Melbourne School of Psychological Sciences - Research Publications
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ItemMetabolic patterns and seizure outcomes following anterior temporal lobectomy(WILEY, 2019-02)OBJECTIVE: We investigated the relationship between the interictal metabolic patterns, the extent of resection of 18 F-fluorodeoxyglucose positron emission tomography (18 FDG-PET) hypometabolism, and seizure outcomes in patients with unilateral drug-resistant mesial temporal lobe epilepsy (MTLE) following anterior temporal lobe (TL) resection. METHODS: Eighty-two patients with hippocampal sclerosis or normal magnetic resonance imaging (MRI) findings, concordant 18 FDG-PET hypometabolism, and at least 2 years of postoperative follow-up were included in this 2-center study. The hypometabolic regions in each patient were identified with reference to 20 healthy controls (p < 0.005). The resected TL volume and the volume of resected TL PET hypometabolism (TLH) were calculated from the pre- and postoperative MRI scans coregistered with interictal 18 FDG-PET. RESULTS: Striking differences in metabolic patterns were observed depending on the lateralization of the epileptogenic TL. The extent of the ipsilateral TLH was significantly greater in left MTLE patients (p < 0.001), whereas right MTLE patients had significantly higher rates of contralateral (CTL) TLH (p = 0.016). In right MTLE patients, CTL hypometabolism was the strongest predictor of an unfavorable seizure outcome, associated with a 5-fold increase in the likelihood of seizure recurrence (odds ratio [OR] = 4.90, 95% confidence interval [CI] = 1.07-22.39, p = 0.04). In left MTLE patients, greater extent of resection of ipsilateral TLH was associated with lower rates of seizure recurrence (p = 0.004) in univariate analysis; however, its predictive value did not reach statistical significance (OR = 0.96, 95% CI = 0.90-1.02, p = 0.19). INTERPRETATION: The difference in metabolic patterns depending on the lateralization of MTLE may represent distinct epileptic networks in patients with right versus left MTLE, and can guide preoperative counseling and surgical planning. Ann Neurol 2019; 1-10 ANN NEUROL 2019;85:241-250.
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ItemEnhanced Sensitivity to Angry Voices in People with Features of the Broader Autism Phenotype(SPRINGER/PLENUM PUBLISHERS, 2018-11)The present study examined whether the ability to recognize vocal emotional expressions is negatively related to features of the Broader Autism Phenotype (BAP) in the general population. We assessed 61 typically developing adults on a BAP self-report measure (Broader Autism Phenotype Questionnaire) and a purpose-developed online emotion recognition task for efficient delivery of non-linguistic vocal stimuli corresponding to the six basic emotions. Contrary to expectations, we found that higher self-ratings of rigid BAP traits correlated with better recognition accuracy and higher intensity ratings for angry voices. We interpret this anger-specific association as an advantage for enhanced threat detection in the BAP and discuss this finding in the broader context of personality research and interpersonal theory.
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ItemNo Preview AvailableUsing spatial manipulation to examine interactions between visual and auditory encoding of pitch and time(FRONTIERS MEDIA SA, 2010)Music notations use both symbolic and spatial representation systems. Novice musicians do not have the training to associate symbolic information with musical identities, such as chords or rhythmic and melodic patterns. They provide an opportunity to explore the mechanisms underpinning multimodal learning when spatial encoding strategies of feature dimensions might be expected to dominate. In this study, we applied a range of transformations (such as time reversal) to short melodies and rhythms and asked novice musicians to identify them with or without the aid of notation. Performance using a purely spatial (graphic) notation was contrasted with the more symbolic, traditional western notation over a series of weekly sessions. The results showed learning effects for both notation types, but performance improved more for graphic notation. This points to greater compatibility of auditory and visual neural codes for novice musicians when using spatial notation, suggesting that pitch and time may be spatially encoded in multimodal associative memory. The findings also point to new strategies for training novice musicians.
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ItemNeurobiological, cognitive, and emotional mechanisms in Melodic Intonation Therapy(FRONTIERS MEDIA SA, 2014-06-02)Singing has been used in language rehabilitation for decades, yet controversy remains over its effectiveness and mechanisms of action. Melodic Intonation Therapy (MIT) is the most well-known singing-based therapy; however, speculation surrounds when and how it might improve outcomes in aphasia and other language disorders. While positive treatment effects have been variously attributed to different MIT components, including melody, rhythm, hand-tapping, and the choral nature of the singing, there is uncertainty about the components that are truly necessary and beneficial. Moreover, the mechanisms by which the components operate are not well understood. Within the literature to date, proposed mechanisms can be broadly grouped into four categories: (1) neuroplastic reorganization of language function, (2) activation of the mirror neuron system and multimodal integration, (3) utilization of shared or specific features of music and language, and (4) motivation and mood. In this paper, we review available evidence for each mechanism and propose that these mechanisms are not mutually exclusive, but rather represent different levels of explanation, reflecting the neurobiological, cognitive, and emotional effects of MIT. Thus, instead of competing, each of these mechanisms may contribute to language rehabilitation, with a better understanding of their relative roles and interactions allowing the design of protocols that maximize the effectiveness of singing therapy for aphasia.
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ItemA Retrospective Study of Survivors of Endovascular Coiling for Posterior and Anterior Aneurysms Medical and Patient Perspectives(LIPPINCOTT WILLIAMS & WILKINS, 2015-08)This article documents the longer-term medical and psychosocial outcomes of patients referred for endovascular coiling.There is limited research investigating outcome following endovascular coiling for posterior compared to anterior circulation aneurysms, and minimal understanding of how medical outcomes relate to patient experiences of treatment and quality of life.We studied a consecutive cohort of 80 patients referred Australia wide for endovascular coiling between 1995 and 2003 (49% posterior; 76% ruptured; 69% women, mean age 51.5 years). We used a mixed methods approach, assessing medical outcome with the Modified Rankin Scale (MRS) in 61 patients (76%), and health-related quality of life and psychosocial functioning using the EuroQol questionnaire and a qualitative semistructured interview in 49 patients (61%).Despite the high proportion of posterior aneurysms, the majority of patients (80%) showed good medical outcomes as indicated by regained independence of activities of daily living (MRS score ≤3). Patients with unruptured aneurysms were significantly more likely to show good outcomes (P < 0.04), whereas aneurysm location (posterior, anterior, or mixed) showed no significant effect. In patients with good medical outcomes, greater functional disability was associated with neurological complications surrounding treatment (P < 0.05). Good outcomes correlated with higher EuroQol ratings (P < 0.001) and the experience of less change after treatment (P < 0.001), although psychosocial adjustment issues were reported by most of the patients, including those with no medical symptoms.These results support the long-term efficacy of endovascular coiling, particularly for posterior circulation aneurysms. They have implications for guiding clinicians and patients in their choice of treatment, as well as the provision of psychological counseling for patient adjustment issues posttreatment.
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ItemLooking beyond lesions for causes of neuropsychological impairment in epilepsy(LIPPINCOTT WILLIAMS & WILKINS, 2019-02-12)OBJECTIVE: Patients with temporal lobe epilepsy (TLE) are similar in their epileptology regardless of whether they have a lesion evident on MRI; this study aims to prospectively clarify whether they are also similar in their neuropsychological profiles. METHODS: Participants comprised 152 adults: 79 patients with TLE and 73 healthy controls. Patients and controls did not differ in age, sex, or education (p > 0.05). Sixty-two percent of patients had an MRI-resolvable lesion (39% with presumed hippocampal sclerosis [HS-TLE], 61% with a lesion other than HS [MRI-positive TLE]); the remaining 38% of patients were lesion-negative. Psychometric measures well established in epilepsy were used. RESULTS: Relative to controls, all 3 patient subgroups showed significantly impaired autobiographical, verbal, and visual memory (p < 0.05-0.001) and significantly more depression and anxiety (p < 0.05-0.01). Yet, contrary to expectations, the 3 TLE subgroups did not differ in their severity of memory or mood impairment (p > 0.05). Lower Full-Scale IQ predicted memory impairments across all TLE subtypes, with early age at seizure onset a predictor unique to MRI-negative TLE. CONCLUSIONS: MRI-negative TLE is associated with memory and mood dysfunction equivalent to that seen in patients with hippocampal sclerosis and other MRI-resolvable pathologies. As such, neuropsychological impairments in TLE are not contingent on a macroscopic lesion and might be an intrinsic property of the underlying network disease.
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ItemIdentification of a Neurocognitive Mechanism Underpinning Awareness of Chronic Tinnitus(NATURE PORTFOLIO, 2017-11-09)Tinnitus (ringing in the ears) is a common auditory sensation that can become a chronic debilitating health condition with pervasive effects on health and wellbeing, substantive economic burden, and no known cure. Here we investigate if impaired functioning of the cognitive control network that directs attentional focus is a mechanism erroneously maintaining the tinnitus sensation. Fifteen people with chronic tinnitus and 15 healthy controls matched for age and gender from the community performed a cognitively demanding task known to activate the cognitive control network in this functional magnetic resonance imaging study. We identify attenuated activation of a core node of the cognitive control network (the right middle frontal gyrus), and altered baseline connectivity between this node and nodes of the salience and autobiographical memory networks. Our findings indicate that in addition to auditory dysfunction, altered interactions between non-auditory neurocognitive networks maintain chronic tinnitus awareness, revealing new avenues for the identification of effective treatments.
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ItemThe genetic basis of music ability(FRONTIERS MEDIA SA, 2014-06-27)Music is an integral part of the cultural heritage of all known human societies, with the capacity for music perception and production present in most people. Researchers generally agree that both genetic and environmental factors contribute to the broader realization of music ability, with the degree of music aptitude varying, not only from individual to individual, but across various components of music ability within the same individual. While environmental factors influencing music development and expertise have been well investigated in the psychological and music literature, the interrogation of possible genetic influences has not progressed at the same rate. Recent advances in genetic research offer fertile ground for exploring the genetic basis of music ability. This paper begins with a brief overview of behavioral and molecular genetic approaches commonly used in human genetic analyses, and then critically reviews the key findings of genetic investigations of the components of music ability. Some promising and converging findings have emerged, with several loci on chromosome 4 implicated in singing and music perception, and certain loci on chromosome 8q implicated in absolute pitch and music perception. The gene AVPR1A on chromosome 12q has also been implicated in music perception, music memory, and music listening, whereas SLC6A4 on chromosome 17q has been associated with music memory and choir participation. Replication of these results in alternate populations and with larger samples is warranted to confirm the findings. Through increased research efforts, a clearer picture of the genetic mechanisms underpinning music ability will hopefully emerge.
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ItemThe musical environment and auditory plasticity: hearing the pitch of percussion(FRONTIERS MEDIA SA, 2013-10-24)Although musical skills clearly improve with training, pitch processing has generally been believed to be biologically determined by the behavior of brain stem neural mechanisms. Two main classes of pitch models have emerged over the last 50 years. Harmonic template models have been used to explain cross-channel integration of frequency information, and waveform periodicity models have been used to explain pitch discrimination that is much finer than the resolution of the auditory nerve. It has been proposed that harmonic templates are learnt from repeated exposure to voice, and so it may also be possible to learn inharmonic templates from repeated exposure to inharmonic music instruments. This study investigated whether pitch-matching accuracy for inharmonic percussion instruments was better in people who have trained on these instruments and could reliably recognize their timbre. We found that adults who had trained with Indonesian gamelan instruments were better at recognizing and pitch-matching gamelan instruments than people with similar levels of music training, but no prior exposure to these instruments. These findings suggest that gamelan musicians were able to use inharmonic templates to support accurate pitch processing for these instruments. We suggest that recognition mechanisms based on spectrotemporal patterns of afferent auditory excitation in the early stages of pitch processing allow rapid priming of the lowest frequency partial of inharmonic timbres, explaining how music training can adapt pitch processing to different musical genres and instruments.
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ItemPitch and Plasticity: Insights from the Pitch Matching of Chords by Musicians with Absolute and Relative Pitch(MDPI, 2013-12)Absolute pitch (AP) is a form of sound recognition in which musical note names are associated with discrete musical pitch categories. The accuracy of pitch matching by non-AP musicians for chords has recently been shown to depend on stimulus familiarity, pointing to a role of spectral recognition mechanisms in the early stages of pitch processing. Here we show that pitch matching accuracy by AP musicians was also dependent on their familiarity with the chord stimulus. This suggests that the pitch matching abilities of both AP and non-AP musicians for concurrently presented pitches are dependent on initial recognition of the chord. The dual mechanism model of pitch perception previously proposed by the authors suggests that spectral processing associated with sound recognition primes waveform processing to extract stimulus periodicity and refine pitch perception. The findings presented in this paper are consistent with the dual mechanism model of pitch, and in the case of AP musicians, the formation of nominal pitch categories based on both spectral and periodicity information.