The effect of modality onset asynchrony and processing time on the recognition of text-supplemented speech.

This study examined the effect of modality onset asynchrony and response processing time for the recognition of text-supplemented speech. Speech and text were periodically interrupted by noise or black bars, respectively, to preserve 50% of the sentence and presented in unimodal and multimodal conditions. Sentence recognition and response errors were assessed for responses made simultaneous with the stimulus or after its presentation. Increased processing time allowed for the cognitive repair of initial response errors in working memory. Text-supplemented speech was best recognized with minimal temporal asynchrony. Overall, text supplementation facilitated the recognition of degraded speech when provided sufficient processing time.

Comparison of Patient-Reported and Caregiver-Reported Swallowing-Related Quality of Life in Parkinson's Disease.

This pilot study explored agreement on swallowing-related quality-of-life scores reported by individuals with Parkinson's disease (PD) and their caregivers. Thirty-six patient-caregiver pairs completed the Swallowing Quality of Life Questionnaire (SWAL-QOL) using an online survey format. Additional background and clinical information was ascertained. A Wilcoxon signed-rank test was completed to compare the means of scores between individuals with PD and caregivers. Factors potentially influencing SWAL-QOL scores (age, employment status, sex, ethnicity, race, previous history of swallowing evaluation or treatment, caregiver concern about patient cognition, caregiver burden, and time since onset of disease) were explored using Spearman Coefficient Correlation tests. The Holm-Bonferroni method was used to adjust for multiple comparisons. Results did not reveal significant differences in SWAL-QOL scores between individuals with PD and caregiver pairs. There was a moderate degree of reliability and agreement between paired patient and caregiver scores, with the average ICC measures being 0.598 (95% CI [358, 0.748]) (F(71, 72) = 2.451, p < 0.0001). After adjusting for multiple comparisons, caregiver burden was found to be the only significant factor associated with caregivers' reported scores. No significant influential factor on reported scores by individuals with PD was found. These pilot results suggest individuals with PD and their caregivers may report similar swallowing-related quality-of-life scores. Further, caregiver burden appears to be an influential factor for caregiver-reported scores. Future studies should investigate the clinical benefits of including caregiver SWAL-QOL ratings in assessments, either as a supplement to patient scores to identify discrepancies across the dyad or in place of patient scores if needed. Further, caregiver burden and its influence on dysphagia identification and management should be explored, with targeted interventions to manage caregiver burden.

Older adult recognition error patterns when listening to interrupted speech and speech in steady-state noise.

This study examined sentence recognition errors made by older adults in degraded listening conditions compared to a previous sample of younger adults. We examined speech recognition errors made by older normal-hearing adults who repeated sentences that were corrupted by steady-state noise (SSN) or periodically interrupted by noise to preserve 33%, 50%, or 66% of the sentence. Responses were transcribed and coded for the number and type of keyword errors. Errors increased with decreasing preservation of the sentence. Similar sentence recognition was observed between SSN and the greatest amount of interruption (33%). Errors were predominately at the word level rather than at the phoneme level and consisted of omission or substitution of keywords. Compared to younger listeners, older listeners made more total errors and omitted more whole words when speech was highly degraded. They also made more whole word substitutions when speech was more preserved. In addition, the semantic relatedness of the substitution errors to the sentence context varied according to the distortion condition, with greater context effects in SSN than interruption. Overall, older listeners made errors reflecting poorer speech representations. Error analyses provide a more detailed account of speech recognition by identifying changes in the type of errors made across listening conditions and listener groups.

Detailed Vision Screening Results from a Cohort of Individuals with Aphasia.

BACKGROUND: Visual functioning is often affected in persons with aphasia following stroke and other brain injuries. Characterizing the visual functioning of persons with aphasia is imperative in both clinical and research domains; however, visual functioning of persons with aphasia is infrequently assessed or described in either domain. AIMS: This study aims to examine the utility of various visual screening measures as indicated by Hallowell (2008) and document the results of the screening tools for a cohort of persons with aphasia. METHODS & PROCEDURES: Twenty-three individuals with chronic aphasia completed a detailed vision screening using a visual case history, the Visual Activities Questionnaire, the McDowell Vision Screening, an Amsler grid, the line bisection task, and the National Institute of Health Stroke Scale item 3-visual. OUTCOMES & RESULTS: Two-thirds of the participants reported significant visual histories with only one participant reporting stroke-related visual deficits. On average, the group rated visual difficulty during daily activities as never or rarely occurring, with the least difficulty reported for color discrimination and the most difficulty with visual acuity and visual search, though still only occurring rarely. All participants passed the cover/uncover screening task measuring ocular alignment and motility, the color perception screening task, and several tasks measuring ocular function. Failing scores, however, were assigned for about half of the participants for distance visual acuity, and only three participants for near visual acuity. Visual fields were normal for about two-thirds of the participants and all participants presented with normal visual attention. CONCLUSIONS: The results suggest that visual deficits are common in persons with aphasia, but are not necessarily related to the stroke that the person experienced. The results highlight the need to screen the vision of persons with aphasia both for clinical purposes and research protocols to ensure visual deficits are treated, compensated for, or controlled.

Relationship Between Single Word Reading, Connected Text Reading, and Reading Comprehension in Persons With Aphasia.

Purpose This study examined the relationship between single word reading, connected text reading, and comprehension in persons with aphasia. Method Thirteen persons with aphasia read orally from the Arizona Battery for Reading and Spelling real-word and nonword lists and the Gray Oral Reading Tests-Fifth Edition. The comprehension questions following each paragraph of the Gray Oral Reading Tests-Fifth Edition were answered and scored. The Reading Comprehension Battery for Aphasia-Second Edition provided a measure of silent reading comprehension. Descriptive statistics and Spearman correlation were used to examine associations among reading measures. Results Persons with aphasia showed associations between single word reading and connected text reading accuracy; however, single word reading ability was not associated with oral or silent reading comprehension. Conclusions Although preliminary, the findings provide support for word-level reading abilities underlying connected text reading accuracy but suggest additional cognitive mechanisms are involved in text-level reading comprehension that are not explained by single word reading alone. The findings indicate clinicians should use caution when inferring comprehension abilities from single word reading performance as reading comprehension abilities are likely best assessed using text-level comprehension assessments.

Task-Related Differences in Eye Movements in Individuals With Aphasia.

Background: Neurotypical young adults show task-based modulation and stability of their eye movements across tasks. This study aimed to determine whether persons with aphasia (PWA) modulate their eye movements and show stability across tasks similarly to control participants. Methods: Forty-eight PWA and age-matched control participants completed four eye-tracking tasks: scene search, scene memorization, text-reading, and pseudo-reading. Results: Main effects of task emerged for mean fixation duration, saccade amplitude, and standard deviations of each, demonstrating task-based modulation of eye movements. Group by task interactions indicated that PWA produced shorter fixations relative to controls. This effect was most pronounced for scene memorization and for individuals who recently suffered a stroke. PWA produced longer fixations, shorter saccades, and less variable eye movements in reading tasks compared to controls. Three-way interactions of group, aphasia subtype, and task also emerged. Text-reading and scene memorization were particularly effective at distinguishing aphasia subtype. Persons with anomic aphasia showed a reduction in reading saccade amplitudes relative to their respective control group and other PWA. Persons with conduction/Wernicke's aphasia produced shorter scene memorization fixations relative to controls or PWA of other subtypes, suggesting a memorization specific effect. Positive correlations across most tasks emerged for fixation duration and did not significantly differ between controls and PWA. Conclusion: PWA generally produced shorter fixations and smaller saccades relative to controls particularly in scene memorization and text-reading, respectively. The effect was most pronounced recently after a stroke. Selectively in reading tasks, PWA produced longer fixations and shorter saccades relative to controls, consistent with reading difficulty. PWA showed task-based modulation of eye movements, though the pattern of results was somewhat abnormal relative to controls. All subtypes of PWA also demonstrated task-based modulation of eye movements. However, persons with anomic aphasia showed reduced modulation of saccade amplitude and smaller reading saccades, possibly to improve reading comprehension. Controls and PWA generally produced stabile fixation durations across tasks and did not differ in their relationship across tasks. Overall, these results suggest there is potential to differentiate among PWA with varying subtypes and from controls using eye movement measures of task-based modulation, especially reading and scene memorization tasks.

Functional Characterization of the Human Speech Articulation Network.

A number of brain regions have been implicated in articulation, but their precise computations remain debated. Using functional magnetic resonance imaging, we examine the degree of functional specificity of articulation-responsive brain regions to constrain hypotheses about their contributions to speech production. We find that articulation-responsive regions (1) are sensitive to articulatory complexity, but (2) are largely nonoverlapping with nearby domain-general regions that support diverse goal-directed behaviors. Furthermore, premotor articulation regions show selectivity for speech production over some related tasks (respiration control), but not others (nonspeech oral-motor [NSO] movements). This overlap between speech and nonspeech movements concords with electrocorticographic evidence that these regions encode articulators and their states, and with patient evidence whereby articulatory deficits are often accompanied by oral-motor deficits. In contrast, the superior temporal regions show strong selectivity for articulation relative to nonspeech movements, suggesting that these regions play a specific role in speech planning/production. Finally, articulation-responsive portions of posterior inferior frontal gyrus show some selectivity for articulation, in line with the hypothesis that this region prepares an articulatory code that is passed to the premotor cortex. Taken together, these results inform the architecture of the human articulation system.

Spatial genetic structure in American black bears (Ursus americanus): female philopatry is variable and related to population history.

Previously, American black bears (Ursus americanus) were thought to follow the pattern of female philopatry and male-biased dispersal. However, recent studies have identified deviations from this pattern. Such flexibility in dispersal patterns can allow individuals greater ability to acclimate to changing environments. We explored dispersal and spatial genetic relatedness patterns across ten black bear populations-including long established (historic), with known reproduction >50 years ago, and newly established (recent) populations, with reproduction recorded <50 years ago-in the Interior Highlands and Southern Appalachian Mountains, United States. We used spatially explicit, individual-based genetic simulations to model gene flow under scenarios with varying levels of population density, genetic diversity, and female philopatry. Using measures of genetic distance and spatial autocorrelation, we compared metrics between sexes, between population types (historic and recent), and among simulated scenarios which varied in density, genetic diversity, and sex-biased philopatry. In empirical populations, females in recent populations exhibited stronger patterns of isolation-by-distance (IBD) than females and males in historic populations. In simulated populations, low-density populations had a stronger indication of IBD than medium- to high-density populations; however, this effect varied in empirical populations. Condition-dependent dispersal strategies may permit species to cope with novel conditions and rapidly expand populations. Pattern-process modeling can provide qualitative and quantitative means to explore variable dispersal patterns, and could be employed in other species, particularly to anticipate range shifts in response to changing climate and habitat conditions.

Speech recognition error patterns for steady-state noise and interrupted speech.

Listening in various types of adverse listening conditions may lead to different errors in speech recognition. Young adults repeated sentences degraded by steady-state noise or periodically interrupted by noise preserved at varying proportions. Recognition errors were analyzed according to the noise type and speech proportion. Across noise types, as word recognition decreased, the occurrence of phonemic substitutions and whole word omissions increased. Listeners made more whole word omission and substitution errors during steady-state noise. Part word errors occurred most frequently when listening to speech presented in steady-state noise or interrupted by noise with the smallest speech proportion preserved.

Integration of partial information for spoken and written sentence recognition by older listeners.

Older adults have difficulty understanding speech in challenging listening environments. Combining multisensory signals may facilitate speech recognition. This study measured recognition of interrupted spoken and written sentences by older adults for different preserved stimulus proportions. Unimodal performance was first examined when only interrupted text or speech stimuli were presented. Multimodal performance with concurrently presented text and speech stimuli was tested with delayed and simultaneous participant responses. Older listeners performed better in unimodal speech-only compared to text-only conditions across all proportions preserved. Performance was also better in delayed multimodal conditions. Comparison to a younger sample suggests age-related amodal processing declines.

Integration of Partial Information Within and Across Modalities: Contributions to Spoken and Written Sentence Recognition.

PURPOSE: This study evaluated the extent to which partial spoken or written information facilitates sentence recognition under degraded unimodal and multimodal conditions. METHOD: Twenty young adults with typical hearing completed sentence recognition tasks in unimodal and multimodal conditions across 3 proportions of preservation. In the unimodal condition, performance was examined when only interrupted text or interrupted speech stimuli were available. In the multimodal condition, performance was examined when both interrupted text and interrupted speech stimuli were concurrently presented. Sentence recognition scores were obtained from simultaneous and delayed response conditions. RESULTS: Significantly better performance was obtained for unimodal speech-only compared with text-only conditions across all proportions preserved. The multimodal condition revealed better performance when responses were delayed. During simultaneous responses, participants received equal benefit from speech information when the text was moderately and significantly degraded. The benefit from text in degraded auditory environments occurred only when speech was highly degraded. CONCLUSIONS: The speech signal, compared with text, is robust against degradation likely due to its continuous, versus discrete, features. Allowing time for offline linguistic processing is beneficial for the recognition of partial sensory information in unimodal and multimodal conditions. Despite the perceptual differences between the 2 modalities, the results highlight the utility of multimodal speech + text signals.

Predicting aphasia type from brain damage measured with structural MRI.

Chronic aphasia is a common consequence of a left-hemisphere stroke. Since the early insights by Broca and Wernicke, studying the relationship between the loci of cortical damage and patterns of language impairment has been one of the concerns of aphasiology. We utilized multivariate classification in a cross-validation framework to predict the type of chronic aphasia from the spatial pattern of brain damage. Our sample consisted of 98 patients with five types of aphasia (Broca's, Wernicke's, global, conduction, and anomic), classified based on scores on the Western Aphasia Battery (WAB). Binary lesion maps were obtained from structural MRI scans (obtained at least 6 months poststroke, and within 2 days of behavioural assessment); after spatial normalization, the lesions were parcellated into a disjoint set of brain areas. The proportion of damage to the brain areas was used to classify patients' aphasia type. To create this parcellation, we relied on five brain atlases; our classifier (support vector machine - SVM) could differentiate between different kinds of aphasia using any of the five parcellations. In our sample, the best classification accuracy was obtained when using a novel parcellation that combined two previously published brain atlases, with the first atlas providing the segmentation of grey matter, and the second atlas used to segment the white matter. For each aphasia type, we computed the relative importance of different brain areas for distinguishing it from other aphasia types; our findings were consistent with previously published reports of lesion locations implicated in different types of aphasia. Overall, our results revealed that automated multivariate classification could distinguish between aphasia types based on damage to atlas-defined brain areas.

Contrasting effects of errorless naming treatment and gestural facilitation for word retrieval in aphasia.

We compared the effects of two treatments for aphasic word retrieval impairments, errorless naming treatment (ENT) and gestural facilitation of naming (GES), within the same individuals, anticipating that the use of gesture would enhance the effect of treatment over errorless treatment alone. In addition to picture naming, we evaluated results for other outcome measures that were largely untested in earlier ENT studies. In a single participant crossover treatment design, we examined the effects of ENT and GES in eight individuals with stroke-induced aphasia and word retrieval impairments (three semantic anomia, five phonological anomia) in counterbalanced phases across participants. We evaluated effects of the two treatments for a daily picture naming/gesture production probe measure and in standardised aphasia tests and communication rating scales administered across phases of the experiment. Both treatments led to improvements in naming of trained words (small-to-large effect sizes) in individuals with semantic and phonological anomia. Small generalised naming improvements were noted for three individuals with phonological anomia. GES improved use of corresponding gestures for trained words (large effect sizes). Results were largely maintained at one month post-treatment completion. Increases in scores on standardised aphasia testing also occurred for both ENT and GES training. Both ENT and GES led to improvements in naming measures, with no clear difference between treatments. Increased use of gestures following GES provided a potential compensatory means of communication for those who did not improve verbal skills. Both treatments are considered to be effective methods to promote recovery of word retrieval and verbal production skills in individuals with aphasia.

Perceived Benefits and Barriers to Family Planning Education among Third Year Medical Students.

PURPOSE: The purpose of the current study is to explore third- year medical students' interest in learning about family planning, exposure to family planning (contraception and abortion) and perceived barriers and benefits to family planning education in their obstetrics and gynecology rotation. METHOD: We conducted four focus groups with 27 third-year medical students near the end of their rotation in obstetrics and gynecology. RESULTS: Students desired education in family planning but perceived limited exposure during their rotation. Most students were aware of abortion but lacked factual information and abortion procedural skills. They felt systemic and faculty-related barriers contributed to limited exposure. Students discussed issues such as lack of time for coverage of contraception and abortion in the curricula and rotation itself. Perceived benefits of clinical instruction in family planning included increased knowledge of contraceptive management and abortion the ability to care for and relate to patients, opportunity for values clarification, and positive changes in attitudes towards family planning. CONCLUSIONS: Medical students who desire full education in family planning during their obstetrics and gynecology rotation may face barriers to obtaining that education. Given that many medical students will eventually care for reproductive-age women, greater promotion of opportunities for exposure to family planning within obstetrics and gynecology rotations is warranted.

Efficacy of immobilizing free-ranging elk with Telazol and xylazine hydrochloride using transmitter-equipped darts.

From January 1999 to April 2002, 14 free-ranging elk were darted with a mixture of Telazol reconstituted with xylazine hydrochloride (HCl) in a forested habitat in southwestern Oklahoma and north-central Arkansas. Elk were darted from ground blinds, tree stands, or a vehicle at distances of 14-46 m and were recovered 37-274 m from the dart site. Elk were located using radiotelemetry with 3-cc disposable Pneu-dart transmitter darts. Mean+/-SD dose of Telazol and xylazine HCl was 590+/-192 mg/ml and 276+/-153 mg/ml, respectively, and mean time to standing after injection of reversal agent was 27 min (range: 1-65 min). The combination of Telazol and xylazine HCl successfully immobilized free-ranging elk, and transmitter-equipped darts permitted successful location of sedated elk by two people in areas of dense forest cover. The dose required to sedate elk appeared to vary depending on physiology and behavior, but no drug-induced mortality occurred despite the wide variance in the doses administered. We recommend 500 mg Telazol reconstituted with 300 mg xylazine HCl as an initial dose for a >or=200 kg elk. If needed to achieve full sedation, up to 3 additional ml of the mixture may be administered without adverse effects.