The purpose of this study was to investigate aspects of pitch perception of auditors when presented with musical tones whose frequencies were modulated. Research problems were: estimation of the effect of musical training upon pitch perception; estimation of the effect of stimuli of differing tonal qualities and frequency ranges upon perception; and estimation of the effect of solo and ensemble performances upon pitch perception. Subjects for the study were thirty musicians and thirty nonmusicians. Subjects were students at North Texas State University and Paris Junior College who had volunteered for the study. A test containing thirty-six items was developed which required subjects to match a tone created by a sawtooth wave generator to a simultaneously presented musical tone performed with vibrato. Each subject was tested individually, and allowed three attempts to match each test item. After the third playing of each item, a reading was taken of the frequency selected by the subject, Using the split half method, reliability for the test was found to be .86 for nonmusicians and .88 for musicians. ANOVA evaluation of responses of subjects indicated that there was a significant difference.in the location of pitch among musicians and nonmusicians, with musicians locating the pitch somewhat higher in the frequency spectrum than nonmusicians. Neither group located the pitch of modulated musical tones at the geometric mean of the modulation. Differences located in responses of the groups were consistant with regard to stimuli of varying frequency levels and timbres, and were unaffected by either solo or ensemble performance of the stimulus. Subsidiary findings indicated that among musicians no significant differences in pitch perception may be traced to the major performing instrument of the subject; differences in these subgroups and nonmusicians were consistant with the findings comparing musicians as "a whole and nonmusicians. Suggestions were made concerning application of the findings to musical training and concerning possibilities for further investigation in perception of pitch.

Cochlear implant (CI) devices afford many profoundly deaf individuals worldwide partially restored hearing ability. Although CI users achieve remarkable speech perception with contemporary multichannel CI devices, their music perception ability is generally unsatisfactory. Improved CI-mediated music perception ability requires that the underlying constraints hindering processing of music-relevant information need to be identified and understood. This study puts forward a systematic approach, informed by the neurocognitive mechanisms underlying music perception in normal hearing (NH), for investigating implant-mediated music perception. Psychoacoustical experiments were used to explore the extent to which music-relevant information delivered to the central auditory system following peripheral electrical stimulation supports music perception. Task-specific stimuli and test procedures were developed to assess perception of pitch, rhythm and loudness information, both as separate and in combined form, in sound-field listening conditions. CI users’ unsuccessful judgement of the musical character of short, novel single-voice melodies suggests that insufficient information reaches the central auditory processing system to effect a unified musical percept. This is despite sound field frequency discrimination behaviour being better than had been expected and rhythm perception ability with regard to short tone sequences of varying pitch and rhythmic complexity being comparable to that of NH listeners. CI listeners also performed similarly to NH listeners during pitch-dependent loudness perception tasks. Within the framework of a hierarchical, modular processing system underlying music perception, it appears that early pitch processing deficits propagate throughout the music processing system to exert an overriding inhibitory perceptual effect. The outcomes of this study not only underline the importance of delivering sufficient pitch information to the electrically stimulated auditory system but also show that music perception in CI-mediated hearing should be investigated and understood as the outcome of an integrated perceptual system. / Thesis (PhD)--University of Pretoria, 2011. / Electrical, Electronic and Computer Engineering / Unrestricted

No description available.

Although many researchers investigate the senses separately, most people have a coherent conscious experience of the world that is not divided into separate perceptions of vision, hearing, or other senses. The brain integrates the information received from our senses into a unified representation of the world around us. Previous research has demonstrated that what people perceive with one sense can influence their perception of stimuli with the other senses (Roffler & Butler, 1968; Marks, 2000). The current set of studies was designed to illuminate the associations between musical pitch and visuospatial motion. The first two experiments with infants revealed that 11-month-old infants are sensitive to associations between ascending and descending musical pitch and the direction of an object’s motion. Additionally, two more experiments with infants revealed that infants of the same age do not show the associations of rightward motion with ascending pitch and leftward motion with descending pitch that adults have demonstrated in some experiments (Eitan & Granot, 2006). The fifth experiment tested the influence of ascending and descending musical stimuli on making a visuospatial motion to a target location. Adult subjects demonstrated faster reaction times when using a trackball to move a cursor to a target location on a computer screen when the direction of the target was congruent with the musical stimulus to which they were listening. The effect was stronger for vertical target locations than for horizontal target locations. The results of these studies indicate that both infants and adults are sensitive to associations between musical pitch and visuospatial motion in the vertical plane, and adults may also make associations between musical pitch and visuospatial motion in the horizontal plane. / text

L’amusie congénitale est un trouble neuro-développemental se définissant par des difficultés à percevoir la musique, et ce malgré une ouïe et une intelligence normales. Un déficit de discrimination fine des hauteurs serait à l’origine de ce trouble, qui se traduit notamment par une incapacité à détecter les fausses notes. afin de mieux comprendre les facteurs génétiques contribuant à la manifestation de l’amusie congénitale, la présente étude avait pour objectif: (a) de déterminer si la performance sur diverses tâches musicales et auditives était plus similaire chez les jumeaux identiques (monozygotes ; MZ) que chez les jumeaux non-identiques (dizygotes ; DZ) et (b) d’explorer les variables relatives à l’environnement musical des jumeaux, afin de mieux comprendre les contributions de l’environnement et de la génétique dans les différences sous-tendant les habiletés musicales. De plus, le profil des sujets amusiques a été analysé afin de vérifier s’il correspondait à celui décrit dans la littérature, faisant état de difficultés tonales, mais non rythmiques. Huit paires de jumeaux MZ et six paires de jumeaux DZ, parmi lesquelles au moins un des co-jumeaux était potentiellement amusique, ont pris part à cette étude. Les tâches consistaient en un test en ligne de perception mélodique et rythmique, un test de détection des différences de hauteurs, ainsi qu’un test de chant. L’analyse de la performance et de l’environnement musical des jumeaux MZ et DZ ne révèle aucune distinction comportementale entre ces deux groupes en ce qui concerne les habiletés musicales. Cela suggère que celles-ci puissent être davantage influencées par l’environnement partagé que par les facteurs génétiques. Enfin, les jumeaux amusiques ont le profil habituel d’habiletés musicales. En effet, ils commettent des erreurs de perception et de production musicale au niveau mélodique, mais ont une perception rythmique préservée. D’autres études, notamment avec de plus grands échantillons de jumeaux, seront nécessaires afin d’élucider la possible étiologie génétique sous-tendant l’amusie congénitale. / Music is an important part of every known culture, and its universality raises the question of a possible biological basis. Musical disorders, such as congenital amusia, offer compelling insight into these roots. In order to examine the genetic basis of this phenotype, we used a classical twin study paradigm. Our study had two main goals: (a) investigate if identical (monozygotic; MZ) co-twins perform more similarly on auditory and musical tasks than non-identical (dizygotic; DZ) co-twins and (b) explore the twins’ musical environments in order to better understand the contribution of environmental versus genetic factors in the differences underlying musical abilities. In addition, we sought to replicate previous investigations that demonstrated impaired pitch processing but intact rhythm perception in amusic participants. To do so, we tested eight pairs of MZ and six pairs of DZ twins in which at least one of the co-twins was potentially amusic. Participants completed an online amusia test, a pitch detection task and a singing task. We observed no performance or musical environment differences between MZ and DZ twins, suggesting that musical abilities might be more influenced by the twins’ shared environment than by genetic factors. In addition, and as reported in previous studies, amusics made pitch processing errors in both perception and production, but rhythmic perception was preserved. Future studies, particularly those with access to larger twin samples, will be able to further elucidate the roles of environmental and genetic factors in the amusic phenotype.

L’amusie congénitale est un trouble neuro-développemental se définissant par des difficultés à percevoir la musique, et ce malgré une ouïe et une intelligence normales. Un déficit de discrimination fine des hauteurs serait à l’origine de ce trouble, qui se traduit notamment par une incapacité à détecter les fausses notes. afin de mieux comprendre les facteurs génétiques contribuant à la manifestation de l’amusie congénitale, la présente étude avait pour objectif: (a) de déterminer si la performance sur diverses tâches musicales et auditives était plus similaire chez les jumeaux identiques (monozygotes ; MZ) que chez les jumeaux non-identiques (dizygotes ; DZ) et (b) d’explorer les variables relatives à l’environnement musical des jumeaux, afin de mieux comprendre les contributions de l’environnement et de la génétique dans les différences sous-tendant les habiletés musicales. De plus, le profil des sujets amusiques a été analysé afin de vérifier s’il correspondait à celui décrit dans la littérature, faisant état de difficultés tonales, mais non rythmiques. Huit paires de jumeaux MZ et six paires de jumeaux DZ, parmi lesquelles au moins un des co-jumeaux était potentiellement amusique, ont pris part à cette étude. Les tâches consistaient en un test en ligne de perception mélodique et rythmique, un test de détection des différences de hauteurs, ainsi qu’un test de chant. L’analyse de la performance et de l’environnement musical des jumeaux MZ et DZ ne révèle aucune distinction comportementale entre ces deux groupes en ce qui concerne les habiletés musicales. Cela suggère que celles-ci puissent être davantage influencées par l’environnement partagé que par les facteurs génétiques. Enfin, les jumeaux amusiques ont le profil habituel d’habiletés musicales. En effet, ils commettent des erreurs de perception et de production musicale au niveau mélodique, mais ont une perception rythmique préservée. D’autres études, notamment avec de plus grands échantillons de jumeaux, seront nécessaires afin d’élucider la possible étiologie génétique sous-tendant l’amusie congénitale. / Music is an important part of every known culture, and its universality raises the question of a possible biological basis. Musical disorders, such as congenital amusia, offer compelling insight into these roots. In order to examine the genetic basis of this phenotype, we used a classical twin study paradigm. Our study had two main goals: (a) investigate if identical (monozygotic; MZ) co-twins perform more similarly on auditory and musical tasks than non-identical (dizygotic; DZ) co-twins and (b) explore the twins’ musical environments in order to better understand the contribution of environmental versus genetic factors in the differences underlying musical abilities. In addition, we sought to replicate previous investigations that demonstrated impaired pitch processing but intact rhythm perception in amusic participants. To do so, we tested eight pairs of MZ and six pairs of DZ twins in which at least one of the co-twins was potentially amusic. Participants completed an online amusia test, a pitch detection task and a singing task. We observed no performance or musical environment differences between MZ and DZ twins, suggesting that musical abilities might be more influenced by the twins’ shared environment than by genetic factors. In addition, and as reported in previous studies, amusics made pitch processing errors in both perception and production, but rhythmic perception was preserved. Future studies, particularly those with access to larger twin samples, will be able to further elucidate the roles of environmental and genetic factors in the amusic phenotype.

<p> Hearing provides a vital means for infants to discover their environment and communicate with their caregivers. Identifying and discriminating the pitch of sounds is critical for infants in order to acquire information from speech and music. Therefore, how infants process pitch is a fundamental question in research on auditory development. The focus of this dissertation is the use of auditory event related potentials (ERPs) derived from electroencephalogram (EEG) recordings to examine the maturation of pitch perception in early infancy. </p> <p> Pitch perception in adults has been extensively studied, but little is known about the development of pitch perception during early infancy. Infant mismatch responses (MMRs) are ERP components that are elicited by infrequent changes in auditory stimuli. MMR is a promising tool to study infant pitch perception because it can be elicited without attention or a behavioural response. However, previous studies on MMRs in infants have reported inconsistent results, some reporting frontally positive responses while others report frontally negative mismatch responses. In Chapter 2, we examined MMRs to simple pitch changes in infants between 2 and 4 months of age and found both types of infant MMRs are present, but the morphological distributions and developmental trajectories are different. In Chapter 3, we reported that both types of infant MMRs are affected similarly by the amplitude of pitch change but only the positive MMR becomes stronger when stimulus presentation rate increases, which suggests different neural mechanisms for the two types of infant MMRs. The studies reported in Chapter 4 found that only the negative MMR can be elicited readily by changes in pitch patterns, suggesting that it may be functionally similar to mismatch negativity (MMN) in adults. </p> <p> The experiments in Chapter 5 used MMR as the indication of whether infants automatically integrate the frequency components of a complex tone into a single pitch percept, even when the fundamental frequency component (corresponding to the pitch) is removed. Previous studies show that adult MMN is elicited by a pitch change in such tones missing the fundamental. Previous behavioural studies using a conditioned head tum method show that 7-month-olds also perceive pitch with tones missing the fundamental. The results of the present study indicate that infants as young as 4 months of age integrate components into a single pitch percept, but evidence for this in younger infants could not be found. </p> <p> In conclusion, the current dissertation established a promising procedure utilizing infant MMR to study infant pitch perception and contributed to the knowledge of early development of pitch perception by demonstrating dramatic changes in brain response to pitch in harmonic tones in infants between 2 and 4 months old, and to pitch in tones in infants missing the fundamental between 3 and 4 months old . </p> / Thesis / Doctor of Philosophy (PhD)

Thèse de doctorat présenté en vue de l'obtention du doctorat en psychologie - recherche intervention, option neuropsychologie clinique (Ph.D) / Les traumatismes craniocérébraux (TCC) peuvent entraîner de lourdes conséquences physiques, cognitives, émotionnelles et comportementales. Parmi celles-ci, l’agitation est très fréquente et se caractérise par une hyperactivité motrice, une désorientation, des problèmes d'attention, une labilité émotionnelle, une désinhibition et de l’agressivité. Elle interfère avec le rétablissement et les processus de réadaptation, mais il n'existe pas à ce jour de consensus sur son traitement, outre la contention physique ou la prise de médicaments, qui peuvent respectivement causer des blessures ou entraver la récupération. De récentes données suggèrent que les interventions musicales peuvent réduire l’agitation chez les patients TCC mais la capacité des patients TCC à percevoir et traiter la musique pendant la phase aiguë post-blessure n'a pas été établie. Le premier article de cette thèse visait à évaluer la perception musicale chez les patients TCC hospitalisés en phase aiguë. Dans la présente étude, 42 patients ayant subi un TCC ont été comparés à un groupe témoin. Tous les participants ont complété les tests de Scale et Rhythm de la Montreal Battery of Evaluation of Amusia pour mesurer la perception musicale, et le test d’empan numérique pour mesurer la mémoire verbale à court terme. Comparativement au groupe témoin, les patients TCC ont obtenu des performances significativement inférieures; 43% d'entre eux présentaient des déficits de traitement de la hauteur et 40% des déficits de traitement du rythme. Les patients présentant des lésions à l'hémisphère droit ont obtenu des résultats plus faibles que ceux présentant des lésions à l'hémisphère gauche. Les déficits de traitement de la hauteur et du rythme coexistaient dans 31% des cas, ce qui suggère l'existence de réseaux neuronaux partiellement dissociables. Le deuxième article est une revue non systématique dont l’objectif était de caractériser l'agitation et son traitement. Plusieurs types d’interventions comportementales, dont les interventions musicales, ont été explorées dans cette revue. Les limites méthodologiques ont été discutées et des recommandations ont été faites pour une approche plus systématique de la recherche utilisant des études de cas et de séries de cas chez les patients agités. Le troisième article est une étude pilote de phase II dans laquelle sont inclus des patients ayant subi un TCC modéré à sévère (n = 3) ou un accident vasculaire cérébral de l'artère cérébrale moyenne (n = 1). Ils ont été exposés à leurs musiques préférées, de la musique classique relaxante et un extrait sonore non musical (cascade) pendant la phase aiguë de récupération. Les comportements d’agitation ont été évalués à l'aide de l'Échelle d’Agitation (Agitated Behaviour Scale), de mesures actigraphiques et d’une observation qualitative. Les résultats indiquent que l’agitation a diminué lors de l’écoute de la musique classique relaxante et la cascade. L’agitation est restée stable lors de la musique préférée, mais certains patients ont exprimé des émotions positives ou présenté un comportement plus organisé, comme taper du pied ou chanter. Compte tenu des importantes limites méthodologiques dans ce champ d’études, la présente étude a permis d’explorer la faisabilité et l’effet d’une intervention musicale, ce qui permettra de guider les études futures. / Traumatic brain injury (TBI) has serious physical, cognitive, emotional, and behavioural consequences. Agitation is highly prevalent among patients with TBI, and is characterized by motor hyperactivity, disorientation, attention problems, emotional lability, disinhibition, and aggression. It often results in decreased engagement in rehabilitative treatment, and poorer functional outcomes. There is no consensus on the treatment for agitation. Most often, it is managed with medication and physical restraints, which may cause injury or impede cognitive recovery. Few studies examine novel non-pharmacological interventions for agitation in TBI patients. However, recent evidence suggests that music interventions may decrease agitated behavior in TBI patients. The ability of TBI patients to perceive and process music during the acute phase has not been established, though it may influence the efficacy of preferred music interventions. The first article of this thesis evaluated music perception in acutely hospitalized TBI patients. Music perception deficits have been identified in populations with acquired brain injury due to epilepsy, stroke, and after aneurysmal clipping. However, few studies have evaluated deficits following TBI, resulting in an underdiagnosis in this population. Forty-two patients completed the Scale and Rhythm tests of the Montreal Battery for the Evaluation of Amusia to measure music perception, and Digit Span Forward to measure verbal short-term memory. TBI patients were more often impaired than controls, with 43% demonstrating pitch processing deficits, and 40% demonstrating rhythm processing deficits. Patients with right hemisphere damage performed more poorly than those with left hemisphere damage. Pitch and rhythm deficits co-occurred 31% of the time, suggesting partly dissociable neural networks. Results are discussed in the context of current research and clinical implications. The second article was a non-systematic review in which we characterized agitation and its treatment. We explored behavioural interventions, including music interventions, occupational therapy, the Intervention Contingencies Awareness Relationship behavioural model, operant contingency management, and general therapeutic activities. The methodological limitations were discussed and recommendations made for a more systematic approach to research using case and case series studies in agitated patients. The third article was a phase-II development-of-concept pilot study in which four patients with moderate to severe TBI (n = 3), and middle cerebral artery stroke: (n = 1) were exposed to preferred music, relaxing classical music, and a nonmusical control (waterfall) during the acute phase of recovery. Agitated behaviours were assessed using the Agitated Behavior Scale, actigraphy, and qualitative observation. Agitated behaviour decreased during relaxing classical music, and waterfall. It remained stable in the preferred music condition. However, certain patients expressed positive emotions and organized behaviour such as tapping or singing along. Given important methodological limitations in current studies, a phase-II study allowed for the evaluation of outcomes and the practicality of delivering music listening interventions, which may guide future studies.