Neural correlates of human action observation in hearing and deaf subjects.
(73/256)
Accumulating evidence has suggested the existence of a human action recognition system involving inferior frontal, parietal, and superior temporal regions that may participate in both the perception and execution of actions. However, little is known about the specificity of this system in response to different forms of human action. Here we present data from PET neuroimaging studies from passive viewing of three distinct action types, intransitive self-oriented actions (e.g., stretching, rubbing one's eyes, etc.), transitive object-oriented actions (e.g., opening a door, lifting a cup to the lips to drink), and the abstract, symbolic actions-signs used in American Sign Language. Our results show that these different classes of human actions engage a frontal/parietal/STS human action recognition system in a highly similar fashion. However, the results indicate that this neural consistency across motion classes is true primarily for hearing subjects. Data from deaf signers shows a non-uniform response to different classes of human actions. As expected, deaf signers engaged left-hemisphere perisylvian language areas during the perception of signed language signs. Surprisingly, these subjects did not engage the expected frontal/parietal/STS circuitry during passive viewing of non-linguistic actions, but rather reliably activated middle-occipital temporal-ventral regions which are known to participate in the detection of human bodies, faces, and movements. Comparisons with data from hearing subjects establish statistically significant contributions of middle-occipital temporal-ventral during the processing of non-linguistic actions in deaf signers. These results suggest that during human motion processing, deaf individuals may engage specialized neural systems that allow for rapid, online differentiation of meaningful linguistic actions from non-linguistic human movements. (+info)
Deafness and visual enumeration: not all aspects of attention are modified by deafness.
(74/256)
Previous studies have demonstrated that early deafness causes enhancements in peripheral visual attention. Here, we ask if this cross-modal plasticity of visual attention is accompanied by an increase in the number of objects that can be grasped at once. In a first experiment using an enumeration task, Deaf adult native signers and hearing non-signers performed comparably, suggesting that deafness does not enhance the number of objects one can attend to simultaneously. In a second experiment using the Multiple Object Tracking task, Deaf adult native signers and hearing non-signers also performed comparably when required to monitor several, distinct, moving targets among moving distractors. The results of these experiments suggest that deafness does not significantly alter the ability to allocate attention to several objects at once. Thus, early deafness does not enhance all facets of visual attention, but rather its effects are quite specific. (+info)
Career and workplace experiences of Australian university graduates who are deaf or hard of hearing.
(75/256)
This article reports on the experiences of a group of deaf and hard-of-hearing alumni of Griffith University in south-east Queensland, Australia. Participants completed a survey answering questions about their communication patterns and preferences, working lives, career barriers or difficulties anticipated and encountered, and workplace accommodations used or sought. Results revealed a range of career barriers and workplace difficulties encountered by these participants, as well as solutions found and strategies used by them. Differences in employment sector, job-search activities, difficult workplace situations, and use of accommodations were noted between 2 groups: those who communicated primarily in Australian Sign Language and considered themselves to have a Deaf or bicultural identity and those who communicated primarily in spoken English and considered themselves to have a hearing identity. Implications for university services supporting deaf and hard-of-hearing students are outlined, and suggestions for further research are made. (+info)
Enhancing early communication through infant sign training.
(76/256)
Existing research suggests that there may be benefits to teaching signing to hearing infants who have not yet developed vocal communication. In the current study, each of 4 infants ranging in age from 6 to 10 months was taught a simple sign using delayed prompting and reinforcement. In addition, Experiment 1 showed that 2 children independently signed in a variety of novel stimulus conditions (e.g., in a classroom, with father) after participating in sign training under controlled experimental conditions. In Experiment 2, crying and whining were replaced with signing when sign training was implemented in combination with extinction. (+info)
Factors predicting recall of mathematics terms by deaf students: implications for teaching.
(77/256)
In this study of deaf high school students, imagery and familiarity were found to be the best predictors of geometry word recall, whereas neither concreteness nor signability of the terms was a significant predictor variable. Recall of high imagery terms was significantly better than for low imagery terms, and the same result was found for high- over low-familiarity and signability. Concrete terms were recalled significantly better than abstract terms. Geometry terms that could be represented with single signs were recalled significantly better than those that are usually fingerspelled or those represented by compound signs. Teachers with degrees and/or certification in mathematics had significantly higher self-ratings for the strongest predictor variables, imagery (visualization), and familiarity, as compared with those without such formal training. Based on these findings, implications for mathematics instruction, teacher education, and research are provided. (+info)
What really matters in the early literacy development of deaf children.
(78/256)
With much earlier identification of hearing loss come expectations that increasing numbers of deaf children will develop literacy abilities comparable to their hearing age peers. To date, despite claims in the literature for parallel development between hearing and deaf learners with respect to early literacy learning, it remains the case that many deaf children do not go on to develop age-appropriate reading and writing abilities. Using written language examples from both deaf and hearing children and drawing on the developmental models of E. Ferreiro (1990) and D. Olson (1994), the discussion focuses on the ways in which deaf children draw apart from hearing children in the third stage of early literacy development, in the critical move from emergent to conventional literacy. Reasons for, and the significance of, this deviation are explored, with an eye to proposing implications for pedagogy and research, as we reconsider what really matters in the early literacy development of deaf children. (+info)
Adapting tests of sign language assessment for other sign languages--a review of linguistic, cultural, and psychometric problems.
(79/256)
Given the current lack of appropriate assessment tools for measuring deaf children's sign language skills, many test developers have used existing tests of other sign languages as templates to measure the sign language used by deaf people in their country. This article discusses factors that may influence the adaptation of assessment tests from one natural sign language to another. Two tests which have been adapted for several other sign languages are focused upon: the Test for American Sign Language and the British Sign Language Receptive Skills Test. A brief description is given of each test as well as insights from ongoing adaptations of these tests for other sign languages. The problems reported in these adaptations were found to be grounded in linguistic and cultural differences, which need to be considered for future test adaptations. Other reported shortcomings of test adaptation are related to the question of how well psychometric measures transfer from one instrument to another. (+info)
Naming and categorization in young children: v. manual sign training.
(80/256)
Following pre-training with everyday objects, 8 children aged from 2 to 4 years learned to produce one manual sign (fists placed one above the other, in front of body) to one stimulus and an alternative manual sign (shoulders touched with ipsilateral hands) to the other stimulus, with each of three pairs of different arbitrary wooden shapes (Set 1). The six stimuli then were presented in category match-to-sample tests, which all subjects passed. Three of the children were next trained to produce the manual signs (denoted as fist/shoulder) for an additional six arbitrary stimuli, Set 2. All 3 children went on to pass category match-to-sample tests for Set 2, and for Set 1 and Set 2 combined. In the final experimental phase, 2 of the children were trained, for one of the six stimulus pairs, to produce the vocal tact "zag" to one stimulus and "vek" to the other. Both children showed category transfer of these vocalizations in test trials with each of the remaining five stimulus pairs, and all the stimuli combined in a 12-stimulus array. In line with Horne and Lowe's (1996) naming account, manual sign naming was found to be as effective as vocal naming in establishing arbitrary stimulus categorization, measured in terms of category sorting and transfer of function. The findings also have implications for the training of verbal repertoires in people with learning disabilities. (+info)