High neuromagnetic activation in the left prefrontal and frontal cortices correlates with better memory performance for abstract words

The present study aimed to clarify the spatiotemporal characteristics of memory processing for abstract and concrete words. Neuromagnetic responses to memory encoding and recognition tasks of abstract and concrete nouns were obtained in 18 healthy adults using a whole-head neuromagnetometer. During memory encoding, abstract words elicited larger responses in the left temporal area 300–500 ms after the stimulus onset. The average peak latency of the right inferior frontal and left prefrontal responses to abstract words was about 70–85 ms longer than that to concrete words. Furthermore, greater activation in the left inferior frontal and anterior prefrontal regions was correlated with better recognition memory for abstract words. These findings are consistent with the proposition that both word types are processed with differential integration of semantic information. The present results suggest that the left prefrontal and frontal regions play an important role in both semantic and memory processing for abstract words.

► We measured neuromagnetic memory responses to abstract and concrete words.
► Peak latency of bilateral frontal activations was longer for abstract words.
► Left inferior frontal activation correlated with memory for abstract words.
► Left frontal cortex is important in semantic and memory processing of abstract words.