Severe motor impairments can severely restrict interaction with one's surroundings. Brain computer interfaces combined with text-based communication systems, such as the P300 Speller, have allowed individuals with motor disabilities to spell messages with their EEG signals. Although providing full composition flexibility, they enable communication rates of only a few characters per minute. Utterance-based communication systems have been developed for individuals with disability and have greatly increased communication speeds, but have yet to be applied to BCIs. This paper proposes an utterance-based communication system using the P300-BCI in which words are organized in a network structure that facilitates rapid retrieval. In trials with able-bodied participants, the proposed system achieved greater message speeds, but rated lower in effectiveness than the P300 Speller. Nonetheless, subject preferences and reports of self-perceived effectiveness suggested an inclination towards the proposed word system and thus further investigation of word-based networks is warranted in brain-controlled AAC systems.

L'electroencefalografia (EEG) és una tècnica no invasiva que permet l'estudi de l'activitat elèctrica espontània cerebral, i que es caracteritza per oferir una elevada resolució temporal que es situa en l'ordre dels mil·lisegons. Aquesta tècnica permet obtenir informació sobre les respostes neuronals gràcies al fet que capta l'activitat electromagnètica relacionada amb els corrents elèctrics desencadenats per la circulació de ions a través dels canals iònics de la membrana de la neurona. La limitació principal d'aquesta tècnica és que estudiada amb els procediments tradicionals presenta una pobra resolució espacial, deguda entre altres raons a que les mesures es prenen en el cuir cabellut, molt lluny de les fonts cerebrals que generen els potencials elèctrics mesurats, el que implica una gran atenuació dels senyals elèctrics cerebrals originals, ja que el senyal elèctric ha de travessar diferents teixits.L'activitat elèctrica cerebral pot ser també provocada (evocada) constituint els potencials evocats, que són un senyal que s'obté amitjant fragments de l'EEG, que es produeixen com a conseqüència de l'activitat neuronal relacionada amb el processament cerebral d'un estímul sensorial, activitat motora o una activitat cognitiva. Aquest treball posa en evidència que es poden aconseguir guanys quantitatius amb l'aplicació de tècniques matemàtiques en a l'estudi dels potencials evocats cerebrals, i també avenços rellevants en la seva interpretació. També es fonamenta l'interès de no centrar els estudis de les característiques de la resposta evocada en les mesures tradicionals (latència, amplitud), i la necessitat d'estudiar la dinàmica espacio-temporal de les fonts. Aquest enfocament permet aconseguir nova informació crucial tant en el coneixement de la resposta cerebral en subjectes normals, com en la possibilitat de detectar alteracions funcionals cerebrals en una patologia determinada, en concret en l'alcoholisme. L'abordatge proposat per analitzar les respostes elèctriques cerebrals evocades, permet obtenir informació sobre el funcionalisme cerebral que d'altra manera no és accessible. Finalment es descriu que els potencials evocats estan generats per nombrosos components independents que poden presentar multiplicitat de fonts cerebrals. En conclusió, aquest treball posa de relleu l'interès i la necessitat de l'aplicació d'algorismes matemàtics en l'estudi dels potencials evocats, que siguin capaços d'augmentar la resolució espacial, d'estudiar la dinàmica de les fonts que generen els potencials evocats, i de comparar diferències en la l'evolució temporal d'aquestes fonts per l'estudi de del funcionament cerebral. A més, obre una via per estudiar les fonts dels components estadísticament independents dels potencials evocats estudiant els "trials" originals, evitant així la pèrdua d'informació relacionada amb l'amitjat que tradicionalment s'utilitza per l'estudi dels potencials evocats. Finalment es demostra l'aplicabilitat dels nous enfocaments proposats tant en l'estudi del funcionalisme cerebral normal, com en un trastorn mental de tanta transcendència com l'alcoholisme.

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Οι υπνικές άτρακτοι είναι χαρακτηριστικές κυματομορφές του ηλεκτροεγκεφαλογραφήματος (ΗΕΓ) του σταδίου 2 του ήσυχου (NREM) ύπνου, που έχουν υπναγωγικό ρόλο και σχετίζονται με διαδικασίες μνήμης και μάθησης. Μια υπνική άτρακτος είναι ομάδα ρυθμικά επαναλαμβανόμενων κυρίως αρνητικών κυμάτων με πλάτος που σταδιακά αυξάνεται και στη συνέχεια, σταδιακά μειώνεται, εντός της ζώνης συχνοτήτων 12-15 Hz (ζώνη συχνοτήτων ρυθμού σίγμα) και με διάρκεια μεταξύ 0.5 και 2 δευτερολέπτων. Η απεικόνιση, για μια κορυφή της ατράκτου, της κατανομής καποιας ηλεκτροεγκεφαλογραφικής μεταβλητής (π.χ. του ηλεκτρικού δυναμικού) στο πεδίο των ηλεκτροδίων καλείται τοπογραφία της κορυφής αυτής. Σκοπός της μελέτης ήταν να διερευνηθεί η τοπογραφία των ταχέων υπνικών ατράκτων κατά μέσο όρο, έτσι από ένα σύνολο 1449 γρήγορων ατράκτων επιλέχθηκαν προς ανάλυση 843 οι οποίες εμφανίζονταν σποραδικά και τουλάχιστον 3 δευτερόλεπτα μακριά από άλλα εμφανή εγκεφαλογραφικά συμβάντα που θα μπορούσαν να τις επηρεάσουν. Οι υπνικές άτρακτοι σημαδεύτηκαν πάνω στο ΗΕΓ οπτικά στην πρώτη, στην μεσαία και στην τελευταία αρνητική κορυφή τους, ακολούθησε προ-επεξεργασία, αποθορυβοποίηση των δεδομένων και εν συνεχεία μεσοποίηση τους στο πεδίο του χρόνου και των συχνοτήτων. Από την ανάλυση προκύπτει ότι η μέση τοπογραφία των ατράκτων στην αρχή, στη μέση και στο τέλος μεγιστοποιείται κεντρικά της κεφαλής και είναι σχετικά σταθερή και στις τρεις περιπτώσεις με μικρή τάση μετατόπισης προς τα εμπρός καθώς το φαινόμενο εξελίσσεται. Ομως, οι μεμονωμένες άτρακτοι εμφανίζουν μεγάλη ποικιλία προτύπων κίνησης του σημείου μεγίστης ισχύος η οποία δεν αποτυπώνεται στο μέσο όρο αλλά γίνεται αντιληπτή εξετάζοντας την τοπογραφία ενός μεγάλου αριθμού ατράκτων πριν τη μεσοποίηση. / Sleep spindles are characteristic waveforms of NREM sleep stage 2 electroencephalogram (EEG) which are involved in the generation and preservation of sleep as well as learning and memory processes. A sleep spindle is a group of rhythmic waves with gradually increasing and then decreasing amplitude (crescendo decrescendo morphology) within the frequency band 11-15 Hz and duration from 0.5 to 2 seconds. The voltage map of all electrodes for a spindle’s peak is called topography of the peak (power distribution visualization). The purpose of this study was to investigate the topography of fast spindles average thus, from a set of 1449 fast spindles, 843 were at least 3 seconds away from other EEG notable events which could affect them and were chosen for the average study. Sleep spindles were marked on EEG signal visually at first, middle and last negative peak, the next steps were preprocessing and denoising and finally averaging in time and in frequency domains. After the analysis we conclude that the average topography of the spindles at their start, middle and end is relatively stable and maximizes at the center of the head with a little tension to move forward as the phenomenon evolves. However, individual spindles show a great variety of movement patterns of the point of maximal electrical potential which patterns are not depicted in their average but can be understood by examining a large number of spindles before averaging.

This study proposes a series of 3 experiments to explore how the use of mental imagery affects expert vs. novice golfers differently, by comparing alpha and beta waves. In Experiment 1 experts and novices will putt under a pressure task or no pressure task. The researcher will analyze golfers’ putting success rate in addition to examining alpha and beta waves. Experiment 2 will expand upon the expected results of Experiment 1, focusing on experts’ and novices’ use of task-relevant and task-irrelevant mental imagery as pre-performance routines just before a putting task, with all conditions facing pressure. Finally, Experiment 3 will explore experts’ vs. novices’ use of task-relevant and task-irrelevant mental imagery the day before the pressure putting task. Researchers are expected to find increases in alpha wave activity to occur prior to the putting task in experts regardless of condition, which is consistent with the attention-arousal set theory’s concept of an optimal state of performance. Novices should display increases in alpha wave activity and reach their optimal state of performance when the type of mental imagery they use helps them relax, which should lead to a higher putting success rate.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-03T20:50:58Z No. of bitstreams: 1 RenzoAlvesDantasTorrecuso_DISSERT.pdf: 1737986 bytes, checksum: f9d866873658833b64e66fc8af70e980 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-17T20:59:12Z (GMT) No. of bitstreams: 1 RenzoAlvesDantasTorrecuso_DISSERT.pdf: 1737986 bytes, checksum: f9d866873658833b64e66fc8af70e980 (MD5) / Made available in DSpace on 2017-11-17T20:59:12Z (GMT). No. of bitstreams: 1 RenzoAlvesDantasTorrecuso_DISSERT.pdf: 1737986 bytes, checksum: f9d866873658833b64e66fc8af70e980 (MD5) Previous issue date: 2017-08-28 / Para atribuir sentido a uma seq??ncia de sons de uma m?sica, nosso c?rebro precisa encaixar e recombinar eventos ac?sticos em um fluxo continuo dentro de uma hierarquia sint?tica. Embora essas unidades de informa??o sejam ouvidas em seq??ncias com conex?es locais (uma ap?s a outra), assume-se que depend?ncias de longo prazo s?o estabelecidas contando com tra?os de mem?ria para sustentar a recursividade no tempo. Apesar disso ser um consenso te?rico e emp?rico, ainda n?o existe uma evid?ncia fisiol?gica clara da dimens?o temporal das rela??es sint?ticas na m?sica. N?s investigamos se h? atividade neural quantific?vel da exist?ncia de uma representa??o mental para regras fundamentais de sintaxe m?sical, como os acordes t?nica-dominante-t?nica. Para tal, utilizamos eletroencefalografia (EEG) comparamos a atividade el?trica do c?rebro em 24 indiv?duos (12 m?sicos, 12 n?o m?sicos) produzida por vers?es originais e harmonicamente modificadas de corais de J. S. Bach. Os corais eram compostos por duas frases: a primeira iniciada por um acorde de t?nica e chegando a um acorde dominante dois compassos depois (primeira frase), e a segunda concluiu em um acorde de t?nica tr?s compassos ap?s a dominante. As vers?es modificadas foram criadas elevando ou diminuindo as notas da primeira, mantendo assim a segunda frase intacta. Comparamos a resposta el?trica do c?rebro para o ?ltimo acorde em ambas as vers?es. / In order to make sense out of a sequence of sounds in music, our brain must meaningfully fit and recombine acoustic events into a hierarchic online stream. Although these information units are auditively delivered in sequences with local connections (one after the other), it is assumed that long-term dependencies are established counting on memory traces to sustain recursiveness in time. Despite theoretical and empirical consensus, there is yet no clear physiological evidence of the temporal dimension of syntactic relations in music. We investigated whether there is quantifiable neural activity suggesting the existence of a mental representation for fundamental music syntax rules like tonic-dominant-tonic chords. For such, we compared brain electric activity in 24 subjects (12 musicians, 12 non-musicians) aroused by original and harmonically modified versions of J.S. Bach chorales, using electroencephalography (EEG). Chorales were built by two phrases: initiated by a tonic and arriving in a dominant chord two bars away (first phrase), and concluded in a tonic chord three bars after the dominant (second phrase). Modified versions were created either by elevating or lowering the first, therefore keeping the second phrase intact. We compared the brain electric response for the last chord in both versions. Our data produced event related potentials (ERP) which suggest that the subjects? brain processed modified versions differently than originals. We observed an amplitude difference in the negativities peaking around 210 ms after the last chord onset. This finding replicates previous studies on harmonic disruptions processed in the same latency, but differs regarding brain source contributions: our data revealed a more posterior than anterior effect. Considering that last chords were the same acoustic event in both versions, we hypothesize that the amplitude differences plausibly indicate that the syntactic expectancy (long-term dependency between the tonic, dominant and tonic chord) may relate to brain mechanisms of processing non local connections, establishing a hierarchical storage of acoustic events in memory. We interpret that our parietal findings parallels with literature on mathematical sequence processing which suggest posterior brain regions to be engaged on complex calculation requiring the storage of numbers magnitude in memory for further computation. Our study overcame an obstacle not to date surpassed: observe and separate brain electric activity raised by long-term syntactic disruption in music from the overlap of local mismatch detection.

Grupper och grupprestationer har studerats länge utifrån olika perspektiv och discipliner, vilket har gett upphov till ett flertal teorier och förklaringsmodeller som innefattar olika tillvägagångssätt för hur grupper kan studeras. I denna uppsats förklaras begreppen grupper, grupprocesser och grupprestationer utifrån olika perspektiv och discipliner innan ett neurovetenskapligt perspektiv på grupper och grupprestationer antas. Detta för att redogöra för hur kognitiv neurovetenskap och neurovetenskapliga mätmetoder som electroencephalography (EEG) och functional magnetic resonance imaging (fMRI) kan förhålla sig till forskning på grupper, grupprocesser och grupprestationer. Syftet med uppsatsen är att beskriva hur grupper kan studeras utifrån ett neurovetenskapligt perspektiv samt hur kognitiv neurovetenskap kan komplettera studier på grupper och grupprestationer. Först presenteras en förklaring på vad grupper, grupprocesser och grupprestationer är, inklusive en redogörelse för relevanta begrepp som ledarskap, gruppsammanhållning och gruppkognition. Detta följs sedan av hur grupper och grupprestationer kan studeras ytterligare med ett neurovetenskapligt perspektiv, för att avslutas med problematik och möjligheter för kognitiv neurovetenskap inom forskningsfältet.

Human flexible behaviour is often seen in everyday life tasks. These tasks (e.g., making coffee) are composed of actions (e.g., pouring sugar) that are typically nested within a large task structures made of superordinate components and nested subcomponents. Task switching has been adopted widely as an effective tool to explore the mechanisms of flexible behaviour and can be easily adapted to real-life situations. The core hypothesis explored in this thesis was that there might be another level of control that is responsible for coordinating and scheduling actions in task switching, which I label "meta-control". My first project aimed to establish robust behavioural evidence of meta-control. To test this hypothesis, switching efficiency was treated as a measure of meta-control influence. In a novel design, participants' beliefs about switch probability were manipulated through explicit instruction, allowing manipulation of meta-level control independent of the specific sequence of tasks required. The first three behavioural experiments demonstrated behaviorally that instructions influenced the efficiency of switching even when low-level (bottom-up) experience was matched, and that this effect was motivation-dependent. In follow-up studies, this meta-control influence was found to bias voluntary task selection. Two EEG studies aimed to characterize the level at which instruction affected processing. Motor and task levels were examined with lateralized motor potentials and oscillatory alpha power, respectively. Effects of instruction only existed on alpha power. Overall, the results suggest that expectancy prompts the adoption of distinct control modes across sequences of trials. The second project explored meta-control in a task switching paradigm with a hierarchical task structure in very short (2-4 trial) sequences that were preceded by instructions about switch frequency or switch position. The experiments focused on the benefits and costs of sequence structure, based on the hypothesis that trial sequences are treated as coherent units. Three behavioural studies were conducted for testing this hypothesis. The first utilized instructions about switch frequency to test for sequence transition effects and their influence on switching performance at the trial level. In two subsequent experiments, instructions made explicit the position of a task switch. The results confirmed that instructions about switch position helped participants to build useful sequence representations, and that alternating between sequences influenced trial-level switch processes. Generally, sequence representations have a persisting influence across trials and a pronounced impact at the first trial position of sequences. The experiments in this thesis provide evidence of meta-control in task switching. The first conclusion is that meta-control can be studied with the novel experimental design introduced in this thesis and was found to be reward dependent. The second conclusion is that meta-control acts as a set of parameters that can modulate the mode of control in a sustained way across trials.

Široká, Martina. Use of neuromarketing in the public sector communication on Trencin city example. Diploma thesis. Brno : FRRMS MENDELU v Brně, Czech Republic, 2015. The diploma thesis deals with the topic of neuromarketing, related to the public sector marketing communication, using the example of Slovakian city Trencin. The goal of the submitted thesis is to assess the possibility of use of neuromarketing techniques in the communication of a city and public. A graphical billboard draft, based on the results of visual left-right perception neuromarketing research, is the tool to reach the main goal. The diploma thesis consists of the theoretical part, which introduces the basic terms regarding the importance and possibilities of communication in public sector, followed by neuromarketing issue and its techniques description. The practical part, with an initial proposal of a billboard design, aims to public sector purposes in Trencin city. It uses the results of the undertaken opinion poll and neuromarketing research. The final part is generalizing possibilities of the use of neuromarketing in the public sector communication.

Mental workload was investigated using electroencephalography (EEG) and National Aeronautics and Space Administration Task Load Index (NASA-TLX). The purpose of the study was to investigate the impact of passive and interactive learning on mental workload. The passive group (N = 5) had passive learning by reading a document regarding fire and safety when working in a laboratory, while the interactive group (N = 6) in addition to reading also had interactive learning by working with the same document in a group. On a follow-up test with EEG and NASA-TLX five days after the learning session, the subjects had a knowledge test based on the earlier learning. The results showed no significant divergence between the groups in mental workload measured with EEG and NASA-TLX or performance on a knowledge test. The subjects had difficulties remembering the fire and safety-routines on the knowledge test, which is consistent with previous research on risk communication. There was no correlation between EEG and NASA-TLX, which may be due to the difficulty in making accurate estimates of mental workload. / Mental arbetsbelastning har undersökts med elektroencefalografi (EEG) och National Aeronautics and Space Administration Task Load Index (NASA-TLX). Syftet med studien var att undersöka påverkan av passiv och interaktiv inlärning på mental arbetsbelastning. Den passiva gruppen (N = 5) fick passiv inlärning genom att läsa dokumentet ”Hälsa och Säkerhet vid kemiskt arbete på laboratorier, Kemiteknik (Säkerhet vid kemiskt arbete)” medan den interaktiva gruppen (N = 6) utöver genomläsningen även fick interaktiv inlärning genom att prata och samverka interaktivt i en grupp. Fem dagar efter inlärningen genomförde försökspersonerna ett kunskapstest baserat på den tidigare inlärningen med mätning av EEG samt NASA-TLX. Resultaten visade inte någon signifikant skillnad mellan grupperna i mental arbetsbelastning mätt med EEG och NASA-TLX eller prestation mätt med ett kunskapstest. Försökspersonerna hade svårt att minnas information från brand- och säkerhetsrutinerna på kunskapstestet, vilket är i enlighet med tidigare forskning om riskkommunikation. Inget samband erhölls mellan EEG och NASA-TLX, något som kan bero på svårigheten att träffsäkert skatta mental arbetsbelastning.