Biomedical subjects

B Lyxell

Publications and source records attributed to B Lyxell.

At least 19 recordsLinked to original sources

PubMed2001

Speech-reading of synthetic and natural faces: effects of contextual cueing and mode of presentation.

A natural and a synthetic face were compared with regard to speech-reading performance, with a visual and an audio-visual condition, and with three levels of contextual cueing in an experiment with 90 normal-hearing subjects. Auditory presentation (speech in noise) served as a control condition. The results showed main effects for type of face, presentation mode and contextual cueing, and also an interaction between presentation mode and type of face, such that performance was superior for the natural compared with the synthetic face, and especially in the audio-visual mode. Audio-visual speech-reading was more accurate than visual and auditory presentation and contextual cueing improved performance overall. It is suggested that a synthetic face can be a valuable and useful support if proper cueing and an auditory signal are provided, but it is outperformed by a natural face with regard to complementarity to an underspecified auditory speech signal.

Adult↗

PubMed2001

Cognitive correlates of visual speech understanding in hearing-impaired individuals.

This study examined the extent to which different measures of speechreading performance correlated with particular cognitive abilities in a population of hearing-impaired people. Although the three speechreading tasks (isolated word identification, sentence comprehension, and text tracking) were highly intercorrelated, they tapped different cognitive skills. In this population, younger participants were better speechreaders, and, when age was taken into account, speech tracking correlated primarily with (written) lexical decision speed. In contrast, speechreading for sentence comprehension correlated most strongly with performance on a phonological processing task (written pseudohomophone detection) but also on a span measure that may have utilized visual, nonverbal memory for letters. We discuss the implications of this pattern.

Journal Article↗

PubMed2001

Effects of tactile training on visual speechreading: performance changes related to individual differences in cognitive skills.

We report on a follow-up study of the Rönnberg, Andersson, Lyxell, & Spens (1998) speech tracking training study. The purpose was to examine, initially and after training, the effects of different tactile aids on tasks of visual speechreading. We also examined cognitive prerequisites for initial baseline speechreading and posttraining speechreading performance. Compared with speechreading alone, tactile aids impaired sentence-based speechreading at first, although performance improved with training. No effects of vibrotactile aids or training were obtained for visual word-decoding. Initial baseline speechreading performance and posttraining performance correlated with cognitive skills, but the size of the correlations changed. The size of the correlations also varied with the different tactually mediated speechreading conditions.

Journal Article↗

PubMed2001

Cognitive effects in dichotic speech testing in elderly persons.

OBJECTIVE: To study the effect of chronologic age on central auditory functions using dichotic speech tests and to study whether and how the age effect in dichotic listening is related to cognitive ability. DESIGN: Dichotic speech tests and cognitive tests were performed on 30 bilaterally hearing-impaired subjects, with a pure-tone average better than 50 dB HL. They were between 42 and 84 yr of age and were divided into an older and a younger group comprising 15 subjects each. The dichotic test material were digits, low-redundancy sentences and consonant-vowel syllables. The subjects reported stimuli heard in both ears (free report) or in one ear (directed report to left or right ear). The cognitive test battery comprised tests focusing on short-term memory, verbal information-processing speed and phonologic processing. RESULTS: A decreased overall performance in all dichotic speech tests was observed in the older group. In the syllable test the older subjects showed poorer results when focusing on the stimuli heard in the left ear, as compared with when focusing on stimuli heard in the right ear, whereas the younger group showed almost equal results for left- and right ear-focusing conditions. An age effect was also seen in reaction times recorded in the cognitive tests and in the scores of the reading span test. These cognitive parameters correlate with the results of the dichotic test when focusing to the left, but not when focusing to the right in the directed report condition. In the free report condition the overall performance showed a high correlation with cognitive test parameters. CONCLUSIONS: Effects of chronologic age in dichotic speech tests in the elderly have been verified. The degree of effect is dependent on test material, way of reporting and focusing condition. The different listening tasks in dichotic tests put different demands on cognitive ability shown by a varying degree of correlations between cognitive function and dichotic test parameters. Also, the results indicate a strong connection between age-related cognitive decline in the elderly and problems to perceive stimuli presented to the left ear.

Adult↗

PubMed2000

Visual speechreading and cognitive performance in hearing-impaired and normal hearing children (11-14 years).

BACKGROUND: Previous research has demonstrated that parts of the variation in adults' speechreading performance can be explained by the characteristics of some cognitive components. However, these results apply to populations of adults and less is known as to how results for populations of adults can be generalised to populations of children. AIM: This study aimed to examine cognitive and visual skills in a group of bilaterally, moderately hearing-impaired children and a group of normal hearing children and how these two skills relate to variability in speechreading of context-embedded sentences. SAMPLE: Twenty-three hearing-impaired children (mean age: 12.7) and 23 normal hearing children (mean age: 12.5) matched for age, sex, verbal ability and school grades. The mean 'better ear' auditory threshold for the hearing-impaired was 44.8 dB. RESULTS: The hearing-impaired children outperformed the normal hearing children on a sentence-based speechreading task and on a visual-visual word-decoding task, but not on a word-discrimination task. Differing from the case of adults, most cognitive tasks proved to be significantly related to sentence-based speechreading performance, where working memory capacity and visual word-decoding skill proved to be the strongest predictors. CONCLUSIONS: Speechreading is more cognitively demanding for children than for adults as they have not developed their cognitive abilities to the same extent as adults. Thus, they have to devote more processing capacity, relative to their total cognitive processing capacity, to the speechreading task. Skilled visual word-decoding and cognitive skills, together with everyday exposure to situations where speechreading is required, are some of the candidates for explanation of the hearing-impaired children's superior speechreading skill.

Adolescent↗

PubMed1999

A speechreading expert: the case of MM.

The present case study of MM, who acquired both sign language and spoken language in her early preschool years-and then reached the normal milestones of development in each language--revealed that her speechreading expertise is associated with cognitive functions such as high working memory capacity and phonological skills. Her cognitive profile is in accord with previous case studies of extremely good speechreading skill. MM's enhanced right prefrontal/frontal cerebral blood flow activation during speechreading seems to be indicative of efficient visual scanning, but it is also possibly due to her strategy for phonological decoding of visual speech.

Adult↗

PubMed1999

Speech-reading: cognitive predictors and displayed emotion.

The present study had three aims: to examine the effects of displayed emotion and message length on speech-reading performance, and how measures of working memory (cf. Baddeley 1986) and verbal information processing speed relate to speech-reading performance. Words and sentences with either positive or negative meaning were used in a word decoding and a sentence-based speech-reading test. A total of 48 normal-hearing subjects participated. The results revealed general effects of displayed emotion, message meaning and message length and no effect of displayed emotion vs message length. Furthermore, working memory but not verbal information processing speed nor accuracy predicted speech-reading performance. The results were discussed with respect to a model of face-processing (Bruce & Young 1986) and with respect to clinical implications.

Adult↗

PubMed1999

Phonological deterioration in adults with an acquired severe hearing impairment: a deterioration in long-term memory or working memory?

The purpose of this study was to examine the phonological processing skills in individuals with an acquired severe hearing impairment. The subjects were tested on cognitive tasks that vary in their demands on phonological processing. The severely hearing impaired individuals performed at a significantly lower level on the word-word rhyme judgements task, but performed on a par with the control group on the picture-word rhyme judgements task and the lexical decision-making task. The results indicate that the phonological processing skills in individuals who have acquired a severe hearing loss in adult life deteriorate. The results are discussed with respect to theoretical and clinical implications.

Adult↗

PubMed1999

Adolescent identity--a qualitative approach: self-concept, existential questions and adult contacts.

In-depth interviews were performed with 12 adolescents (Swedish students, 16-19 years). Three questions were probed; what do adolescents say on the subjects of (a) themselves, (b) their existential questions, and (c) their adult contacts. The first two questions were aimed at elucidating the process of identity development, the last one at factors that may be influencing this process. The results showed that (a) balancing and controlling one's own needs and wishes in relation to others' was a central issue, (b) existential questions mainly concerned the personal future, (c) adult contacts outside the family were scarce and (d) all respondents expressed a need for adult contacts as sources of knowledge and experience. The conclusions are that identity formation during late adolescence consists of integrative issues where adults play a specific and important role.

Adolescent↗

PubMed1998

Phonological deterioration in adults with an acquired severe hearing impairment.

The study examined the phonological processing skills in a group of adults who have acquired a severe hearing loss in adult life. These severely hearing-impaired individuals performed at a significantly lower level on the rhyme judgement tasks and the letter span task, but on a par with the control group on other cognitive tests. A correlation analysis showed that duration of hearing loss is negatively related to performance on the rhyme judgement tasks and letter span task. The results indicate that the phonological processing skills in individuals who have acquired a severe hearing loss in adult life deteriorates. The results are discussed with respect to theoretical and clinical implications.

Adult↗

PubMed1998

Cognition as a bridge between signal and dialogue: communication in the hearing impaired and deaf.

This paper is an overview of the research we have carried out at Linköping University on cognitive aspects of visual language processing and related communicative forms. In the first section, a cognitive individual difference perspective on speechreading is introduced. In the second, compensatory perceptual mechanisms are discussed on the basis of behavioral and neurophysiological data. The third section addresses further the issue of perceptual versus cognitive compensation, and the fourth and fifth sections apply a set of cognitive tests based on the concept of working memory for poorly specified language input to data on the successes and failures with cochlear implants, tactile aids and hearing aids.

Cognition↗

PubMed1998

Vibrotactile speech tracking support: cognitive prerequisites.

Fourteen postlingually hearing-impaired participants took part in an intervention study on the potential benefit of three types of tactile aids (i.e., the Tactilator, Minivib 3, and the Tactaid 7). Although training by means of computerized tracking had substantial effects on speech tracking rate, no differential effects of type of aid emerged. However, a cognitive test battery revealed that training efficacy is directly dependent on the cognitive prerequisites of the individual speechreader. The speed with which an individual can make phonological judgments (i.e., rhyme judgments) and visual word decoding from lipreading proved to be critical cognitive skills. We conclude that these skills must be further assessed and taken into account when rehabilitation/training programs are launched.

Journal Article↗

PubMed1998

Phonological representation and speech understanding with cochlear implants in deafened adults.

In the present study cognitive performance in 15 deafened adult cochlear implant candidates was examined and related to level of speech understanding after 12 months of experience with the implant. The implant group performed on par with normal hearing controls in all cognitive tasks used in the study with one exception: Performance was significantly lower in cognitive tasks where use of a phonological representation of sound is a key task-demand. Observations of the implanted individuals' level of speech understanding indicate that only those individuals who, pre-operatively, were in possession of phonological representations comparable to that of normal hearing could follow and understand a speaker that was out of sight. The results are discussed with respect to (a) deterioration in the phonological representation of sounds as a function of absence of external auditory stimulation, and (b) the role of cognitive factors in predicting success in speech understanding with the implant.

Adult↗

PubMed1996

Self-concept and questions of life: identity development during late adolescence

The purpose of the present study was to explore identity development in late adolescent (18-20) years. Three areas were examined: (a) self-concept, (b) existential questions; content and communication patterns, and (c), connections between (a) and (b). The population consisted of 44 Swedish college students. Three methods were used: a questionnaire, the writing of a short essay and a self-evaluation test, Structural Analysis of Social Behavior (SASB). The results demonstrated a positive and stable self-concept for the majority of the group, and that questions of life mainly concerned questions of future. The quality of the self-concept (positive vs. negative) was significantly related to how subjects experienced adults' interest in their existential questions. Several issues are discussed: the importance of the social environment for identity development not only during early childhood but also during adolescence, the use of the SASB method in this age group and the need for placing processes of integration into focus in research concerning late adolescence.

Journal Article↗

PubMed1996

Verbal information-processing capabilities and cochlear implants: implications for preoperative predictors of speech understanding.

In this study, we examined preoperative verbal cognitive capacity in 11 deafened adults who were cochlear implant candidates and reexamined level of speech understanding after 6-8 months' experience with the implant. Verbal cognitive performance in the implant group was compared in a group of normal hearing subjects and in nonimplanted group of deafened adults. The three groups performed on par with each other with an exception: The individuals in the cochlear implant group and the nonimplanted group of deafened adults performed significatly worse than those of normal hearing in tasks in which use of internal speech is a key feature (i.e., rhyme judgement and lexical decision tasks). Postoperative observations of the implanted individuals' level of speech understanding suggest that it is possible to predict the level of speech understanding by means of a properative cognitive assessment. The characteristics of three verbal cognitive abilities prove to be critical indicators of 6 - 8 months' postoperative outcome: internal speech functioning, speed of verval information processing, and working memory capacity - the first factor proved the most decisive. We discuss the results with respect to direct versus indirect predictors of outcomes from cochlear implant operations and the effect of auditory deprivation on deafened adults' capability to process auditory information.

Journal Article↗

PubMed1996

Facial expressions and speechreading performance.

In the present study, the role of facial expressions in visual speechreading (lipreading) was examined. Speechreading was assessed by three different tests: sentence-based speechreading, word-decoding, and word discrimination. Twenty-seven individuals participated as subjects in the study. The results revealed that no general improvement as a function of expression was obtained across all tests. Nevertheless, skilled speechreaders could significantly improve their performance as a function of emotional expression in the word-decoding and word-discrimination conditions. Furthermore, a correlational analysis indicated that there was a significant relationship between the subjects' rating of confidence regarding their responses to each test-item and performance on speechreading tests where lexical analysis is a necessary task-demand. The results are discussed with respect to how information from facial expressions is integrated with the information given by the lip movements in visual speechreading, and also with respect to general models of face-processing (i.e., Bruce & Young, 1986; Young & Bruce, 1991).

Adult↗

PubMed1996

Lipreading with auditory low-frequency information. Contextual constraints.

The present experimental study investigated potential relations among three variables: (1) an audiovisual speech signal (i.e., low-frequency supplemented lipreading as opposed to pure lipreading), (2) typical, as opposed to atypical, sentences in a particular script (e.g., in a restaurant), and (3) the presence/absence of additional context (in the particular script) in 60 normal hearing subjects. All three variables revealed significant main effects, but no interactions were observed. The general facilitatory effect for the audiovisual signal is in line with previous research, but this effect was relatively weak compared to the main effect of typicality, which relies on cognitive activation of scripts. In a separate analysis, the typicality variable was also the only variable that interacted significantly with speechreading skill, typical sentences being perceived relatively easier by the skilled as opposed to the less skilled individual. The clinical implications of cognitive factors in hearing-aid fitting procedures, the construction of speech materials, and selection of individuals for rehabilitation were discussed.

Humans↗

PubMed1994

Skilled speechreading: a single-case study.

In a case study the cognitive characteristics of a skilled visual speechreader (SJ) was examined and compared to a group. SJ is a 56 year old woman, skilled in visual speechreading. She differs from most of the 119 individuals in the control group, as she uses a particular speechreading strategy in which she attempts to repeat overtly each spoken word as soon as it has been uttered, and to summarize and fill in missing pieces of information whenever it is possible (e.g., during pauses) during the conversation. SJ outperformed the control group on three types of tasks; a reading span task, performance in the asymptote level in the serial position curve, and verbal inference-making. SJ's results were discussed with respect to (a) how they related to the general case (i.e., models based on group-data) and to (b) her speechreading strategy. From a clinical perspective it was suggested that it might be possible to practice the strategy as such, but any possible improvement is dependent on the individual's capability to process information in this way.

Cognition↗