# Beyond comprehensible input: a neuro-ecological critique of Krashen's hypothesis in language education

## TL;DR

This paper challenges the idea that language is learned through simple input by showing how brain science and interactive learning better explain language development.

## Contribution

It introduces a neuro-ecological framework to critique and replace Krashen's CI hypothesis with interactive, affordance-based learning.

## Key findings

- Language acquisition is an active, embodied process involving interaction and feedback.
- Affordances in the learning environment, not just input, drive meaningful language growth.
- AI and adaptive systems can support individualized learning beyond the i+1 model.

## Abstract

This article critically reassesses the Comprehensible Input (CI) hypothesis in language education by drawing on recent advances in neurolinguistics and an ecological perspective on learning. While the CI hypothesis claims that language is acquired by understanding input slightly beyond a learner's current competence (i+1), converging evidence from brain research shows that language development is an active and embodied process supported by interaction, feedback, and multimodal engagement. From the ecological point of view, affordances are the perceivable opportunities for action that arise in the ongoing coupling of learner and environment. Using this combined neuro-ecological lens, the paper critically reviews empirical studies from the last three decades and demonstrates that meaningful language growth depends on learners detecting and acting on such affordances rather than merely processing linear and simplified input. Adaptive and AI-supported learning systems further illustrate how contemporary technologies can operate these mechanisms and offer individualized, scalable alternatives to the static i+1 model. The analysis argues that CI should no longer serve as a central doctrine in language education and calls for pedagogies that reflect the interactive, affordance-rich processes revealed by current brain and language science.