Recent neuroscientific and computational evidence supports the view that reinforcement processing relies on distinct mechanisms for reward and punishment rather than a single one-dimensional valence scale.
The retrieved literature consistently points to distinct neural circuits, neurotransmitter pathways, and computational architectures underlying reward and punishment processing. Papers 4, 5, and 6 explicitly demonstrate that reward and punishment (or pain and pleasure) are processed via separable mechanisms and dissociable neural networks rather than a monolithic valence dimension. There are no papers refuting this claim.