Public perceptions of traumatic brain injury: predictors of knowledge and the effects of education.

AIM: Existing research suggests that the public demonstrates inadequate knowledge about traumatic brain injury (TBI), indicating a need for public education initiatives; however, limited research exists on the effectiveness of these initiatives. The purposes of this study were to (1) identify whether any demographic/personal variables (e.g. gender, age, experience with TBI) predicted TBI knowledge and (2) determine whether presenting an educational video to members of the general public would improve knowledge about TBI. METHODS: Participants included 392 adults recruited from a state fair. Participants were divided into two groups, one of which viewed a 6-min video about TBI, and one which viewed an unrelated video. Participants completed measures relating to their backgrounds and knowledge about TBI. RESULTS: Greater educational attainment and professional experience with TBI were predictive of better TBI knowledge (F(1, 336) = 13.76 and 6.92, respectively, p < 0.01); no other demographic or personal variables predicted knowledge. Participants who viewed the TBI video demonstrated significantly better knowledge than participants who did not (F(1, 336) = 52.41, p < 0.0001). CONCLUSION: These results indicate that public education can result in immediate gains in public knowledge about TBI. Further research should include randomized controlled trials to determine long-term effectiveness of public education campaigns.

Bias in the perception of phonetic detail in children's speech: A comparison of categorical and continuous rating scales.

Previous research has shown that continuous rating scales can be used to assess phonetic detail in children's productions, and could potentially be used to detect covert contrasts. Two experiments examined whether continuous rating scales have the additional benefit of being less susceptible to task-related biasing than categorical phonetic transcriptions. In both experiments, judgements of children's productions of /s/ and /θ/ were interleaved with two types of rating tasks designed to induce bias: continuous judgements of a parameter whose variation is itself relatively more continuous (gender typicality of their speech) in one biasing condition, and categorical judgements of a parameter that is relatively less continuous (the vowel they produced) in the other biasing condition. One experiment elicited continuous judgements of /s/ and /θ/ productions, while the other elicited categorical judgements. The results of Experiment 1 showed that the influence of acoustic characteristics on continuous judgements of /s/ and /θ/ was stable across biasing conditions. In contrast, the results of Experiment 2 showed that the influence of acoustic characteristics on categorical judgements of /s/ and /θ/differed systematically across biasing conditions. These results suggest that continuous judgements are psychometrically superior to categorical judgements, as they are more resistant to task-related bias.

Gradient perception of children's productions of /s/ and /θ/: A comparative study of rating methods.

Past studies have shown incontrovertible evidence for the existence of covert contrasts in children's speech, i.e. differences between target productions that are nonetheless transcribed with the same phonetic symbol. Moreover, there is evidence that these are relevant to forming prognoses and tracking progress in children with speech sound disorder. A challenge remains to determine the most efficient and reliable methods for assessing covert contrasts. This study investigates how readily listeners can identify covert contrasts in children's speech when using a continuous rating scale in the form of a visual analogue scale (VAS) to denote children's productions. Individual listeners' VAS responses were found to correlate statistically significantly with a variety of continuous measures of children's production accuracy, including judgements of binary accuracy pooled over a large set of listeners. These findings reinforce the growing body of evidence that VAS judgements are potentially useful clinical measures of covert contrast.

Effect of Speaker Age on Listener Perceptions of Word-Final /l/.

PURPOSE: This study investigated an effect of speaker age on listeners' perception of word-final /l/ produced by child and adult speakers of Southern White Vernacular English, a dialect that shows higher rates of word-final /l/ vocalization than other dialects of English. METHOD: Stimuli included children and adults' word-final /l/ embedded in monosyllabic words in two vowel contexts (/i, ɪ/ and /ɔ, ɑ/). A total of 25 monolingual adult listeners listened to each word and were asked to judge the /l/-likeness using a visual analog scale. Average listener ratings and three acoustic measures (F2 transition rate [F2 TR] and F2-F1 [Hz] values at 20% and 80% time points along the vowel-/l/ duration) were analyzed. RESULTS: Adult productions were rated more as correct /l/ than those of children in both vowel contexts, despite the similarity in their F2 TR and F2-F1 values at the 80% time point. Correlation between the acoustic measures and the average listener ratings were weak for all three measures for adults' productions. For children's productions, while the correlation with F2 TR values were weak, moderate significant correlations were found for F2-F1 values at the 20% and 80% time points. In terms of vowel context, word-final /l/ in the high front vowel context was rated more as /l/ than those in low back vowel context. CONCLUSIONS: Findings suggest that listeners are more likely to accept word-final /l/ as being correct when produced by adult speakers, regardless of their acoustic characteristics, but more likely to perceive an error when produced by a child and attend more to acoustic information for their perceptual judgment. This highlights the importance of considering children's dialectal background when judging word-final /l/, which is more likely to be vocalized in certain dialects and certain vowel contexts, and thus can be misjudged without such consideration.

Deconstructing phonetic transcription: covert contrast, perceptual bias, and an extraterrestrial view of Vox Humana.

This article honours Adele Miccio's life work by reflecting on the utility of phonetic transcription. The first section reviews the literature on cases where children whose speech appears to neutralize a contrast in the adult language are found on closer examination to produce a contrast (covert contrast). This study presents evidence from a new series of perception studies that covert contrast may be far more prevalent in children's speech than existing studies would suggest. The second section presents the results of a new study designed to examine whether naïve listeners' perception of children's /s/ and /theta/ productions can be changed experimentally when they are led to believe that the children who produced the sounds were older or younger. Here, it is shown that, under the right circumstances, adults report more tokens of /theta/ to be accurate productions of /s/ when they believe a talker to be an older child than when they believe the talker to be younger. This finding suggests that auditory information alone cannot be the sole basis for judging the accuracy of a sound. The final section presents recommendations for supplementing phonetic transcription with other measures, to gain a fuller picture of children's production abilities.

Self-regulation strategies used by students with brain injury while transitioning to college.

PURPOSE: Students with TBI enter college with strategies that they have used prior to being injured yet often without knowing which ones will be effective in helping them to be successful. The purpose here is to describe how semi-structured interviews were used to identify self-regulated learning strategies, to demonstrate the utility and reliability of coding self-regulated learning strategies, and to provide examples of student-centered goals derived from survey and interview responses. METHODS: College students completed the College Survey for Students with Brain Injury (CSS-BI) and were interviewed before and after coaching support that focused on teaching self-regulated learning. Responses to interview questions about strategies were coded using a modified version of Zimmerman and Martinez-Pons's (1986) schema. Coders also rated strategies for specificity. RESULTS: Strategies were reliably coded into 16 categories of self-regulation. Inter and intra-reliability were strong. Four of the five students reported using a larger variety of self-regulation strategies and strategies that were more specific after coaching support. DISCUSSION AND CONCLUSIONS: It is possible to reliably code self-regulation learning strategies reported by college students with TBI. These measures have potential as functional 'outcomes' for students who are transitioning to college. Interview responses can be used to collaboratively create student-centered goals.