CHROME · Cortical hierarchy of memories - deciphering the neuronal mechanisms of serial dependence in the human brain
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2022-09-01 → 2025-11-19
- EU contribution
- €174,806
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Cortical hierarchy of memories - deciphering the neuronal mechanisms of serial dependence in the human brain
What we perceive at any moment is not a direct snapshot of the external world. Rather, perception is shaped by incoming sensory input and filtered through prior experience. For example, in medical image analysis, a doctor may misidentify—or miss—a detail because earlier images biased their expectations. While it has long been recognized that perception involves inference based on memory, scientific research has often treated perception and memory as separate processes. This project set out to bridge that gap by investigating how different forms of memory shape what we perceive in the present. The research focused on serial dependence, a phenomenon where recent visual experiences systematically bias current perception. The project aimed to identify what determines whether these biases are “attractive” (pulling perception toward the past) or “repulsive” (pushing it away), to understand the timescales of these effects, and to reveal the brain mechanisms involved. Several important findings emerged. First, the project uncovered stable individual differences in serial dependence: some people consistently showed attractive biases, others repulsive ones. This suggests that serial dependence reflects a trait-like cognitive strategy, not just situational noise. Second, the research demonstrated that longer-term memories held in working memory can override short-term perceptual history, indicating that the brain flexibly prioritizes different sources of information depending on task demands. Third, the findings showed a temporal dissociation: recent history shapes objective discrimination, while more distant experience influences subjective visibility. Finally, the project revealed that even non-conscious experiences can support long-term learning and prediction, suggesting that perceptual continuity relies on both conscious and non-conscious memory systems. Together, these results advance the understanding of how perception and memory interact. They show that multiple memory systems—short- and long-term, conscious and non-conscious—jointly shape perceptual experience. These insights lay the groundwork for a more integrated understanding of perception in both healthy and clinical populations.
Data: CORDIS, © European Union
Project objective
“Perception is never purely in the present–it has to draw on experience of the past.” O. Sacks illustrates a grounding principle in cognitive neuroscience: Eyes are not vision. Instead, seeing is an inferential process, with the brain integrating incoming with past sensory information. This idea, that perception and memory are deeply intertwined, has shaped many theories of neural computation. Yet research on these building blocks of cognition has largely evolved in separate fields. In the long-term, I aim to overcome this conceptual divide and understand the mechanistic principles by which memory and perception shape each other. In this fellowship, I will lay the foundation for this research vision and acquire the skills necessary to lead a group on this innovative program. I will work with authorities in invasive electrophysiology (L. Melloni) and dynamical systems (V. Priesemann) to tackle a current frontier in the neurosciences and unravel the brain and circuit-level mechanisms of serial dependence. A perceptual memory integrating past with current percepts, serial dependence offers a unique window into the interplay of perception and memory: It comes in multiple flavors (attractive & repulsive effects) and occurs at multiple timescales. A simple, untested hypothesis may account for this diversity: I propose that there is a hierarchy of perceptual memories, with different integration times and tuning features, all acting jointly to shape perception. I will test this innovative framework with behavioral studies (to map the spatio-temporal tuning profile of serial dependence), computational modeling (to probe how intrinsic timescales of a hierarchically organized neural network affect serial dependence), and non-invasive and invasive electrophysiology (to identify the cortical & hippocampal brain mechanisms supporting serial dependence). If successful, this work will provide a unifying framework of how memory, in the form of serial dependence, alters perception.
Original text from CORDIS.
Participants
- MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV · MUNCHENCoordinatorGermany
Links
Data: CORDIS, © European Union