In the Memory Modulation Lab, we use the tools of cognitive neuroscience to answer questions about memory and the brain, such as:
- How does the brain make and maintain memories?
- How do emotional experiences modulate learning of new information?
- How does the context of an individual moment shape its representation in memory?
Our research incorporates a combination of cognitive neuroscience methods, including fMRI (multivariate pattern analysis, functional connectivity, high-resolution imaging, etc.) and EEG (time-frequency analysis).
How does the brain make and maintain memories?
For several decades, research on the neural basis of memory has focused on the medial temporal lobes (MTL), including the hippocampus and its surrounding cortical areas. MTL regions appear to play different roles in memory, but are typically described as an integrated system apart from other cortical systems. Yet, different MTL regions reliably engage with distinct cortical networks, and these networks appear to play a role in many cognitive functions, not just memory. Based on these observations, we have argued that memory function can be best understood as arising from distinct yet interacting cortico-hippocampal systems: an anterior temporal system that supports item memory and a posterior medial system that supports context memory. Our research focuses on characterizing these networks by measuring functional interactions between MTL regions and other cortical areas and by relating these interactions to regional specialization during memory formation and retrieval.
How do emotional experiences modulate learning of new information?
Memories for emotional experiences are more durable than neutral memories, but not all aspects of memory are enhanced. For example, emotional arousal reliably enhances item memory but not necessarily memory for the surrounding context. One possible reason for these memory differences is that the mechanisms of emotional arousal affect cortico-hippocampal systems in different ways. In other words, emotion might push around memory systems to favor some types of memory representations over others. We are currently testing this hypothesis in a few different ways, including high-resolution imaging of amygdala and hippocampal contributions to emotional memory as well as new work on the influence of emotional contexts on the temporal dynamics of learning.
How does the context of an individual moment shape its representation in memory?
Context plays a crucial role in guiding how an individual moment will be remembered. Memories encoded in the same context elicit more similar neural patterns than memories encoded in different contexts, but this context "code" appears to differ between brain regions and even within subregions of the hippocampus. We are currently investigating how context is represented in parallel by different hippocampal and cortical areas. In another line of research, we are also investigating how the context of an individual moment influences whether or not that moment will be stored in long-term memory. For instance, we recently discovered that the likelihood of remembering something depends not only on what the brain was doing during learning, but also on how it interacts with events that happen after learning-- e.g., whether someone was stressed out afterward. In this way, memories for individual moments are not formed in isolation, but rather they can be influenced by the emotional tone of their surrounding context.