Language comprehension is the process of extracting meaning from spoken or written language — arguably the most complex and rapid cognitive achievement humans perform routinely. In normal conversation, we process about 150-200 words per minute, accessing word meanings, building syntactic structures, computing sentence meanings, drawing inferences, and updating our discourse model, all in real time with minimal conscious effort.
Key Structures
- Wernicke's area — The left posterior superior temporal region involved in speech comprehension and the mapping of sound to meaning.
- Superior temporal gyrus — The upper temporal lobe gyrus containing auditory cortex and regions critical for speech perception and social cognition.
- Angular gyrus — A parietal region at the junction of temporal and parietal lobes, involved in semantic processing, reading, and number cognition.
- Prefrontal cortex — The anterior portion of the frontal lobe, critical for executive functions including planning, decision-making, working memory, and cognitive control.
- Eye — The sensory organ for vision, whose optical components focus light onto the retina for neural transduction.
- Lexical Access — The process of retrieving a word's phonological form, meaning, and grammatical properties from the mental lexicon — a rapid feat accomplished in approximately 200 milliseconds.
- Discourse Processing — The cognitive processes involved in understanding connected text and conversation — building coherent mental representations that integrate information across sentences.
- Levels of Processing — Craik and Lockhart's framework proposing that memory retention depends on the depth of processing at encoding — deeper, more meaningful processing leads to stronger memories.
Key Functions
Process and extract meaning from spoken or written language through word recognition, syntactic parsing, semantic integration, and pragmatic inference.
Levels of Processing
Comprehension involves multiple levels of processing operating in parallel. Lexical access retrieves word meanings from the mental lexicon. Syntactic parsing builds hierarchical phrase structures. Semantic interpretation computes the meaning of phrases and sentences. Pragmatic interpretation determines the speaker's intended meaning in context. Discourse processing integrates sentence meanings into a coherent representation of the text or conversation.
Incremental Processing
A fundamental finding is that comprehension is incremental: listeners and readers do not wait until the end of a sentence to begin interpretation. Eye-tracking studies show that readers fixate words that disambiguate sentences immediately, visual world experiments show that listeners direct their eyes to likely referents before they are named, and ERP studies show that semantic anomalies are detected within 400 ms of word onset. This incrementality means that comprehenders are actively predicting upcoming input based on what they have already processed.
Language comprehension is increasingly understood as a predictive process. Comprehenders generate expectations about upcoming words, structures, and meanings based on context. These predictions are reflected in reduced processing (faster reading times, smaller N400) for predictable words and increased processing for unpredictable ones. Predictive processing may explain the speed and efficiency of comprehension: by pre-activating likely upcoming information, the system reduces the computational demands of processing each word from scratch.
Disorders
- Wernicke's aphasia — Fluent but meaningless speech with severely impaired comprehension; paraphasias; neologisms; poor self-monitoring.
- Reading comprehension deficit
- Specific language impairment — Significant language learning difficulties in children with normal hearing, intelligence, and no neurological damage.