Initial right hemisphere activation of subordinate word meanings is not due to homotopic callosal inhibition

Previous results (Burgess & Simpson, 1988a) have suggested that subordinate meanings are activated in the right hemisphere only when they have been inhibited in the left hemisphere. Such findings are consistent with a homotopic callosal inhibition view of hemispheric interaction (Cook, 1986). The current study employed prime-target stimulus onset asynchronies intermediate to those used by Burgess and Simpson and obtained equivalent priming of subordinate meanings over visual fields. These data rule out homotopic callosal inhibition as the mechanism responsible for initial activation of subordinate meanings in the right hemisphere and challenge homotopic inhibition as a general mechanism of interhemispheric interaction.     

Cerebral hemispheric mechanisms in the retrieval of ambiguous word meanings

Targets related to ambiguous primes were projected to the left and right visual fields in a lexical priming experiment with stimulus onset asynchronies (SOA) of 35 and 750 msec. Right visual field results were similar to our earlier results with central projection (G. B. Simpson & C. Burgess, 1985, Journal of Experimental Psychology: Human Perception and Performance, 11, 28-39). Facilitation was found for the more frequent meaning at both SOAs and a decrease in facilitation for the less frequent meaning at the longer SOA. In contrast, left visual field results indicated a decay of facilitation for the more frequent meaning at the longer SOA, while activation for the subordinate meaning increased. Results suggest that, while automatic processing occurs in both hemispheres, only the left hemisphere engages in controlled processing of ambiguous word meanings. In addition, the present results support the idea that the right hemisphere has a special role in ambiguity resolution and that the right hemisphere lexicon possesses a richer endowment than earlier thought.     

Hemispheric Differences in Context Sensitivity During Lexical Ambiguity Resolution

Three experiments were conducted to investigate the influence of contextual constraint on lexical ambiguity resolution in the cerebral hemispheres. A cross-modal priming variant of the divided visual field task was utilized in which subjects heard sentences containing homonyms and made lexical decisions to targets semantically related to dominant and subordinate meanings. Experiment 1 showed priming in both hemispheres of dominant meanings for homonyms embedded in neutral sentence contexts. Experiment 2 showed priming in both hemispheres of dominant and subordinate meanings for homonyms embedded in sentence contexts that biased a central semantic feature of the subordinate meaning. Experiment 3 showed priming of dominant meanings in the left hemisphere (LH), and priming of the subordinate meaning in the right hemisphere (RH) for homonyms embedded in sentences that biased a peripheral semantic feature of the subordinate meaning. These results are consistent with a context-sensitive model of language processing that incorporates differential sensitivity to semantic relationships in the cerebral hemispheres.     

Interhemispheric communication via direct connections for alternative meanings of ambiguous words

A priming experiment was used to investigate Burgess and Simpson's (1988) claim that interhemispheric cooperation plays an essential role in the interpretation of ambiguous text. In doing so, the merits of two models of interhemispheric cooperation, the homotopic inhibition theory (Cook, 1986) and the direct connections model (Collins & Coney, 1998), were examined. Priming of alternative meanings of ambiguous words was measured using homographs and their dominant (e.g., BARK-DOG) and subordinate meanings (e.g., BARK-TREE) as related pairs in a lexical decision task, with normal university students as subjects. Stimulus pairs were temporally separated by stimulus onset asynchronies (SOAs) of 180 and 350 ms and were independently projected to the left or right visual fields (LVF or RVF). At the shorter SOA, priming was restricted to LVF-RVF presentations, with homograph primes directed to the LVF equally facilitating responses to RVF targets which were associated with their dominant and subordinate meanings. This suggests that within 180 ms, a homograph projected to the right hemisphere activates a range of alternative meanings in the left hemisphere. At an SOA of 350 ms, LVF-RVF priming was obtained along with RVF-LVF and RVF-RVF priming. Evidently at this stage of processing, an ambiguous word directed to either hemisphere activates a range of alternative meanings in the contralateral hemisphere, while RVF primes also activate subordinate, but not dominant meanings in the left hemisphere. A homograph directed to the LVF did not activate dominant or subordinate meanings within the right hemisphere at either SOA. Generally, ambiguous words directed to either hemisphere activated a more extensive array of meanings in the contralateral hemisphere than in the hemisphere to which the prime was directed. This confirms the importance of interhemispheric cooperation in generating alternate meanings of ambiguous words. Strong support was found for the direct connections model (Collins & Coney, 1998), but no support for the homotopic inhibition theory (Cook, 1986).     

汉语同形歧义词歧义消解的两半球差异

实验探讨汉语同形歧义词(homographs)歧义消解的过程及大脑两半球的差异。被试为华中科技大学96名大学生,实验采用词汇判断任务。句子语境呈现在被试的视野中央,探测词在SOA(stimulus onset asynchronism)为100毫秒或400毫秒时呈现在左视野或右视野。结果发现,(1)当SOA为100毫秒时,在左视野(右半球)上,与语境一致的同形歧义词的主要意义得到激活,与语境不一致的次要意义也有一定程度的激活。在右视野(左半球)上,只有与语境一致的同形歧义词的主要意义得到激活。(2)当SOA为400毫秒时,在左、右视野(两半球)上,与语境一致的同形歧义词的主要意义和次要意义都得到激活。结果表明,大脑左半球对汉语歧义词的歧义消解具有一定的优势,语境敏感模型可以较好地解释本实验的结果。     

Semantic and associative priming in the cerebral hemispheres: some words do, some words don't ... sometimes, some places

This study investigated spreading activation for words presented to the left and right hemispheres using an automatic semantic priming paradigm. Three types of semantic relations were used: similar-only (Deer-Pony), associated-only (Bee-Honey), and similar + associated (Doctor-Nurse). Priming of lexical decisions was symmetrical over visual fields for all semantic relations when prime words were centrally presented. However, when primes and targets were lateralized to the same visual field, similar-only priming was greater in the LVF than in the RVF, no priming was obtained for associated-only words, and priming was equivalent over visual fields for similar + associated words. Similar results were found using a naming task. These findings suggest that it is important to lateralize both prime and target information to assess hemisphere-specific spreading activation processes. Further, while spreading activation occurs in either hemisphere for the most highly related words (those related by category membership and association), our findings suggest that automatic access to semantic category relatedness occurs primarily in the right cerebral hemisphere. These results imply a unique role for the right hemisphere in the processing of word meanings. We relate our results to our previous proposal (Burgess & Simpson, 1988a; Chiarello, 1988c) that there is rapid selection of one meaning and suppression of other candidates in the left hemisphere, while activation spreads more diffusely in the right hemisphere. We also outline a new proposal that activation spreads in a different manner for associated words than for words related by semantic similarity.     

Exploring the contribution of the cerebral hemispheres to language comprehension deficits in adults with developmental language disorder

A divided visual field, priming paradigm was used to observe how adults who have a history of developmental language disorder (DLD) access lexically ambiguous words. The results show that sustained semantic access to subordinate word meanings (such as BANK-RIVER), which is seen in control subjects, is disrupted in the right cerebral hemisphere for this special population of readers. In the left hemisphere, only the most dominant meaning of the ambiguous word shows sustained priming in both controls and DLD participants. Therefore, for the DLD readers the subordinate meanings of words are not primed in either hemisphere and, thus, may not be available during online processing and integration of discourse. This right hemisphere lexical access deficit might contribute to the language comprehension difficulties exhibited by adult readers with a history of DLD.     

Age-related changes in processing speed modulate context use during idiomatic ambiguity resolution

ABSTRACT

The goal of the current study was to investigate whether age-related changes in processing speed, as indexed by verbal fluency, modulate context use in the resolution of ambiguous idioms (e.g., tie the knot). Younger and older adults completed a cross-modal priming experiment where they decided whether visual word targets were related in meaning to idiomatically or literally biased auditory sentence primes. Older adults with high verbal fluency, similar to younger adults, showed context-dependent facilitation in both biasing sentence contexts. In contrast, older adults with low verbal fluency did not show facilitation of literal meanings in literally biased sentence contexts, likely because they had difficultly inhibiting the dominant figurative meaning. These findings argue that age-related changes in context use during ambiguity resolution are restricted to older adults with reduced processing speed. The results also suggest that verbal fluency may reflect the speed in recruiting frontally-mediated selection mechanisms during ambiguity resolution.     

Hemispheric asymmetries in meaning selection: Evidence from the disambiguation of homophonic vs. heterophonic homographs

Research investigating hemispheric asymmetries in meaning selection using homophonic homographs (e.g., bank), suggests that the left hemisphere (LH) quickly selects contextually relevant meanings, whereas the right hemisphere (RH) maintains a broader spectrum of meanings including those that are contextually irrelevant (e.g., Faust & Chiarello, 1998). The present study investigated cerebral asymmetries in maintaining the multiple meanings of two types of Hebrew homographs: homophonic homographs and heterophonic homographs (e.g., tear). Participants read homographs preceded by a biasing, or a non-biasing sentential context, and performed a lexical decision task on targets presented laterally, 1000 ms after the onset of the sentence-final ambiguous prime. Targets were related to either the dominant or the subordinate meaning of the preceding homograph, or unrelated to it. When targets were presented in the LVF/RH, dominant and subordinate meanings, of both types of homographs, were retained only when they were supported by context. In a non-biasing context, only dominant meanings of homophonic homographs were retained. Alternatively, when targets were presented in the RVF/LH, priming effects for homophonic homographs were only evident when meanings were supported by both context and frequency (i.e., when context favored the dominant meaning). In contrast, heterophonic homographs resulted in activation of dominant meanings, in all contexts, and activation of subordinate meanings, only in subordinate-biasing contexts. The results challenge the view that a broader spectrum of meanings is maintained in the right than in the left hemisphere and suggest that hemispheric differences in the time course of meaning selection (or decay) may be modulated by phonology.     

Hemispheric asymmetries in meaning selection: Evidence from the disambiguation of homophonic vs. heterophonic homographs

Research investigating hemispheric asymmetries in meaning selection using homophonic homographs (e.g., bank), suggests that the left hemisphere (LH) quickly selects contextually relevant meanings, whereas the right hemisphere (RH) maintains a broader spectrum of meanings including those that are contextually irrelevant (e.g., Faust & Chiarello, 1998). The present study investigated cerebral asymmetries in maintaining the multiple meanings of two types of Hebrew homographs: homophonic homographs and heterophonic homographs (e.g., tear). Participants read homographs preceded by a biasing, or a non-biasing sentential context, and performed a lexical decision task on targets presented laterally, 1000 ms after the onset of the sentence-final ambiguous prime. Targets were related to either the dominant or the subordinate meaning of the preceding homograph, or unrelated to it. When targets were presented in the LVF/RH, dominant and subordinate meanings, of both types of homographs, were retained only when they were supported by context. In a non-biasing context, only dominant meanings of homophonic homographs were retained. Alternatively, when targets were presented in the RVF/LH, priming effects for homophonic homographs were only evident when meanings were supported by both context and frequency (i.e., when context favored the dominant meaning). In contrast, heterophonic homographs resulted in activation of dominant meanings, in all contexts, and activation of subordinate meanings, only in subordinate-biasing contexts. The results challenge the view that a broader spectrum of meanings is maintained in the right than in the left hemisphere and suggest that hemispheric differences in the time course of meaning selection (or decay) may be modulated by phonology.     

维吾尔族与汉族的大学生在汉语歧义词消解中的语境促进效应及反应抑制效应

词汇歧义是语言的普遍现象。在汉语中, 歧义词的种类繁多, 是少数民族学生汉语学习困难的重要原因之一。通过两个实验, 考察在不同加工时间条件下维吾尔族和汉族的大学生在汉语歧义词消解中的语境促进效应及抑制效应。结果发现, 两个民族的大学生均出现了语境促进效应, 但在短时加工条件下, 汉族大学生的语境促进效应显著大于维吾尔族大学生, 在长时加工条件下, 两个民族的大学生的语境促进效应并无显著差异。在短时加工条件下, 仅汉族大学生可以有效地抑制无关信息的干扰; 在长时加工条件下, 两个民族的大学生均可以有效地抑制无关信息的干扰。整个研究表明, 在汉语歧义词消解中, 随着加工时间增加, 维吾尔族大学生的语境促进效应和对无关信息的抑制均可以达到与汉族大学生相近的水平。     

The Effects of a Verbal and a Figural Creativity Training on Different Facets of Creative Potential

This study investigated the effects of different types of creativity interventions on different facets of creative potential, also including more school-related creativity demands. In a sample of 77 fourth-graders in the age between 9 and 12 years, we administered a verbal and a figural creativity training, realized in two school lessons over two consecutive days each. As outcome measures, creative potential in both the verbal and the figural domain by means of two well-established divergent thinking tasks was assessed. As additional measures of creative potential, a story completion task and a picture painting task were administered to examine training effects on more school-related types of creative behavior. The verbal training was found to increase both verbal and figural divergent thinking ability, but not creative potential in the story completion and the picture painting task. The figural training yielded significant training effects only regarding the picture painting task. Findings suggest a specific training effect of the figural creativity training, and moreover indicate that the verbal creativity training, rather than stimulating “verbal” creative abilities per se, was more strongly concerned with domain-general creativity processes including ideational fluency, flexibility, and originality that are characteristics of divergent thinking tasks across different domains.     

汉语歧义句的加工

通过两个实验,对汉语歧义句多种解释的意义频率和语境位置在句子歧义解析过程中的效应进行了考察。实验结果表明：（１）前语境为被试提供了某种预期信息,它对句子歧义解析的效应大于后语境;（２）在句子歧义解析过程中,不管有语境或无语境,不管是前语境或后语境,被试提取歧义句的主要意思比提取次要意思快;（３）歧义句的多种解释的激活,有一个时间进程,在短延迟间隔条件下,歧义句的主要意思可以被激活并形成表征,但次要意思的激活和表征则需要较长的时间     

Resolving syntactic category ambiguity: An eye-movement analysis

In two experiments, participants' eye movements were monitored as they read sentences containing biased syntactic category ambiguous words with either distinct (e.g., duck) or related (e.g., burn) meanings or unambiguous control words. In Experiment 1, prior context was consistent with either the dominant or subordinate interpretation of the ambiguous word. The subordinate bias effect was absent for the ambiguous words in gaze duration measures. However, effects of ambiguity did emerge in other measures for the ambiguous words preceded by context supporting the subordinate interpretation. In Experiment 2, context preceding the target words was neutral. Ambiguity effects only arose when posttarget context was consistent with the subordinate interpretation of the ambiguous words, indicating that readers initially selected the dominant interpretation. Results support immediate theories of syntactic category ambiguity resolution, but also suggest that recovery from misanalysis of syntactic category ambiguity is more difficult than for lexical-semantic ambiguity in which alternate interpretations do not cross syntactic category.     

Contextual insensitivity in schizophrenic language processing: evidence from lexical ambiguity

The authors investigated whether contextual failures in schizophrenia are due to deficits in the detection of context or the inhibition of contextually irrelevant information. Eighteen schizophrenia patients and 24 nonpsychiatric controls were tested via a cross-modal semantic priming task. Participants heard sentences containing homonyms and made lexical decisions about visual targets related to the homonyms' dominant or subordinate meanings. When sentences moderately biased subordinate meanings (e.g., the animal enclosure meaning of pen), schizophrenia patients showed priming of dominant targets (e.g., paper) and subordinate targets (e.g., pig). In contrast, controls showed priming only of subordinate targets. When contexts strongly biased subordinate meanings, both groups showed priming only of subordinate targets. The results suggest that inhibitory deficits rather than context detection deficits underlie contextual failures in schizophrenia.     

Visible homonyms are ambiguous, subliminal homonyms are not: a close look at priming

Homonyms, i.e. ambiguous words like ‘score’, have different meanings in different contexts. Previous research indicates that all potential meanings of a homonym are first accessed in parallel before one of the meanings is selected in a competitive race. If these processes are automatic, these processes of selection should even be observed when homonyms are shown subliminally. This study measured the time course of subliminal and supraliminal priming by homonyms with a frequent (dominant) and a rare (subordinate) meaning in a neutral context, using a lexical decision task. In the subliminal condition, priming across prime-target asynchronies ranging from 100 ms to 1.5 s indicated that the dominant meaning of homonyms was facilitated and the subordinate meaning was inhibited. This indicates that selection of meaning was much faster with subliminal presentation than with supraliminal presentation. Awareness of a prime might decelerate an otherwise rapid selection process.     

Sensitivity to local sentence context information in lexical ambiguity resolution: evidence from left- and right-hemisphere-damaged individuals

Using a cross-modal semantic priming paradigm, the present study investigated the ability of left-hemisphere-damaged (LHD) nonfluent aphasic, right-hemisphere-damaged (RHD) and non-brain-damaged (NBD) control subjects to use local sentence context information to resolve lexically ambiguous words. Critical sentences were manipulated such that they were either unbiased, or biased toward one of two meanings of sentence-final equibiased ambiguous words. Sentence primes were presented auditorily, followed after a short (0 ms) or long (750 ms) interstimulus interval (ISI) by the presentation of a first- or second-meaning related visual target, on which subjects made a lexical decision. At the short ISI, neither patient group appeared to be influenced by context, in sharp contrast to the performance of the NBD control subjects. LHD nonfluent aphasic subjects activated both meanings of ambiguous words regardless of context, whereas RHD subjects activated only the first meaning in unbiased and second-meaning biased contexts. At the long ISI, LHD nonfluent aphasic subjects failed to show evidence of activation of either meaning, while RHD individuals activated first meanings in unbiased contexts and contextually appropriate meanings in second-meaning biased contexts. These findings suggest that both left (LH) and right hemisphere (RH) damage lead to deficits in using local contextual information to complete the process of ambiguity resolution. LH damage seems to spare initial access to word meanings, but initially impairs the ability to use context and results in a faster than normal decay of lexical activation. RH damage appears to initially disrupt access to context, resulting in an over-reliance on frequency in the activation of ambiguous word meanings.     

Structural influences on the resolution of lexical ambiguity: an analysis of hemispheric asymmetries

Structural influences on lexical ambiguity resolution in the two cerebral hemispheres was investigated using a divided visual field procedure. Participants were presented with auditory Wh- sentences containing an ambiguous word, where the grammatical role of the word was apparent only at a sentence-final verb (e.g., "Which BANK did the woman see?"). Following a sentence, either immediately or after 600 ms, a target word was presented in either the right or left visual field. Targets were related to the ambiguous word's dominant meaning (MONEY), the subordinate meaning (RIVER), or were unrelated. With left visual field presentation, priming occurred for both dominant- and subordinate-related targets at a 0 ms delay, but only for dominant-related targets at 600 ms. With left visual field presentation, priming occurred for subordinate-related targets only at both delays. The results suggest that grammatical assignment triggers the selection of meaning in the left hemisphere, whereas processing in the right hemisphere operates independently of structural analyses.     

Barking up the wrong tree? Lexical ambiguity resolution in children with language impairments and autistic spectrum disorders

Lexical ambiguity resolution was investigated in 9- to 17-year-olds with language impairment (LI, n=20), autistic spectrum disorder (ASD) plus language impairment (ALI, n=28), ASD and verbal abilities within the normal range (ASO, n=20), and typically developing children (TD, n=28). Experiment 1 investigated knowledge of dominant and subordinate meanings of ambiguous words. The LI and ALI groups knew fewer subordinate meanings than did the ASO and TD groups. Experiment 2 used a modified version of the paradigm to investigate contextual facilitation and suppression of irrelevant meanings. All groups demonstrated contextual facilitation, responding quickly and more accurately to words following a biased context. However, children with ALI and LI did not use context as efficiently as did their peers without language deficit. Furthermore, for the LI and ALI groups, errors in the suppression condition reflected poor contextual processing. These findings challenge the assumptions of weak central coherence theory and demonstrate the need for stringent language controls in the study of autistic cognition.     

Automatic effects of deviancy cues on creative cognition

Three experiments test the existence of an automatic deviancy‐creativity link. Using a lexical decision task, in Experiment 1 we found a semantic link between deviancy and creativity words in that decision times for creativity‐related words were enhanced after subliminal deviancy priming. In Experiment 2, participants were led to think about either a punk or an engineer and afterwards were administered creative insight and analytical reasoning problems. According to a pretest, punks and engineers were judged as differing in uniqueness but not in creativity. Participants given ‘punk’ priming solved more creative insight problems and fewer analytical reasoning problems than those given ‘engineer’ priming. In Experiment 3, participants were incidentally exposed to abstract artworks symbolically expressing either the concept of conformity or deviancy and were subsequently asked to solve a creative generation task. Exposure to the artwork representing deviancy led to generation of more creative solutions than exposure to that representing conformity. Copyright © 2005 John Wiley & Sons, Ltd.