CDRL: A Reinforcement Learning Framework Inspired by Cerebellar Circuits and Dendritic Computational Strategies
Organizations: Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.
Abstract
Reinforcement learning (RL) has achieved notable performance in high-dimensional sequential decision-making tasks, yet remains limited by low sample efficiency, sensitivity to noise, and weak generalization under partial observability. Most existing approaches address these issues primarily through optimization strategies, while the role of architectural priors in shaping representation learning and decision dynamics is less explored. Inspired by structural principles of the cerebellum, we propose a biologically grounded RL architecture that incorporate large expansion, sparse connectivity, sparse activation, and dendritic-level modulation. Experiments on noisy, high-dimensional RL benchmarks show that both the cerebellar architecture and dendritic modulation consistently improve sample efficiency, robustness, and generalization compared to conventional designs. Sensitivity analysis of architectural parameters suggests that cerebellum-inspired structures can offer optimized performance for RL with constrained model parameters. Overall, our work underscores the value of cerebellar structural priors as effective inductive biases for RL.
Figures & tables
| Param. | Ball Spd. (H) | Ball Spd. (V) | Paddle Len. | Paddle Spd. |
| Train | 12 | 8 | 80 | 5 |
| Test 1 | 15 | 10 | 80 | 5 |
| Test 2 | 18 | 12 | 80 | 5 |
| Test 3 | 12 | 8 | 60 | 5 |
| Test 4 | 12 | 8 | 20 | 5 |
| Test 5 | 12 | 8 | 80 | 2 |
| Model | Baseline | CDRL-dendrite | CDRL |
| win rate (%) | 91.20 3.54 | 97.20 1.47 | 97.60 1.85 |
| reward | 8.38 0.85 | 9.71 0.50 | 10.07 1.97 |
Appendix figures & tables4 assets
Supplementary material from the paper’s appendix.
Appendix
| Parameter | Value | Parameter | Value | Parameter | Value |
| Ball X speed | 12 | Paddle width | 10 | Ball Y speed | 8 |
| Paddle height | 80 | Paddle speed | 5 | FPS | 1920 |
| Max score | 21 | Action noise | 0.0 | Stack size | 4 |
| Parameter | Value | Parameter | Value |
| Model type | Baseline / CDRL | GPU ID | 0 / 1 |
| Input channels | 4 | Batch size | 64 |
| Num episodes | 1500 | Gamma | 0.99 |
| Epsilon start | 1.0 | Epsilon end | 0.01 |
| Epsilon decay | 200000 | Learning rate | 5e-07 |
| Memory size | 100000 | Dendritic gate | Enabled / Disabled |
| Obs / Act | 0.00 | 0.05 | 0.10 | 0.15 | 0.20 | 0.30 |
| 0.00 | 0.92 0.04 0.99 0.01 | 0.93 0.04 0.98 0.01 | 0.90 0.04 0.97 0.02 | 0.87 0.07 0.95 0.03 | 0.84 0.06 0.93 0.02 | 0.73 0.13 0.86 0.04 |
| 1.00 | 0.88 0.11 0.98 0.01 | 0.83 0.16 0.96 0.01 | 0.84 0.11 0.96 0.03 | 0.80 0.14 0.94 0.03 | 0.79 0.15 0.89 0.06 | 0.62 0.09 0.79 0.08 |
| 2.00 | 0.58 0.31 0.84 0.22 | 0.54 0.29 0.81 0.25 | 0.54 0.31 0.79 0.25 | 0.51 0.29 0.76 0.25 | 0.52 0.23 0.72 0.22 | 0.42 0.21 0.62 0.20 |
| 3.00 | 0.50 0.29 0.73 0.26 | 0.48 0.30 0.70 0.27 | 0.45 0.23 0.72 0.24 | 0.46 0.25 0.66 0.25 | 0.40 0.21 0.61 0.23 | 0.40 0.18 0.57 0.21 |
| 5.00 | 0.30 0.09 0.56 0.25 | 0.33 0.05 0.54 0.23 | 0.30 0.07 0.54 0.22 | 0.28 0.07 0.49 0.21 | 0.32 0.04 0.46 0.23 | 0.29 0.07 0.44 0.20 |
| 10.00 | 0.27 0.07 0.37 0.22 | 0.31 0.06 0.38 0.18 | 0.29 0.06 0.35 0.19 | 0.26 0.06 0.34 0.17 | 0.28 0.04 0.31 0.15 | 0.27 0.01 0.28 0.14 |
| Obs / Act | 0.00 | 0.05 | 0.10 | 0.15 | 0.20 | 0.30 |
| 0.00 | 0.92 0.04 1 0.01 | 0.93 0.04 0.97 0.01 | 0.90 0.04 0.96 0.03 | 0.87 0.07 0.97 0.01 | 0.84 0.06 0.95 0.03 | 0.73 0.13 0.92 0.05 |
| 1.00 | 0.88 0.11 0.90 0.10 | 0.83 0.16 0.92 0.08 | 0.84 0.11 0.90 0.09 | 0.80 0.14 0.91 0.08 | 0.79 0.15 0.88 0.09 | 0.62 0.09 0.85 0.09 |
| 2.00 | 0.58 0.31 0.62 0.24 | 0.54 0.29 0.64 0.23 | 0.54 0.31 0.63 0.27 | 0.51 0.29 0.62 0.27 | 0.52 0.23 0.59 0.24 | 0.42 0.21 0.60 0.21 |
| 3.00 | 0.50 0.29 0.48 0.23 | 0.48 0.30 0.51 0.26 | 0.45 0.23 0.46 0.26 | 0.46 0.25 0.51 0.21 | 0.40 0.21 0.46 0.24 | 0.40 0.18 0.49 0.20 |
| 5.00 | 0.30 0.09 0.34 0.24 | 0.33 0.05 0.31 0.23 | 0.30 0.07 0.33 0.24 | 0.28 0.07 0.30 0.18 | 0.32 0.04 0.31 0.18 | 0.29 0.07 0.32 0.15 |
| 10.00 | 0.27 0.07 0.29 0.05 | 0.31 0.06 0.28 0.04 | 0.29 0.06 0.31 0.07 | 0.26 0.06 0.31 0.08 | 0.28 0.04 0.28 0.06 | 0.27 0.01 0.27 0.06 |
Reinforcement Learning
Reinforcement learning studies how agents learn sequential decisions from rewards and interaction, balancing exploration, performance, safety, and adaptation.
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