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1. Bayesian inference by visuomotor neurons in the prefrontal cortex

   https://doi.org/10.1073/pnas.2420815122  

   Langlois, Thomas A; Charlton, Julie A; Goris, Robbe_L T (April 2025, Proceedings of the National Academy of Sciences)

   Perceptual judgments of the environment emerge from the concerted activity of neural populations in decision-making areas downstream of the sensory cortex. When the sensory input is ambiguous, perceptual judgments can be biased by prior expectations shaped by environmental regularities. These effects are examples of Bayesian inference, a reasoning method in which prior knowledge is leveraged to optimize uncertain decisions. However, it is not known how decision-making circuits combine sensory signals and prior expectations to form a perceptual decision. Here, we study neural population activity in the prefrontal cortex of macaque monkeys trained to report perceptual judgments of ambiguous visual stimuli under two different stimulus distributions. We isolate the component of the neural population response that represents the formation of the perceptual decision (the decision variable, DV), and find that its dynamical evolution reflects the integration of sensory signals and prior expectations. Prior expectations impact the DV’s trajectory both before and during stimulus presentation such that DV trajectories with a smaller dynamic range result in more biased and less sensitive perceptual decisions. We show that these results resemble a specific variant of Bayesian inference known as approximate hierarchical inference. Our findings expand our understanding of the mechanisms by which prefrontal circuits can execute Bayesian inference. 

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2. Statistical learning dynamically shapes auditory perception

   https://doi.org/10.1038/s41539-025-00328-z  

   Luthra, Sahil; Luor, Austin; Tierney, Adam T; Dick, Frederic; Holt, Lori L (December 2025, npj Science of Learning)

   Abstract Humans implicitly pick up on probabilities of stimuli and events, yet it remains unclear how statistical learning builds expectations that affect perception. Across 29 experiments, we examine the influence of task-irrelevant distributions—defined across acoustic frequency—on both tone detection in noise and tone duration judgments. The shape and range of the frequency distributions impact suppression and enhancement effects, as does a given tone's position within the range. Perception adapts quickly to changing distributions, but past distributions influence future judgments. Massed exposure to a single frequency impacts perception along a range of subsequently encountered frequencies. A novel bias emerges as well: lower frequencies are perceived as longer and higher ones as shorter. Probability-driven learning dynamically shapes perception, driven by interacting influences of sensory processing, distributional learning, and selective attention that sculpt a gain function involving modest enhancement of more-likely stimuli, and robust suppression of less-likely stimuli. 

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3. Selective filtering of relevant sensory signals in parietal cortex

   https://doi.org/10.21203/rs.3.rs-8564427/v1  

   Runyan, Caroline; Bassi, Constance; Saxena, Saloni; Smyer, Mabry; Ryan, James; Huang, Chengcheng (April 2026, Research Square)

   Abstract Animals must flexibly adjust their behavior to respond appropriately in changing behavioral situations, in order to survive and thrive. The posterior parietal cortex (PPC) has been implicated in flexible decision-making, as it encodes sensory stimuli depending on their behavioral relevance [1] and is required to adapt to changes in stimulus-response contingencies in behavioral tasks [2]. Here, we show that while mice performed an auditory decision-making task, the temporal organization of neural activity differed across excitatory and inhibitory interneuron subtypes, with pyramidal neurons sparsely encoding task-related information. Sensory responses of all cell types were modulated according to behavioral relevance in the task, and signatures of this modulation were evident even before the presentation of sensory stimuli. Population activity patterns preceding stimulus presentation predicted the strength of sensory responses and even the mouse's behavioral accuracy in the task. A network model revealed that randomly organized inhibitory connectivity could replicate the selective filtering of sensory responses, but that context-dependent inputs to the network must be targeted to neurons responding to behaviorally relevant cues, and avoid those responding to irrelevant cues. Our results reveal a selective filtering mechanism in cortical circuits underlying flexible decision-making. 

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4. Sensory population activity reveals downstream confidence computations in the primate visual system

   https://doi.org/10.1073/pnas.2426441122  

   Boundy-Singer, Zoe M; Ziemba, Corey M; Goris, Robbe_L T (July 2025, Proceedings of the National Academy of Sciences)

   Perception is fallible. Humans know this, and so do some nonhuman animals like macaque monkeys. When monkeys report more confidence in a perceptual decision, that decision is more likely to be correct. It is not known how neural circuits in the primate brain assess the quality of perceptual decisions. Here, we test two hypotheses. First, that decision confidence is related to the structure of population activity in the sensory cortex. And second, that this relation differs from the one between sensory activity and decision content. We trained macaque monkeys to judge the orientation of ambiguous stimuli and additionally report their confidence in these judgments. We recorded population activity in the primary visual cortex and used decoders to expose the relationship between this activity and the choice-confidence reports. Our analysis validated both hypotheses and suggests that perceptual decisions arise from a neural computation downstream of visual cortex that estimates the most likely interpretation of a sensory response, while decision confidence instead reflects a computation that evaluates whether this sensory response will produce a reliable decision. Our work establishes a direct link between neural population activity in the sensory cortex and the metacognitive ability to introspect about the quality of perceptual decisions. 

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5. The midbrain reticular formation in contextual control of perceptual decisions

   Shaker, Jordan R; Schroeter, Jeremy N; Birman, Daniel; Steinmetz, Nicholas A (March 2026, Neuron)

   Flexibly responding to sensory cues is fundamental to animal behavior. However, growing evidence suggests that the relevant neural circuits have been incompletely resolved. We investigated the midbrain reticular formation's (MRF) role, training mice to apply an abstract rule mapping identical visual stimuli to opposing actions across contexts. Large-scale recordings revealed that neurons in MRF, along with several canonical decision-making areas, maintained persistent representations of task context in pre-stimulus activity. These representations predicted divergent population dynamics, putatively routing stimuli toward context-appropriate actions. The MRF was the only recorded region containing neuronal populations that both predicted lapses in contextual control pre-stimulus and exhibited contextually modulated premotor responses. The MRF also showed task-specific sensory plasticity. Context-coding neurons were aligned with cortical inputs, suggesting spatial organization. These findings support the hypothesis that the MRF is a key node for setting and implementing abstract contextual states within the distributed circuitry for flexible perceptual decisions. 

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