Shift of visual field preference for Hebrew words in native speakers learning to read

Lateralization for Hebrew words was tested in both the visual and auditory modalities in Israeli children learning to read their native language, Hebrew. A left visual field preference for tachistoscopically presented words was found in the second graders in contrast to a right visual field preference for the same words in the third graders. Children in both grades showed a right ear dominance for similar words presented dichotically. These data suggest right hemisphere involvement in acquiring reading skills of a native language.     

Evidence for scanning with unilateral visual presentation of letters

When letters and words are presented tachistoscopically, material from the right visual field (RVF) can be reported more accurately than that from the left visual field (LVF). The RVF superiority may reflect either left hemispheric dominance for language or directional scanning. Previous studies have deliberately focused on the cerebral asymmetry factor while "controlling" scanning and, thus, have cast some doubt on the potency of the scanning factor. Two experiments were conducted to show that scanning can induce a RVF superiority comparable to that often associated with cerebral asymmetry. The first experiment required bilingual subjects to report six English or six Hebrew letters, shown briefly in either the LVF or RVF, with order of report controlled. A RVF superiority found with English characters was matched by an equal but opposite LVF effect with Hebrew. In a second experiment, five English characters were shown briefly in either the LVF or RVF, and subjects had to identify a single character indicated by a post exposural cue. Using a spatial cue to by pass scanning, there were no field differences; with an ordinal position cue--a procedure thought to force scanning--there was a strong RVF superiority. The results show clearly that scanning can induce visual field differences.     

The role of the native language in auditory and visual context effect modalities

Facilitation of memory for target stimuli due to similar context in the learning and testing phases is known as “context effect” (CE). The present study aimed to investigate the interaction between CE as elicited by the consistency of the language of presentation (Hebrew vs. English) with the native language (Hebrew vs. English) in both auditory and visual modalities. Overall, 120 individuals participated in the experiment. As predicted, CE was evident when the language of presentation remained consistent between study and test. Contrary to our prediction, Hebrew speakers remembered more English words, and vice versa. A possible explanation is that this difference is due to the cognitive effort invested when processing a less dominant language, thus resulting in better recognition. This study has several practical implications, including a recommendation that academic institutions test students in the language in which the material was presented in order to measure the students' knowledge more accurately.     

Electrophysiological evidence for priming in response to words and pseudowords in first and second language

The study purpose was to indicate when language-specific processing first occurs and how first and second language priming processes interact. Event-related potentials were recorded from 14 normal native Hebrew speakers, in a variation of lexical decision task, to pairs of stimuli (S1, S2) in Hebrew, English, Hebrew pseudowords, and English pseudowords. Although no behavioral priming was observed, priming by pseudowords in either language affected both N400 and the late positive component of event related potential. N1 and P2 latencies were longer to S2 in semantically related pairs, indicating that language-specific processing may take place as early as auditory cortex. Different processing of first and second language was evident only in response to pseudowords.     

Orthographic directionality and thematic role illustration in English and Arabic

This study tested the hypotheses that people had a bias for drawing agents on the left of a picture when given a verb stimulus targeting an active or passive event (e.g., "kicked" or "is kicked") and that orthographic directionality would influence the way events were illustrated. Monolingual English speakers, who read and write left-to-right, and Arabic speakers, who read and write right-to-left, drew agents and patients in response to verb stimuli. We found no significant orthographic directionality effects and no preference for positioning agents on the left of pictures in either group or sentence type. Instead, participants drew agents on the right regardless of language or sentence type, and this was exaggerated in English speakers illustrating passive verbs. These findings support the existence of a preference for placing agents in the right hemispace that may result from asymmetrical hemispheric (i.e., left>right) activation induced by language processing. Our results are consistent with findings that people prefer pictures in which focus is on the right, a preference strongest in pictures with no implicit directionality of movement. This suggests that the methodology of the current study encouraged a static rather than dynamic interpretation of the verb in most participants.     

Lateralization effects in the perception of Hebrew and English words

A series of four experiments was conducted on Israelis with a good knowledge of English, Anglo-Saxons with a good knowledge of Hebrew, and full Bilinguals of the two languages. In all experiments words were presented vertically and measurements of both accuracy and response times were taken. Experiments 1 and 2 examined the perception of Hebrew words in unilateral and bilateral conditions, respectively; Experiments 3 and 4 examined the perception of both Hebrew and English words in these two conditions. The results revealed right visual field advantage in the perception of words in both languages and in all groups. A reversal between the two conditions was not found. The data support the hypothesis whereby nonnative languages are less lateralized than native ones, but they indicate that full bilinguals are more, not less, lateralized than monolinguals. Various hypothesis regarding the relationship between lateralization and bilingualism are discussed.     

Directional tendencies of Hebrew, Japanese, and English readers.

Consistent left-right and right-left reading habits are associated with corresponding directional tendencies in the reproduction of horizontally displayed visual stimuli. Inconsistent reading habits should therefore be associated with inconsis tent directional tendencies. This hypothesis was tested on Japanese readers whose reading habits were inconsistent by asking them to reproduce four series of 12-item horizontal stimulus arrays. The hypothesis was partially supported by the data which showed that, like Hebrew readers who also have inconsistent reading habits, the directional tendencies shown by the 68 Japanese readers were significantly weaker on some tasks that those shown by the 16 English readers whose left-right reading habits were consistent. The data were interpreted as showing that acquired reading habits may affect directionality in perception of visual stimuli.     

Cerebral asymmetry for American Sign Language: The effects of moving stimuli

Previous studies of cerebral asymmetry for the perception of American Sign Language (ASL) have used only static representations of signs; in this study we present moving signs. Congenitally deaf, native ASL signers identified moving signs, static representations of signs, and English words. The stimuli were presented rapidly by motion picture to each visual hemifield. Normally hearing English speakers also identified the English words. Consistent with previous findings, both the deaf and the hearing subjects showed a left-hemisphere advantage to the English words; likewise, the deaf subjects showed a right hemisphere advantage to the statically presented signs. With the moving signs, the deaf showed no lateral asymmetry. The shift from right dominance to a more balanced hemispheric involvement with the change from static to moving signs is consistent with Kimura's position that the left hemisphere predominates in the analysis of skilled motor sequencing (Kimura 1976). The results also indicate that ASL may be more bilaterally represented than is English and that the spatial component of language stimuli can greatly influence lateral asymmetries.     

Visual span of apprehension in patients with unilateral cerebral lesions

The visual span of apprehension for random letter and digit sequences, approximations to English sequences and non-symbolic line stimuli was measured in patients with unilateral cerebral lesions. The left hemisphere group was significantly impaired relative to the right hemisphere group and a control group on all three types of visual span task. The deficit was most marked in patients with left posterior lesions. The visual span deficits were not related to other language deficits. The findings are discussed in terms of a modality-specific defect of visual short-term memory.     

Ear asymmetries in dichotic listening tasks which increase in difficulty

Accuracy and laterality of ear preference in repeating 2, 3 and 4 word pairs (WP) of dichotic stimuli in English and French were determined in 80 right-handed subjects (anglophone/francophone, male/female), who were tested in both their native language (L1) and nonnative language (L2). Relative performance accuracy decreased as a function of word pairs per trial (from 2 to 4) as well as language (from L1 to L2). Right-lateral preference in turn increased as a function of WP (from 2 to 4) as well as language (L1 to L2). Right-ear advantage (REA) in L2 decreased as a function of language proficiency (low to high). REA was observed in over 90% of subjects. A rationale for greater lateralization of L2 performance is offered.     

CROSS-CULTURAL DIFFERENCES IN DIRECTIONALITY*

The assumption that the directions of writing single letters and series of letters in a given language affect the directional preferences for reproducing single and multiple stimuli, respectively, was tested on three groups of subjects with different reading and writing habits; English readers, Hebrew readers, and Arabic readers. The subjects were presented with single stimuli and with series of stimuli for reproduction, and the horizontal directions of their responses were recorded. Confirming the hypothesis, the data pointed to the complexities of the effects of reading and writing habits on directional preferences among readers of different languages.     

Cross-cultural differences in mental representations of time: evidence from an implicit nonlinguistic task

Across cultures people construct spatial representations of time. However, the particular spatial layouts created to represent time may differ across cultures. This paper examines whether people automatically access and use culturally specific spatial representations when reasoning about time. In Experiment 1, we asked Hebrew and English speakers to arrange pictures depicting temporal sequences of natural events, and to point to the hypothesized location of events relative to a reference point. In both tasks, English speakers (who read left to right) arranged temporal sequences to progress from left to right, whereas Hebrew speakers (who read right to left) arranged them from right to left, replicating previous work. In Experiments 2 and 3, we asked the participants to make rapid temporal order judgments about pairs of pictures presented one after the other (i.e., to decide whether the second picture showed a conceptually earlier or later time-point of an event than the first picture). Participants made responses using two adjacent keyboard keys. English speakers were faster to make "earlier" judgments when the "earlier" response needed to be made with the left response key than with the right response key. Hebrew speakers showed exactly the reverse pattern. Asking participants to use a space-time mapping inconsistent with the one suggested by writing direction in their language created interference, suggesting that participants were automatically creating writing-direction consistent spatial representations in the course of their normal temporal reasoning. It appears that people automatically access culturally specific spatial representations when making temporal judgments even in nonlinguistic tasks.     

Visual field asymmetries for motion processing in deaf and hearing signers

Recently, we reported a strong right visual field/left hemisphere advantage for motion processing in deaf signers and a slight reverse asymmetry in hearing nonsigners (Bosworth & Dobkins, 1999). This visual field asymmetry in deaf signers may be due to auditory deprivation or to experience with a visual-manual language, American Sign Language (ASL). In order to separate these two possible sources, in this study we added a third group, hearing native signers, who have normal hearing and have learned ASL from their deaf parents. As in our previous study, subjects performed a direction-of-motion discrimination task at different locations across the visual field. In addition to investigating differences in left vs right visual field asymmetries across subject groups, we also asked whether performance differences exist for superior vs inferior visual fields and peripheral vs central visual fields. Replicating our previous study, a robust right visual field advantage was observed in deaf signers, but not in hearing nonsigners. Like deaf signers, hearing signers also exhibited a strong right visual field advantage, suggesting that this effect is related to experience with sign language. These results suggest that perceptual processes required for the acquisition and comprehension of language (motion processing in the case of ASL) are recruited by the left, language-dominant, hemisphere. Deaf subjects also exhibited an inferior visual field advantage that was significantly larger than that observed in either hearing group. In addition, there was a trend for deaf subjects to perform relatively better on peripheral than on central stimuli, while both hearing groups showed the reverse pattern. Because deaf signers differed from hearing signers and nonsigners along these domains, the inferior and peripheral visual field advantages observed in deaf subjects is presumably related to auditory deprivation. Finally, these visual field asymmetries were not modulated by attention for any subject group, suggesting they are a result of sensory, and not attentional, factors.     

Complementary and lateralized forms of processing in Bufo marinus for novel and familiar prey

Amphibian vision is one of the most comprehensively studied of all vertebrate sensory systems. However, the processes of object recognition and memory in anuran amphibians have resisted satisfactory explanation. Our research shows that insight to the issue of visual discrimination and recognition in toads may be gained by investigation of the specialized and complementary functions carried out by the left and right brain hemispheres. We report that specialized processes associated with the left eye (right hemisphere) of the Bufo marinus toad carry out decisions to view and strike at complex prey stimuli recognized as 'novel.' This was demonstrated in the toads' preferences when provided a choice between identical novel insect models presented simultaneously into the left and right lateral, monocular visual fields. In a second experiment, videotaped trials of toad groups competing in an open field for live crickets were analysed for lateralized prey-catching behaviour. Concomitant with a preference for directing agonistic strikes at conspecifics within the left visual hemifield, toads were found to possess a significant preference for directing predatory responses at the familiar prey viewed in the right visual hemifield. The preference for directing prey-catching responses at freely moving crickets in the right visual hemifield supports the earlier findings drawn from automated and familiar model insect prey. We present a hypothesis explaining differences in hemispheric processing in toads responding to 'novel' and 'familiar' prey types, utilizing a range of long-term memories found to be lateralized in other vertebrates.     

Cambridge University versus Hebrew University: The impact of letter transposition on reading English and Hebrew

Is reading similarly affected by letter transposition in all alphabetic orthographies? “The Cambridge University effect,” demonstrating that jumbled letters have little effect on reading, was examined using rapid serial visual presentation (RSVP) in English and in Hebrew. Hebrew-English bilinguals were presented sentences in both languages containing words with transposed letters. Sentences were presented rapidly on the screen word by word, and participants had to reproduce the sequence of words perceived. We found a marked difference in the effect of transpositions in the two languages. In English, transpositions had little effect on performance, whereas in Hebrew, performance deteriorated dramatically for words with transposed letters. The differential effects of transposition are accounted for by the difference in lexical organization in Hebrew and in English, suggesting that models of reading in alphabetic orthographies may be language specific.     

Doomed to Read in a Second Language: Implications for Learning

The aim of the study was to elucidate whether and how reliance on a second language impacts the learning of new information under very basic learning conditions. The paradigm used to investigate this issue required individuals to learn a series of associations between numerals and particular letter strings. Participants were two groups of university students: (1) individuals for whom spoken Hebrew was the mother tongue and written Hebrew a primary orthography (L1 group), and (2) individuals for whom Hebrew, both spoken and written, was a second language (L2 group). Data were collected under two conditions. In the language-dependent condition (LDC), the paradigm required learning associations between eight numerals and the letter strings of eight familiar Hebrew words. In the language-independent condition (LIC), it required learning associations between eight numerals and eight random letter strings in Hebrew. Results suggest that learners may be significantly disadvantaged when compelled to learn new information mediated in a second language. This disadvantage appears to manifest itself at a very basic learning level and in instances where new information is mediated by language that is fairly overlearned by the L2 learner.     

Strategies for visual word recognition and orthographical depth: a multilingual comparison

We investigated the psychological reality of the concept of orthographical depth and its influence on visual word recognition by examining naming performance in Hebrew, English, and Serbo-Croatian. We ran three sets of experiments in which we used native speakers and identical experimental methods in each language. Experiment 1 revealed that the lexical status of the stimulus (high-frequency words, low-frequency words, and nonwords) significantly affected naming in Hebrew (the deepest of the three orthographies). This effect was only moderate in English and nonsignificant in Serbo-Croatian (the shallowest of the three orthographies). Moreover, only in Hebrew did lexical status have similar effects on naming and lexical decision performance. Experiment 2 revealed that semantic priming effects in naming were larger in Hebrew than in English and completely absent in Serbo-Croatian. Experiment 3 revealed that a large proportion of nonlexical tokens (nonwords) in the stimulus list affects naming words in Hebrew and in English, but not in Serbo-Croatian. These results were interpreted as strong support for the orthographical depth hypothesis and suggest, in general, that in shallow orthographies phonology is generated directly from print, whereas in deep orthographies phonology is derived from the internal lexicon.     

Quantitative and Qualitative Hemispheric Asymmetry for Processing Japanese Kana

Native Japanese speakers identified three-letter kana stimuli presented to the left visual field and right hemisphere (LVF/RH), to the right visual field and left hemisphere (RVF/LH), or to both visual fields and hemispheres simultaneously (BILATERAL trials). There were fewer errors on RVF/LH and BILATERAL trials than on LVF/RH trials. Qualitative analysis of error patterns indicated that there were many fewer errors of first-letter identification than of last-letter identification, suggesting top-to-bottom scanning of the kana characters. In contrast to similar studies presenting nonword letter trigrams to native English speakers, qualitative error patterns were identical for the three visual field conditions. Taken together with the results of earlier studies, the results of the present experiment indicate that the ubiquitous RVF/LH advantage reflects a left-hemisphere superiority for phonetic processing that generalizes across specific languages. At the same time, qualitative aspects of hemispheric asymmetry differ from one language to the next and may depend on such things as the way in which individual characters map onto the pronunciation of words and nonwords.     

Hemispheric, attentional, and processing speed factors in the treatment of developmental dyslexia

Aim of the study is to analyze the contributions of hemispheric, attentional, and processing speed factors to the effects of neuropsychological treatment of developmental dyslexia. Four groups of dyslexic children (M-type dyslexia) were treated over a period of four months. A first group (n = 9) underwent Bakker's Hemisphere-Specific Stimulation, with presentation of words in the right and left visual field. A second group (n = 7) received the same stimuli randomly in either visual hemifield. A third group (n = 8) received the same words presented centrally at fixation point. A fourth group (n = 6) received central stimuli with fixed presentation time (1500 ms). The children were tested before and after treatment on reading and spelling measures. All groups improved significantly after treatment on all variables. However, the group that was treated with centrally presented stimuli improved more than the other groups in spelling measures. A possible explanation is that rapid, simultaneous presentation to both hemispheres enhances interhemispheric exchange, which could produce an advantage in tasks requiring a high degree of integration between left and right hemispheric functions, such as spelling. The absence of significant differences in reading improvement may point to the role of memory functions or strategic factors characterizing all the treatment programs, possibly overweighing the effect of the other factors.     

Functional specificity of the visual word form area: general activation for words and symbols but specific network activation for words

The functional specificity of the brain region known as the Visual Word Form Area (VWFA) was examined using fMRI. We explored whether this area serves a general role in processing symbolic stimuli, rather than being selective for the processing of words. Brain activity was measured during a visual 1-back task to English words, meaningful symbols (e.g., $, %), digits, words in an unfamiliar language (Hebrew), and geometric control stimuli. Mean activity in the functionally defined VWFA, as well as a pattern of whole-brain activity identified using a multivariate technique, did not differ for words and symbols, but was distinguished from that seen with other stimuli. However, functional connectivity analysis of this region identified a network of regions that was specific to words, including the left hippocampus, left lateral temporal, and left prefrontal cortex. Results support the hypothesis that activity in the VWFA plays a general role in processing abstract stimuli; however, the left VWFA is part of a unique network of brain regions active only during the word condition. These findings suggest that it is the neural "context" of the VWFA, i.e., the broader activity distributed in the brain that is correlated with VWFA, that is specific for visual word representation, not activity in this brain region per se.