Several lines of evidence suggest that asymmetric anterior brain activation is related to affective style, linking left hemisphere activation to positive affect and right hemisphere activation to negative affect. However, previous reports of left frontal hypoactivation in depressed patients were not confirmed in recent studies. This study evaluated additional characteristics of resting EEG alpha (8–13 Hz) asymmetry in 15 clinically depressed patients and 22 healthy adults by recording EEG activity on two separate occasions, 2–4 weeks apart. Across both sessions, group differences in anterior EEG asymmetry were compatible with the original hypothesis. However, groups differed in temporal stability of anterior EEG asymmetry, which was retest reliable in controls but not depressed patients. In contrast, temporal stability of posterior EEG asymmetry was acceptable in both groups. Increased variability of anterior EEG asymmetry may be a characteristic feature for depression, and, if so, this would challenge the notion that anterior EEG alpha asymmetry is a trait marker for depression. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

No / PURPOSE: To examine foveal structure in amblyopia using spectral-domain optical coherence tomography (SD-OCT). DESIGN: Prospective, cross-sectional study. PARTICIPANTS AND CONTROLS: Two subject groups were recruited to the study: 85 amblyopes (34 adults, 51 children) and 110 visually normal controls (44 adults, 66 children). METHODS: A detailed eye examination, including an SD-OCT scan, was performed in all participants. A total of 390 eyes of 195 subjects were imaged using a 3-dimensional (3D) macula scan covering a nominal 6 x 6-mm area with a resolution of 256 x 256 (65,536 axial scans). Data from the B-scans bisecting the fovea both horizontally and vertically were fitted with a mathematical model of the fovea to determine a range of foveal parameters. MAIN OUTCOME MEASURES: Foveal thickness, foveal pit depth, and foveal pit slope. RESULTS: Bilateral differences between the eyes of amblyopes compared with visually normal controls were found. The difference between foveal structure in amblyopic participants relative to structure in subjects with normal vision persisted even when variables such as age, ethnicity, axial length, and sex were taken into account. Amblyopes showed increased foveal thickness (+8.31 mum; P = 0.006) and a reduction in pit depth in the horizontal meridian (-10.06 mum; P = 0.005) but not in the vertical meridian (P = 0.082) when compared with subjects with normal vision. Foveal pit slopes were found to be approximately 1 degree flatter in the nasal (P = 0.033) and temporal (P = 0.014) meridians in amblyopes, but differences between amblyopes and controls in the superior (P = 0.061) and inferior (P = 0.087) meridians did not reach statistical significance. No statistically significant interocular differences were found in the foveal structure between amblyopic and fellow eyes. CONCLUSIONS: Differences were found in the foveal structure in both eyes of amblyopes compared with subjects with normal vision. These differences consisted of increased foveal thickness, reduced pit depth when measured along the horizontal meridian, and flattening of the nasal and temporal sides of the foveal pit.

Nach dem Prinzip synchronisierter Reimwörter wurde ein deutscher dichotischer Hörtest entwickelt und erprobt (Fused Words, FW10b). Die Reliabilitätskennwerte lagen für die innere Konsistenz bei alpha=0,89 und für die Re-Test-Reliabilität im Bereich von r-tt=0,67 bis r-tt=0,87. Der dichotische Test korrelierte hoch mit einem Paralleltest (r=.73, FW12k). In mehreren Untersuchungen fand sich keine Assoziation des dichotischen Lateralisationsergebnisses mit dem Hormonzyklus bei Frauen. Zwischen der Klassifikation im Wada-Test und der Klassifikation im dichotischen Test wurde eine hohe prozentuale Übereinstimmung beobachtet (91%). Auch in einer externen Studie wurde eine hohe Konkordanz mit einem fMRT Paradigma gefunden (97%, Hund-Georgiadis et al 2002). Unter Rechtshändern hatten 70% einen Rechts-Ohr-Vorteil, 23% einen Links-Ohr-Vorteil; bei 7% wurde kein Ohr-Vorteil beobachtet. Es bestand eine hohe Assoziation zwischen dem Lateralitätsquotient der Händigkeit und dem Lateralitätsindex Lambda aus dem dichotischen Test (R=0,76, r=0,72). Bei epilepsiechirurgischen Kandidaten mit links- oder rechtsseitigen Temporallappenläsionen, die alle durch einen Wada-Test als unilateral links-hemisphärisch sprachdominant kategorisiert worden waren, wurden Läsionseffekte analysiert (Hippocampus-Sklerose vs. extra-hippocampale Läsionen). Wie erwartet ergaben sich massive Läsionseffekte für die Patienten mit den Läsionen in der linken sprachdominanten Hemisphäre. In der linken extra-hippocampalen Untergruppe kam es zu einer signifikanten Abnahme der Rechts-Ohr-Punkte und gleichzeitig zu einem signifikanten Anstieg der Links-Ohr-Punkte. Die Einbeziehung von neokortikalen und anderen extra-hippocampalen Strukturen in die temporalen Läsionen war von entscheidender Bedeutung für die Unterdrückung der Antworten vom kontralateralen (rechtsseitigen) Ohr. Die Zunahme der Links-Ohr-Punkte in der Gruppe mit linksseitigen extra-hippocampalen Läsionen deutet eine kompensatorische Verlagerung von Sprachfunktionen auf die rechte Hemisphäre an, die durch den Wada Test nicht erfasst wurde. / Following the principle of synchronized rhyming words a German dichotic listening test was developed and tested (fused words, FW10b). Reliability coefficients for the inner consistency were at alpha=0,89 and for the re-test-reliability between r-tt=0,67 and r-tt=0,87. The dichotic test FW10b was highly correlated with a parallel test (r=.73, FW12k). None of several studies did show any association between the dichotic language lateralization and the hormonal cycle in women. A high percentage of agreement was observed between the Wada classification and the classification by the dichotic test (91%). Furthermore Hund-Georgiadis et al. (2002) found a high percentage of concordance with the lateralization by a fMRI paradigm in an external study (97%). Among right-handers 70% showed a right ear advantage, 23% had a left ear advantage, and 7% had no ear advantage. There was a high association between the laterality quotient of the handedness inventory and the laterality index Lambda of the dichotic listening test FW10b (R=0.76, r=0.72). Lesion effects were analyzed in epilepsy surgical candidates with left and right temporal lobe lesions (hippocampus sclerosis vs. extra-hippocampal lesions), who were all categorized as left-hemispheric language dominant by a Wada-test. As expected, massive lesion effects were apparent in those patients who had their lesions in the left language dominant hemisphere. In the subgroup with left extra-hippocampal lesions there was a significant decrease of right-ear-points and at the same time a significant increase of left-ear-points. The involvement of neocortex and other extra-hippocampal structures in temporal lobe lesions were of crucial importance for the suppression of contralateral (right) ear responses. The elevation of left-ear-points in the left-lateral group indicated a partial compensational shift of language functions to the right hemisphere, which was not detected by the Wada procedure.

Summaries in Afrikaans and English / Text in Afrikaans / Two opposing approaches to beginning reading are used, namely the phonological and global approach, under which the whole word, whole sentence and whole language methods are classed. The whole crux of the controversy is situated in beginning reading as an explicit, intensive and systematic method of teaching phonics, as opposed to implicit beginning reading through discrimination of global configurations, augmented by psycholinguistic guesses within reading context. Arguments about the advantages and disadvantages of the opposing methods have been hurdled to and fro for decades without any discernible gain. The question emerged whether research on brain physiology with respect to language and reading, a relatively new field of study, could shed light on the foundation of an accountable method for beginning reading. Renewed insights to the controversial differences were gained, and brain physiologically accountable parameters as a base for a beginning reading method were framed from these insights. / Twee opponerende aanvangsleesbenaderings word in die skole gebruik, naamlik die fonologiese benadering en die geheelbenadering, waaronder die geheelwoord-, geheelsinen die geheeltaalmetode ressorteer. Die kern van die verskil tussen die aanvangsleesbenaderings le in aanvangslees as eksplisiete, intensiewe en sistematiese foneemonderrig, teenoor implisiete aanvangslees wat die waarneming van globale konfigurasies, aangevul deur psigolinguistiese raaiskote binne die leeskonteks, aanmoedig. In die polemiek om die beste leesmetode word argumente oor die voor- en nadele ten opsigte van die begronding van hierdie opponerende metodes reeds dekades heen en weer geslinger. Navorsingsresultate word eindeloos, sonder duidelike winste, met mekaar vergelyk. Dit het die vraag laat onstaan of navorsing ten opsigte van die breinfisiologie met betrekking tot taal en lees, 'n relatief nuwe studieveld, moontlik lig sou kon werp op die begronding van 'n verantwoordbare aanvangsleesmetode. Die literatuurstudie ten opsigte van breinfisiologie het vernuwende insigte oor die polemiese begrondingsverskille na vore gebring, en breinfisiologies-verantwoordbare parameters as basis vir 'n aanvangsleesmetode is uit hierdie insigte opgestel. / Psychology of Education / M. Ed. (Psychology of Education)

A inferência do curso temporal da atividade neural a partir do efeito BOLD é um importante problema, ainda em aberto. A forma da curva BOLD não reflete diretamente as características temporais da atividade eletrofisiológica dos neurônios. Nessa tese, é introduzido o conceito de tempo de processamento neural (TPN) como um dos parâmetros do modelo biofísico da função de resposta hemodinâmica (HRF). O objetivo da introdução desse conceito é obter estimativas mais acuradas da duração da atividade neural a partir do efeito BOLD, que possui auto grau de nãolinearidade. Duas formas de estimar os parâmetros do modelo do efeito BOLD foram desenvolvidas. A validade e aplicabilidade do conceito de TPN e das rotinas de estimação foram avaliadas por simulações computacionais e análise de séries temporais experimentais. Os resultados das simulações e da aplicação foram comparados com medidas da forma da HRF. O experimento analisado consistiu em um paradigma de tomada de decisão na presença de distratores emocionais. Esperase que o TPN em áreas sensoriais primárias seja equivalente ao tempo de apresentação de estímulos. Por outro lado, o TPN em áreas relacionadas com a tomada de decisão deve ser menor que a duração dos estímulos. Além disso, o TPN deve depender da condição experimental em áreas relacionadas ao controle de distratores emocionais. Como predito, o valores estimados do TPN no giro fusiforme foram equivalentes à duração dos estímulos e o TPN no giro do cíngulo dorsal variou com a presença de distrator emocional. Observou-se ainda lateralidade do TPN no córtex pré-frontal dorsolateral. As medidas da forma da HRF obtidas por um método convencional não dectectaram as variações observadas no TPN / The extraction of information about neural activity dynamics related to the BOLD signal is a challenging task. The temporal evolution of the BOLD signal does not directly reflect the temporal characteristics of electrical activity of neurons. In this work, we introduce the concept of neural processing time (NPT) as a parameter of the biophysical model of the hemodynamic response function (HRF). Through this new concept we aim to infer more accurately the duration of neuronal response from the highly nonlinear BOLD effect. We describe two routines to estimate the parameters of the HRF model. The face validity and applicability of the concept of NPT and the estimation procedures are evaluated through simulations and analysis of experimental time series. The results of both simulation and application were compared with summary measures of HRF shape. We analysed an experiment based on a decision-making paradigm with simultaneous emotional distracters. We hypothesize that the NPT in primary sensory areas is approximately the stimulus presentation duration. On the other hand, the NPT in brain areas related to decisionmaking processes should be less than the stimulus duration. Moreover, in areas related to processing of an emotional distracter, the NPT should depend on the experimental condition. As predicted, the NPT in fusiform gyrus is close to the stimulus duration and the NPT in dorsal anterior cingulate gyrus depends on the presence of an emotional distracter. Interestingly, the estimated NPTs in the dorsolateral prefrontal cortex indicate functional laterality of this region. The analysis using standard measures of HRF did not detect the variations observed in our method (NPT)

A inferência do curso temporal da atividade neural a partir do efeito BOLD é um importante problema, ainda em aberto. A forma da curva BOLD não reflete diretamente as características temporais da atividade eletrofisiológica dos neurônios. Nessa tese, é introduzido o conceito de tempo de processamento neural (TPN) como um dos parâmetros do modelo biofísico da função de resposta hemodinâmica (HRF). O objetivo da introdução desse conceito é obter estimativas mais acuradas da duração da atividade neural a partir do efeito BOLD, que possui auto grau de nãolinearidade. Duas formas de estimar os parâmetros do modelo do efeito BOLD foram desenvolvidas. A validade e aplicabilidade do conceito de TPN e das rotinas de estimação foram avaliadas por simulações computacionais e análise de séries temporais experimentais. Os resultados das simulações e da aplicação foram comparados com medidas da forma da HRF. O experimento analisado consistiu em um paradigma de tomada de decisão na presença de distratores emocionais. Esperase que o TPN em áreas sensoriais primárias seja equivalente ao tempo de apresentação de estímulos. Por outro lado, o TPN em áreas relacionadas com a tomada de decisão deve ser menor que a duração dos estímulos. Além disso, o TPN deve depender da condição experimental em áreas relacionadas ao controle de distratores emocionais. Como predito, o valores estimados do TPN no giro fusiforme foram equivalentes à duração dos estímulos e o TPN no giro do cíngulo dorsal variou com a presença de distrator emocional. Observou-se ainda lateralidade do TPN no córtex pré-frontal dorsolateral. As medidas da forma da HRF obtidas por um método convencional não dectectaram as variações observadas no TPN / The extraction of information about neural activity dynamics related to the BOLD signal is a challenging task. The temporal evolution of the BOLD signal does not directly reflect the temporal characteristics of electrical activity of neurons. In this work, we introduce the concept of neural processing time (NPT) as a parameter of the biophysical model of the hemodynamic response function (HRF). Through this new concept we aim to infer more accurately the duration of neuronal response from the highly nonlinear BOLD effect. We describe two routines to estimate the parameters of the HRF model. The face validity and applicability of the concept of NPT and the estimation procedures are evaluated through simulations and analysis of experimental time series. The results of both simulation and application were compared with summary measures of HRF shape. We analysed an experiment based on a decision-making paradigm with simultaneous emotional distracters. We hypothesize that the NPT in primary sensory areas is approximately the stimulus presentation duration. On the other hand, the NPT in brain areas related to decisionmaking processes should be less than the stimulus duration. Moreover, in areas related to processing of an emotional distracter, the NPT should depend on the experimental condition. As predicted, the NPT in fusiform gyrus is close to the stimulus duration and the NPT in dorsal anterior cingulate gyrus depends on the presence of an emotional distracter. Interestingly, the estimated NPTs in the dorsolateral prefrontal cortex indicate functional laterality of this region. The analysis using standard measures of HRF did not detect the variations observed in our method (NPT)

Summaries in Afrikaans and English / Text in Afrikaans / Two opposing approaches to beginning reading are used, namely the phonological and global approach, under which the whole word, whole sentence and whole language methods are classed. The whole crux of the controversy is situated in beginning reading as an explicit, intensive and systematic method of teaching phonics, as opposed to implicit beginning reading through discrimination of global configurations, augmented by psycholinguistic guesses within reading context. Arguments about the advantages and disadvantages of the opposing methods have been hurdled to and fro for decades without any discernible gain. The question emerged whether research on brain physiology with respect to language and reading, a relatively new field of study, could shed light on the foundation of an accountable method for beginning reading. Renewed insights to the controversial differences were gained, and brain physiologically accountable parameters as a base for a beginning reading method were framed from these insights. / Twee opponerende aanvangsleesbenaderings word in die skole gebruik, naamlik die fonologiese benadering en die geheelbenadering, waaronder die geheelwoord-, geheelsinen die geheeltaalmetode ressorteer. Die kern van die verskil tussen die aanvangsleesbenaderings le in aanvangslees as eksplisiete, intensiewe en sistematiese foneemonderrig, teenoor implisiete aanvangslees wat die waarneming van globale konfigurasies, aangevul deur psigolinguistiese raaiskote binne die leeskonteks, aanmoedig. In die polemiek om die beste leesmetode word argumente oor die voor- en nadele ten opsigte van die begronding van hierdie opponerende metodes reeds dekades heen en weer geslinger. Navorsingsresultate word eindeloos, sonder duidelike winste, met mekaar vergelyk. Dit het die vraag laat onstaan of navorsing ten opsigte van die breinfisiologie met betrekking tot taal en lees, 'n relatief nuwe studieveld, moontlik lig sou kon werp op die begronding van 'n verantwoordbare aanvangsleesmetode. Die literatuurstudie ten opsigte van breinfisiologie het vernuwende insigte oor die polemiese begrondingsverskille na vore gebring, en breinfisiologies-verantwoordbare parameters as basis vir 'n aanvangsleesmetode is uit hierdie insigte opgestel. / Psychology of Education / M. Ed. (Psychology of Education)

Title: The impact of the exclusion of the visual analyzer on the swimmer's ability to swim straight while doing the crawl Goals: The goal of this work is to determine the impact of the exclusion of the visual analyzer on one's ability to swim straight while doing the crawl; to find and analyze the angle of the deviation from the set central line, if any, using measurable variables; to find the critical spots in the fulfillment of a set movement assignment where the swimmer deviated from his straight swimming direction, to make a qualitative analysis of these spots in relation to the individually optimal technique, and to propose potential corrections of the time and space of movements of the upper limbs work and the body. Methods: A qualitative analysis with a manual measurement of the deviation from the straight direction of swimming per constant distance. Analysis of a video- recording to find the critical points in the crawl technique. Questionnaire to deal with participants' upper limbs laterality. Results: We managed to determine some causes of the deviation from the straight swimming direction without visual control. The achieved results proved that breathing was an important aspect when doing the crawl having influence on the ability to swim straight: The impact of laterality on the...

La disconnessione frontostriatale è considerata il correlato neurale della disfunzione esecutiva nei pazienti con malattia di Parkinson (MP), una patologia neurodegenerativa che si presenta nella fase iniziale come una sindrome clinica asimmetrica con sintomi predominanti nel lato destro o sinistro associati alla perdita neuronale nella sostanza grigia profonda dell'emisfero cerebrale controlaterale. Nella tesi, è stato indagato un particolare aspetto della disfunzione esecutiva nella MP espressa quando è richiesto di selezionare le parole nel contesto di alternative in competizione, cercando differenze in relazione all'insorgenza clinica dei sintomi motori. A livello neurostrutturale, sono state esplorate le alterazioni della sostanza grigia e bianca nelle sottopopolazioni di MP, verificando se la capacità di selezionare le parole è associata ad indici di integrità della materia sostanza grigia e bianca nelle sottopopolazioni di PD. Infine, a livello neurofunzionale, è stato esplorato se la connettività delle regioni cerebrali associate alla disfunzione esecutiva in MP è modulata dalla riserva cognitiva, un fattore di efficienza cognitiva dovuto ad esperienze di vita cognitivamente stimolanti che possono contribuire alla resilienza nel fronteggiare al meglio la neurodegenerazione. Le evidenze raccolte indicano che la lateralità di insorgenza dei sintomi motori e la riserva cognitiva dovrebbero essere prese in considerazione nella valutazione delle funzioni cognitive nei pazienti con MP. / Frontostriatal disconnection is considered the neural correlate of executive dysfunction in patients with Parkinson’s disease (PD), a neurodegenerative pathology that exhibits at the initial phase as an asymmetric clinical syndrome with right or left sided predominant symptoms associated with neuronal loss in the deep grey matter of the contralateral cerebral hemisphere. In the current thesis, it was investigated a particular aspect of the executive dysfunction in PD expressed when it is required to select words in the context of competing alternatives, looking for differences according to the clinical onset of motor symptoms. At the neurostructural level, grey and white matter alterations were explored in PD subpopulations, testing if the ability to select words is associated with indices of grey and white matter integrity in PD subpopulations. Finally, at the neurofunctional level, it was explored if the connectivity of brain regions associated with the executive dysfunction in PD is modulated by the cognitive reserve, a factor of cognitive efficiency due to lifelong experiences that may contribute to the resilience against neurodegeneration. The evidence collected indicates that laterality of clinical motor symptom onset and cognitive reserve should be taken into account in the assessment of cognitive functions in patients with PD.

Sehnen übertragen die Muskelkräfte und ihre Eigenschaften beeinflussen unsere Bewegungsleistungen. Infolge mechanischer Belastungen adaptieren Sehnen. Die Effekte spezifischer Parameter des mechanischen Dehnungsstimulus sowie allgemeiner Belastungsbedingungen auf die Anpassung sind bisher ungeklärt und sollen durch die vorliegende Arbeit beleuchtet werden. Das adaptive Potential wurde durch einen Vergleich der Sehneneigenschaften zwischen beiden Beinen, in Bezug auf seitenabhängige Belastungen, experimentell untersucht. Um den Effekt verschiedener interventionsinduzierter Belastungen auf die Anpassung zu bestimmen, wurde ein systematischer Review nebst Metaanalyse durchgeführt. Der Einfluss spezifischer Parameter des Dehnungsstimulus (Rate und Dauer) wurde mittels zweier Trainingsinterventionen untersucht. Der Vergleich zwischen den Achillessehneneigenschaften des dominanten und nicht dominanten Beins zeigte einen signifikanten Unterschied des Young''s Modulus (Materialeigenschaften), mutmaßlich eine Folge seitenabhängiger Alltagsbelastungen. Die Metaanalyse ermittelte hohe Effektgrößen auf die mechanischen und Materialeigenschaften sowie eine niedrige Effektgröße auf die Morphologie, mit einem signifikanten Einfluss der unterschiedlichen Belastungen. Die beiden Interventionen belegten, dass eine hohe Rate der Dehnung und eine lange Dauer keinen übergeordneten Stimulus zur Sehnenanpassung im Vergleich zu einer hohen Magnitude und niedrigen Frequenz darstellen. Die Ergebnisse zeigen, dass Materialeigenschaften sensitiver gegenüber Belastungsänderungen sind und im Vergleich zur Morphologie zeitiger adaptieren. Die Interventionsresultate lassen den Schluss zu, dass eine hohe Dehnungsmagnitude, eine adäquate Dauer und repetitive Belastung essentiell für einen effektiven Stimulus sind. Die Ergebnisse liefern wichtige Erkenntnisse bezüglich einer Verbesserung von Sehneneigenschaften im Kontext der athletischen Leistung sowie Verletzungsprävention und -rehabilitation. / Tendons transmit the force exerted by a muscle and their properties influence human locomotor performance. Furthermore, tendons adapt to mechanical loading. The effect of specific parameters of the mechanical strain stimulus as well as general loading conditions on tendon adaptation is not completely understood and, therefore, the focus of research in the present thesis. Adaptive responses were investigated by means of a comparison of tendon properties between both legs to assess the effect of side-dependent loading pattern. A systematic review and meta-analysis was applied to examine the influence of various intervention-induced loading conditions on the magnitude of adaption. To investigate specific parameters of the mechanical strain stimulus (rate and duration), two controlled exercise interventions were conducted. The comparison of the Achilles tendon properties between the non-dominant and dominant leg revealed a significant difference of the Young''s modulus (i.e. material properties), likely a result of side-dependent daily loading pattern. The meta-analysis revealed high intervention effect sizes on the tendon mechanical and material properties and a low effect size on the morphology, with a notable effect of the various loading conditions. The two exercise interventions showed that a higher rate of strain and longer duration did not provide a superimposed effect for tendon adaptation compared to high magnitude and low frequency. The findings indicate that the material properties seem to be more sensitive and quicker in response to changes in the loading conditions compared to the morphological properties. The results of the two interventions suggest that a high strain magnitude, an appropriate strain duration and repetitive loading are essential for an effective stimulus. These findings provide valuable information with regard to the improvement of tendon properties in the context of athletic performance as well as injury prevention and rehabilitation.