The development and evaluation of a Comprehension of Prosody (COP) Test: Measuring accuracy and Response Time in a computerised test of prosody comprehension for use in clinical populations

Abstract Prosody refers to the melodic features of speech that convey information about a speaker’s emotions, attitude or intent. Effective communication relies on the ability to decode the often subtle prosodic components of speech. As such deficits with comprehending prosody could impact significantly on social functioning and interpersonal relationships across settings for school, work, and home. Populations known to have prosody comprehension deficits include those with Acquired Brain Injuries, Schizophrenia, Multiple Sclerosis, and Parkinson’s disease to name a few. These populations are also known to lack social competence. Despite the prevalence of prosody comprehension deficits across a range of clinical groups, there are currently no reliable and easily obtainable tests of prosody comprehension available. Consequentially, the primary aim of this research project was to develop a useful and sensitive clinical test of prosody comprehension to identify deficits in individuals with a variety of clinical presentations. Chapter 1 reviews the current theories explaining the processes underlying prosody comprehension. In general these theories proved inadequate to account for the range of findings in the literature, and a new conceptual neurocognitive network model was proposed. This model facilitated the understanding of the processes underlying Emotional and Linguistic prosody comprehension and was employed to guide the development of a Comprehension of Prosody (COP) Test. Improving the sensitivity of previously used tasks to detect deficits became a major aim of the current project. Specifically, it was proposed that the COP Test would ensure 1) stimuli in the assessment tasks would be reliable and show content validity, 2) that assessment of comprehension would be by using tasks that were ecologically valid and diverse in their task demands, and 3) that prosody assessment gauged both speed and accuracy of comprehension. Chapter 2 details the construction of stimuli and recording of prosodic portrayals by actors to cover the two broad domains of emotional and linguistic prosody. Further, Chapters 2, 3, and 4 report on successive inter-rater reliability studies that aimed to ensure stimuli used were easily recognised by healthy participants. The subsequent removal of stimuli with lower inter-rater agreement resulted in a final COP Test that contained tasks that were brief, yet retained stimuli that were easy to recognise in the absence of neurological impairment. Chapters 3 and 4 present the results of two experiments involving healthy participants. The primary aim of the studies reported were to evaluate the various tasks of the COP Test – the 5 Emotion Naming, the Emotion Matching, and the Linguistic Naming tasks –to ensure they were distinct, that they assessed abilities across categories of prosody and semantic contexts and show potential clinical usefulness, and that response time as a gauge of speed of prosody comprehension provided additional sensitivity of measurement compared to accuracy alone. This was confirmed and allowed for the exploration of how the COP Test would apply to populations with known prosody comprehension deficits. Chapter 5 presents findings from a sample of patients with Multiple Sclerosis and compares their performance with that of a healthy age matched control group, and Chapter 6 summarises a series of single case studies where volunteers with Multiple Sclerosis, Acquired Brain Injury, and Schizophrenia were administered the COP Test, and The Awareness of Social Inference Test (TASIT), with their performance compared to norms split by age. Both of these studies attested to the sensitivity of the tasks and measures (i.e., accuracy and response time) to detect discrete deficits and deliver a unique deficit (and strength) profile across Emotional and Linguistic tasks, across prosodic categories, and semantic conditions. Finally Chapter 7 amalgamates the results of all empirical studies and highlights clinical and theoretical contributions made by the research. It was concluded that the COP Test has the potential to be used as a reliable and sensitive clinical tool for the assessment of prosody comprehension