Writing is thinking: toward a neuropsychological model of scientific writing as knowledge construction.

Scientific writing has historically been conceptualized as a communicative act-the registration of knowledge elaborated through independent cognitive processes. This article challenges that assumption and proposes that scientific writing constitutes an active neurocognitive system of knowledge construction and a privileged domain for metacognitive self-regulation in advanced learning contexts. We present the Integrated Neuropsychological Model of Scientific Writing (MNIEC), a theoretical framework integrating four neurocognitive systems-the Constructive Executive System (CES), the Extended Working Memory System (EWMS), the Semantic Simulation System (SSS), and the Epistemological Metacognitive Monitoring System (EMMS)-within a unified functional architecture. The central mechanism is the Epistemological Construction Cycle (ECC), a recursive five-phase process-conceptual activation, working memory simulation, symbolic externalization, metacognitive evaluation, and conceptual reorganization-through which scientific writing can function as an active mechanism of knowledge construction, particularly when recursive metacognitive evaluation and conceptual reorganization are engaged. The model integrates evidence from executive function neuropsychology, working memory architecture, large-scale brain network dynamics, epistemological metacognition, and predictive coding, grounded in five nuclear principles. Four testable hypotheses and experimental paradigms are derived. Implications are discussed for metacognitive training in scientific education, academic impostor syndrome, and the cognitive impact of large language models. The MNIEC proposes a neuropsychological framework for a systematic research agenda on scientific writing as metacognitive knowledge construction.