Mapping Early Memory Trajectories Across Species (ATLAS)
 

Research Scientists
Sarah D. Power (Project Leader)

Ulman Lindenberger

Early Memory Development
Maternal Immune Activation and Early Memory Systems
Brain Plasticity and the Emergence of Individuality

The ATLAS project investigates how memories are encoded, maintained, and retrieved during early development, and how variation in these processes shapes individual learning trajectories. It aims to move beyond average developmental patterns to understand the substantial variability that exists between individuals. Children differ markedly in how they explore their environments, encode information, and retain experiences over time. These differences may represent early signatures of cognitive individuality with implications for later developmental outcomes. The project was initiated in January 2026.

While research at the MPI for Human Development focuses on humans, ATLAS is embedded in a broader framework of cross-species collaboration. The project places particular emphasis on developing human research that enables meaningful comparison with animal models. ATLAS prioritizes the development of behavioral paradigms and application of analytical tools that can be applied across species, allowing shared questions to be addressed despite differences in experimental constraints. Within this framework, ATLAS focuses on core processes that provide anchors across humans and rodents, including memory development, interactions between the immune system and the developing brain, and brain plasticity.

Currently, the project pursues three strands of research, which are described below.

Early Memory Development

Although toddlers learn rapidly, episodic memories formed early in life are rarely retained into adulthood. This phenomenon, known as infantile amnesia, has been observed across species and remains a central puzzle in cognitive neuroscience. ATLAS seeks to understand why early memories are forgotten, whether they persist in latent form, and how early memory trajectories shape later cognitive outcomes. Rather than treating early forgetting as a deficit, the project approaches it as a window into the developing brain.

Building on the ECHO study (see RHYME project), ATLAS investigates how toddlers encode, retain, and retrieve episodic memories across extended periods. In the ECHO study, toddlers aged 18–24 months completed a hide-and-seek task with objects hidden in distinct contexts, allowing examination of the formation and delayed retrieval (up to six months) of object–location–context memories. Substantial variability exists between children: While some toddlers retained memories for extended periods, others showed rapid forgetting after relatively short delays. We will examine whether early individual variability in memory retention predicts later developmental outcomes through longitudinal follow-up studies in which children are revisited approximately one year after their initial participation. These studies examine how the time window of forgetting changes across development and whether early memory trajectories relate to later cognition and school readiness.

Maternal Immune Activation and Early Memory Systems

The second research strand investigates how prenatal immune challenges shape early memory systems. This research originated in doctoral work by Sarah Power, which examined maternal immune activation (MIA) in rodent models. In these experiments, pregnant dams were exposed to viral-like immune activation during gestation. Male offspring did not exhibit the typical pattern of infantile amnesia observed in control animals; instead, they retained memories formed during early development that would normally be forgotten. These findings suggest maternal immune activation can alter memory development by modifying how memories are encoded and retained early in life. The COVID-19 pandemic provided an opportunity to examine whether similar processes occur in humans. Within the ECHO study, a subset of toddlers was born to mothers who experienced COVID-19 infection during pregnancy. Preliminary findings suggest differences in memory retention patterns compared to children whose mothers did not experience infection during pregnancy. ATLAS will investigate the longer-term implications of these differences, including links to later cognition, social behavior, and neurodevelopmental outcomes (see Figure 1).

Grant support from the Canadian Institute for Advanced Research (CIFAR) further will enable us to examine how maternal immune activation shapes behavioral signatures across species by integrating human cohort data with established rodent models. In collaboration with Staci Bilbo (Duke University), Tomás Ryan (Trinity College Dublin), Alexander Mathis (École Polytechnique Fédérale de Lausanne, EPFL), and Mackenzie Mathis (EPFL), we will apply advanced computational approaches, including DeepLabCut for behavioral tracking and CEBRA for multimodal data alignment, to identify shared behavioral patterns linking maternal immune activation to neurodevelopmental outcomes and memory development.

Brain Plasticity and the Emergence of Individuality

Individuality emerges through dynamic interactions between brain, behavior, and environment. Through the WildBrain study, which has received three-year funding from the Innovation Fund of the Max Planck Society and will start in June 2026, the project will investigate how variation in environmental experience shapes brain plasticity and behavior, contributing to the emergence of individuality in humans and rodents (Freund et al., 2013; Hille et al., 2024). A central focus of this work is how individuals differ in two key behavioral domains: spatial exploration and social engagement. These behaviors represent fundamental interactions with the environment and may provide conserved markers of individuality across species. The WildBrain study examines whether stable patterns of exploration and social interaction reflect individual differences in brain plasticity and whether such markers of individuality are already present in early childhood (see Figure 2).

To address this question, the WildBrain study integrates behavioral profiles of individuality (e.g., spatial exploration and social engagement), environmental exposure data (e.g., GPS and ecological momentary assessments in humans, RFID tracking in mice), and neural measures (including magnetic resonance imaging in rodents and humans as well in vivo dendritic imaging and markers of neurogenesis in rodents) within using a longitudinal, within-subject research design. Using multivariate and cross-modal analyses, the team will seek to align levels of analysis across time and species to examine how evolving behavioral patterns, including increasingly stable individual differences, relate to individual differences in brain plasticity. This work is conducted in close collaboration with Simon Kühn (Center for Environmental Neuroscience), Tobias Bonhoeffer (MPI for Biological Intelligence), Gerd Kempermann (TUD Dresden University of Technology), and Franz Schilling (Technical University of Munich).

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