The relationship between active hand and ear advantage in the native and foreign language

In an experimental design involving two auditorily presented competing commands (one to each ear), 144 right-handed subjects (72 male and 72 female) were asked to provide motor responses. Half of each group of subjects was responding with their right hand and the other half with the left. The test was applied in the subjects' native language (Croatian) and in English, which they had learned as a foreign language. Ear advantage was determined by calculating laterality indices from the order of responding to the commands. On average, right-ear advantage was found in all conditions. Analysis of results revealed the effect of the active hand in Croatian (with significant decrease in the right-ear advantage when using the left hand). The same trend failed to reach significance in English. In responses to English stimuli, there was a significant effect of gender (with men exhibiting a lower right-ear advantage than women). The same trend was not significant for Croatian stimuli. The consistently lower right-ear advantage found in male subjects is contrary to the traditional assumptions that men are more lateralized than women and warrants further investigation.     

Hemispheric specialization for speech perception in language deficient kindergarten children

Twenty right-handed kindergarten children with superior language skills and twenty with deficient language skills (as defined by performance on an elicited sentence repetition task) were tested (1) for hemispheric specialization for speech perception with a dichotic CV syllable task and (2) for relative manual proficiency by means of a battery of hand tasks. Reading readiness and aspects of other cognitive abilities were also assessed. The superior children evidenced a mean right-ear advantage of 14.5%, which is consistent with normal values reported by other investigators using the same stimuli. The language deficient group evidenced essentially no mean ear advantage (0.5) with half of these subjects exhibiting left-ear superiority. The findings suggest relationships among cerébral dominance, language proficiency (including reading readiness), and general cognitive functioning.     

Monaural ear differences for reaction times to speech with a many-to-one mapping paradigm

On each trial, subjects were presented monaurally with single synthetic speech syllables. In Experiment I, when /ba/ and /ta/ specified one response, and /da/ and /ka/ another response, a right-ear advantage in reaction time was observed; when/ba/ specified one response and all the other stimuli specified the other response, no ear effect was observed. Unsuccessful attempts to obtain a monaural right-ear advantage for consonants in some reaction-time tasks might be due to some kind of prephonetic matching between a representation of the stimulus attended to and the presented stimulus, the output of this match providing sufficient information for response. In Experiment II, /bi/ and /b ? / specified one response and /b?/ and/bu/ the other response, but no ear effect was observed. It was concluded that the right-ear advantage displayed for consonants in the corresponding condition of Experiment I was not the pure effect of a particular stimulus-response mapping, but depended also on the phonetic properties of consonants.     

A developmental perspective on reading dysfunction: Accuracy and rate criteria in the subtyping of dyslexic children

Children referred with specific reading dysfunction were subtyped as accuracy disabled or rate disabled according to criteria developed from an information processing model of reading skill. Multiple measures of oral and written language development were compared for two subtyped samples matched on age, sex, and IQ. The two samples were comparable in reading fluency, reading comprehension, word knowledge, and word retrieval functions. Accuracy disabled readers demonstrated inferior decoding and spelling skills. The accuracy disabled sample proved deficient in their understanding of oral language structure and in their ability to associate unfamiliar pseudowords and novel symbols in a task designed to simulate some of the learning involved in initial reading acquisition. It was suggested that these two samples of disabled readers may be best described with respect to their relative standing along a theoretical continuum of normal reading development.     

Development of cerebral dominance: dichotic listening asymmetry in normal and learning-disabled children

The magnitude of the dichotic right-ear advantage was assessed in 48 normal and 48 learning-disabled children representing an age range of approximately 5 years. All subjects were matched according to age, sex, and handedness. An analysis of results indicated a significant right-ear advantage in both the normal and learning-disabled children, but revealed no developmental trends for either group. Differences observed in the performance of the learning-disabled and normal children may reflect variability in selective attention rather than differences in the degree of cerebral lateralization. These results suggest a need for a reconceptualization of the causative factors affecting children with learning disorders and lend support to the notion that cerebral lateralization is not a developmental phenomenon.     

Atypical Hemispheric Specialization in Intellectual Deficiency

In order to determine the relation between hemispheric specialization for language and intellectual deficiency, two groups of lower-IQ subjects were compared to normal-IQ controls on word-dichotic listening tasks. Two conditions in which stimuli differed by their level of phonological complexity were used. Normal controls showed the expected right-ear advantage in both conditions. Moreover, they showed a greater magnitude of ear difference on the condition requiring higher-order phonological processing. In the mentally deficient group, almost half the subjects exhibited a left-ear advantage and they showed no difference between the two conditions in terms of the magnitude of ear difference. These results point to the presence of atypical hemispheric specialization in mentally deficient subjects.     

Cerebral lateralization, preferred cognitive mode, and reading ability in normal children

In a sample of 105 children (aged 6 to 12), a stylistic preference for a verbal approach to problem-solving correlated positively with reading ability (independently of age) and degree of right-ear advantage in the report of dichotic stop consonant-vowel syllables (but not with verbal intelligence or hand preference). Verbal strategic preference may: (1) foster the acquisition of reading skill, and (2) bias attention toward input from the right by generating differential left-hemisphere activation.     

The effect of head turn on auditory asymmetry

In two experiments, right-handed men and women were tested for ear differences in report of dichotically presented digits, with their heads straight ahead, turned 90 degrees to the left, and turned 90 degrees to the right. In Experiment 1, head turn was controlled simply by asking the subjects to fixate an appropriately located point; a right-ear advantage occurred under all conditions of head turn among the men, but only in the head-straight condition among the women. In Experiment 2, head turn was controlled by having the subjects direct a flashlight attached to their heads toward the fixation point. This eliminated the right-ear advantage under all head conditions for the men, but for the women the right-ear advantage was, if anything, more pronounced when their heads were turned than when straight. These results suggest that auditory asymmetry depends in part on whether space is perceived as divided into left and right sides, and in part of the balance between spatial and verbal requirements. Both factors, and the asymmetry itself, may interact with sex.     

Predicting brain organization from dichotic listening performance: Cortical and subcortical functional asymmetries contribute to perceptual asymmetries

The patterns of perceptual asymmetry elicited by dichotic speech and complex pitch stimuli were evaluated in a group of 28 normal, right-handed subjects. As in previous studies, between 70 and 75% of the subjects showed a right-ear advantage for speech and left-ear advantage for pitch. However, less than half of the subjects (46%) showed the expected pattern on both tests. It is argued that the assumption of symmetrical, contralateral auditory pathway superiority during dichotic stimulation is only appropriate in roughly half of the dextral population. In the remaining half, significant subcortical asymmetries and/or a lack of contralateral advantage appear to be present. The assessment of complementary cortical functions should provide a way to reduce the confounding of cortical and subcortical contributions to auditory perceptual asymmetries, and thus provide a more accurate behavioral index of brain organization.     

Hemispheric asymmetries in faculty and student musicians and nonmusicians during melody recognition tasks

Current research has suggested that musical stimuli are processed in the right hemisphere except in musicians, in whom there is an increased involvement of the left hemisphere. The present study hypothesized that the more musical training persons receive, the more they will rely on an analytic/left-hemispheric processing strategy. The subjects were 10 faculty and 10 student musicians, and 10 faculty and 10 student nonmusicians. All subjects listened to a series of melodies (some recurring and some not) and excerpts (some actual and some not) in one ear and, after a rest, to a different series of melodies in the other ear. The task was to identify recurring vs. nonrecurring melodies and actual vs. nonactual excerpts. For student musicians, there was a right-ear/left-hemispheric advantage for melody recognition, while for student nonmusicians, the situation was the reverse. Neither faculty group showed any ear preference. There were no significant differences for excerpt recognition. Two possible explanations of the faculty performance were discussed in terms of physical maturation and a functionally more integrated hemispheric approach to the task.     

Attentional biases and the right-ear effect in dichotic listening

Most dichotic listening experiments permit subjects to deploy attention in any way they choose. We argue that this adds uncontrolled variance to the observed right-ear advantage. In the first experiment, more robust laterality effects were obtained in an identification task with focused than with divided attention. Such differences were not found in the second experiment, when a detection procedure was used. Virtually all the laterality effect observed in the second study could be attributed to subjects who were biased attenders, in the sense that they exhibited more intrusions from the right ear to the left than vice versa. However, rather than indicating that laterality effects are simply attentional bias, this effect can be attributed to an asymmetry of perceptual discrimination.     

Influence of oral language and phonological awareness on children's bilingual reading

The purpose of this study was to assess the roles of oral language and phonological awareness on reading performance in grade 3 bilingual students. Several hierarchical models assessed the best predictors of third grade English and Spanish word attack, word identification and reading comprehension. Predictor variables were measures of phonological awareness, expressive vocabulary, receptive vocabulary, and syntax in both English and Spanish. The results showed that within language contributions of expressive vocabulary and syntax best predicted literacy when compared to phonological awareness measures.     

Ear asymmetry in recognition of unfamiliar voices

Female right-handed subjects were presented with a memory set consisting of five unfamiliar female voices. They were then tested with a recognition procedure in which samples of voice, memory set or novel, 2 or 4 sec in duration, were heard in one ear and a competing noise stimulus was heard in the other ear. There was an overall left-ear advantage in accuracy of recognition. This advantage held particularly for identifications of memory-set voices in the second half of trials. Internal analyses indicated that the left-ear advantage could not be attributed to greater retroactive interference during right-ear presentation. Congruent with studies of recognition of unfamiliar faces, the findings suggested right-hemisphere superiority in the recognition of unfamiliar voices.     

Left hemisphere selectivity for processing duration in normal subjects

The role of the left cerebral hemisphere for the discrimination of duration was examined in a group of normal subjects. Two tasks were presented: the first required a reaction-time response to the offset of monaural pulse sequences varying in interpulse duration, and the second required the discrimination of small differences in durations, within a delayed-comparison paradigm. In each task a right-ear advantage was obtained when the durations were 50 msec or less. No ear advantage was obtained for the larger durations of 67 to 120 msec. Since the perceptual distinctiveness of phonemes may be provided by durations approximating 50 msec, the nature of the relationship between the left hemisphere's role in temporal processing and speech processing may be elaborated.     

Sentential structure and the perceptual span in normal reading development

An eye-voice span paradigm was adopted to determine whether children use different aspects of sentence structure to facilitate decoding early in the course of reading development. Eightyfour Grade 1 and Grade 2 children, representing four levels of early reading competence, and 15 skilled adult subjects read from four textual conditions; materials varied in the extent to which the texts were semantically and/or syntactically constrained. The more precocious the young reader, the longer his reported span. The better readers' and the adults' advantage was greater the more linguistically constrained the reading material. These data support a continuous model fo reading development and are compatible with an interactive definition of early reading behavior.     

Monaural right-ear advantage in a target-identification task

Subjects were monaurally presented with consonant—vowel syllables to the right or left ear, with or without simultaneous noise to the other ear. The subject's task on each trial was to indicate whether or not the item presented was the target item /ba/. A right-ear advantage in reaction time was obtained: 14 msec for target items, 6 msec for nontarget items. The size of this effect was comparable in the presence vs. absence of competing noise. No consistent individual differences were found in the size of the right-ear advantage for this task, although such differences were obtained in a dichotic-perception pretest.It is argued that data of this type do not permit inferences about the use of particular ear/hemisphere neural pathways.     

汉语儿童英语口语词汇与阅读学习的关系

以120名四、五年级小学儿童为被试,探讨汉语儿童英语口语词汇与阅读学习的关系,并检验了英语语音意识在其中的中介作用。结果表明:(1)汉语儿童的英语口语词汇与阅读学习之间存在密切关系。控制一般认知能力和母语口语词汇的影响后,英语口语词汇对阅读学习仍具有显著的预测作用。其中,英语口语词汇产生对于英语单词认读的预测作用更重要,英语口语词汇理解则对英语单词理解的预测作用更重要。(2)英语口语词汇产生既可以直接作用于英语单词认读、理解和假词拼读,也部分通过英语语音意识的中介间接作用于英语阅读;英语口语词汇理解对英语单词理解也具有直接作用,并部分地通过英语语音意识的中介发挥间接作用     

Use of a statistical significance criterion in drawing inferences about hemispheric dominance for language function from dichotic listening data

A dichotic listening test (composed of VCV nonsense syllables) was administered to 31 right-handed subjects. A χ² statistical significance criterion was then applied to the resulting ear differences in subjects. Fifteen subjects had ear differences significant at the p < .10 levels. Of these, 14 had right-ear advantages, an incidence consistent with the incidence of left-hemisphere language dominance derived from neurological data. Incidence for the total group of 31 subjects, however, showed the overabundance of left-ear-superior protocols typical of studies that report ear-dominance scores with no statistical criterion.     

Reading ability and disfluency in stuttering and nonstuttering elementary school children

This study was aimed at comparing the reading abilities of elementary school children who stutter with their nonstuttering peers. Forty-four stuttering children from four grade levels were matched with a group of normally fluent controls on the basis of age, sex, and grade level. Reading ability was assessed by means of three Dutch standardized tests yielding a total of six scores. Disfluency scores during oral reading were also obtained for each subject. Results indicated significant differences between the two groups on reading rate and reading errors, but not on reading comprehension. Analysis of reading errors did not show qualitative differences among subjects: stuttering and nonstuttering children made the same kinds of reading errors. Similarly, the two groups did not differ with respect to performances at different grade levels. Among both groups of subjects performances became better with increasing grade on four of the six measures. Correlational analyses indicated that the measures of reading ability used in this study were significantly associated with frequency of disfluency for the nonstuttering children. In contrast, no significant relationship was found between reading ability and disfluency in the stuttering group, except for reading rate. Results are discussed with respect to the possible interaction between verbal performance and linguistic competence in reading ability measures, particularly for the stuttering child.     

Hemispheric asymmetry effects in children studied by dichotic listening and visual half-field testing

Dichotic listening (DL) and visual half-field (VHF) testing were used to study hemisphere asymmetry in a developmental perspective. Five-, 8-, and 11-year-old children were presented lists of fused words using a DL technique in Experiment 1, and 8- and 11-year-old children were presented pictures of common objects using a VHF technique in Experiment 2. In both experiments, measures of identification, free recall, and recognition of the words/pictures were employed. The results revealed effects of ear input (right-ear advantage) and half-field presentation (right visual half-field advantage) for all age groups, although the magnitude of this lateralization effect differed between the three memory measures. The results are discussed in relation to developmental aspects of language laterality, and in relation to the clinical utility of non-invasive lateralization techniques.