Behavioral and neural studies of working memory, executive processes, and knowledge representation

Implicit category learning: Is it possible to learn new categories and concepts with no awareness of doing so, and no intact hippocampus to mediate the learning?
We are testing early-Alzheimer’s patients in a situation in which a sequence of related items is presented, and the patient is simply told to look at the items; later the patient is told that the items in fact belong to a category. To determine whether the patient implicitly learned the category, he or she is then asked to decide whether each of a series of test items in fact belongs to the category. If AD patients can reliably make these judgments, they have the capacity for implicit learning, and they may be taught new material via this system.

Placebo effects
In recent work we have demonstrated that when a placebo is administered to a person in pain, not only does the person report less pain, but there is also a reduction of neural activity in the pain centers of the brain. We are now asking how this neural placebo effect compares to the effect of a real analgesic. We are using functional Magnetic Resonance Imaging (fMRI) to image volunteers who are experiencing heat pain, under the influence of either a placebo injection or an injection of an opiod-based analgesic.

Grossman, M., Smith, E.E., Koenig, P., Glosser, G., Rhee, J., and Dennis, K. (2003). Categorization of object descriptions in Alzheimer’s disease and frontotemporal demential: limitation in rule-based processing. Cognitive, Affective, & Behavioral Neuroscience, 3 (2), 120-132.

Wager, T., Rilling, J. K., Smith, E. E., Sokolik, A., Casey, K. L., Davidson, R. J., Kosslyn, S. M., Rose, R. M., Cohen, J. D. (2004). Placebo decreases fMRI activation in pain centers in the anticipation and experience of pain. Science, 303, 1162-1167.

• PSYC W2215 Cognitive Psychology: Mind and Brain
• PSYC W3215 Memory without Awareness
• PSYC G9165 Research Sem. in Cognition