Biology subjects

Erlich, J. C.

Publications and source records attributed to Erlich, J. C..

9 recordsLinked to original sources

bioRxiv2025

A frontal motor circuit for economic decisions and actions

Flexible behaviour requires transforming abstract cognitive representations, such as value preferences, into concrete motor actions. During economic decision-making, individuals evaluate options to guide choices and then transform these choices into specific actions to obtain rewards. Understanding how neural circuits convert these abstract economic decisions into spatial actions remains challenging because decision formation and motor planning are typically intertwined. Here we introduce a mouse task that temporally dissociates value-guided decisions from spatial action planning, and show that a frontal motor network implements the transformation across decision stages through dynamic circuit reconfiguration. Using cortex-wide imaging and optogenetic perturbations, we identified a frontal motor circuit that was causally required for both abstract and motor stages of choice. During the abstract decision stage, neurons in this circuit encoded option values and economic choices independently of sensorimotor contingencies, and unilateral silencing impaired decisions without spatial bias. In contrast, during spatial planning, value and spatial signals were non-linearly integrated to guide action selection, and unilateral silencing produced an ipsilateral bias. A dynamical model captured this transformation, predicting a mode switch from cooperative interhemispheric maintenance of economic choice to competitive, lateralized control of actions, which we validated with simultaneous bilateral recordings. These findings demonstrate how frontal motor circuits reconfigure their interactions to bridge abstract cognition and concrete actions, providing a circuit-level mechanism for flexible, value-guided behaviour.

neuroscience↗

bioRxiv2025

Flexible selection of working memory representations to reduce cognitive cost

Across psychology 1-4, economics 5,6, machine learning 7, and neuroscience 8,9, it is well established that choosing a good internal representation can make complex problems easier to solve. Thus, intelligent behavior depends not only on what is stored in working memory, but on the format in which it is stored. Selecting a lower-load format can substantially reduce the mental effort required for a task, since working-memory load is a major contributor to cognitive cost 10-12. Whether non-human animals make such representational choices, and how these choices are implemented in neural circuits, has remained unclear. Here we show that rats flexibly adjust the format of working memory to reduce cognitive cost. In an egocentric task that encourages an action-based code, rats maintained the relevant information as a stable motor plan supported by frontal cortex. When the same behavioral problem was reformulated in allocentric coordinates, the action-based code became costly, and rats instead stored a sensory trace in auditory cortex. A cost-sensitive model explains which internal format should be used under each task variant and predicted that simplifying the allocentric task would reduce the advantage of a sensory code and drive reinstatement of frontal motor planning; this prediction was confirmed, as rats rapidly returned to a motorplan representation and the frontal cortex again became necessary for performance. These results demonstrate that flexible representational selection is not unique to humans 13 but is present in rodents and reflected in circuit-level reallocation of working memory. This establishes a neural basis for classic theories linking problem representation to computational efficiency and provides a path toward a circuit-level understanding of how the brain selects internal formats to reduce cognitive cost.

neuroscience↗

bioRxiv2025

Intertemporal choice across short and long time horizons: an fMRI study

This preregistered fMRI study investigates the neural mechanisms underlying intertemporal choices involving waiting and postponing. On a behavioral level, choices made regarding rewards available in seconds that require waiting compared to choices about rewards postponed to a number days are surprisingly similar. The explanation to this short/long time scales gap is lacking even after considering time perception and external factors, such as stress. To address that this study is the first to examine the overlapping and distinct neural circuitry involved in the intertemporal choices over seconds and days, and the waiting period within subject. Our results revealed considerable overlap in brain activation during choices that consider seconds and days delays to reward in the executive control (dACC, dlPFC) and prospection (PCC/precuneus, dmPFC) networks, but not in the valuation network. Consistent with existent literature we found the valuation network activation (both vmPFC and ventral striatum) being parametrically modulated by individual subjective values of delayed rewards. Overall, the key network determined through representational similarity and decoding analyses was prospection accounting for similarity in activation during decision making across time scales of delays and discriminating between waiting and postponing the reward. These findings enhance our understanding of the neural underpinnings of intertemporal choices and their implications for real-life decisions occurring across varying time horizons, such as paying to skip advertisements while watching videos or deciding on the next-day delivery service.

neuroscience↗

bioRxiv2025

Mice dynamically adapt to opponents in competitive multi-player games

Competing for resources in dynamic social environments is fundamental for survival and requires continuous monitoring of both self and others to guide effective choices. Yet most of our understanding of value-based decision-making comes from studying individuals in isolation, leaving open key questions about how animals adapt their strategies during social competition. Here, we developed an ethologically relevant multi-player game in which freely moving mice made valuebased decisions in a competitive spatial foraging task. We found that mice integrated real-time spatial information about both themselves and their opponents to flexibly shift their preferences toward safer, low-payout options when appropriate. Analyses of mice behaviour and reinforcement learning agents revealed that these adaptations could not be explained by simple reward learning, but were instead consistent with optimal decision strategies guided by opponent features. Using a dynamical model of decision-making, we found that competition increased choice variability and sensitivity to initial conditions, generating testable predictions for future neural recordings and perturbations. Together, our findings reveal a fundamental mechanism for flexible competitive foraging and propose novel frameworks for quantitatively understanding value-based decision-making in fast-changing social environments.

neuroscience↗

bioRxiv2022

Encoding of spatial location by frontal orienting field neurons

The neural mechanisms of motor planning have been extensively studied in rodents. Preparatory activity in the frontal cortex predicts upcoming choice, but limitations of typical tasks have made it challenging to determine whether the spatial information is in a self-centered direction reference frame or a world-centered position reference frame. Here, we trained rats to make delayed visually-guided orienting movements to six different directions, with four different target positions for each direction, which allowed us to disentangle direction versus position tuning in neural activity. We recorded single unit activity from the rat frontal orienting field (FOF) in the secondary motor cortex, a region involved in planning orienting movements. Population analyses revealed that the FOF encodes two separate 2D maps of space. First, a 2D map of the planned and ongoing movement in a self-centered direction reference frame. Second, a 2D map of the animals current position on the port wall in a world-centered reference frame. Thus, preparatory activity in the FOF represents self-centered upcoming movement directions, but FOF neurons multiplex both self- and world-reference frame variables at the level of single neurons. Neural network model comparison supports the view that despite the presence of world-centered representations, the FOF receives the target information as self-centered input and generates self-centered planning signals.

neuroscience↗

bioRxiv2021

Frontal but not parietal cortex is required for decisions under risk

Neurons in frontal and parietal cortex encode task variables during decision-making, but causal manipulations of the two regions produce strikingly different results. For example, silencing the posterior parietal cortex (PPC) in rats and monkeys produces minimal effects in perceptual decisions requiring integration of sensory evidence, but silencing frontal cortex profoundly impairs the same decisions. Here, we tested the causal roles of the rat frontal orienting field (FOF) and PPC in economic choice under risk. On each trial, rats chose between a lottery and a small but guaranteed surebet. The magnitude of the lottery was independently varied across trials and was indicated to the rat by the pitch of an auditory cue. As in perceptual decisions, both unilateral and bilateral PPC muscimol inactivations produced minimal effects. FOF inactivations produced substantial changes in behavior even though our task had no working memory component. We quantified control and bilateral inactivation behavior with a multi-agent model consisting of a mixture of a rational utility-maximizing agent (U = V{rho}) with two habitual agents that either choose surebet or lottery. Effects of FOF silencing were best accounted for by a decrease in{rho} , the exponent of the utility function. The decrease in{rho} could be parsimoniously explained by a dynamical model where the FOF is part of a network that represents the value of the lottery to compare against a remembered boundary representing the value of the surebet. This dynamical model predicted that neurons in the FOF should increase their activity with increasing lottery values. In line with our predictions, single neurons recorded in the FOF encoded the value of the lottery even when controlling for choice. These results together demonstrate that FOF is a critical node in the neural circuit for decision under risk.

neuroscience↗

bioRxiv2021

Does endogenous variation in stress modulate risk and time preferences?

Stress is a normal part of our everyday lives. It alerts us to changes in our environment working as an early warning system. However, when stress is prolonged, it can become harmful. The deleterious effects of stress on brain function are well established: chronic stress significantly impairs cognitive function reducing our ability to solve problems and to regulate behavior and, therefore, may lead to more challenges that can further exacerbate stress. An important class of decisions that may be made under stress includes those between rewards delivered immediately vs. those delivered in the future. Not considering or devaluing future outcomes (delay discounting) can result in adverse outcomes such as not buying health insurance, gambling or drug use. To date, however, little is known about how chronic stress influences economic decisions that differ in the time of outcome delivery. A handful of studies suggest that increased stress may lead to more impulsive choices in subjects of average socioeconomic status and stress levels. Here, we addressed this gap by using a longitudinal design to determine whether chronic stress measures (via questionnaires, saliva and hair samples) are associated with the economic choices under different time scales within subject (N = 34). We found that the degree to which people think it is worth waiting, i.e. individuals discount factor, over seconds, but not over days, varied reliably with endogenous stress. These results are imperative to studying stress in a variety of contexts: e.g., the variation in consumers impulse purchases could be attributed to the variation in individual stress responses to the environment, even in healthy adults.

animal behavior and cognition↗

bioRxiv2018

Time preferences are reliable across time-horizons and verbal vs. experiential tasks

Individual differences in delay-discounting correlate with important real world outcomes, e.g. education, income, drug use, & criminality. As such, delay-discounting has been extensively studied by economists, psychologists and neuroscientists to reveal its behavioral and biological mechanisms in both human and non-human animal models. However, two major methodological differences hinder comparing results across species. Human studies present long time-horizon options verbally, whereas animal studies employ experiential cues and short delays. To bridge these divides, we developed a novel language-free experiential task inspired by animal decision-making studies. We find that subjects time-preferences are reliable across both verbal/experiential differences and also second/day differences. When we examined whether discount factors shifted or scaled across the tasks, we found a surprisingly strong effect of temporal context. Taken together, this indicates that subjects have a stable, but context-dependent, time-preference that can be reliably assessed using different methods; thereby, providing a foundation to bridge studies of time-preferences across species.

animal behavior and cognition↗

bioRxiv2018

Collicular circuits for flexible sensorimotor routing

Historically, cognitive processing has been thought to rely on cortical areas such as prefrontal cortex (PFC), with the outputs of these areas modulating activity in lower, putatively simpler spatiomotor regions, such as the midbrain superior colliculus (SC). Using a rat task in which subjects switch rapidly between task contexts that demand changes in sensorimotor mappings, we report a surprising role for the SC in non-spatial cognitive processes. Before spatial response choices could be formed, neurons in SC encoded task context more strongly than neurons in PFC, and bilateral SC silencing impaired behavioral performance. Once spatial choices could begin to be formed, SC neurons encoded the choice faster than PFC, while bilateral SC silencing no longer impaired choices. A set of dynamical models of the SC replicates our findings. Our results challenge cortically-focused views of cognition, and suggest that ostensibly spatiomotor structures can play central roles in non-spatiomotor cognitive processes.

neuroscience↗