New article by Martin Maier and Rasha Abdel Rahman:
Transient and Long-Term Linguistic Influences on Visual Perception: Shifting Brain Dynamics With Memory Consolidation
This paper investigates categorical perception, the phenomenon that we can distinguish faster between different stimuli when they also have different names. We tested how this is influenced by memory consolidation, the process by which our brain solidifies new information during sleep. In two experiments, participants learned to categorize unfamiliar objects by learning their names. In one experiment, we tested how fast they could tell apart the objects immediately after category learning. In the other experiment, we introduced a two-day break between the learning and the test session, leaving enough time for memory consolidation. We found that linguistic categories influenced visual perception in both experiments, but with very different underlying neural dynamics.
Specifically, the pattern observed in several prior EEG studies, characterized by a mismatch response during early and high-level visual perception (P1 and N170 components), as well as selective attention (N2 component), only emerged with memory consolidation. Without consolidation, only an N170 effect was observed, which was, interestingly, in the opposite direction to the “canonical” pattern. We argue that this is because memory consolidation alters how objects and their associated names are encoded in the brain, resulting in more distributed “visuo-linguistic” representations. This way, language can enhance the efficiency of object discrimination both in the short and long-term.