Processing the emotions in words: The complementary contributions of the left and right hemispheres

A dual-process model is suggested for the processing of words with emotional meaning in the cerebral hemispheres. While the right hemisphere and valence hypotheses have long been used to explain the results of research on emotional stimulus processing, including nonverbal and verbal stimuli, data on emotional word processing are mostly inconsistent with both hypotheses. Three complementary lines of research data from behavioral, electrophysiological, and neuroimaging studies seem to suggest that both hemispheres have access to the meanings of emotional words, although their time course of activation may be different. The left hemisphere activates these words automatically early in processing, whereas the right hemisphere gains access to emotional words slowly when attention is recruited by the meaning of these words in a controlled manner. This processing dichotomy probably corroborates the complementary roles the two hemispheres play in data processing.     

Access to perceptual and conceptual information in the left and right hemispheres.

It is assumed that there are hemispheric differences in the type of information available for the processing of word meanings, e.g., categorical or associative information. In the present experiment, we used a semantic priming paradigm to examine whether perceptual or conceptual properties of word meanings would be associated with the left or right hemisphere. The present experiment also examined time-course activation of these properties across the hemispheres, using short and long stimulus onset asynchronies. The results indicated that perceptual information is available only in the right hemisphere at an early rather than a late stage of target processing, while conceptual information is available in both hemispheres at both early and later stages of target processing. It is suggested that the imagery system in the right hemisphere may contribute to the perceptual priming observed in this hemisphere.     

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。     

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.     

Cross-language influences: translation status affects intraword sense relatedness

Many words have more than one meaning, and these meanings vary in their degree of relatedness. In the present experiment, we examined whether this degree of relatedness is influenced by whether or not the two meanings share a translation in a bilingual’s other language. Native English speakers with Spanish as a second language (i.e., English-Spanish bilinguals) and native Spanish speakers with English as a second language (i.e., Spanish-English bilinguals) were presented with pairs of phrases instantiating different senses of ambiguous English words (e.g., dinner date–expiration date) and were asked to decide whether the two senses were related in meaning. Critically, for some pairs of phrases, a single Spanish translation encompassed both meanings of the ambiguous word (joint-translation condition; e.g., mercado in Spanish refers to both a flea market and the housing market), but for others, each sense corresponded to a different Spanish translation (split-translation condition; e.g., cita in Spanish refers to a dinner date, but fecha refers to an expiration date). The proportions of “yes” (related) responses revealed that, relative to monolingual English speakers, Spanish–English bilinguals consider joint-translation senses to be less related than split-translation senses. These findings exemplify semantic cross-language influences from a first to a second language and reveal the semantic structure of the bilingual lexicon.     

第二语言水平对双语者语言抑制能力的影响——来自英语–汉语单通道双语者和英语–美国手语双通道双语者的证据

采用同形异义词干扰任务考察第二语言水平对英语–汉语单通道双语者和英语–美国手语双通道双语者语言抑制能力的影响。结果发现:(1)高水平英语–汉语单通道双语者的语言抑制能力较强,但低水平英语–汉语单通道双语者与英语单语者的语言抑制能力没有显著差异,说明少量的双语经验不足以导致双语认知优势;(2)不同水平的英语–美国手语双通道双语者的语言抑制能力差异不显著。所以如此,与英语–美国手语双通道双语者不存在口语和手语的双语表征加工竞争有关。整个研究表明,双语认知优势效应与双语者的二语水平以及通道经验有关。     

The bilingual advantage in novel word learning

The present study examined whether bilingualism facilitates acquisition of novel words in adults with different language histories. Word-learning performance was tested in monolingual English speakers, early English—Spanish bilinguals, and early English—Mandarin bilinguals. Novel words were phonologically unfamiliar to all participants, and they were acquired in association with their English translations. At testing, both bilingual groups outperformed the monolingual group. These findings indicate that bilingualism facilitates word-learning performance in adults, and they suggest a general bilingual advantage for novel word learning.     

Visual field asymmetries for rhyme and syntactic category judgments in monolinguals and fluent early and late bilinguals

A tachistoscopic study investigated hemispheric specialization among monolingual and fluent French-English bilingual adults for speeded rhyme and syntactic category matching. A right visual field superiority was obtained for both types of verbal judgments. This effect was more pronounced in late bilinguals than in early bilinguals or monolinguals. In addition, bilingual subgroup differences in response latency and strategy were found, suggesting a preference for semantic processing among early bilinguals and for surface processing among late bilinguals, consistent with previous findings. Possible theoretical implications of these differences are outlined.     

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.     

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.     

Hemispheric Differences in the Processing of Words Learned Early Versus Later in Childhood

The research investigated whether there are hemispheric differences in processing for words acquired early in childhood (early AoA) and words acquired later in childhood (late AoA). We hypothesized that because of recent evidence suggesting that there is a right hemisphere dominance in early childhood, early AoA words would be represented in the right hemisphere, and late AoA words would be represented in the left hemisphere. This hypothesis differs from an early view that late AoA words would be represented in the left hemisphere, and early AoA words would be represented in both hemispheres (Gazzaniga, 1974). We report two experiments using the divided visual field (DVF) technique. The results showed that there was a right visual field (RVF)/left hemisphere (LH) advantage only for late AoA words. For early AoA words, there was a left visual field (LVF)/right hemisphere advantage (RH). Implications for theories of hemispheric differences in word processing are discussed.     

Language processing in bilinguals

The present study investigated the language processing strategies of three subgroups of adult bilinguals with different histories of language acquisition: infant bilinguals whose bilinguality dated from infancy; childhood bilinguals who became bilingual around 5 years of age; and adolescent bilinguals who had become bilingual at secondary school age only. All were completely balanced bilinguals in French and English at the time of testing. The experimental procedure, a language recognition task, required the subjects to indicate, by pressing a response button, whether each of a series of words, presented monaurally through earphones, was French or English. Concomitantly, left and right hemisphere EEG activity was monitored, with measures taken of latency to N₁, latency to P₂, and N₁-P₂ peak-to-peak amplitudes. Results indicated shorter latencies to N₁ in the left than in the right hemisphere for the infant and childhood bilinguals but shorter latencies in the right hemisphere for the adolescent bilinguals. Overall, the N₁ latency was shorter for the adolescent subgroup than for the two other subgroups. There were no RT differences. The findings appear to reflect strategy differences: The adolescent group seemed to rely more on a right hemisphere-based, possibly more gestalt-like or melodic strategy, while the early bilinguals relied more on a left hemisphere-based, possibly semantic or analytic type of strategy. The results are discussed in terms of previous research on bilingual subtypes and general forms of language processing among bilinguals.     

Hemispheric differences in picture-word interference

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.     

Interlinguistic conflict: Word–word Stroop with first and second language colour words

The congruency (or Stroop) effect is a standard observation of slower and less accurate colour identification to incongruent trials (e.g. “red” in green) relative to congruent trials (e.g. “red” in red). This effect has been observed in a word–word variant of the task, when both the distracter (e.g. “red”) and target (e.g. “green”) are colour words. The Stroop task has also been used to study the congruency effect between two languages in bilinguals. The typical finding is that the congruency effect for L1 words is larger than that for L2 words. For the first time, the present report aims to extend this finding to a word–word variant of the bilingual Stroop task. In two experiments, French monolinguals performed a bilingual word–word Stroop task in which target word language, language match, and congruency between the distracter and target were manipulated. The critical manipulation across two experiments concerned the target language. In Experiment 1, target language was manipulated between groups, with either French (L1) or English (L2) target colour words. In Experiment 2, target words from both languages were intermixed. In both experiments, the congruency effect was larger when the distracter and target were from the same language (language match) than when they were from different languages (language mismatch). Our findings suggested that this congruency effect mostly depends on the language match between the distracter and target, rather than on a target language. It also did not seem to matter whether the language-mismatching distracter was or was not a potential response alternative. Semantic activation of languages in bilinguals and its implications on target identification are discussed.

     

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.     

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.     

Markedness effects in Norwegian–English bilinguals: Task-dependent use of language-specific letters and bigrams

This study investigates how bilinguals use sublexical language membership information to speed up their word recognition process in different task situations. Norwegian–English bilinguals performed a Norwegian–English language decision task, a mixed English lexical decision task, or a mixed Norwegian lexical decision task. The mixed lexical decision experiments included words from the nontarget language that required a “no” response. The language specificity of the Bokmål (a Norwegian written norm) and English (non)words was varied by including language-specific letters (“smør”, “hawk”) or bigrams (“dusj”, “veal”). Bilinguals were found to use both types of sublexical markedness to facilitate their decisions, language-specific letters leading to larger effects than language-specific bigrams. A cross-experimental comparison indicates that the use of sublexical language information was strategically dependent on the task at hand and that decisions were based on language membership information derived directly from sublexical (bigram) stimulus characteristics instead of indirectly via their lexical representations. Available models for bilingual word recognition fail to handle the observed marker effects, because all consider language membership as a lexical property only.     

Bilingualism and brain functional asymmetry

The task of the neural organization of the native language, acquired by a direct method and of another language, studied at school, performed correspondingly by the left and the right hemispheres, was studied in the bilingual patient after unilateral electroconvulsive therapy used in psychiatry. It was established that in such a bilingual type the right hemisphere is concerned with the formation of deep semantic structures of the native language while the left hemisphere is responsible for the formation of second language deep structures and of surface structures of both languages. The effect of language learning method on cerebral organization of bilingualism is postulated.     

Sequential processing in hemispheric word recognition: the impact of initial letter discriminability on the OUP naming effect

The cerebral hemispheres have been proposed to engage different word recognition strategies: the left hemisphere implementing a parallel, and the right hemisphere, a sequential, analysis. To investigate this notion, we asked participants to name words with an early or late orthographic uniqueness point (OUP), presented horizontally to their left (LVF), right (RVF), or both fields of vision (BVF). Consistent with past foveal research, Experiment 1 produced a robust facilitatory effect of early OUP for RVF/BVF presentations, indicating the presence of sequential processes in lexical retrieval. The effect was absent for LVF trials, which we argue results from the disadvantaged position of initial letters of words presented in the LVF. To test this proposition, Experiment 2 assessed the discriminability of various letter positions in the visual fields using a bar-probe task. The obtained error functions highlighted the poor discriminability of initial letters in the LVF and latter letters in the RVF. To confirm that this asymmetry in initial letter acuity was responsible for the absent OUP effect for LVF presentations, Experiment 3 replicated Experiment 1 using vertical stimulus presentations. Results indicated a marked facilitatory effect of early OUP across visual fields, supporting our contention that the lack of OUP effect for LVF presentations in Experiment 1 resulted from poor discriminability of the initial letters. These findings confirm the presence of sequential processes in both left and right hemisphere word recognition, casting doubt on parallel models of word processing.     

Native-Language Phonological Interference in Early Hakka–Mandarin Bilinguals’ Visual Recognition of Chinese Two-Character Compounds: Evidence from the Semantic-Relatedness Decision Task

Previous research has indicated that, in viewing a visual word, the activated phonological representation in turn activates its homophone, causing semantic interference. Using this mechanism of phonological mediation, this study investigated native-language phonological interference in visual recognition of Chinese two-character compounds by early Hakka–Mandarin bilinguals. A visual semantic-relatedness decision task in Chinese was given to native Mandarin speakers and early Hakka–Mandarin bilinguals. Both participant groups made more false positive errors and responded more slowly to the pair of two-character compounds containing a homophone; but only Hakka–Mandarin bilinguals made more false positive errors and responded more slowly to the pair containing a near-homophone. We concluded that phonology is needed in both native and nonnative speakers’ meaning access of Chinese two-character compounds and that native-language phonological interference is universal in L2 visual word recognition, not language type dependent; phonological and orthographic information are “interactive-compensatory” in helping Hakka readers’ resolve the interference.