Introduction. Based on the brain science theory of “how people learn” and in order to modernize the methodology of psycholinguistic research, this research used documentary analysis and addressed the standpoint that the 4MAT Teaching and Learning Model can be subsumed into or superimposed on the Kirkpatrick Four-Level Evaluation Model, and vice versa. Meanwhile, the phase of language input and output is analyzed on the basis of the two Models above. In the end, some implications arise so as to provide reference for prospective researchers and practitioners in psycholinguistics. The aim of the study. The 4MAT Teaching and Learning Model and the Kirkpatrick Four-Level Evaluation Model are both widely applied, so a deliberate literature review to clarify the integration and the unity between them is conducted that expects to make some theoretical references inspired by the unity available to a wide range of linguistic teaching design and learning performance evaluation. The authors argue that the references interconnect teaching design and learning performance evaluation in light of language input and output and therefore help linguistic teachers/trainers with a whole and valid scheme at the very beginning of student learning, and this is the unity that also corresponds to Kirkpatrick & Kirkpatrick’s standpoint: “The end is the beginning”. Research methods. The study was conducted using the semantic differential scaling and the method of documentary analysis. Results. A combination of brain science theory and Fractal Information Theory has verified initially how the 4MAT Teaching and Learning Model and the Kirkpatrick Four-Level Evaluation Model subsume and superimpose in terms of the theoretical framework, i.e., the unity between a teaching theory and a learning performance evaluation theory. Such integration not only originates from the inherent unity verified by a thoughtful literature review but also receives theoretical support from interdisciplinary studies. Meanwhile, this integration is intertwined with language input and output in a psycholinguistic/neurolinguistic manner. Conclusions. A primary investigation using brain science theory and other theories to analyze the integration between the 4MAT Teaching and Learning Model and the Kirkpatrick Four-Level Evaluation Model shows the unity between both models. This investigation led to achieving the purpose of the study: modernizing the methodology of psycholinguistic research. With implementing the components/stages of language input and output as this article proposed, it is expected to be promising in extending and applying both models theoretically and practically in linguistics and other relevant areas in the future. As it comes to studies, it is recommended that the two Models be connected to analyze more teaching models and/or learning performance evaluation models for unity, inquire performance evaluation in collaborations with scenarios in practice, or even associate other disciplines under the implementation of Fractal Information Theory. A possible suggestion for psycholinguistic researchers is to design curricular and lessons based on the Unified Models (Figure 1 & 2) proposed in this study and evaluate instructional efficacy and student learning performance. Another potential research direction is to use each quadrant of the Unified Models and analyze related components in more specific language input and output phases: listening, reading, speaking, writing, and even smaller components in the four types of language skills. As it comes to practice, especially in psycholinguistics and/or other relevant disciplines, the key to apply the two target Models simultaneously depends on how to regulate respective quadrants/levels pro rata as well as the wholeness between them to simultaneously achieve “dynamic equilibrium” in the 4MAT Teaching and Learning Model and “The end is the beginning” in the Kirkpatrick Four-Level Evaluation Model.