Function of the human cerebellum in timing and auditory-motor synchronisation

This thesis is divided into two main parts: introduction and experimental research. Chapter 1 and Chapter 2 in the introduction provide a theoretical background for the experimental research presented in Chapters 4–6. Chapter 3 includes a description of the general methods, set-up and measures used in the experimental research. Chapter 1 opens with some general considerations on the concept of time in cognitive psychology, followed by a classification of timing abilities. Timing processing is conceptualized as the ability of the brain to track the passage of time and to process temporal properties of exogenous sensory stimuli. Timing ability is thought to be fundamental to both perception and action. After a general introduction on timing, the topic moves onto auditory-motor synchronisation, a behaviour that is thought to rely on temporal processing. This section includes an account of auditorymotor synchronization both in human and in other species, and a discussion of the clinical relevance of auditory-motor synchronization. Chapter 2 is dedicated to the cerebellum, a structure at the back of the brain that is the focus of the work presented in this thesis. The chapter includes a description of cerebellar anatomy, function and dysfunction. The second part of the thesis opens with a general method section, Chapter 3, which includes a concise description of techniques, methods and measures used in the experimental research, as well as some descriptions for standard practices. Following on, Chapter 4 is a report of two behavioural experiments on perceptual timing (Zeni & Holmes, 2018). The aim of these experiments was to examine whether a regular sequence of sounds can modulate the perceived duration of time intervals embedded in the sequence, as shown by Barnes and Jones (2000). These experiments should have provided the grounding for the following research on motor timing, but the result did not replicate. An argument was made around the impact of methodological choices on the results. Chapter 5 is a report of two cerebellar transcranial magnetic stimulation (TMS) experiments that were run to examine whether single-pulse TMS delivered over the cerebellum could be used to interfere with auditory-motor synchronization, studied with the finger-tapping task. Notice that a similar use of repetitive TMS had been proven successful. Both intermittent and continuous rhythmic movements were examined, to test the hypothesis of dissociation between these two movement types, as suggested by previous behavioural and clinical evidence. TMS affected fingertapping performance, but the effect observed, which was short-lasting and not hemispheric-specific, most likely resulted from the discomfort and the nonhabituating startle-like reflex elicited by TMS, rather than from a direct interference of the stimulation with cerebellar function. Chapter 6 is a report of a two-session, simultaneous EMG-fMRI experiment on the function of the cerebellum in auditory-motor synchronization. In this experiment, both intermittent and continuous rhythmic movements, both paced and unpaced by an external auditory stimulus, were examined. Intermittent and continuous rhythmic movements are thought to require different processing, and the cerebellum is suggested to be involved in this dissociation. More specifically, temporally constrained intermittent movements are thought to rely on cerebellar functioning. Representational similarity analysis was used to test whether the difference between intermittent and continuous movements and between paced and unpaced tasks were encoded in the functional activity of the cerebellum. Alternative models built out of behavioural data were tested to decide whether the cerebellum was more likely to encode aspects specific to synchronisation performance, rather than motor execution. Contrary to predictions, continuous movements activated the cerebellum (ipsilateral lobules V, VI and VIII) more than intermittent movements. Moreover, this activation was more likely to reflect differences in the motor component of the task, rather than aspects of synchronisation performance. The thesis concludes with a general discussion of the experimental work, reported in Chapter 7. This final chapter includes a summary of the research questions addressed, a description of how the conclusions are supported by the results and are integrated in the existing body of knowledge. Limitations and implication for future studies were also discussed

PENGARUH PENJUALAN, BIAYA PRODUKSI DAN BIAYA PEMASARAN TERHADAP LABA PERUSAHAAN (PADA PT. BINA MEGAH INDOWOOD GRESIK TAHUN 2015-2018)

Penelitian ini bertujuan untuk mengetahui pengaruh secara parsial dan simultan varibel penjualan, biaya produksi, biaya pemasaran terhadap laba perusahaan pada PT. Bina Megah Indowood Gresik Tahun 2015-2018. Jenis penelitian ini adalah deskriptif kuantitatif yaitu penelitian dengan cara eksperimen dan survei dengan pendekatan kuantitatif. Sampel dalam penelitian ini sebanyak 48 laporan bulanan, dengan menggunakan uji normalitas, multikolonearitas, heteroskedastisitas dan autokorelasi, uji hipotesis yaitu ujit t, uji f, uji koefesien determinasi (R2) dengan SPSS versi 24.Dari hasil pengujian uji t dapat diketahui bahwa (X1) Penjualan diperoleh dengan nilai signifikan yaitu 0,000 lebih kecil dari 0,05 menunjukkan bahwa Penjualan berpengaruh signifikan terhadap Laba Perusahaan, (X2) Biaya Produksi diperoleh dengan nilai 0,000 lebih kecil dari 0,05 yang berarti Biaya produksi berpengaruh signifikan terhadap Laba perusahaan, (X3) Biaya pemasaran diperoleh dengan nilai signifikansi sebesar 0,165 lebih besar dari 0,05 yang berarti Biaya pemasaran tidak berpengaruh signifikan terhadap Laba perusahaan, sedangkan dari hasil pengujian uji F diketahui bahwa penjualan, biaya produksi dan biaya pemasaran berpengaruh terhadap laba perusahaan secara bersama-sama atau simultan

The effect of a regular auditory context on perceived interval Duration

In the auditory domain, the perceived duration of time intervals is influenced by background sounds – the auditory context in which the intervals are embedded – even when the background may be ignored. Previous research has shown that a regular context made of evenly spaced sounds improves participants’ discrimination of intervals close in duration to the context intervals. These results have been explained in terms of attention and anticipation. The present study reconsiders the effect of context regularity, focusing on the relationships among the intervals in the context and the interval to be estimated. The influence of a regular compared to a non-regular auditory context on interval discrimination was examined with a two interval forced choice task, which required participants to discriminate between the durations of two time intervals. Duration perception was more precise when the intervals to be discriminated were preceded by a regular compared to a non-regular context. This effect of the regular context, however, was not selective for the duration of the first interval to be estimated, contrary to suggestions based on previous evidenc

Treatment of food processing wastes for the production of medium chain fatty acids via chain elongation

The production of medium chain fatty acids (MCFAs) through reverse β-oxidation was investigated both on synthetic and real substrates. From preliminary batch tests emerged that caproic acid was maximized under an acetate/ethanol molar ratio of 5:1 at neutral pH. This ratio was then adopted in different semi-continuous tests operating with different amounts of the two reactants. It emerged that the MCFAs yield reached the maximum level of 6.7% when the total molar substrate amount was around 40–45 mmol/d, while the process was inhibited for values higher than 400 mmol/d. Semi-continuous tests using real waste as substrates, namely food waste condensate, cheese whey, and winery wastewater, confirmed the results obtained with the synthetic substrates. Better performances were obtained when an adequate molar ratio of the acetate and the electron-donor compound was naturally present. Therefore, a MCFAs yield of 25% and 10.5% was obtained for condensate of food waste and acidic cheese whey, respectively. Regarding MCFAs composition, caproic acid was the dominant form but small concentrations of octanoic acid were also found in the tests where ethanol was the electron donor (synthetic substrates and food waste condensate). Octanoic acid was not produced in test where lactic acid represented the electron donor molecules (cheese whey). Condensate and synthetic samples were dominated by Pseudoclavibacter caeni with an abundance of 38.19% and 33.38% respectively, while Thomasclavelia (24.13%) and Caproiciproducens (11.68%) was the most representative genus in acidic cheese whey sample

Locating primary somatosensory cortex in human brain stimulation studies: Experimental evidence

Transcranial magnetic stimulation (TMS) over human primary somatosensory cortex (S1) does not produce immediate outputs. Researchers must therefore rely on indirect methods for TMS coil positioning. The 'gold standard' is to use individual functional and structural magnetic resonance imaging (MRI) data, but the majority of studies don't do this. The most common method to locate the hand area of S1 (S1-hand) is to move the coil posteriorly from the hand area of primary motor cortex (M1-hand). Yet, S1-hand is not directly posterior to M1-hand. We localised the index finger area of S1-hand experimentally in four ways. First, we re-analysed functional MRI data from 20 participants who received vibrotactile stimulation to their 10 digits. Second, to assist the localisation of S1-hand without MRI data, we constructed a probabilistic atlas of the central sulcus from 100 healthy adult MRIs, and measured the likely scalp location of S1-index. Third, we conducted two experiments mapping the effects of TMS across the scalp on tactile discrimination performance. Fourth, we examined all available neuronavigation data from our laboratory on the scalp location of S1-index. Contrary to the prevailing method, and consistent with systematic review evidence, S1-index is close to the C3/C4 electroencephalography (EEG) electrode locations on the scalp, approximately 7-8 cm lateral to the vertex, and approximately 2 cm lateral and 0.5 cm posterior to the M1-FDI scalp location. These results suggest that an immediate revision to the most commonly-used heuristic to locate S1-hand is 45 required. The results of many TMS studies of S1-hand need reassessment

Body composition by simple anthropometry, bioimpedance and DXA in preschool children: interrelationships among methods

Objetivo. Comparar la composición corporal estimada por dos métodos antropométricos simples y por impedanciometría (BIA, por sus siglas en inglés) y absorciometría de doble haz de rayos X (DXA, por sus siglas en inglés) y estudiar las correlaciones existentes entre ellos, en una población preescolar de Argentina. Población, material y métodos. Se estudió transversalmente una población clínicamente sana, de edad comprendida entre 4 y 6 años, de 230 niños (118 varones y 112 niñas), que concurrían a Jardines Integrales de La Matanza, Argentina. Se determinó el índice de masa corporal (IMC), la circunferencia de cintura (Cci) y el contenido de grasa corporal, expresado como porcentaje, por BIA (Maltron BF900) y por DXA (densitómetro Lunar DPX-L, software pediátrico). Resultados. En IMC y Cci no se observaron diferencias estadísticamente significativas entre ambos sexos, pero sí en el porcentaje de grasa corporal por BIA o DXA. La correlación entre BIA y ambos métodos antropométricos fue moderada (r de Pearson= 0,43-0,53), al igual que entre DXA y Cci (r= 0,66), mientras que las demás correlaciones fueron fuertes (r= 0,71-0,83). Las medidas obtenidas por BIA y DXA no concordaron (prueba de Bland Altman); sin embargo, las diferencias se distribuyeron en forma homogénea a lo largo del eje horizontal e independientemente de las medias. BIA reprodujo valores más bajos de porcentaje de grasa corporal que DXA (p <0,0001). Conclusiones. Existe buena correlación entre los métodos antropométricos sencillos y la bioimpedancia y DXA. Sin embargo, los resultados no son intercambiables, incluso entre BIA y DXA.Objective.To examine the interrelationships of body composition variables derived from simple anthropometry, bioelectrical impedance (BIA) and dualenergy X-ray absorptiometry (DXA). Population, material and methods. A total of 230 healthy preschool children (118 males and 112 females) age 4-6 years, attending a day care center, were examined to determine body mass index (BMI) and waist circumference (WC). Percentage of body fat content (%BF) was predicted by BIA (Maltron BF900) and DXA (Lunar DPX-L, pediatric software). Results. BMI and WC did not show significant differences among sex, while %BF by BIA or DXA did. BIA measures were lower than DXA´s (p <0.0001). Correlation between BIA vs. anthropometric methods and WC vs. DXA were moderate (Pearson r= 0.43 to 0.53), whereas the other correlations were strong (r= 0.71 to 0.83). However Bland Altman comparison showed wide limits of agreement between BIA and DXA; BIA significantly underestimated %BF as determined by DXA (p <0.0001). Conclusion. The methods used to estimate body composition in healthy preschool children highly correlated. However, the Bland Altman procedure suggests that BIA and DXA should not be used interchangeably.Fil: Rodriguez, Patricia N.. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Bioquímica General y Bucal; ArgentinaFil: Bermúdez, Enrique E.. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Bioquímica General y Bucal; ArgentinaFil: Rodriguez, Gabriela Soledad. Hospital del Niño; ArgentinaFil: Spina, Maria A.. Hospital del Niño; ArgentinaFil: Zeni, Susana Noemi. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Bioquímica General y Bucal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Friedman, Silvia María. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Bioquímica General y Bucal; ArgentinaFil: Exeni, Ramón Alfonso. Hospital del Niño; Argentin

Function of the human cerebellum in timing and auditory-motor synchronisation

This thesis is divided into two main parts: introduction and experimental research. Chapter 1 and Chapter 2 in the introduction provide a theoretical background for the experimental research presented in Chapters 4–6. Chapter 3 includes a description of the general methods, set-up and measures used in the experimental research. Chapter 1 opens with some general considerations on the concept of time in cognitive psychology, followed by a classification of timing abilities. Timing processing is conceptualized as the ability of the brain to track the passage of time and to process temporal properties of exogenous sensory stimuli. Timing ability is thought to be fundamental to both perception and action. After a general introduction on timing, the topic moves onto auditory-motor synchronisation, a behaviour that is thought to rely on temporal processing. This section includes an account of auditorymotor synchronization both in human and in other species, and a discussion of the clinical relevance of auditory-motor synchronization. Chapter 2 is dedicated to the cerebellum, a structure at the back of the brain that is the focus of the work presented in this thesis. The chapter includes a description of cerebellar anatomy, function and dysfunction. The second part of the thesis opens with a general method section, Chapter 3, which includes a concise description of techniques, methods and measures used in the experimental research, as well as some descriptions for standard practices. Following on, Chapter 4 is a report of two behavioural experiments on perceptual timing (Zeni & Holmes, 2018). The aim of these experiments was to examine whether a regular sequence of sounds can modulate the perceived duration of time intervals embedded in the sequence, as shown by Barnes and Jones (2000). These experiments should have provided the grounding for the following research on motor timing, but the result did not replicate. An argument was made around the impact of methodological choices on the results. Chapter 5 is a report of two cerebellar transcranial magnetic stimulation (TMS) experiments that were run to examine whether single-pulse TMS delivered over the cerebellum could be used to interfere with auditory-motor synchronization, studied with the finger-tapping task. Notice that a similar use of repetitive TMS had been proven successful. Both intermittent and continuous rhythmic movements were examined, to test the hypothesis of dissociation between these two movement types, as suggested by previous behavioural and clinical evidence. TMS affected fingertapping performance, but the effect observed, which was short-lasting and not hemispheric-specific, most likely resulted from the discomfort and the nonhabituating startle-like reflex elicited by TMS, rather than from a direct interference of the stimulation with cerebellar function. Chapter 6 is a report of a two-session, simultaneous EMG-fMRI experiment on the function of the cerebellum in auditory-motor synchronization. In this experiment, both intermittent and continuous rhythmic movements, both paced and unpaced by an external auditory stimulus, were examined. Intermittent and continuous rhythmic movements are thought to require different processing, and the cerebellum is suggested to be involved in this dissociation. More specifically, temporally constrained intermittent movements are thought to rely on cerebellar functioning. Representational similarity analysis was used to test whether the difference between intermittent and continuous movements and between paced and unpaced tasks were encoded in the functional activity of the cerebellum. Alternative models built out of behavioural data were tested to decide whether the cerebellum was more likely to encode aspects specific to synchronisation performance, rather than motor execution. Contrary to predictions, continuous movements activated the cerebellum (ipsilateral lobules V, VI and VIII) more than intermittent movements. Moreover, this activation was more likely to reflect differences in the motor component of the task, rather than aspects of synchronisation performance. The thesis concludes with a general discussion of the experimental work, reported in Chapter 7. This final chapter includes a summary of the research questions addressed, a description of how the conclusions are supported by the results and are integrated in the existing body of knowledge. Limitations and implication for future studies were also discussed

An instance of presyncope during magnetic stimulation of the median nerve, and instances of presyncope and syncope during evaluation of resting motor threshold with transcranial magnetic stimulation (TMS)

We report three MS-related events that occurred at the Centre for Integrative Neuroscience and Neurodynamics, University of Reading, Reading, and the School of Psychology, University of Nottingham, Nottingham, both in the UK