and category learning and have developed a model of object perception.  Finally, we have conducted research examining methodological issues, such as those related to the use of individual vs. aggregate data.