Coherent concepts are computed in the anterior temporal lobes

TLDR

Semantic representations require more than simple feature combination, yet the computation of coherent concepts—integrating modality‑invariant information—has received little attention in neuroscience. Semantic dementia patients with anterior temporal lobe atrophy show impaired coherent concept computation, becoming more influenced by superficial than conceptual similarities.

Abstract

In his Philosophical Investigations , Wittgenstein famously noted that the formation of semantic representations requires more than a simple combination of verbal and nonverbal features to generate conceptually based similarities and differences. Classical and contemporary neuroscience has tended to focus upon how different neocortical regions contribute to conceptualization through the summation of modality-specific information. The additional yet critical step of computing coherent concepts has received little attention. Some computational models of semantic memory are able to generate such concepts by the addition of modality-invariant information coded in a multidimensional semantic space. By studying patients with semantic dementia, we demonstrate that this aspect of semantic memory becomes compromised following atrophy of the anterior temporal lobes and, as a result, the patients become increasingly influenced by superficial rather than conceptual similarities.