Phonetic variability across talkers imposes additional processing costs during speech perception, evident in performance decrements for mixed- vs. single-talker speech. However, within-talker phonetic variation across different utterances is another, relatively unexplored source of variability in speech, and it is unknown how processing costs from within-talker variation compare to those from between-talker variation. Because cognitive consequences of talker variability are typically measured from two-alternative forced- choice tasks, whereas naturalistic speech processing occurs in a much larger decision space, it is also unclear how the effects of across-talker and within-talker variability scale and interact when there are more options to choose between during word identification. Here, we measured response times in a speeded word identification task that factorially manipulated three dimensions of speech variability: number of talkers (one vs. four), number of target word choices (two vs. six), and number of talker-specific exemplars per word (one vs. eight). Across all eight experimental levels, larger decision spaces led to significantly slower word identification. Word identification was also slower in conditions with mixed talkers and conditions with multiple exemplars. However, performance decrements between mixed- vs. single-talker speech were only present when variability in the other two dimensions was low, but decrements between multi- vs. single-token speech were present under all conditions. This pattern of interactions suggests complex processing relationships between type, token, and talker variability and provides preliminary evidence for how both within- and between-talker variability impose additional processing costs in speech perception.

Reduced abilities in talker identification are observed when listeners are presented with the voices of familiar talkers while in an unfamiliar emotional tone. Despite the acoustic variations caused by different emotional states, listeners tend to demonstrate extraordinary abilities in matching the voices to their corresponding talkers, which suggests their perceptual constancies of voice-identity correspondence. However, the distinctive acoustic-perceptual correlates contributing to the formation of perceptual constancy have been rarely studied from the aspect of within-talker variability (i.e., how do listeners know they are hearing the same talkers when many of the key acoustic features of their voices are inconsistent across different contexts?). This study investigated the influence of variation in the emotional tone of voice on listeners’ abilities for talker identification. We explicitly trained our participants with five voices in an emotional state and tested their generalization abilities in talker identification by presenting them with the same talkers’ voices in the trained emotional state and the other untrained emotional state. Our results showed that listeners were more accurate when they were presented with trained emotional states than untrained emotional states. The improved accuracy supported that listeners benefitted from their early experience with the voices across multiple contexts to form their constant perceptual representations of voice identities. We also observed a significant correlation between the difference of mean fundamental frequency (f0) and accuracy, suggesting the differences of mean f0 tended to be a distinctive parameter to quantify the invariant features in the vocal signals.

Despite the ambiguous many-to-many mapping between acoustic signals and target phonemes, human listeners quickly overcome and adapt to inconsistencies during speech perception. However, the processing cost of speech perception increases when a change of the talker occurs and preceding context speech was found to reduce the processing cost. The magnitude of the response time difference between the single- and mixed-talker condition is called the interference effect. The literature indicates that that the interference effect is reduced by increasing length of speech context preceding target speech, but the quantity of the information embedded in that speech context does not further impact processing cost. In this study, we further explored the relationship between the duration of the preceding speech context and its facilitative effect in talker adaptation. The results indicated that even though response times were always shorter in the single-talker condition than the mixed-talker condition, the facilitative effect of preceding context speech became constant for durations longer than beyond 600ms, rather than eventually eliminating the interference effect at some carrier phrase of sufficient duration. Therefore, wo mechanisms are proposed to subserve talker adaptation: a feed-forward, extrinsic process that reduces the interference effect by integrating prior speech context of up to 600ms, and a top-down, intrinsic process that unfolds over longer timescales by allocating cognitive resources to cope with potential talker variability, leading to a global processing time increase.

Includes bibliographical references. / This study focused on women who consumed alcohol during pregnancy. The study population was situated in the West Coast/Winelands, a rural area in the Western Cape Province of South Africa. The study was done in a community which is classified as one of the many previously disadvantaged groups in South Africa. This study was done as part of a larger three-year project on Fetal Alcohol Syndrome Prevention in the Western Cape and Gauteng Provinces of South Africa. The phenomenon of drinking during pregnancy was used as a case example of health compromising occupations in the South African context. Prenatal alcohol exposure may result in brain damage that affects behaviors of those affected. The beliefs, norms, values and perceptions of mothers regarding alcohol consumption are also an important aspect in maintaining healthy pregnancies.

This thesis explored the occupational choices of young adolescents in a southern peninsula Cape Town community of Lavender Hill in South Africa. Informed by current research and prior professional and personal experiences with young adolescents in Lavender Hill, the research question asked: 'What informs occupational choice among young adolescents in Lavender Hill?' This complemented the research aim, which was to generate insight into the nature of the occupational choices of a group of young adolescents in Lavender Hill, and the factors that influenced their occupational choices.

Background: This study is a critical description and explanation of the situated nature of the professional role transition process experienced by occupational therapists working in specialised education in post-apartheid South Africa. The study posed the research question: How do occupational therapists experience the process of professional role transition within specialised education in the Western Cape? The study was framed conceptually within critical social theory and occupational science. Aim: The study aimed to describe and analyse a single instrumental case of professional role transition experienced by five occupational therapists currently working at special school resource centres in two education districts in the Western Cape, South Africa Objectives: The objectives of the study were to: Describe and explain the process of professional role transition as experienced by occupational therapists along a trajectory from 1994 to 2013; Provide insights into the occupational therapists' perceptions, thoughts, feelings and attitudes on their professional role transition experience; Determine whether there are any role changes present and the possible impact this might have on the role and scope and development of occupational therapy practice within specialised education; and Outline the influences the socio political context has on the role of occupational therapists working in special school resource centres in the Western Cape.

Incudes bibliographical references.

No description available.

BACKGROUND: Two challenging concerns prompted this research. The first was post 1994 South African society’s historically entrenched dehumanized/ing condition. And the second was the ill-positionedness and ill-preparedness of occupational science accompanied occupational therapy to do something about it. Appropriate concepts to imagine and generate potentially humanizing and healing responses to violent-divided-wounded human relations were found to be lacking in both professional and public discourses. This study therefore conceived of and applied an original conceptual depiction of being human as ‘enacting humanity affirmations’. Two questions were asked: how are affirmations of our humanity enacted in everyday post 1994 apartheid South Africa? And, how is human occupation and health implicated in enacted humanity affirmations? Consistent with the values and power rationality nature of the first research question, this study was philosophically grounded in critical contemporary interpretations of Aristotle’s intellectual virtue phronesis, and the African relational ethic Ubuntu. METHODOLOGY: Case study was heuristically employed as both a method and the object of study, along with narrative enquiry to generate storied exemplars. Maximum variation sampling aimed for heterogeneity of participants. The stories which made up the instrumental collective case were selected on the criterion of encountering likely resonance within South Africa. Situated within a dehumanized/ing context, incidents-embedded instances of enacted humanity affirmations were handled as bounded systems. Information was gathered through and from multiple methods and sources, including narrative interviews, participants’ reflective journals, multiple documents review, and researcher’s notes. Data analysis proceeded from co-constructions of nine case narratives, an across-case thematic analysis, to thesis building. Together, these informed what this study’s case is about, what it is a case of, and for. Critical reflexivity was exercised by on-going attention to power issues in research interactions, and attempts to enact reciprocal gestures and shared decision-making. FINDINGS/DISCUSSION: This study is a case about everyday enacted humanity affirmations which present as remarkable, disrupting seemingly normalized systemic oppressive power dynamics. Three main themes emerged: 'spectra of relational agency possibilities'; 'embodied-embedded radical sens-abilities'; and, 'never forget how made to feel'. Interpretations and discussion of these findings make this study a case of revealing and disrupting the violent deceptive western(ized) ontological and epistemological premise that being human is a given for all. Redressing historically inflicted harm done to our humanity necessitates that the geo- and body-political epistemic positions, from where to generate applicable understandings of human occupation and health, are delinked from ‘whiteness’. CONCLUSION: This study builds a case for advancing an understanding of being human as occupation and health. Being human was found to be radically relational, and not a given but a political potentiality which manifests on a continuum of enacted harmful negations and salutogenic affirmations of our humanity. Also, cultivation of our being human as shared identity-integrity can advance humanity-health. These insights allow for potentially humanizing and healing societal responses to violent-divided-wounded human relations. This has implications for how occupational therapy and occupational science can position and prepare for being a humanizing and healing resource through research, practice, and education.

Introduction: Adults with intellectual disability (ID) have a right to be included in post-school education (PSE) opportunities such as learnership programmes. They face many barriers, however, including the fact that learning facilitators do not know how to include and teach these learners with ID in a PSE context. Problem: No literature or documented evidence has been captured about inclusive educational approaches describing how learning facilitators taught adults with ID in three learnership programmes that can be used to develop training programmes that will equip learning facilitators with the necessary skills for teaching this group of learners. Rationale: Learning facilitators need to be adequately trained, equipped and supported to meet specific learning needs of adults with ID in learnerships. This study will provide a resource of practice-based educational strategies that could serve as the basis for this training. Aim: To describe how learning facilitators in learnership programmes at Organisation X provided teaching to adults with ID. Method: An indepth, moderately structured, open-ended interview method was used to collect data from six participants. Three Universal Design for Learning (UDL) principles and related guidelines were used to inform how the interview questions were structured. Findings: The main theme was “a learnership takes time, patience and many adjustments but it has to be done” that comprised three categories: namely “dealing with intellectual disability”, “streamlining learnership strategies” and “perceiving the 'just right’ learnership”. The sub-categories identified were populated into the UDL Framework. Discussion: Learnership programmes with adults with ID are time consuming and personally demanding for learning facilitators, but adults with ID have a right to access these programmes. Training programmes for learning facilitators need to include aspects of how to deal with learners with ID, what curriculum differentiation strategies need to be streamlined, and how to create the 'just right’ learnership. Conclusions: Learning facilitators believe that learners with ID have the right to access PSE and participate in learnerships. The success of post-school learnerships lies in providing the “just right” curriculum that offers support for both educator and learner.