Biomedical subjects

Edward T Auer

Publications and source records attributed to Edward T Auer.

3 recordsLinked to original sources

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↗

PubMed2002

The influence of the lexicon on speech read word recognition: contrasting segmental and lexical distinctiveness.

The neighborhood activation model (NAM; P. A. Luce & Pisoni, 1998) of spoken word recognition was applied to the problem of predicting accuracy of visual spoken word identification. One hundred fifty-three spoken consonant-vowel-consonant words were identified by a group of 12 college-educated adults with normal hearing and a group of 12 college-educated deaf adults. In both groups, item identification accuracy was correlated with the computed NAM output values. Analysis of subsets of the stimulus set demonstrated that when stimulus intelligibility was controlled, words with fewer neighbors were easier to identify than words with many neighbors. However, when neighborhood density was controlled, variation in segmental intelligibility was minimally related to identification accuracy. The present study provides evidence of a common spoken word recognition system for both auditory and visual speech that retains sensitivity to the phonetic properties of the input.

Adolescent↗