听觉障碍人群检测任务基于位置的返回抑制

基于位置的返回抑制（IOR）是指对先前注意过的位置上靶子反应变慢的现象。探讨听觉障碍被试检测任务IOR的时程和量是否受听觉剥夺的影响。实验1中,听觉障碍被试和听力正常组被试具有相同的IOR时程和量;但在取消中央线索化的实验2中,当SOA为350ms时,听力正常被试没有出现IOR,听觉障碍被试出现了IOR,说明听觉障碍被试的注意脱离快于听力正常被试。听觉障碍被试对外周靶子的反应快于听力正常被试,表明听障人群外周注意资源增强。这些结果表明听觉障碍被试的空间注意更具有效性和策略性。     

The effects of spatial attention on motion processing in deaf signers,hearing signers,and hearing nonsigners

Visual abilities in deaf individuals may be altered as a result of auditory deprivation and/or because the deaf rely heavily on a sign language (American Sign Language, or ASL). In this study, we asked whether attentional abilities of deaf subjects are altered. Using a direction of motion discrimination task in the periphery, we investigated three aspects of spatial attention: orienting of attention, divided attention, and selective attention. To separate influences of auditory deprivation and sign language experience, we compared three subject groups: deaf and hearing native signers of ASL and hearing nonsigners. To investigate the ability to orient attention, we compared motion thresholds obtained with and without a valid spatial precue, with the notion that subjects orient to the stimulus prior to its appearance when a precue is presented. Results suggest a slight advantage for deaf subjects in the ability to orient spatial attention. To investigate divided attention, we compared motion thresholds obtained when a single motion target was presented to thresholds obtained when the motion target was presented among confusable distractors. The effect of adding distractors was found to be identical across subject groups, suggesting that attentional capacity is not altered in deaf subjects. Finally, to investigate selective attention, we compared performance for a single, cued motion target with that of a cued motion target presented among distractors. Here, deaf, but not hearing, subjects performed better when the motion target was presented among distractors than when it was presented alone, suggesting that deaf subjects are more affected by the presence of distractors. In sum, our results suggest that attentional orienting and selective attention are altered in the deaf and that these effects are most likely due to auditory deprivation as opposed to sign language experience.     

Cognitive adaptations arising from nonnative experience of sign language in hearing adults

Three experiments examined spatial transformation abilities in hearing people who acquired sign language in early adulthood. The performance of the nonnative hearing signers was compared with that of hearing people with no knowledge of sign language. The two groups were matched for age and gender. Using an adapted Corsi blocks paradigm, the experimental task simulated spatial relations in sign discourse but offered no opportunity for linguistic coding. Experiment 1 showed that the hearing signers performed significantly better than the nonsigners on a task that entailed 180 degree rotation, which is the canonical spatial relationship in sign language discourse. Experiment 2 found that the signers did not show the typical costs associated with processing rotated stimuli, and Experiment 3 ruled out the possibility that their advantage relied on seen hand movements. We conclude that sign language experience, even when acquired in adulthood by hearing people, can give rise to adaptations in cognitive processes associated with the manipulation of visuospatial information.     

中央线索化对听觉障碍人群辨别任务返回抑制的影响

选取一组先天聋被试和与之匹配的听力正常被试,采用线索提示范式考察中央线索化对听觉障碍被试在辨别任务中基于位置返回抑制的影响。实验结果发现,在有中央线索化的任务实验中,听力正常和听觉障碍被试都出现了返回抑制,但是听觉障碍被试消失得比听力正常被试早。无中央线索化的辨别任务实验中,听力正常被试组仅在SOA=650ms时,听觉障碍被试没有发现返回抑制现象。结果表明听觉障碍被试辨别任务的返回抑制更易受中央线索化条件的影响,听障被试的空间注意调节机制更具策略性和有效性。     

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.     

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.     

Temporal processing in deaf signers

The auditory and visual modalities differ in their capacities for temporal analysis, and speech relies on more rapid temporal contrasts than does sign language. We examined whether congenitally deaf signers show enhanced or diminished capacities for processing rapidly varying visual signals in light of the differences in sensory and language experience of deaf and hearing individuals. Four experiments compared rapid temporal analysis in deaf signers and hearing subjects at three different levels: sensation, perception, and memory. Experiment 1 measured critical flicker frequency thresholds and Experiment 2, two-point thresholds to a flashing light. Experiments 3-4 investigated perception and memory for the temporal order of rapidly varying nonlinguistic visual forms. In contrast to certain previous studies, specifically those investigating the effects of short-term sensory deprivation, no significant differences between deaf and hearing subjects were found at any level. Deaf signers do not show diminished capacities for rapid temporal analysis, in comparison to hearing individuals. The data also suggest that the deficits in rapid temporal analysis reported previously for children with developmental language delay cannot be attributed to lack of experience with speech processing and production.     

Parafoveal attention in congenitally deaf and hearing young adults

This reaction-time study compared the performance of 20 congenitally and profoundly deaf, and 20 hearing college students on a parafoveal stimulus detection task in which centrally presented prior cues varied in their informativeness about stimulus location. In one condition, subjects detected a parafoveally presented circle with no other information being present in the visual field. In another condition, spatially complex and task-irrelevant foveal information was present which the subjects were instructed to ignore. The results showed that although both deaf and hearing people utilized cues to direct attention to specific locations and had difficulty in ignoring foveal information, deaf people were more proficient in redirecting attention from one spatial location to another in the presence of irrelevant foveal information. These results suggest that differences exist in the development of attentional mechanisms in deaf and hearing people. Both groups showed an overall right visual-field advantage in stimulus detection which was attenuated when the irrelevant foveal information was present. These results suggest a left-hemisphere superiority for detection of parafoveally presented stimuli independent of cue informativeness for both groups.     

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.     

The associative learning of the deaf: The effects of word imagery and signability

In two experiments, deaf and hearing subjects learned paired associate lists in which rated visual imagery and signability (a measure of the ease with which a word can be represented as a gestural sign) were orthogonally varied. Visual presentation of three alternating study-recall trials resulted in significant positive effects of imagery for both deaf and hearing subjects, whereas signability facilitated recall only for deaf subjects. Examination of the relation between item attributes and reported learning strategy indicated that both deaf and hearing subjects used imaginal mediators more frequently for high-imagery than low-imagery pairs. A gestural sign strategy was reported almost exclusively by deaf subjects, particularly for high-signability pairs. These results suggest that an examination of the effects of sign language variables will contribute to an understanding of the qualitative differences in the associative learning of the deaf and hearing.     

Semantic and formational clustering in deaf and hearing subjects’ free recall of signs

To investigate whether formational properties of sign language are used spontaneously to organize long-term memory, 16 deaf college students were given a free recall task with items that could be categorized either by shared semantic category or by shared sign language hand shape. Both presentation and response modes (signed or written) were varied between subjects. Analyses revealed no effects of mode on trials to criterion or number of items recalled at 1 week. The clustering that occurred was exclusively semantic, with significantly higher clustering scores during acquisition trials in subjects required to sign their responses. In Experiment 2, formational clustering was encouraged by including formational similarity as the only experimenter-defined basis of categorization, by increasing formational similarity within categories, and by testing only subjects with high signing skills. Input and output modes were again varied between subjects. Subjects were deaf college students with deaf parents (n = 10) or hearing parents (n = 16), and hearing adults with deaf parents (n = 8). Again, spontaneous clustering by formational similarity was extremely low. In only one case— deaf subjects with hearing parents given signed input—did formational clustering increase significantly across the eight acquisition trials. After the categorical nature of the list was explained to subjects at a 1-week retention session, all groups clustered output by formational categories. Apparently, fluent signers do have knowledge of the formational structure of signs, but do not spontaneously use this knowledge as a basis of mnemonic organization in long-term memory.     

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。     

视觉语言对听觉障碍人群阅读能力的影响及作用机制

听觉障碍人群由于听觉部分或完全受损, 视觉语言——唇读和手语就成为其阅读能力发展的主要途径。唇读有助于听觉障碍人群形成语音表征, 与词汇知识相互影响, 且可以促进字词阅读及阅读理解的水平; 口语或书面语的加工可以激活相应的手语表征, 手语影响着听觉障碍人群各个层次的阅读能力。未来研究应该关注语音意识、词汇知识等技能在视觉语言影响听觉障碍人群阅读能力过程中的作用机制, 并以视觉语言为中心, 发展出适合汉语听觉障碍人群阅读能力习得的理论模型。     

Short-term memory coding by deaf signers: the primary language coding hypothesis reconsidered

Shand (Cognitive Psychology, 1982, 14, 1-12) hypothesized that strong reliance on a phonetic code by hearing individuals in short-term memory situations reflects their primary language experience. As support for this proposal, Shand reported an experiment in which deaf signers' recall of lists of printed English words was poorer when the American Sign Language translations of those words were structurally similar than when they were structurally unrelated. He interpreted this result as evidence that the deaf subjects were recoding the printed words into sign, reflecting their primary language experience. This primary language interpretation is challenged in the present article first by an experiment in which a group of hearing subjects showed a similar recall pattern on Shand's lists of words, and second by a review of the literature on short-term memory studies with deaf subjects. The literature survey reveals that whether or not deaf signers recode into sign depends on a variety of task and subject factors, and that, contrary to the primary language hypothesis, deaf signers may recode into a phonetic code in short-term recall.     

Language access and theory of mind reasoning: evidence from deaf children in bilingual and oralist environments

This investigation examined whether access to sign language as a medium for instruction influences theory of mind (ToM) reasoning in deaf children with similar home language environments. Experiment 1 involved 97 deaf Italian children ages 4-12 years: 56 were from deaf families and had LIS (Italian Sign Language) as their native language, and 41 had acquired LIS as late signers following contact with signers outside their hearing families. Children receiving bimodal/bilingual instruction in LIS together with Sign-Supported and spoken Italian significantly outperformed children in oralist schools in which communication was in Italian and often relied on lipreading. Experiment 2 involved 61 deaf children in Estonia and Sweden ages 6-16 years. On a wide variety of ToM tasks, bilingually instructed native signers in Estonian Sign Language and spoken Estonian succeeded at a level similar to age-matched hearing children. They outperformed bilingually instructed late signers and native signers attending oralist schools. Particularly for native signers, access to sign language in a bilingual environment may facilitate conversational exchanges that promote the expression of ToM by enabling children to monitor others' mental states effectively.     

听障人群的工作记忆机制

听障人群听觉通道受损,使用手语交流,提供了独特的切入点来探讨工作记忆的结构和功能。研究表明,听障人群具备在功能上与正常人的语音环路平行的手语复述机制。通过发声训练,听障人群也可采用语音编码,即语音环路可被通达。听障人群具有与正常人相当的语言工作记忆资源,但是这种资源在具体使用时受视觉通道处理特性的限制。越来越多的研究支持互补理论,认为手语的使用增强了听障人群非语言的视空间处理能力。     

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.     

Cerebral lateralization of deaf and hearing individuals for linguistic comparison judgments.

A group of congenitally deaf adults and a group of hearing adults, both fluent in sign language, were tested to determine cerebral lateralization. In the most revealing task, subjects were given a series of trials in which they were fist presented with a videotaped sign and then with a word exposed tachistoscopically to the right visual field or left visual field, and were required to judge whether the word corresponded to the sign or not. The results suggested that the comparison processes involved in the decision were performed more efficiently by the left hemisphere for hearing subjects and by the right hemisphere for deaf subjects. However, the deaf subjects performed as well as the hearing subjects in the left hemisphere, suggesting that the deaf are not impeded by their auditory-speech handicap from developing the left hemisphere for at least some types of linguistic processing.