Dr Mukul Chandra Bora
(Vice Chancellor)
&
Mr Rupam Gogoi
(Associate Professor in English, North Lakhimpur University, Assam)
Neurolinguistics is an interdisciplinary scientific field that combines neuroscience and linguistics to study how the human brain behaves, reacts and controls the process of acquisition, comprehension and production of language. In other words, it is at the crossroads of linguistics, neuroscience, psychology, cognitive science, and increasingly artificial intelligence of the 21st century, and its main aim is to understand the neural architecture and cognitive mechanisms of the human brain that make it learn language, which is a unique human capability. Neurolinguistics basically addresses fundamental questions such as: How does the brain decode speech sounds? What neural circuits enable us to form sentences? Why do some brain injuries disrupt language while others spare it? How do infants acquire language? How does bilingualism shape the brain? And last but not least, how might neuroscience improve language education, AI models, and rehabilitation for language disorders? With the help of neuroimaging technologies like fMRI (functional magnetic resonance imaging), PET (positron emission tomography), EEG (electroencephalogram), MEG (magnetoencephalography) and modern computational modelling, neurolinguistics sheds light on the biological foundations of language and continues to evolve rapidly as new tools which will allow the scientists to examine the brain with unprecedented detail and precision are developed. Neurolinguistics emerged in the 19th century with Paul Broca and Carl Wernicke, who established links between specific brain regions and language functions—speech production and comprehension—forming the early localisationist model. Later research showed language relies on distributed neural networks, yet their work laid the foundation. During the 20th century, advances from psychology, linguistics (including Chomsky’s generative grammar), and neurology, along with modern neuroimaging and computational tools, shaped neurolinguistics as a modern scientific discipline.
Neural Organization of Language Processing:
The human brain’s ability to process language involves a network of interconnected regions rather than a single “language centre”; the left brain, or hemisphere, plays a dominant role for almost all the people, and hemispheres contribute to different linguistic functions.
Left Hemisphere Language Areas Broca’s area (inferior frontal gyrus): Involved in speech production, grammatical processing, and syntactic organization and its damage leads to non-fluent aphasia.
Wernicke’s area (superior temporal gyrus): Responsible for language comprehension and semantic processing.
Angular gyrus: Supports reading, writing, and multimodal integration of sensory information.
Supramarginal gyrus: Plays a role in phonological processing and verbal working memory.
Primary auditory cortex: The first cortical region to receive auditory information, essential for speech perception.
Right Hemisphere Contributions: Although less involved in syntax and core semantics, the right hemisphere is essential for:
n Prosody (intonation, rhythm, emotion in speech)
n Figurative language (metaphor, irony)
n Pragmatics (social use of language)
n Discourse-level comprehension (global coherence, narrative structure)
Damage to right-hemisphere areas can result in difficulty understanding jokes, sarcasm, or subtle linguistic cues.
The Dual-Stream Model: One of the most influential modern frameworks is the dual-stream model of language processing, which proposes:
Ventral stream: Maps sound to meaning and supports comprehension and semantic interpretation.
Dorsal stream: Maps sound to articulatory patterns, and its role is important for speech production, repetition, and phonological working memory.
Overall, this model reflects a complex, distributed architecture where comprehension and production operate through distinct but interconnected neural pathways.
Language Comprehension: How the Brain Understands Speech: The comprehension of language involves several sequential and overlapping stages:
Acoustic Processing: The auditory cortex receives raw sound signals.
Phonological Processing: Sounds are categorised into meaningful units (phonemes).
Lexical Access: The brain retrieves the meanings of words from the mental lexicon.
Syntactic Parsing: Sentence structure is analysed, primarily involving Broca’s area and temporal regions.
Semantic Integration: Word meanings are combined to form coherent interpretations.
These processes occur incredibly fast—within milliseconds. EEG and MEG studies reveal specific neural signatures, such as the N400 response, which appears when the brain encounters an unexpected or semantically incongruent word.
Producing language is equally intricate and involves concept formation, lemma selection (choosing words), morphological encoding, phonological encoding, motor planning and articulation.
Broca’s area, the motor cortex, basal ganglia, and cerebellum play critical roles in coordinating these processes.
Neurolinguistics of Bilingualism: Bilingualism offers profound insights into how flexible and adaptive the brain is, and research on these issues of neurolinguistics shows that:
Early bilinguals tend to store both languages in overlapping neural networks.
Late bilinguals may use more distinct or compensatory areas.
Code-switching relies heavily on executive-control regions such as the anterior cingulate cortex.
Bilinguals often show enhanced cognitive flexibility and delayed onset of dementia symptoms.
Neurolinguistics of Language Acquisition: First Language Acquisition: Infants are born with remarkable linguistic sensitivity. They can discriminate almost all phonetic contrasts across languages, a capacity that narrows around 10–12 months in a process known as perceptual narrowing. Neurolinguistics shows:
n Early exposure shapes neural circuits for phonology.
n Grammar acquisition may rely on innate cognitive mechanisms.
n The brain undergoes synaptic pruning and strengthening as language develops.
Second Language Acquisition
The learning of a second language varies according to:
n Age of acquisition
n Intensity of exposure
n Motivation
n Cognitive abilities
n Immersion environment
Neurolinguistics reveals that:
n Younger learners often achieve native-like pronunciation due to heightened plasticity.
n Adults rely more on explicit learning and prefrontal systems.
n High-proficiency learners show neural patterns like native speakers.
Applications of Neurolinguistics: Neurolinguistics has wide-reaching practical implications across fields.
1. Clinical Interventions
n Designing targeted therapies for aphasia and dyslexia.
n Creating personalised rehabilitation programmes based on neural profiles.
n Using TMS and tDCS (transcranial direct current stimulation) to support recovery.
2. Education
n Improving language-teaching methodologies.
n Understanding reading difficulties to develop better literacy programmes.
n Designing curricula based on neuroscientific principles.
3. Artificial Intelligence and NLP
Insights from neurolinguistics inform:
n Speech recognition systems
n Language-generation models
n Machine translation
n Cognitive architectures for AI
Conversely, AI models also help simulate and test theories of human language processing.
4. Brain-Computer Interfaces (BCIs)
Emerging research aims to decode:
n Internal speech
n Intent to speak
n Meaning representation
Such technologies could restore communication for individuals with paralysis or severe speech disorders.
Neurolinguistics is a vibrant and rapidly growing field dedicated to unravelling one of humanity’s most extraordinary abilities, i.e., the capacity for language. Starting from its historical origins in the discoveries of Broca and Wernicke to the cutting-edge neuroimaging and computational models of today, neurolinguistics bridges biological and cognitive perspectives on language. By examining how the brain perceives, processes, and produces language, researchers gain insights into the nature of human communication, the effects of brain injury, the intricacies of bilingualism, and the foundations of language acquisition. Its applications spread across medicine, education, artificial intelligence, and brain–computer technologies, and as tools and theories advance, neurolinguistics will continue to illuminate the neural basis of language, enhancing our understanding of the human mind.
Neurolinguistics strongly supports mother tongue-based learning, as the brain’s natural processes for language acquisition are most efficient in the first language learnt during early childhood. Research shows that the mother tongue forms the foundation of cognitive development, conceptual understanding, and future language learning. When children are taught in their first language, they process information more effectively because the neural structures for that language are already well developed. This reduces cognitive load, allowing learners to focus on understanding concepts rather than decoding unfamiliar linguistic forms.
During early childhood—when brain plasticity is at its peak—neural circuits related to phonology, grammar, and meaning are finely tuned through exposure to the home language. This linguistic framework becomes the primary lens through which children perceive and understand the world. Strong literacy skills acquired in the mother tongue also transfer positively to second-language learning, as similar neural pathways are activated across languages. Learners with a solid first-language foundation develop better metalinguistic awareness, enabling easier and more effective multilingual learning later. In contrast, beginning education in an unfamiliar language places a dual cognitive burden on children, often slowing comprehension, academic progress, and the development of critical thinking skills. Mother-tongue instruction additionally provides emotional security, strengthens cultural identity, and increases classroom engagement, as emotionally meaningful language is processed more deeply by the brain.
These neurolinguistic insights closely align with India’s National Education Policy (NEP) 2020, which emphasises foundational literacy, multilingualism, and learner-centred, experiential pedagogy. By advocating instruction in the mother tongue or regional language during the foundational years, NEP 2020 reflects scientific understanding of brain development and language learning, thereby promoting stronger cognitive growth and effective multilingual education across Bharat.