Meaning in the Brain: Combination, Concreteness, Coherence

We present intracranial recordings that tap into some elementary components of linguistic meaning, with implications for our understanding of sentence processing and the distribution of concepts across the cortex. First, we review the spatiotemporal dynamics of basic phrase processing, exploring cortical signatures of combining two simple words into a larger phrase. We find a unique response in posterior superior temporal sulcus to meaningful phrases, relative to pairs of words that have no meaning. Second, we review cortical responses to concrete (“chair”) and abstract (“time”) words, revealing how abstract words rely on inferior frontal language areas while concrete words yield greater activation across lateral and medial temporal cortices. Third, we explore cortical responses for a naming-to-definition task involving either coherent or incoherent sentences. We find greater broadband gamma activity in medial parietal cortex and inferior frontal sulcus for sentences that generate a coherent meaning. Overall, these three independent directions for exploring language reveal how the human brain processes some of the most crucial aspects of meaning necessary for worldly engagements: combining words; understanding concrete concepts; processing meaningful sentences."

Learning Objectives:

1. Identify aspects of human language that are essential for everyday interactions.

2. Isolate areas of cortex that these language functions appear to rely on.

3. Consider implications of these findings for therapeutic interventions in aphasia.