Zohar Eviatar

Brain correlates of discourse processing: An fMRI investigation of irony and conventional metaphor comprehension

Higher levels of discourse processing evoke patterns of cognition and brain activation that extend beyond the literal comprehension of sentences. We used fMRI to examine brain activation patterns while 16 healthy participants read brief three-sentence stories that concluded with either a literal, metaphoric, or ironic sentence. The fMRI images acquired during the reading of the critical sentence revealed a selective response of the brain to the two types of nonliteral utterances. Metaphoric utterances resulted in significantly higher levels of activation in the left inferior frontal gyrus and in bilateral inferior temporal cortex than the literal and ironic utterances. Ironic statements resulted in significantly higher activation levels than literal statements in the right superior and middle temporal gyri, with metaphoric statements resulting in intermediate levels in these regions. The findings show differential hemispheric sensitivity to these aspects of figurative language, and are relevant to models of the functional cortical architecture of language processing in connected discourse.

Bilingual Is as Bilingual Does: Metalinguistic Abilities of Arabic-Speaking Children.

ADDRESS FOR CORRESPONDENCEZohar Eviatar, Institute of Information Processing and Decision Making, University of Haifa,Mount Carmel, Haifa, Israel 31905. Email: zohare@psy.haifa.ac.ilABSTRACTThe study explores the effects of the relationship between exposure to two languages in childhoodand metalinguistic abilities. Arabic-speaking children who had been exposed to both spoken andliterary Arabic were compared to Russian–Hebrew bilinguals and Hebrew monolinguals. All of thechildren were in kindergarten or first grade. The tests included language arbitrariness, phonologicalawareness, and vocabulary. As compared to the Hebrew monolinguals, the Russian–Hebrew bilin-guals revealed the following pattern: higher performance on arbitrariness and phonological aware-ness tasks and lower performance on the vocabulary measure. The results of the Arab childrenmimicked those of the Russian–Hebrew bilinguals and differed from those of the Hebrew monolin-guals. We conclude that exposure to literary Arabic requires the same intensive language analysesas those demanded of children exposed to languages as different as Russian and Hebrew.

The characteristics of arabic orthography slow its processing.

The present study was designed to evaluate whether the complexity of Arabic orthography increases its perceptual load, thus slowing word identification. Adolescent Arabic speakers who mastered Hebrew as a second language completed oral and visual versions of the Trail Making Test (TMT; J. E. Parington & R. G. Lieter, 1949) in both languages. Oral TMT required declaiming consecutive numbers or alternation between numbers and letters. Visual TMT required connecting Arabic or Indian numbers and alternation between letters and numbers. Performance in Hebrew and Arabic oral TMT did not differ. Performance was significantly slower in Arabic visual TMT. These results indicate that Arabic speakers process Arabic orthography (1st language) slower than Hebrew orthography (2nd language) and suggest that this is due to the complexity of Arabic orthography.

Individual variation in hemispheric asymmetry: multitask study of effects related to handedness and sex.

: Functional hemispheric asymmetries were examined for right- or left-handed men and women. Tasks involved (a) auditory processing of verbal material, (b) processing of emotions shown on faces, (c) processing of visual categorical and coordinate spatial relations, and (d) visual processing of verbal material. Similar performance asymmetries were found for the right-handed and left-handed groups, but the average asymmetries tended to be smaller for the left-handed group. For the most part, measures of performance asymmetry obtained from the different tasks did not correlate with each other, suggesting that individual subjects cannot be simply characterized as strongly or weakly lateralized. However, ear differences obtained in Task 1 did correlate significantly with certain visual field differences obtained in Task 4, suggesting that both tasks are sensitive to hemispheric asymmetry in similar phonetic or language-related processes.

Orthography and the hemispheres: visual and linguistic aspects of letter processing.

Hebrew and Arabic are Semitic languages with a similar morphological structure and orthographies that differ in visual complexity. Two experiments explored the interaction of the characteristics of orthography and hemispheric abilities on lateralized versions of a letter-matching task (Experiment 1) and a global-local task (Experiment 2). In Experiment 1, native Hebrew readers and native Arabic readers fluent in Hebrew matched letters in the 2 orthographies. The results support the hypothesis that Arabic orthography is more difficult than Hebrew orthography for participants who can read both languages and that this difficulty has its strongest effects in the left visual field. In Experiment 2, native Arabic speakers performed a global-local letter detection task with Arabic letters with 2 types of inconsistent stimuli: different and similar. The results support the hypothesis that the right hemisphere of skilled Arabic readers cannot distinguish between similar Arabic letters, whereas the left hemisphere can.

The effects of word length and emotionality on hemispheric contribution to lexical decision

The effects of emotionality and length on lateralized lexical decision of abstract nouns were investigated in 41 normal and three commissurotomized subjects. Emotionality had the same effect in both visual fields: Emotional words were responded to more accurately than neutral words. Length had different effects in the two visual fields: The accuracy of lexical decisions in the left visual field was selectively higher for four-letter words and in the right visual field it was selectively lower for six-letter words. The latency of lexical decisions revealed equivalent length effects in both visual fields. Of the commissurotomy patients, only L.B.s left hemisphere performed above chance and revealed a length effect. Length effects are interpreted to reflect a change from a parallel graphic analysis to a sequential parsing strategy when resources are limited. Such a change can occur for words or nonwords in either visual hemifield.

Perceptual load in the reading of Arabic: Effects of orthographic visual complexity on detection

Previous research has suggested that reading Arabic is slower than reading Hebrew or English, even among native Arabic readers. We tested the hypothesis that at least part of the difficulty in reading Arabic is due to the visual complexity of Arabic orthography. Third- and sixth-grade native readers of Arabic who were studying Hebrew in school were asked to detect a vowel diacritic in the context of Hebrew words and nonwords, Arabic words and nonwords (including connected and unconnected Arabic letters), and nonletter stimuli that resembled Arabic or Hebrew letters. Participants were better at detecting target vowels in Hebrew than in any of the Arabic conditions. Moreover, target detection in Arabic was better for letter strings containing connected letters than for those containing unconnected letters. The findings extend previous results on Hebrew versus Arabic reading and support a perceptual load account of the source of processing difficulty in reading Arabic. Performance in the Arabic conditions did not reveal a word superiority effect, suggesting that even by sixth grade, reading is not automatized to the point where it can compensate for the the visual complexity of the orthography.

Language Experience and Right Hemisphere Tasks: The Effects of Scanning Habits and Multilingualism ☆ ☆☆ ★

This study explores the effects of multilingualism and reading scanning habits on right hemisphere (RH) abilities. Native Hebrew speakers and Arabic-Hebrew bilinguals performed three tasks. Experiment 1 employed an odd/even decision paradigm on lateralized displays of bar graphs. Both groups of subjects displayed the expected LVFA within the range previously reported for readers of English. Experiment 2 consisted of a chair identification task designed to tap asymmetry of hemispheric arousal and a chimeric face task designed to tap RH specialization for facial emotion. Neither scanning habits nor language experience affected performance on the chair task. Scanning habits seem to have affected performance on the chimeric faces task: there was no preference for the left smile in these right-to-left readers, as opposed to previous results in the literature using left-to-right readers. Correlations between measures from the three tasks and all the subjects scores on an English proficiency test and on a Hebrew test for the bilinguals reveal tentative relationships between proficiency in a second language and RH abilities. The results do not support the hypothesis that multilingualism can affect the manner in which these nonlanguage tasks are subserved by the RH. They do support the hypothesis that scanning habits particular to specific languages can affect performance asymmetries on some nonlanguage tasks that have been posited to reflect RH specialization.

The relationship between theory of mind and autobiographical memory in high-functioning autism and Asperger syndrome

The relationship between theory of mind (ToM) and autobiographical memory (AM) in high-functioning autism (HFA) and Asperger syndrome (AS) has never been investigated. Here, we show that ToM abilities could be predicted by levels of AM in HFA and AS as compared to controls, suggesting that difficulties in AM are closely related to ToM impairments in HFA and AS.

Individual differences in lateralization: effects of gender and handedness.

Male and female left- and right-handers participated in 3 experiments designed to investigate 3 components of performance asymmetry in lateralized tasks. Experiment 1 used a consonant-vowel-consonant (CVC) identification task measuring quantitative differences in hemispheric abilities and hemispheric control and qualitative differences in hemispheric strategies. The quantitative data revealed that left-handers have a smaller performance asymmetry than do right-handers and that both groups have the same degree of increased accuracy when stimuli are presented bilaterally. Handedness affected the qualitative measures of men, not of women. Experiment 2 used nominal and physical letter-matching tasks with bilateral presentations and measured the flexibility of callosal function. The results suggest that left-handers have less flexible interhemispheric communication than do right-handers and show no effect of gender. Experiment 3 used a chair identification task indexing hemispheric arousal bias. Left-handers tended to have more aroused right than left hemispheres, whereas the distribution of right-handers was centered around 0 arousal bias. Intertask analyses revealed a relationship between arousal bias and metacontrol, where individuals with more aroused right hemispheres tended to use a right-hemisphere strategy in the bilateral condition of the CVC experiment. Intercorrelations between measures from the experiments revealed only a limited relationship between metacontrol patterns in the CVC task and a measure of callosal flexibility in the physical letter-matching task. The results are discussed in the context of the relationships between dimensions of hemispheric asymmetry.