Our research involves explicit and implicit memory with a particular focus on explicit recognition judgments; that is, the decision that someone or something was an element of an earlier personal experience. The nature and number of processes involved in recognition memory are currently under debate. Using such methods as 1) statistical modeling of behavioral data, 2) examination of recognition in patients with focal brain damage, 3) functional magnetic resonance imaging (fMRI) of healthy participants during various recognition tasks, and 4) measurement of pupil diameter, we are beginning understand the complex processes which allow us to situate current experiences into our own unique personal pasts.
- 1.The contribution of prefrontal and parietal regions to memory judgments. We are currently examining the role these regions play when one's expectations about memory are violated and have developed a memory framework in which parietal cortex is central to both judgment biasing and exploratory orienting.
- Influence of feedback and instruction upon recognition judgments. Behaviorally, we have found that providing subjects with inaccurate feedback during memory errors heavily affects their recognition judgments. These findings will likely serve as a vehicle for future neuroimaging studies and especially important given that clinical populations often show disturbance in criterion placement.
- The verbal content of memory reports and justifications. Our recent work has used machine learning and other statistical methods to examine the verbal content of justifications of recognition decisions. These data suggest that certain words and combinations of words provided in unguided reports may be diagnostic of particular memory processes.
- Pupil dilation during recognition attempts. We have just collected data demonstrating that the pupils selectively dilated for unexpectedly familiar stimuli (but not unexpectedly novel stimuli) and this suggests that along with fMRI, pupillometry may be useful for understanding the interaction between memory and orienting.