Navigation

…with the Royal Institute of Navigation, the programme discusses the engineering, operation and navigation of driverless vehicles. Contributors include Nick Bailey, Daniel Clarke, Jamie Wilson, Jim Hutchinson, Ramsey Faragher and Edward Cameron, representing the test service, local transport partnership, vehicle manufacturer, automation supplier and navigation community.

…relationship to learning, memory and navigation. He explains how AI models can help investigate these dynamics, alongside questions about model systems, cognitive maps and the relationship between neuroscience experiments and theory.

…for working memory, motor control, and navigation. Theories have proposed that such representations are maintained by a class of recurrently connected networks called ring attractor networks. These networks rely on large numbers of neurons to maintain continuous and stable representations and to accurately integrate incoming signals. The head direction system of the fruit fly, however, seems to achieve these properties with a remarkably small network. These findings challenge our understanding of ring attr

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

…Examples from chess, navigation and generative systems show that competence alone may fail to support a weaker human partner or accommodate unexpected changes. The talk also considers theoretical cases where successful generation does not imply that an agent can identify the model generating its observations.

…(the orbitofrontal cortex, OFC) and navigation (the retrosplenial cortex, RSC), orchestrates the transition between competing goals during navigation. To explore this, we designed a virtual-reality maze task for two Rhesus monkeys, wher

…These tasks include path integration, navigation, Bayesian reasoning, sampling, memorization, and logical inference. The resulting spiking neural network models capture various hippocampal cell types (grid, place, border, etc.), behavioural errors, and a variety of observed neural dyn

…to study sensory integration in a navigation task in two different scenarios. In the first scenario, there is

Hippocampal place cell populations putatively encode allocentric spatial position [1-4]. In bats and rodents, place cells exhibit heterogeneously sized and overlapping receptive (or place) fields [5-9]. These heterogeneous place fields instantiate a multiscale spatial tuning landscape in which the larger place fields of some place cells encompass the relatively more numerous narrowly tuned place fields of other cells (Fig 1a). In this work, we investigate the effectiveness of such multiscale codes for encoding allocentric spatial position. We do so by deriving closed-form expressions for how w

Efficient behavior in our noisy and ambiguous world calls for the strategic use of the arising uncertainty by probabilistic inference [1]. Probabilistic inference in complex dynamic environments is challenging as it requires tracking not only individual latent variables but also the interactions among them. As a result, a neural circuit that optimally encodes these variables would need to be recurrently wired to relay information between them via feedback connections [2]. Given the additional cost of evolving and maintaining these feedback connections, we sought the circumstances under which t

Blindness significantly impacts the ability to acquire spatial information and build a cognitive map to stay oriented in the environment. Possible consequences include reduced autonomy, increased anxiety, social isolation, and overall decreased quality of life. It is therefore important to investigate non-visual cognitive map formation and its underlying neural mechanisms, which are still poorly understood. Therefore, we used fMRI to study the neural correlates of cognitive map formation through touch and audition in individuals with congenital and acquired blindness, and sighted individuals a

…of everyday human activities such as navigation and memory encoding in a more natural way that

…self-motion discrimination, and navigation. While extensive research has explored these functions in non-image forming pathways and higher order visual cortices, the influence of the vestibular system on early stages of visual processing remains less understood. In this study, we aimed to investigate the impact of vestibular inputs on visual responses within key region receiving retinal input: the thalamic Lateral Geniculate Nucleus (LGN). To determine the specific effects of vestibular information on vi

The entorhinal cortex (EC) is a brain region playing an important role in memory and navigational processes. This is driven by its unique cellular organization as well as its extrinsic connectivity. Specific neuronal cell types have been associated with the specific navigation-related functions of the EC such as grid cells, border cells, speed cells or head-direction cells. These cell types have been characterized based on their firing properties, however, still lack a molecular profile. Similarly, detailed anatomical cell types have been described within the different EC layers, including ste

…The RE activity has been implicated in navigation, decision making, and spatial memory consolidation. We have previously shown that the RE activity is critical for the retrieval of spatial memory. Yet, the network mechanisms of the RE contribution to the extended prefrontal-thalamo-hippocampal circuit remain to be explored. It has been suggeste

The medial temporal lobe (MTL) is important for mnemonic processes, navigation and social cognition. At the basis of all these cognitive processes lies the integration of a multitude of stimuli and their classification into conceptual groups. Neurons in human MTL indeed show concept-specific activity profiles in that they fire specifically for pictures presenting concepts of animals, landscapes, faces, concept relations and their grade of novelty. How such representations are organized during moving scenes, where different concepts are presented simultaneously, has so far received little atten

Navigation requires orienting oneself relative to landmarks in the environment, evaluating relevant sensory data, remembering goals, and convert all this information into motor commands that direct locomotion. I will present models, highly constrained by connectomic, physiological and behavioral data, for how these functions are accomplished in the fly brain.

Navigation has long been recognized as one of the most fundamental behaviors in animals and humans. While much has been learned by studying navigation behaviorally and its neuronal underpinnings, there is no comprehensive computational account of the uncertainty and variability governing navigation. Current ideal observer models of navigation frame navigation in terms of perceptual cue integration but omit planning and sequential control and, therefore, cannot explain how trajectories and their endpoint variability arise. Because a vast array of natural sensorimotor behaviors in humans, includ

…in motor control, social behavior, navigation, and beyond. Existing models are only trained with labeled frames (supervised learning). Although effective in many cases, the supervised approach requires extensive image annotation, struggles to generalize to new videos, and produces noisy outputs that hinder downstream analyses. We address each of these limitations by introducing unlabeled video clips to model training and inference, and exploiting their spatio

Cognitive maps associate complex, high-dimensional stimuli, such as visual percepts, with abstract latent variables, such as spatial locations. It has been argued that animals use these abstract spatial features to navigate and infer novel shortcuts in their environments. Employing information theory, we present a simple computational account of how such abstract spatial representations may emerge from interactions with high-dimensional stimuli: We show that learning world models in which the dynamics are parsimonious and apply (approximately) independently of the state in an abstract state sp

…learning, memory, decision making and navigation. Due to recent innovations in recording methods, there is increasing evidence for the existence of attractor dynamics in the brain. Yet, our understanding of how these attractors emerge or disappear in a biological system is lacking. In vitro cultured cortical neurons have been used extensively as a realistic experimental tool to understand the underlying mechanisms in neuronal assemblies. One of the main characteristics of the activity of such networks are the spontaneous synchro

The neural correlates of decision-making have been investigated extensively, and recent work aims to identify under what conditions cortex is actually necessary for making accurate decisions. We discovered that mice with distinct cognitive experiences, beyond sensory and motor learning, use different cortical areas and neural activity patterns to solve the same task, revealing past learning as a critical determinant of whether cortex is necessary for decision tasks. We used optogenetics and calcium imaging to study the necessity and neural activity of multiple cortical areas in mice with diffe

To successfully navigate their environment, animals may generate an internal, abstract and stable representation of the environment that can be updated based on sensory cues, such as visual landmarks or vestibular feedback, or internally generated motor commands. In mammals, neurons that fire when the animal faces a particular direction in the world reference frame have been recorded in mammillary bodies and entorhinal cortex. The heading direction can be read out using a weighted sum of the activation of those cells. This dynamics is well described by a “ring attractor” model: the network has

Navigation occurs through a continuum of space and time. The hippocampus is known to encode the immediate position of moving animals. However, active navigation, especially at high speeds, may require representing navigational information beyond the present moment. Using wireless electrophysiological recordings in freely flying bats we demonstrate that neural activity in area CA1 predominantly encodes nonlocal spatial information up to meters away from the bat’s present position. This spatiotemporal representation extends both forward and backwards in time with an emphasis on future locations