Embodied imagery hypothesis proposes the activation of perceptual-motor systems during language processing. Previous studies primarily used concrete visual stimuli to investigate mental imagery in language processing by native speakers (NSs) and second language (L2) learners, but few studies employed schematic diagrams. The study aims to investigate mental imagery in processing prepositional phrases by English NSs and L2 learners. Using image-schematic diagrams as primes, we examine whether any mental imagery effect is modulated by target preposition (over, in), the abstractness of meaning (spatial, extended), and stimulus onset asynchrony (SOA; 1,040 ms, 2,040 ms). A total of 79 adult L2 learners and 100 NSs of English completed diagram–picture matching and semantic priming phrasal decision tasks. Results revealed interference effects on L2 processing of over phrases and under 2,040 ms SOA, but no such effects were observed in the NS group. The selective interference effects in L2 suggest different mental imagery patterns between L1 and L2 processing, and processing schematic diagram primes requires high cognitive demands, potentially leading to difficulties in integrating visual and linguistic information and making grammaticality judgments. The findings partially validate schematic diagrams as visual representations of concepts and suggest the need for further examination of schematic diagrams with varying degrees of complexity.

Many studies have substantiated the perceptual symbol system, which assumes a routine generation of perceptual information during language comprehension, but little is known about the processing format in which the perceptual information of different dimensions is conveyed simultaneously during sentence comprehension. The current study provides the first experimental evidence of how multidimensional perceptual information (color and shape) was processed during online sentence comprehension in Mandarin. We designed three consecutive sentence–picture verification tasks that only differed in the delay of the display of pictures preceded by declarative sentences. The processing was analyzed in three stages based on time intervals (i.e., 0ms, +750ms, +1500ms). The response accuracy and response time data were reported. The initial stage (i.e., ISI=0ms) attested the match effect of color and shape, but the simulated representation of color and shape did not interact. In the intermediate stage (i.e., ISI=750ms), the routinely simulated color and shape interacted, but the match facilitation was found only in cases where one perceptual information was in mismatch while the other was not. In the final stage (i.e., ISI=1500ms), the match facilitation of one particular perceptual property was influenced by a mismatch with the other perceptual property. These results suggested that multiple perceptual information presented simultaneously was processed in an additive manner to a large extent before entering into the final stage, where the simulated perceptual information was integrated in a multiplicative manner. The results also suggested that color and shape were comparable to object recognition when conjointly conveyed. In relation to other evidence from behavioral and event-related potential studies on sentence reading in the discussion, we subscribed to the idea that the full semantic integration became available over time.

Semantic integration and working memory both decline with age. However, it remains unclear whether the semantic integration decline is independent of working memory decline or whether it can be solely explained by the latter factor. In this event-related potentials experiment, 43 younger adults and 43 cognitively healthy older adults read semantically congruent and incongruent sentences. After controlling for working memory, behavioral accuracy was significantly lower in the older adults than in the younger adults. In addition, the semantic integration related N400 effect (incongruent vs. congruent) for correct trials was apparent in the whole brain in the younger adults but restricted to the posterior region in the older adults. The results clarify the relationship between working memory and semantic integration, and clearly demonstrate that semantic integration decline is independent of working memory decline during aging.

Research has shown that L1 speakers can routinely generate mental imagery corresponding to sentence meaning in reading comprehension. This may reflect an efficient process of semantic integration in which information from the input combines with an individual's linguistic and real world knowledge to form a semantic representation of a sentence. Semantic integration in L2 reading has received limited attention. The present study attempted to examine the activation of mental imagery in reading among L2 speakers and thus to assess the efficiency of semantic integration during L2 reading. L2 Korean learners were tested on a sentence-based picture recognition task in which they were asked to respond to a picture immediately after reading a sentence related to the picture. Results showed that L2 Korean learners resembled native Korean speakers in their ability to generate mental imageries that reflected subtle semantic differences in sentence input.