Jun Xu

Zhongxiang Sun, Haolang Lu, Qiang Ma et al.

Understanding how complex cognitive functions are organized within artificial systems is central to interpreting large language models (LLMs) and relating them to biological cognition. Yet although LLMs exhibit broad cognitive-like behaviours, it remains unclear whether their internal representations form reproducible functional systems that explain behaviour, failure and links to human cognition. Here we present NeuroCogMap, a cognitive neuroscience-inspired framework that organizes internal features of LLMs into functional parcels and links them to interpretable functions, cognitive capabilities and a cognitive hierarchy. These parcels form a stable and semantically coherent organization that is partly conserved across models and functionally linked to model outputs. Within this organization, major LLM failures, including hallucination, bias, refusal failure and sycophancy, correspond to distinct disruptions in representational and behavioural-control systems, yielding internal signatures for mechanism-guided detection and targeted intervention. Beyond model behaviour, NeuroCogMap improves prediction of human cortical responses during naturalistic language comprehension, with the strongest correspondence in higher-order association cortex. At the cognitive level, its internal signatures expose latent strategies that guide refinements of classical models of human decision-making. Together, these findings establish NeuroCogMap as a system-level framework for mapping functional organization in artificial systems and for relating this organization to human cortical function and cognitive behaviour.

Huayi Wang, Jun Xu, Gromit Yeuk-Yin Chan

Many modern AI workflows, ranging from LLM post-training pipelines to agentic reasoning tasks, can be expressed as declarative queries whose expensive predicate is evaluated by a large model or reward function. We propose a query-centric formulation of these workflows and show that classical database techniques, namely approximate query processing (AQP) and proxy-model (PM) based filtering, can substantially reduce the number of expensive model invocations without requiring changes to the underlying models or pipelines. Our first strategy treats the workflow as an online aggregation problem: it progressively samples records, maintains a running aggregate estimate with a confidence interval, and terminates early once the interval stabilizes, accepting the estimate when it falls within a user-specified error bound. Our second strategy trains a lightweight, CPU-resident decision tree on a small set of oracle-labeled examples and uses it to pre-filter records whose outcome can be predicted with high confidence, routing only uncertain records to the expensive model. We evaluate both strategies on TPC-DS aggregate queries and on real LLM post-training pipelines including math reasoning, general instruction following, and code generation. On TPC-DS, Strategy AQP keeps aggregate error under 10% while reaching its adaptive stopping point at 10-15% of oracle calls under balanced distributions, an 85-90% reduction, and Strategy PM reduces oracle calls by 60-70%. On LLM pipelines, Strategy AQP reaches its adaptive stopping point at 20-50% of oracle calls with less than 5% accuracy loss on the structured math and code tasks; open-ended instruction following, scored by a reward model, shows a larger but bounded reduction. Strategy PM reduces reward-model scoring time by up to 19x on structured tasks with less than 10% accuracy loss.