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Open Access Publications from the University of California

Scholarly Works (3 results)

  • Thesis
  • Peer Reviewed
UC Berkeley Electronic Theses and Dissertations (2022)

The orbitofrontal cortex (OFC) is a region critical to value-based decision making. Previous work from our lab showed that the neural population in OFC flip-flops between representing the available options while animals are deliberating between them. While these value dynamics were predictive of subjects' choices, they did not build toward the chosen option preceding the choice. We hypothesised that a downstream region with connections to both OFC and motor regions, for example the anterior cingulate cortex (ACC) or head of the caudate nucleus (CdN), may be integrating over these OFC value dynamics, leading to the choice. We recorded large neural populations simultaneously from OFC and each of these regions while two monkeys used a bidrectional lever to select between pairs of pictures, each associated with a unique probabilistic reward. In the ACC, we indeed observed a motor preparation signal that was influenced by OFC value dynamics on individual trials. However, in the CdN we observed a rapid choice direction signal, locked to the start of the trial instead of the motor response, that was independent of OFC value dynamics. Overall, our results are consistent with parallel, rather than serial, processing underlying value-based decision making.

    Cover page: Prefrontal and Subcortical Dynamics of Value-Based Decision Making
    • Article
    • Peer Reviewed
    UC Berkeley Previously Published Works (2023)
    During decision-making, neurons in the orbitofrontal cortex (OFC) sequentially represent the value of each option in turn, but it is unclear how these dynamics are translated into a choice response. One brain region that may be implicated in this process is the anterior cingulate cortex (ACC), which strongly connects with OFC and contains many neurons that encode the choice response. We investigated how OFC value signals interacted with ACC neurons encoding the choice response by performing simultaneous high-channel count recordings from the two areas in nonhuman primates. ACC neurons encoding the choice response steadily increased their firing rate throughout the decision-making process, peaking shortly before the time of the choice response. Furthermore, the value dynamics in OFC affected ACC ramping-when OFC represented the more valuable option, ACC ramping accelerated. Because OFC tended to represent the more valuable option more frequently and for a longer duration, this interaction could explain how ACC selects the more valuable response.
      Cover page: Value dynamics affect choice preparation during decision-making.
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2022)
      We make complex decisions using both fast judgments and slower, more deliberative reasoning. For example, during value-based decision-making, animals make rapid value-guided orienting eye movements after stimulus presentation that bias the upcoming decision. The neural mechanisms underlying these processes remain unclear. To address this, we recorded from the caudate nucleus and orbitofrontal cortex while animals made value-guided decisions. Using population-level decoding, we found a rapid, phasic signal in caudate that predicted the choice response and closely aligned with animals' initial orienting eye movements. In contrast, the dynamics in orbitofrontal cortex were more consistent with a deliberative system serially representing the value of each available option. The phasic caudate value signal and the deliberative orbitofrontal value signal were largely independent from each other, consistent with value-guided orienting and value-guided decision-making being independent processes.
        Cover page: Fast and slow contributions to decision-making in corticostriatal circuits
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