High feature overlap and incidental encoding drive rapid semantic integration in the fast mapping paradigm

Abstract

Contrary to traditional theories, it has been shown that novel, arbitrary associations can be rapidly integrated into cortical networks through a learning paradigm called fast mapping (FM), possibly bypassing time-consuming hippocampal-neocortical consolidation processes. In the FM paradigm, an unknown item is presented next to a known item and participants answer a question referring to an unfamiliar label, presumably inferring that the label belongs to the unknown item. However, factors driving rapid cortical integration through FM are still under debate. The FM task requires the discrimination between complex objects and the binding of the unknown item to the label. Discriminating between complex and especially highly similar objects is a central function of the perirhinal cortex, a structure also involved in the binding of single elements to a unit. We suggested that triggering perirhinal processing by increasing the demands on item discrimination through increasing feature overlap between the unknown and the known item might foster the binding of the unknown item to the label and their rapid cortical integration. We found lexical integration of the labels after learning through FM, but this was not affected by feature overlap. However, semantic integration of the label immediately after FM encoding was more successful when the items shared many features than when they shared few features. Moreover, effects of rapid semantic integration through FM were reduced if encoding was intentional and if no discrimination was required. This indicates that incidental encoding and a high feature overlap are driving factors for rapid semantic integration through FM. (PsycInfo Database Record (c) 2022 APA, all rights reserved).