Hemispheric differences in the activation of perceptual information during sentence comprehension (original) (raw)
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Neuropsychologia, 2014
To successfully understand a text, readers often mentally represent the shape of an object described in a text (e.g., creating a mental image of a sliced tomato when reading about a tomato on a pizza). However, it is currently unclear how the cerebral hemispheres contribute to these mental images during reading. In the current study, participants were presented with sentences consistent with the shape of an object (i.e., the match condition), sentences inconsistent with the shape of an object (i.e., the mismatch condition), or sentences that did not specify the shape of an object (i.e., the neutral condition). Participants read each sentence and then viewed an image of an object that was quickly presented to either the right visual field-left hemisphere (rvf-LH) or the left visual field-right hemisphere (lvf-RH). Results indicate that when the shape of an object was implicitly described in the text (in Experiment 1), response times for images presented to the rvf-LH were longer in t...
Hemispheric asymmetries in the perceptual representations of words
Brain Research, 2008
The representation of words in sentences can involve the activation and integration of perceptual information. For example, readers who are asked to view pictures of objects relating to a word in a sentence are influenced by perceptual information in the sentence context-readers are faster to respond to a picture of a whole apple after reading, "There is an apple in the bag," than after reading, "There is an apple in the salad." The purpose of this study was to examine how the two cerebral hemispheres use perceptual information about words as a function of sentence context. Patients who had damage to the left or right hemisphere and age-matched control participants read sentences that described, but did not entail, the shape or state of an object. They then made recognition judgments to pictures that either matched or mismatched the perceptual form implied by the sentence. Responses and latencies were examined for a match effectfaster and more accurate responses to pictures in the match than mismatch conditioncontrolling for comprehension ability and lesion size. When comprehension ability and lesion size are properly controlled, lefthemisphere-damaged patients and control participants exhibited the expected match effect, whereas right-hemisphere-damaged participants showed no effect of match condition. These results are consistent with research implicating the right hemisphere in the representation of contextually relevant perceptual information.
Right hemisphere contributions to the comprehension of low-imagery words
Laterality: Asymmetries of Body, Brain and Cognition, 2001
A priming experiment, with normal university students as subjects, was used to investigate whether the right cerebral hemisphere contributes to the comprehension of low-imagery words. Each hemisphere's access to semantic representations of low-imagery words was gauged by comparing responses to low-imagery targets preceded by associated low-imagery primes (e.g., BELIEF-IDEAL) with responses to the same targets when they were preceded by unrelated primes (e.g., FATE-IDEAL). All primes and targets were independently projected to the left or right visual fields (LVF or RVF), and temporally separated by a stimulus onset asynchrony of 250 ms. There was a clear RVF advantage in response speed and accuracy measures, confirming the left hemisphere's advantage in processing low-imagery words. Nonetheless, the priming effects provided evidence that the right hemisphere contributes to the comprehension of low-imagery words, as primes projected to the RVF equally facilitated responses to associated targets subsequently appearing in either visual field. In contrast, primes directed to the LVF did not facilitate responses to associated targets projected to the LVF or RVF. The results suggest that low-imagery words projected to the left hemisphere activated low-imagery associates in both hemispheres to an equivalent degree, whereas low-imagery primes directed to the right hemisphere failed to activate low-imagery associates in either hemisphere. Like Kounios and Holcomb's (1994) study of event-related response potentials evoked by abstract and concrete words, the findings indicate that while the left hemisphere is the primary processor of lowimagery/abstract words, the right hemisphere plays a subsidiary role in the comprehension of these words. Delineation of the cerebral mechanisms underpinning language comprehension has recently focused on the unique contribution of the right cerebral hemisphere. Research in this area indicates that the right hemisphere plays a vital role in the generation of alternative interpretations of ambiguous text (Brownell,
Language comprehenders retain implied shape and orientation of objects
Quarterly Journal of Experimental Psychology, 2009
According to theories of embodied cognition, language comprehenders simulate sensorimotor experiences to represent the meaning of what they read. Previous studies have shown that picture recognition is better if the object in the picture matches the orientation or shape implied by a preceding sentence. In order to test whether strategic imagery may explain previous findings, language comprehenders first read a list of sentences in which objects were mentioned. Only once the complete list had been read was recognition memory tested with pictures. Recognition performance was better if the orientation or shape of the object matched that implied by the sentence, both immediately after reading the complete list of sentences and after a 45-min delay. These results suggest that previously found match effects were not due to strategic imagery and show that details of sensorimotor simulations are retained over longer periods.
Hemispheric differences in picture-word interference
Brain and Language, 1982
In a picture-word version of the Stroop task, 30 right-handed subjects were tested under each of six conditions in which a picture alone or a picture plus a word were presented to the left, the right, or both hemispheres. In two additional conditions the picture was presented to the right hemisphere and the word was simultaneously presented to the left hemisphere, or vice versa. For all conditions, subjects were instructed to name the picture only, as rapidly as possible. Picture naming times were significantly slower for the conditions in which the pictures were accompanied by words than in the respective picture alone conditions. Moreover, simultaneous presentation of a picture and a word to both hemispheres resulted in greater interference (slower picture naming times) than did the simultaneous presentation of the picture and the word to either the left hemisphere alone or the right hemisphere alone. The latter two conditions, in turn, resulted in significantly more interference than did the simultaneous presentation of the picture to one hemisphere and the word to the other hemisphere. This pattern of results suggests that the Stroop effect obtained under normal circumstances is in large part a function of the interference caused by the simultaneous processing of items in the same hemisphere. In contrast to hemispheric differences reported for the color-word Stroop task, the effect of presenting a picture and word simultaneously to the right hemisphere did not differ reliably from that of presenting a picture and word to the left hemisphere. The failure to replicate this aspect of the color-word Stroop is attributed to differences in the abilities of the two hemispheres to process the respective target items (the color or the picture) of the two tasks.
Brain and Language, 2001
In this article we examine whether the distribution of function across the right and left cerebral hemispheres for lexical processing is influenced by the global context within which words are presented. A review of previously published studies indicates that the ubiquitous right visual field (RVF)/left hemisphere advantage for word recognition may be reduced or eliminated for nouns, content words, or high image words, but only when such items are presented along with verbs, function words, or low image words. However, paradoxically, when the former items are presented in more homogeneous contexts, the RVF advantage is uniformly observed. We propose that the processing efficiency of a hemisphere for a given stimulus depends on that item's relation to the other stimuli provided, that is, the global context. This was examined in a visual half-field experiment that varied whether high and low image nouns were presented in homogeneous (blocked lists) or heterogeneous (mixed lists) contexts. An unvarying RVF advantage was observed for high image words in homogeneous contexts, but this advantage was eliminated when the same items were presented in heterogeneous contexts. We suggest that stimulus heterogeneity maximizes reliance on differing, but complementary, computational biases across hemispheres. Hence, the extent to which the left and right hemispheres are recruited for the recognition of individual word types can vary dynamically with variation in the stimulus environment.
Hemispheric asymmetries in semantic processing: Evidence from false memories for ambiguous words
Brain and Language, 2008
Previous research suggests that the left hemisphere (LH) focuses on strongly related word meanings; the right hemisphere (RH) may contribute uniquely to the processing of lexical ambiguity by activating and maintaining a wide range of meanings, including subordinate meanings. The present study used the word-lists false memory paradigm . Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803-814.] to examine whether these differences between the two cerebral hemispheres in semantic processing also affect memory representations for different meanings of ambiguous words. Specifically, we tested the differences between the LH and RH in recollecting unpresented, semantically related, ambiguous words following the presentation of lists of words all related to either the dominant or the subordinate meanings of these ambiguous words. Findings showed that for the unpresented ambiguous words, the LH made more false alarms than the RH for the dominant lists, whereas the opposite pattern emerged for subordinate lists. Moreover, d 0 analyses showed that, whereas the LH was more sensitive to subordinate than dominant meanings, the RH showed no differences in sensitivity for the two types of word-lists. Taken as a whole, these results support the RH coarse semantic coding theory . Coarse semantic coding and discourse comprehension. In Beeman & M., Chiarello, C. (Eds.), Right hemisphere language comprehension: Perspectives from cognitive neuroscience (pp. 255-284). Mahwah, NJ: Erlbaum;. Bilateral brain processes for comprehending natural language. Trends in Cognitive Sciences, 9,[512][513][514][515][516][517][518] indicating that during word recognition, the RH activates and maintains a broader and less differentiated range of related meanings than the LH, including both dominant and subordinate meanings of ambiguous words. Furthermore, the findings suggest that hemispheric differences in ambiguity resolution during language processing extend also to verbal memory.
Hemispheric differences in object identification
Although the right hemisphere is thought to be preferentially involved in visuospatial processing, the specialization of the two hemispheres with respect to object identification is unclear. The present study investigated the effects of hemifield presentation on object and word identification by presenting objects (Experiment 1) and words (Experiment 2) in a rapid visual stream of distracters. In Experiment 1, object images presented in the left visual field (i.e., to the right hemisphere) were identified with shorter display times. In addition, the left visual field advantage was greater for inverted objects. In Experiment 2, words presented in the right visual field (i.e., to the left hemisphere) under similar conditions were identified with shorter display times. These results support the idea that the right hemisphere is specialized with regard to object identification.