Biomedical subjects

Lynne E Bernstein

Publications and source records attributed to Lynne E Bernstein.

3 recordsLinked to original sources

PubMed2005

Improved speech perception in adult congenitally deafened cochlear implant recipients.

OBJECTIVE: To determine whether congenitally deafened adults achieve improved speech perception when auditory and visual speech information is available after cochlear implantation. STUDY DESIGN: Repeated-measures single subject analysis of speech perception in visual-alone, auditory-alone, and audiovisual conditions. SETTING: Neurotologic private practice and research institute. SUBJECTS: Eight subjects with profound congenital bilateral hearing loss who underwent cochlear implantation as adults (aged 18-55 years) between 1995 and 2002 and had at least 1 year of experience with the implant. MAIN OUTCOME MEASURES: Auditory, visual, and audiovisual speech perception. RESULTS: The median for speech perception scores were as follows: visual-alone, 25.9% (range, 12.7-58.1%); auditory-alone, 5.2% (range, 0-49.4%); and audiovisual, 50.7% (range, 16.5-90.8%). Seven of eight subjects did as well or better in the audiovisual condition than in either auditory-alone or visual-alone conditions alone. Three subjects had audiovisual scores greater than what would be expected from a simple additive effect of the information from the auditory-alone and visual-alone conditions alone, suggesting a superadditive effect of the combination of auditory-alone and visual-alone information. Three subjects had a simple additive effect of speech perception in the audiovisual condition. CONCLUSION: Some congenitally deafened subjects who undergo implantation as adults have significant gains in speech perception when auditory information from a cochlear implant and visual information by lipreading is available. This study shows that some congenitally deafened adults are able to integrate auditory information provided by the cochlear implant (despite the lack of auditory speech experience before implantation) with visual speech information.

Adult↗

PubMed2002

Visual speech perception without primary auditory cortex activation.

Speech perception is conventionally thought to be an auditory function, but humans often use their eyes to perceive speech. We investigated whether visual speech perception depends on processing by the primary auditory cortex in hearing adults. In a functional magnetic resonance imaging experiment, a pulse-tone was presented contrasted with gradient noise. During the same session, a silent video of a talker saying isolated words was presented contrasted with a still face. Visual speech activated the superior temporal gyrus anterior, posterior, and lateral to the primary auditory cortex, but not the region of the primary auditory cortex. These results suggest that visual speech perception is not critically dependent on the region of primary auditory cortex.

Acoustic Stimulation↗

PubMed2002

Stimulus-based lexical distinctiveness as a general word-recognition mechanism.

Word recognition is generally assumed to be achieved via competition in the mental lexicon between phonetically similar word forms. However, this process has so far been examined only in the context of auditory phonetic similarity. In the present study, we investigated whether the influence of word-form similarity on word recognition holds in the visual modality and with the patterns of visual phonetic similarity. Deaf and hearing participants identified isolated spoken words presented visually on a video monitor. On the basis of computational modeling of the lexicon from visual confusion matrices of visual speech syllables, words were chosen to vary in visual phonetic distinctiveness, ranging from visually unambiguous (lexical equivalence class [LEC] size of 1) to highly confusable (LEC size greater than 10). Identification accuracy was found to be highly related to the word LEC size and frequency of occurrence in English. Deaf and hearing participants did not differ in their sensitivity to word LEC size and frequency. The results indicate that visual spoken word recognition shows strong similarities with its auditory counterpart in that the same dependencies on lexical similarity and word frequency are found to influence visual speech recognition accuracy. In particular, the results suggest that stimulus-based lexical distinctiveness is a valid construct to describe the underlying machinery of both visual and auditory spoken word recognition.

Adult↗