Neuropsychology Talk

13.04.2026

Memory Modes, not Systems: How dynamic neural states enable comprehension, recollection, and prediction in the context of complex events

Abstract: 
In neuroscience, episodic memory is depicted as a memory system that stores our waking experiences in "engrams" that provide a static and faithful record of the past. But almost a century of research has demonstrated that that human memory is dynamic and constructive. We do not replay the past in its entirety, but instead, rely on prior knowledge, along with a small amount of retrieved details to imagine how the past could have been. How do we reconcile these ideas? Researchers have often assumed implicitly that we automatically encode memories for every   moment of experience, based on the idea that memory should be a comprehensive archive of the past. I will present results that challenge this assumption, and suggest instead that episodic memory is a limited resource, used to cache important information and to subsequently bail us out at computationally critical moments. Our empirical data (from behavioral, fMRI, and intracranial EEG studies), along with computational analyses, suggest that the brain alternates between at least two modes: a transient "contextual mode," governed by cortico-hippocampal interactions that support recording and retrieval of snapshots of cortical activity, and , and a "constructive mode," in which regions in the default mode network construct and maintain a generative model of an event. These modes support online comprehension, as well as encoding and retrieval of events. Beyond episodic memory, conceptualizing cognition in terms of temporally and neurally dynamic modes might be computationally optimal for spatial navigation, planning, and decision-making.

Speaker:

• Prof. Dr. Charan Ranganath (University of California at Davis)

Venue:
IB 4/115 or online: https://ruhr-uni-bochum.zoom.us/j/99038888420?pwd=c1d0blhPWE5ldWZTMW1haTJzUlg4Zz09

Starting time:
4:00 pm