Summary of key findings from human intracranial recording studies of reward, value, and decision-making.
| Study | Title | Key takeaway |
|---|---|---|
| Cohen et al., 2009 [16] | Good Vibrations: Cross-frequency Coupling in the Human Nucleus Accumbens during Reward Processing | Gamma-alpha coupling in the nucleus accumbens acts as a gating mechanism encoding reward information via phase coding. |
| Lega et al., 2011 [17] | Neuronal and oscillatory activity during reward processing in the human ventral striatum | Reward processing in the ventral striatum involves reward-sensitive neurons and distinct oscillatory patterns differentiating positive versus negative feedback. |
| Kishida et al., 2016 [18] | Subsecond dopamine fluctuations in human striatum encode superposed error signals about actual and counterfactual reward | Subsecond dopamine fluctuations encode integrated RPEs, including actual and counterfactual outcomes. |
| Li et al., 2016 [19] | The neural dynamics of reward value and risk coding in the human orbitofrontal cortex | Different OFC subregions encode reward probability, risk, and experienced value at distinct time points during reward anticipation and delivery. |
| Saez et al., 2018 [13] | Encoding of Multiple Reward-Related Computations in Transient and Sustained High-Frequency Activity in Human OFC | Human OFC shows fast transient and sustained high-frequency activity reflecting multiple valuation signals, including risk and outcome regret. |
| Lopez-Persem et al., 2020 [20] | Four core properties of the human brain valuation system demonstrated in intracranial signals | Subjective value is encoded in both OFC and parahippocampal cortex, modulated by pre-stimulus activity, and follows linear and quadratic functions. |
| Gueguen et al., 2021 [21] | Anatomical dissociation of intracerebral signals for reward and punishment prediction errors in humans | Broadband gamma activity encodes reward and punishment outcomes and expectations in anatomically distinct human brain regions. |
| Jamali et al., 2021 [22] | Single-neuronal predictions of others’ beliefs in humans | Neurons in human dmPFC encode others’ beliefs, supporting theory of mind processing at the single-neuron level. |
| Manssuer et al., 2022 [23] | Integrated Amygdala, Orbitofrontal and Hippocampal Contributions to Reward and Loss Coding Revealed with Human Intracranial EEG | Reward anticipation synchronizes hippocampus, amygdala, and OFC activity, implicating these regions in memory and motivation integration. |
| Aquino et al., 2023 [24] | Neurons in human pre-supplementary motor area encode key computations for value-based choice | PreSMA neurons integrate separate choice variables into unified value signals guiding decision making. |
| Collomb-Clerc et al., 2023 [25] | Human thalamic low-frequency oscillations correlate with expected value and outcomes during reinforcement learning | Low-frequency oscillations in thalamic subregions correlate with expected value signals during reward and punishment learning. |
| Hoy et al., 2023 [26] | Asymmetric coding of reward prediction errors in human insula and dorsomedial prefrontal cortex | Insula leads dmPFC in processing and communicating asymmetric RPE signals based on valence and salience. |
| Marciano et al., 2023 [27] | Electrophysiological signatures of inequity-dependent reward encoding in the human OFC | OFC high-frequency activity encodes self and others’ rewards, including social inequity types, reflecting social valuation processes. |
| Batten et al., 2024 [28] | Dopamine and serotonin in human substantia nigra track social context and value signals during economic exchange | Dopamine in the substantia nigra tracks RPEs, while serotonin tracks offer value modulated by social context during economic exchanges. |
| Man et al., 2024 [29] | Temporally organized representations of reward and risk in the human brain | Reward and risk representations in the human brain are temporally organized, revealing how these computations unfold over time. |
This table provides the key takeaway for each study, highlighting electrophysiological signatures, neural computations, and brain regions involved in processing reward, risk, prediction errors, and social valuation. dmPFC: dorsomedial prefrontal cortex; HC: hippocampus; HFA: high-frequency activity; INS: insula; LFO: low-frequency oscillations; OFC: orbitofrontal cortex; PHC: parahippocampal cortex; preSMA: pre-supplementary motor area; RPE: reward prediction error.