Why, where and how do top-down and bottom-up signals interact in the primate brain?

• DOI: 10.31234/osf.io/7mryq_v3
• Publication Date: 2025-05-28T16:00:30Z
• Authors: Yujie Hou; Julien Vezoli; Kenneth Knoblauch; Rainer Göbel; Martin Vinck; Henry Kennedy

Here we propose a roadmap for addressing hierarchical predictive coding theory (hPC) in the primate brain, theorizing that perception arises from integration of bottom-up (BU) pathways carrying sensory evidence with top-down (TD) priors and expectations. However, given conceptual importance hPC higher cognitive function humans there is surprising little concerning location functional mechanisms underlying such BU-TD integration. This will be overcome by parallel experiments non-human primates (NHPs). Molecular characterization NHP cortico-cortical BU TD projection cell types allow tracing these circuits exerting causal control to explore visual paradigms behaving NHPs. Identical human subjects undergoing ultra-high field laminar fMRI scanning indicate homologous brain. In human, long-distance expectations suggest claustrum involved hPC. Recent connectomic transcriptomic characterisation cortical claustral loops enable similar approach pathways’ participation signals as used pathways. Progress further emphasise synergy between neurobiology artificial intelligence important consequences both domains.