Cognitive map

…formation, but use of such a “cognitive map” requires the online representation of desired locations and how to get there, and the neural basis for this function has been more elusive. I will discuss how “theta sweeps” of place and grid cell firing encode the current location (at early phases of each theta cycle) while, at later phases, sampling around the forward direction during exploration and indicating the direction to desired locations during goal-directed navigation. I w

The hippocampus is thought to build a cognitive map that supports navigation, memory, and planning, but what defines such a map and how it is used remain debated. In this talk, I will present computational models in which hippocampal-like representations emerge in recurrent neural networks trained to predict sequences of sensory observations. While spatially tuned units reliably arise, they are not sufficient to form a cognitive map. Instead, map-like representations emerge when recurrent dynamics support multi-step prediction, yielding a population-level encoding of environmental geometry. On

My talk will consist of three subtopics. The brain remembers episodes not in isolation but with their contextual relationships, such as spatial or temporal proximity. This is an essential feature of the brain’s memory, but the underlying mechanism is yet to be explored. Cell assemblies, or engrams, may provide neural representations for such relationships. First, I will show a class of associative memory models that encode and retrieve multiple memory contents linked by an arbitrary graph structure through experience and demonstrate the crucial role of the balance between two inhibitory subnet

…1) a continuous neural manifold that maps spatial and task structure, 2) spatial representations that “sweep” ahead of the animal as it moves through the en

Hippocampal studies provide a rich window into the mechanisms of memory via the paradigm of spatial navigation. To interpret neural responses, it is common practice to first build encoding models using position during locomotion as the label, and then decode the position using this model. Of particular interest is the mismatch between the decoded and the actual position, for instance, replay of non-local trajectories during rest. However, it is unclear whether a priori chosen labels explain neural data the best. By imposing spatial structure to times of immobility, we may be systematically mis

…claims about the existence of a ‘cognitive map’ in honeybees. This raises the question which internal representations of the world (and the animal’

…in mammals, and the construction of a cognitive map of space using a prominent feature – place cells [1] (PCs). It is unclear how PCs’ neural codes are related to memory: turnover of neural representations could be involved in learning, while codes’ stability may support long-term storage and retrieval of memories [2]. In this work, we focus on the analysis of one-photon (1P) calcium imaging data recorded from mouse CA1 during free foraging in a two-dimensional arena with the help of a miniature

Our understanding of the hippocampus has been framed by two landmark discoveries: the discovery by Scoville and Milner that hippocampal damage causes profound and persistent amnesia and the discovery by O’Keefe and Dostrovsky of hippocampal place cells in rodents. However, it has been unclear to what extent spatial representations are present in the primate brain and how to reconcile these representations with the known mnemonic function of this region. I will discuss a series of experiments that have examined neural activity in the hippocampus in monkeys performing behavioral tasks including

…decouple running locomotion from the cognitive map. This BMI associates neural activity with locations on a 1D Virtual Reality (VR) track, and then translates those locations into contextually appropriate actions (Fig

The hippocampus is thought to form the brain substrate of a cognitive map. While the spatial component of this map involves hippocampal ‘place’ cells, non-spatial features may require coupling with other brain areas. This could involve ‘hippocampal sequences’, endogenous activations of successive place cells representing entire trajectories at a highly accelerated rate. These sequences are paced by theta or ripple oscillations, and could participate in learning and memory, as well as goal-directed decision making. However, the association between hippocampal sequences and reward- and goal-rela

…As a population, PCs form a “cognitive map” of the environment that adapts to contextual changes through remapping. The dorsal and ventral parts of the hippocampus have different functional implications in spatial coding. While the dorsal HPC mainly processes spatial information, the ventral HPC encodes valence an

…across neurons representing different cognitive variables that guide the appropriate action selection. Here we used a novel naturalistic behavioral paradigm that does not require pre-training, which allowed studying the underlying neural activity from the very first day of behavior. This paradigm involves tongue-reaching movements towards multiple target-positions, followed by a variable reward outcome. The target was presented on a grid (typically consisting of 4x4 possible target positions) in front of the mouse’s face. We used calcium ima

…playing a pivotal role in not only mapping the animal’s own position but also replaying goal-directed paths. Whether and how spatially-tuned neurons in the hippocampus can also discriminate behavioral contexts targeting different destinations remain, however, unclear.By using a navigation task that requires frequent updates in goal locations, we found that, while a majority of place cells in the hippocampal CA1 maintained the s

…current goals or plans, to update a "cognitive map". The former view has been formalized in a reinforcement learning framework (Mattar and Daw, 2018), which predicts which trajectories should be replayed preferentially ("prioritized") to support pl

…on an attractive neuronal manifold, or cognitive map, in CA3, with topological correspondence to space. Supporting this idea, continuous attractor neural networks (CANNs) show place cell-like tuning for spatial locations, and can be used to simulate plausible trajec

The concept of a cognitive map posits that the brain maintains an internal representation of space. This map is represented in cells of the hippocampus and entorhinal cortex, which carry information about the animal’s location in an environment. These representations are adaptable to changes in the environment; for example, the number of hippocampal place cells that encode a particular location will increase if a reward is delivered at that location. We aimed to investigate what information the two regions of the entorhinal cortex – medial and lateral – may contribute during reward-guided spat

The hippocampus creates a cognitive map of the world to optimize predictions and guide behavior, with the dorsal and ventral hippocampus believed to play unique roles in this process. To understand how such representations evolve with learning and are updated with new experience, we used 2-photon calcium imaging to track the same dCA1 or vCA1 neurons across days as mice learned to associate odor stimuli with different outcomes. During reward (sucrose) associative learning, we find that, initially, odor cues elicited robust responses in dCA1, whereas in vCA1 encoding of odor identity was reduce

Hippocampal place-cell activity is thought to support the formation of a cognitive map that allows the association of an event to its spatial context. It has long been thought that within familiar spatial contexts, such neuronal representations should be stable over time, and that individual place cells should retain their coding properties. However, recent findings have demonstrated that hippocampal codes gradually change over timescales of minutes to weeks. Several studies have suggested that this gradual drift in the ensemble activity patterns of hippocampal neurons could serve as a mechani

…hypothesis is that OFC represents a cognitive map or state space (i.e., a representation of the different states in a task and the transitions between them) [2]. We trained rats on a novel temporal wagering task with partially hidden states (blocks of trials with low or high rewards). Rats must determine how long to wait for a reward, providing an explicit be

Decades of research have shown that temporal encoding context is a powerful organizing principle in memory. When remembering lists of words, subjects tend to recall items together that were presented in nearby list positions (“temporal clustering”). The retrieved context framework explains these results by assuming that new memories are stored along with a slowly changing context representation, which cues similar memories at retrieval. Outside of the laboratory, our experiences unfold over both time and space, raising the question of how spatial context affects memory organization. Studies us