聋人手语视觉表象生成能力的实验研究

通过视觉表象判断实验,对聋手语使用者和听力正常人两类被试视觉表象生成的能力进行了比较。实验发现：与听力正常的人相比,聋手语使用者学习和记忆大写字母的时间短于听力正常的被试,并且两组被试记忆复杂字母的时间都较长;聋被试和听力正常被试采用了相同的字母表征方式。但是,习得手语的年龄对聋手语者生成表象的能力没有明显的影响。     

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 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.     

Cerebral asymmetry in the perception of American sign language.

American Sign Language (ASL) offers a valuable opportunity for the study of cerebral asymmetries, since it incorporates both language structure and complex spatial relations: processing the former has generally been considered a left-hemisphere function, the latter, a right-hemisphere one. To study such asymmetries, congenitally deaf, native ASL users and normally-hearing English speakers unfamiliar with ASL were asked to identify four kinds of stimuli: signs from ASL, handshapes never used in ASL, Arabic digits, and random geometric forms. Stimuli were presented tachistoscopically to a visual hemifield and subjects manually responded as rapidly as possible to specified targets. Both deaf and hearing subjects showed left-visual-field (hence, presumably right-hemisphere) advantages to the signs and to the non-ASL hands. The hearing subjects, further, showed a left-hemisphere advantage to the Arabic numbers, while the deaf subjects showed no reliable visual-field differences to this material. We infer that the spatial processing required of the signs predominated over their language processing in determining the cerebral asymmetry of the deaf for these stimuli.     

Determinants of spelling ability in deaf and hearing adults: Access to linguistic structure

The extent to which ability to access linguistic regularities of the orthography is dependent on spoken language was investigated in a two-part spelling test administered to both hearing and profoundly deaf college students. The spelling test examined ability to spell words varying in the degree to which their correct orthographic representation could be derived from the linguistic structure of English. Both groups of subjects were found to be sensitive to the underlying regularities of the orthography as indicated by greater accuracy on linguistically-derivable words than on irregular words. Comparison of accuracy on a production task and on a multiple-choice recognition task showed that the performance of both deaf and hearing subjects benefited from the recognition format, but especially so in the spelling of irregular words. Differences in the underlying spelling process for deaf and hearing spellers were revealed in an analysis of their misspellings: Deaf subjects produced fewer phonetically accurate misspellings than did the hearing subjects. Nonetheless, the deaf spellers tended to observe the formational constraints of English phonology and morphology in their misspellings. Together, these results suggest that deaf subjects are able to develop an appreciation for the structural properties of the orthography, but that their spelling may be guided by an accurate representation of the phonetic structure of words to a lesser degree than it is for hearing spellers.     

Deaf and hearing adults' recollections of childhood and beyond

Whereas the average age of earliest reportable personal memory among adults is 3 to 3 1/2, there is considerable individual and group variability in the age of earliest autobiographical memory. Some of the variability is thought to be attributable to differential narrative socialisation. In the present research we tested the hypothesis that by virtue of later exposure to language, individuals born deaf to hearing parents will have earliest memories from later in life, relative to hearing individuals. The average age of single earliest identifiable memory for adults who are deaf and adults who are hearing did not differ. Nevertheless, adults who are deaf were found to have less dense representations of early autobiographical memories and to include in their narrative reports fewer categories of information, including visual-spatial information, relative to hearing adults. Participants' ratings of their memories on a number of dimensions were found to have low utility in predicting the content of autobiographical reports from both early and later in life (i.e., after age 10 years).     

Deaf and hearing adults' recollections of childhood and beyond

Whereas the average age of earliest reportable personal memory among adults is 3 to 3½, there is considerable individual and group variability in the age of earliest autobiographical memory. Some of the variability is thought to be attributable to differential narrative socialisation. In the present research we tested the hypothesis that by virtue of later exposure to language, individuals born deaf to hearing parents will have earliest memories from later in life, relative to hearing individuals. The average age of single earliest identifiable memory for adults who are deaf and adults who are hearing did not differ. Nevertheless, adults who are deaf were found to have less dense representations of early autobiographical memories and to include in their narrative reports fewer categories of information, including visual-spatial information, relative to hearing adults. Participants' ratings of their memories on a number of dimensions were found to have low utility in predicting the content of autobiographical reports from both early and later in life (i.e., after age 10 years).     

聋童执行功能发展：聋童与正常儿童的比较

利用标准Dimensional Change Card Sort任务(DCCS),对76名智力正常的3~8岁聋童和78名3~5.5岁的正常儿童进行了对比测试,旨在考察聋童执行功能发展的年龄特征与发展水平。结果发现,3岁组的聋童和正常儿童在DCCS任务上的表现没有显著性差异,但正常儿童在4~4.5岁时进入一个迅速发展期,而聋童要在6岁时才有快速的发展,到7岁后才相当于正常儿童5岁的发展水平,大约滞后2年。研究认为,造成聋童执行功能发展滞后的原因主要有：（1）语言符号系统和聋童特有的符号系统之间可能存在的差异;（2）聋童可能存在计划和灵活性的缺陷;（3）聋童可能存在命名和标识策略上的困难和注意机制的缺陷。结合关于聋童心理理论发展滞后于正常儿童7年以上的报道,心理理论发展和执行功能发展在聋童身上表现出较大的不一致性。     

Signing environment in an institution: Teaching sign vocabulary to residents with mental retardation for communication with deaf peers

Two experiments were conducted so that deaf adults with mental retardation could develop their communication skills in an institution. Deaf and hearing residents were taught sign vocabulary using the following four procedures: sign language lessons in a large group, posters, review lessons, and distribution of a sign language book. Experiment 1 was a pilot study to assess the effect of a sign language lesson, and Experiment 2 was a systematic study to evaluate the 4 procedures using a multiple baseline design. Sign language use in natural settings was monitored for 10 months, starting with the first sign language lesson. Results showed that a sign language lesson was an effective way for most hearing residents to acquire expressive signs. Three out of 4 deaf residents learned expressive signs gradually during experiments. In natural settings, hearing residents were seen to use signs spontaneously with deaf residents in many different social contexts. Additional comprehensive assessment was conducted to confirm whether or not residents could understand one another's expressive signs. Seven out of 10 residents showed correct responses more than 80% of the time.     

Cerebral lateralization of language in deaf and hearing people

In Experiment 1 neither hearing nor prelingually deaf signing adolescents showed marked lateralization for lexical decision but, unlike the hearing, the deaf were not impaired by the introduction of pseudohomophones. In Experiment 2 semantic categorization produced a left hemisphere advantage in the hearing for words but not pictures whereas in the deaf words and signs but not pictures showed a right hemisphere advantage. In Experiment 3 the lexical decision and semantic categorization findings were confirmed and both groups showed a right hemisphere advantage for a face/nonface decision task. The possible effect of initial language acquisition on the development of hemispheric lateralization for language is discussed.     

Deafness and perception of nonverbal expression of emotion

Compensatory sensitivity is said to follow loss of a primary communicative channel. In previous studies in which how accurately deaf and hearing people perceive emotional expression was compared, caricatures or nonverbal behavior of hearing people were stimuli. These studies did not specifically address the possibility that deaf people show nonverbal behavior which might be related to their sign language. To assess this possibility two methodological innovations were made. Stimuli were displayed of nonverbal messages with various emotional contents presented by deaf people in sign language. Also, no verbal labels identified emotional content of the messages. Sixty hearing and 45 deaf male college students watched films of emotional expressions in sign language. The participants tried to identify the emotional content of each film by matching content to one of six photographs of facial expressions. Responses were analyzed for accuracy in perceiving the emotional content. Hearing participants were more accurate in perceiving the display of Happiness. Display of Disgust was perceived better by the deaf participants. No support was found for compensatory sensitivity among the deaf participants.     

Lateralization effects during semantic and rhyme judgement tasks in deaf and hearing subjects

A visual hemifield experiment investigated hemispheric specialization among hearing children and adults and prelingually, profoundly deaf youngsters who were exposed intensively to Cued Speech (CS). Of interest was whether deaf CS users, who undergo a development of phonology and grammar of the spoken language similar to that of hearing youngsters, would display similar laterality patterns in the processing of written language. Semantic, rhyme, and visual judgement tasks were used. In the visual task no VF advantage was observed. A RVF (left hemisphere) advantage was obtained for both the deaf and the hearing subjects for the semantic task, supporting Neville's claim that the acquisition of competence in the grammar of language is critical in establishing the specialization of the left hemisphere for language. For the rhyme task, however, a RVF advantage was obtained for the hearing subjects, but not for the deaf ones, suggesting that different neural resources are recruited by deaf and hearing subjects. Hearing the sounds of language may be necessary to develop left lateralised processing of rhymes.     

Linguistic coding by deaf children in relation to beginning reading success

The coding of printed letters in a task of consonant recall was examined in relation to the level of success of prelingually and profoundly deaf children (median age 8.75 years) in beginning reading. As determined by recall errors, the deaf children who were classified as good readers appeared to use both speech and fingerspelling (manual) codes in short-term retention of printed letters. In contrast, deaf children classified as poor readers did not show influence of either of these linguistically based codes in recall. Thus, the success of deaf children in beginning reading, like that of hearing children, appears to be related to the ability to establish and make use of linguistically recoded representations of the language. Neither group showed evidence of dependence on visual cues for recall.     

Handedness patterns in deaf persons

The handedness patterns of 226 deaf high-school and college students were compared to those of 210 college students with normal hearing. Both groups evidenced many more right-handed than left-handed members, as determined by responses to a hand preference questionnaire and performance on an activity test battery. There was, however, a significantly higher incidence of left-handedness among the deaf subjects than among the hearing. Moreover, the left-handed deaf students were found to be less likely to have deaf relatives, and to have been introduced to sign language later in their development than the deaf student population as a whole. These findings were interpreted as showing that age of acquisition of language was related to the development of handedness patterns, whereas auditory processing experience probably was not.     

汉语聋生与健听生口语叙事和书面叙事发展特征的比较研究

以小学3-5年级的汉语聋生为被试,考察其口语叙事与书面叙事的发展特征,并与健听生比较,揭示聋生叙事发展特征的特异性。结果发现：（1）无论口语叙事还是书面叙事,聋生和健听生在宏观结构上表现相当,但聋生在微观结构上表现较差。（2）在宏观结构和平均句长上,无论健听生还是聋生,书面叙事得分均显著好于口语叙事;（3）在词汇密度上,健听生在口语叙事和书面叙事上的表现相当,但聋生的词汇密度在口语叙事下表现较差。（4）在词汇丰富性和词汇密度指标上,聋生和健听生存在年级间发展特征的差异。研究结果对聋生的叙事教学有重要启示。     

Understanding of friendship and social rules in deaf and hearing adolescents

Children who are profoundly and prelingually deaf and live in residential schools lack ready access to the general language environment and some opportunities of societial interactions. How does this affect their understanding of the social world To probe this question 60 deaf and 60 hearing children, ages 9, 13, and 17, were interviewed regarding friendship and social rules (a game rule, a school rule, driving law). Summary scores for each of the 4 areas yielded age and hearing differences. The major findings were: (1) the developmental pattern of responses was similar for deaf and hearing children; (2) deaf children lagged behind hearing children in their social understanding, most in game rules, least in friendship. The results were related to a constructivist developmental perspective and to previous research on socialization of deaf children.     

No impairment in sign language after right-hemisphere stroke

A 52-year-old right-handed woman who became deaf before the development of speech, suffered an occlusion of the right middle cerebral and a marked stenosis of the right anterior cerebral arteries. She showed no disturbance in the manual sign language or in finger-spelling, in contrast to previous reports of cases with left-sided damage.     

Mechanisms of visuospatial orienting in deafness

The aim of this work was to explore the nature of elementary operations (engage, move, disengage, and filtering) of spatial attention in deaf experts in sign language. Good communication skills require deaf people to rapidly change attention to at least two separate spatial locations, the facial expression and the hand signs of the speaker. Overtraining imposed by sign language demands might have modified certain characteristics of the spatial attention operations. To test that, a spatial orienting task was used in two experiments. Experiment 1 showed that deaf subjects reoriented their attention to the target location faster than hearing subjects in invalid trials. Experiment 2 indicated that inhibition of return decays faster in deaf than in hearing people. These results suggest that deaf subjects can disengage their attention faster than hearing subjects, fostering search of relevant information in more spatial locations.