Scott D. Slotnick - US grants

It has been hypothesized that memory is constructive in nature, where features or components from disparate brain regions combine to form a unified memory. Consistent with this view, it has been shown that memory for objects or sounds can activate the corresponding visual or auditory cortical processing regions. Furthermore, memory for specific categories of objects can activate the corresponding processing regions (e.g., memory for faces can activate face processing regions). However, there is little evidence that memory can activate regions that process detailed features, such as object color, motion, or shape, which would be expected if the constructive memory hypothesis is correct. Through support from the National Science Foundation, Dr. Scott Slotnick and his students at Boston College will investigate whether memory can activate such feature specific processing regions. In particular, it will be determined whether memory for motion can activate motion processing regions and whether memory for shape can activate shape processing regions (and whether such activity is essential for memory). The role of classic memory related cortical regions, namely, the prefrontal cortex and parietal cortex, will also be evaluated in relation to activity in feature processing regions. This research will be conducted by integrating functional magnetic resonance imaging (fMRI), to identify the precise spatial location of cortical activity, event-related potential (ERP) source localization, to identify the precise timing of cortical activity, and transcranial magnetic stimulation (TMS), to identify whether a cortical region of interest is necessary for memory.

This project will provide the most compelling evidence bearing on the constructive memory hypothesis to date. While the combination of fMRI and ERP source localization or fMRI and TMS have been used to study visual perception and attention, these combined methodologies have not been used to study memory or other cognitive functions. As such, the techniques developed to conduct this research will serve as a methodological framework for future cognitive neuroscience studies. Funding of this project will also foster the growth of the neuroscience program at Boston College through direct participation of graduate and undergraduate students in the research, and by providing the basis for new courses that will focus on methods in cognitive neuroscience. More broadly, this project will assess whether memory can be specific for item features, which could explain certain types of memory loss in patients and could also have implications for law (relating to the level of detail in eyewitness testimony).