Influences of Perceptual Fluency on Explicit Testing of Recognition Memory

Northwestern University, Evanston IL

Investigators

Abstract

The ability to accurately recognize information that was previously learned is central to human success. This ability relies on a complex set of brain mechanisms. Traditionally, human memory is subdivided into memory with awareness of retrieval, or explicit memory, and memory without awareness of retrieval, or implicit memory. Surprisingly, it is possible for a person to respond with high accuracy on a memory test in the absence of explicit feelings of familiarity or remembering. With support from the National Science Foundation, Dr. Ken Paller and colleagues at Northwestern University will characterize the circumstances under which implicit recognition is possible. Implicit recognition is found when people have negligible confidence about their memory, whereas explicit memory shows the reverse pattern. Implicit recognition is stronger for stimuli that are learned under conditions that place severe limitations on information processing, even though these conditions lead to very poor explicit memory. By recording brain activity from electrodes placed on the scalp while people perform memory tests, Dr. Paller will investigate which specific brain potentials are associated with implicit memory and which are associated with explicit memory. The results of this research will provide new information about mechanisms of implicit and explicit memory and about how both types of mechanism can drive accurate memory judgments. This research project will provide training opportunities for undergraduate, graduate, and post-doctoral trainees in cognitive neuroscience. Specific findings are expected to be disseminated widely and will lead to numerous insights into how explicit and implicit memory influences everyday behavior. Such knowledge will be important for enhancing our understanding of learning and memory in the classroom, in a court of law, in the acquisition of various cognitive skills, and in interpersonal interactions. The work will also aid efforts to devise rehabilitation strategies for people with memory difficulties due to aging or neurological disorders.