Cochlea-Implantate sind Neuroprothesen, die es Gehörlosen ermöglichen, Zugang zu auditiver Information wieder zu erlangen. Allerdings ist das resultierende Signal stark verzerrt bzw. degradiert und eine erfolgreiche Adaptation oft unvollständig. Das Verständnis zugrundeliegender perzeptueller Lernprozesse ist somit von enormer klinischer Bedeutung. Perzeptuelles Lernen degradierter Sprache lässt sich mittels Noise-Vokodierung bei Hörgesunden simulieren. In Bildgebungsstudien konnte anhand funktioneller Magnetresonanztomographie gezeigt werden, dass perzeptuelles Lernen degradierter Sprache mit einer Aktivitätssteigerung im linken inferior frontal gyrus (IFG) und linken inferior parietal cortex (IPC) assoziiert war. Die vorliegende Studie untersucht den Einfluss von fazilitierender, nicht-invasiver Hirnstromstimulation (anodale transkranielle Gleichstromstimulation, tDCS) über dem linken IFG und linken IPC auf das perzeptuelle Lernen {\\itshape{Noise}}-vokodierter Sprache. Die Probanden trainierten die Diskrimination von Minimal- (\"Tisch\"- \"Fisch\") und identen (\"Tisch\"- \"Tisch\") Wortpaaren, während der erste Stimulus akustisch degradiert, der zweite in geschriebener Form präsentiert wurden. Vor und nach dem Training wurden die trainierten Stimuli und eine gleiche Anzahl untrainierter Stimuli präsentiert. Perzeptuelles Lernen wurde in unserer Studie als eine Verbesserung der Diskriminationsleistung untrainierter Wortpaare operationalisiert. Zudem wurde vor und nach dem Training ein Elektroenzephalogramm abgeleitet. Auf elektrophysiologischer Ebene wurde der Einfluss des Lernvorgangs und der tDCS auf die N400 untersucht, welche mit der Verarbeitung lexiko-semantischer Informationen assoziiert ist. Unsere Ergebnisse zeigen, dass eine anodale tDCS über dem linken IFG perzeptuelles Lernen stark degradierter Sprache fazilitierte, während bei einer Placebo- bzw. einer Stimulation über dem linken IPC kein perzeptuelles Lernen stattfand.

The intent of this project is to develop an auditory training program for kindergarten children which will strengthen auditory perception. The program will identify the essential auditory skills, establish objectives, construct evaluative measures and outline activities that will develop basic auditory perception skills.

Identifying targets in cluttered scenes is critical for our interactions in complex environments. Our visual system is challenged to both detect elusive targets that we may want to avoid or chase and discriminate between targets that are highly similar. These tasks require our visual system to become an expert at detecting distinctive features that help us differentiate between indistinguishable targets. As the human brain is trained on this type of visual tasks, we observe changes in its function that correspond to improved performance. We use functional brain imaging, to measure learning-dependent modulations of brain activation and investigate the processes that mediate functional brain plasticity. I propose that dissociable brain mechanisms are engaged when detecting targets in clutter vs. discriminating between highly similar targets: for the former, background clutter needs to be suppressed for the target to be recognised, whereas for the latter, neurons are tuned to respond to fine differences. Although GABAergic inhibition is known to suppress redundant neuronal populations and tune neuronal representations, its role in visual learning remains largely unexplored. Here, I propose that GABAergic inhibition plays an important role in visual plasticity through training on these tasks. The purpose of my PhD is to investigate the inhibitory mechanisms that mediate visual perceptual learning; in particular, learning to detect patterns in visual clutter and discriminate between highly similar patterns. I show that BOLD signals as measured by functional Magnetic Resonance Imaging (fMRI) do not differentiate between the two proposed mechanisms. In contrast, Magnetic Resonance Spectroscopy (MRS) provides strong evidence for the distinct involvement of GABAergic inhibition in visual plasticity. Further, my findings show GABA changes during the time-course of learning providing evidence for a distinct role of GABA in learning-dependent plasticity across different brain regions involved in visual learning. Finally, I test the causal link between inhibitory contributions and visual plasticity using a brain stimulation intervention that perturbs the excitation-inhibition balance in the visual cortex and facilitates learning.

Egg predation may be the most important mortality factor for North American turtles. This predation can destroy 50-90% of nests in an area. The major predators are striped skunks (Mephitis mephitis) and raccoons (Procyon lotor). Despite differences in their habits and diet, these species appear equally efficient in turtle egg predation, even though these eggs represent a very small portion of their annual food intake. Sight, olfaction, touch and hearing could be used by these predators to find the nests. The aim of this study was to document intra and inter-specific differences in the perception of possible nest-cues used by raccoon and striped skunk. Choice-tests based on food-conditioning were carried out with two visual cues (dark and smooth surface), one olfactory cue (turtle urine) and one tactile cue (soil compaction). Subject performances (number of trials to obtain 80% success rate in the different tests) were compared to assess intra and inter-species, and skunk inter-age differences in sensory perception and learning abilities. As expected raccoons learned the tactile cue discrimination faster than the visual cue discriminations. The tactile cue discrimination was learned as fast as the olfactory cue. As expected skunks learned the olfactory cue discrimination faster than other cue discriminations. When compared, the olfactory cue appeared to be as important for both species even though raccoons had faster learning rates than skunks in all the tests except for one visual test. Juvenile skunks learned faster than adult skunks with four out of six juveniles performing better in the olfactory test. Olfaction may play an important role in nest localization by raccoons and skunks, and sight may also play a role for raccoons. Learning turtle nest cues while with their mother could facilitate their future ability in locating turtle nests.

xviii, 216 p. : ill. (some col.) / The focus of this dissertation is on how language experience shapes perception of a non-native prosodic contrast. In Tokyo Japanese, fundamental frequency (F0) peak and fall are acoustic cues to lexically contrastive pitch patterns, in which a word may be accented on a particular syllable or unaccented (e.g., tsúru 'a crane', tsurú 'a vine', tsuru 'to fish'). In English, lexical stress is obligatory, and it may be reinforced by F0 in higher-level prosodic groupings. Here I investigate whether English listeners can attend to F0 peaks as well as falls in contrastive pitch patterns and whether training can facilitate the learning of prosodic categories. In a series of categorization and discrimination experiments, where F0 peak and fall were manipulated in one-word utterances, the judgments of prominence by naïve English listeners and native Japanese listeners were compared. The results indicated that while English listeners had phonetic sensitivity to F0 fall in a same-different discrimination task, they could not consistently use the F0 fall to categorize F0 patterns. The effects of F0 peak location and F0 fall on prominence judgments were always larger for Japanese listeners than for English listeners. Furthermore, the interaction between these acoustic cues affected perception of the contrast by Japanese, but not English, listeners. This result suggests that native, but not non-native, listeners have complex and integrated processing of these cues. The training experiment assessed improvement in categorization of Japanese pitch patterns with exposure and feedback. The results suggested that training improved identification of the accented patterns, which also generalized to new words and new contexts. Identification of the unaccented pattern, on the other hand, showed no improvement. Error analysis indicated that native English listeners did not learn to attend specifically to the lack of the F0 fall. To conclude, language experience influences perception of prosodic categories. Although there is some sensitivity to F0 fall in non-native listeners, they rely mostly on F0 peak location in language-like tasks such as categorization of pitch patterns. Learning of new prosodic categories is possible. However, not all categories are learned equally well, which suggests that first language attentional biases affect second language acquisition in the prosodic domain. / Committee in charge: Susan Guion Anderson, Chairperson; Melissa A. Redford, Member; Vsevolod Kapatsinki, Member; Kaori Idemaru, Outside Member

Orientador: Luis Antonio Violin Dias Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T19:30:48Z (GMT). No. of bitstreams: 1 Duarte_AnaGrabrielaEsteves_M.pdf: 3755388 bytes, checksum: b5d334a7ff4149571dfe118d2a23282f (MD5) Previous issue date: 2007 / Resumo: O entendimento da Embriologia Humana é fundamental para o diagnóstico e tratamento corretos das malformações congênitas, que são responsáveis pela maioria das mortes na primeira infância em países desenvolvidos e cuja prevalência pode chegar a 21%. No entanto, as disciplinas tradicionais de Embriologia Humana exigem do aluno um rápido entendimento de uma série de mudanças que ocorrem simultaneamente em uma escala macro e microscópica no embrião e, como conseqüência, os estudantes têm dificuldade em compreender os conceitos apresentados e criar mentalmente imagens tridimensionais dos processos envolvidos. O uso de recursos multimídia auxilia na aprendizagem, estimula o conhecimento e a criatividade e possibilita soluções para problemas. Entretanto, pouca atenção tem sido dada ao desenvolvimento, utilização e avaliação dessas estratégias e à real participação do estudante no processo ensino/aprendizado. Sabendo-se que os testes de múltipla escolha, quizzes, são métodos objetivos comumente usados como ferramenta auxiliar de aprendizado, neste estudo foram desenvolvidos quizzes eletrônicos e uma metodologia para a utilização dos mesmos, visando o ensino de Embriologia Humana. Os quizzes eletrônicos correlacionaram conceitos de Embriologia básica com a gênese, o diagnóstico e o tratamento dos defeitos congênitos mais freqüentes e foram construídos de maneira a apresentar uma parte teórica seguida de uma ou mais questões de múltipla escolha, quizzes. A parte introdutória teórica foi composta por animações e esquemas ilustrativos, desenvolvidos no software Flash MX (Macromedia), imagens macroscópicas e microscópicas de embriões, fetos e neonatos encaminhados para autópsia, bem como de recém-nascidos e crianças portadores de defeitos congênitos, e de seus exames de imagens (ultrassons e radiografias). As questões de múltipla escolha foram desenvolvidas de maneira que o aluno pudesse verificar a extensão do seu conhecimento e as suas deficiências, uma vez que os quizzes indicam o porquê das alternativas erradas. O material didático foi organizado e disponibilizado em um ambiente interativo, o qual foi usado durante as monitorias pelos alunos do primeiro ano do curso de Medicina da UNICAMP matriculados nas disciplinas Morfofisiologia Humana I e II, no ano de 2006. Ao final de ambas as disciplinas, os quizzes eletrônicos e a metodologia utilizada foram avaliados pelos alunos, através de instrumentos quantitativos e qualitativos. A avaliação teve como objetivo determinar se os quizzes eletrônicos constituem uma ferramenta importante para o ensino de Embriologia Humana, para o desenvolvimento de raciocínio clínico e para a integração das áreas básica e clínica. Analisando-se os resultados pode-se observar que 98,8% dos alunos tiveram um nível de atitude no mínimo positiva em relação à metodologia de ensino desenvolvida. Enfatizaram que, quanto à qualidade, os quizzes eletrônicos são bons, apresentando parte introdutória clara com animações e imagens de casos clínicos que permitem a resolução das questões de múltipla escolha propostas, sem abordar conteúdo em excesso. Quanto ao objetivo pedagógico, os quizzes eletrônicos estimularam o raciocínio, permitiram fixar e testar os conhecimentos adquiridos em aula, acrescentaram informações novas, tornaram mais interessantes os assuntos complexos de Embriologia, aproximaram a área básica da clínica, abordaram assuntos relevantes à formação profissional e desenvolveram habilidades na resolução de problemas clínicos, o que nos permite concluir que os quizzes eletrônicos constituem sim uma ferramenta complementar adequada para o ensino de Embriologia Humana / Abstract: The Human Embryology understanding is essential for appropriate diagnosis and treatment of congenital anomalies, which are responsible for the majority of the deaths in the first infancy and whose prevalence can reach up to 21% in North America. Traditional Human Embryology courses require students to rapidly understand the various changes that occur simultaneously on a macro and on a microscopic scale in embryos. Thus, the students have difficulties to understand the concepts presented and to create three-dimensional mental images of the processes involved. The use of multimedia assists in the learning process, stimulates the understanding and the creativity, and makes possible solutions to problems proposed. However, little attention has been given to the evaluation of these strategies and to the real commitment of the student to the education/learning process. Multiple-choice tests, called quizzes, are among the most common methods used as an auxiliary learning tool. In this study, there was developed an education methodology for Human Embryology based on electronic quizzes. The quizzes have correlated concepts of basic Embryology with the genesis, diagnosis, and treatment of the more frequent congenital defects. The electronic quizzes were constructed in a way to present a theoretical part, followed by one or more multiple-choice questions regarding the considered subject. The theoretical introductory part involved texts, animations developed by Flash MX (Macromedia), and macro and microscopical digital documentation of embryos, fetuses and neonates referred to autopsy. Newborn babies with inherit disorders were also photographed, at the nursery. The multiple-choice questions were developed for verifying the students¿ knowledge extension and deficiency since the quizzes indicated the reasons why they have chosen the false statements. The didactic material was organized on an educational software used by the students at the first year of UNICAMP Medicine¿s course, attending the Human Morpho-Physiology module, in 2006. At the end of the module, the methodology was considered, using quantitative and qualitative instruments, an important tool for the education of Human Embryology, the development of clinical reasoning, and the integration of the basic and clinical areas. Analyzing the results, one can observe that 98.8% of the students had had an attitude at least positive in relation to the electronic quizzes. Concerning its quality, they had emphasized that the electronic quizzes are good, presenting a clear introductory part with animations and images of clinical cases that allow them to solve all the multiple-choice questions without approaching excessively the content. With regard to the pedagogical goal, the electronic quizzes stimulate the reasoning, allow one to retain and to test the acquired knowledge in classes, add new information, turn some complex subjects of Embryology more interesting, colligate the basic and the clinical areas, deal with relevant concepts concerning the professional formation, and develop abilities in solving clinical problems. Thus, the arguments previously mentioned allow us to conclude that the electronic quizzes constitute an adequate complementary tool for the education of Human Embryology / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural

Intersensory transfer of training was systematically investigated for visual to tactual and tactual to visual situations. College students were trained in one modality on a successive-shape-discrimination task, then transferred to the opposite modality to perform a related-shape-discrimination task. The investigation showed successful transfer in both directions, Transfer from vision to touch was specific to the situation wherein all discriminata were exactly the same In the two tasks. In contrast, transfer from touch to vision appeared to be a function of the subjects' ability to retain some type of schematic representation of the primary object as a mediational device to facilitate visual discrimination between the primary object and one of a slightly different shape.

Le champ des neurosciences connaît depuis quelques décades un développement très important dans la compréhension des corrélats neuronaux de la perception. Le cerveau adulte répond aux variations de l'environnement et à l'expérience par des modifications fonctionnelles et structurales, regroupées sous le terme générique de plasticité, plasticité qui sous-tend l'apprentissage. Cette plasticité affecte la perception sensorielle, olfactive puisque c'est cette modalité qui va nous intéresser, mais également la perception de stimuli dans d'autres modalités sensorielles. Contrairement à des convictions longtemps érigées en dogme mais maintenant dépassées sur la nature fixe du cerveau, il est établi désormais que le cerveau adulte est capable de générer tout au long de la vie de nouveaux neurones qui s'intègrent dans la circuiterie cérébrale complexe, en particulier dans le bulbe olfactif et pourraient jouer un rôle dans l'apprentissage. Des travaux antérieurs de l'équipe ont démontré que l'acquisition de l'apprentissage perceptif dépend de la présence des neurones formés chez l'adulte. Par ailleurs, les systèmes neuromodulateurs comme les systèmes noradrénergique et cholinergique innervent massivement le bulbe olfactif et en particulier les neurInhibiting noradrenergic fibers duroing post learning discrimination testing lblmocked ones cibles de la neurogenèse adulte, les interneurones granulaires. Ils sont depuis longtemps connus pour leur implication dans les processus d'apprentissage en général et olfactif en particulier. Un objectif de la thèse était de déterminer le pattern temporal et spatial de l'innervation des neurones formés chez l'adulte dans le bulbe olfactif et sa modification potentielle par l'apprentissage, par des approches comportementales combinées à des approches neuro-anatomiques. Un autre objectif était d'évaluer le rôle fonctionnel des contacts noradrénergiques mis en place par l'apprentissage en utilisant l'outil optogénétique. Les résultats indiquent que l'innervation des neurones formés chez l'adulte s'installent dès le huitième jour après la naissance des neurones pour le système cholinergique, comme pour le système noradrénergique. L'apprentissage induit une augmentation massive des contacts noradrénergiques sur les neurones formés chez l'adulte qui n'est pas retrouvée pour les fibres cholinergiques, pointant le système noradrénergique comme un acteur majeur de la plasticité induite par l'apprentissage perceptif / The field of neuroscience has experienced explosive growth over the past decade toward understanding the neural correlates of perception. More specifically, the adult brain responds to environmental experience by significant functional and structural modifications, called "neural plasticity" which underlies learning. A main issue in neuroscience is to understand the cellular basis of perceptive plasticity and subsequent behavioral adaptations. Contrary to previously held beliefs about its static nature, the adult brain is in fact capable of generating new neurons that can integrate into its complex circuitry. The birth of new neurons constitutively occurs in two specific regions of the adult mammalian brain (OB and hippocampal dentate gyrus). Adult neurogenesis is a sophisticated biological process whose function has remained a mystery to neuroscience researchers but a role in learning and memory has been proposed. Previous work in our group have shown that perceptive olfactory learning depends on adult neurogenesis. In addition, neuromodulatory systems, including noradrenergic and cholinergic systems massively innervate the olfactory bulb and more specifically the inhibitory interneurons targeted by adult neurogenesis and are long-known for their role in learning and memory. One objective of the present work was to determine the spatial and temporal pattern of the innervation by noradrenergic and cholinergic inputs of developing adult-born neurons and to investigate its modulation by learning. For that purpose, we used behavioral and neuro-anatomical approaches. Another objective was to assess the functional role of centrifugal contacts using an optogenetic approach. Results indicate that the noradrenergic innervation is selectively increased on adult born neurons following perceptual olfactory learning, a phenomenon that was not observed for cholinergic innervation, pointing the noradrenergic system as a key mechanisms involved in perceptual learning. Interestingly, noradrenergic contacts on neurons born during ontogenesis were not affected by learning, suggesting a very specific part played by adult-born neuron in learning associated plasticity. In the same brains, we have analyzed the structural plasticity induced by learning in adult-born and pre-existing neurons. The major finding is that mirroring the increased number of noradrenergic contacts, learning induced an increase in dendritic spines on adult-born, but not on pre-existing neurons

Le bulbe olfactif est le siège d'une neurogenèse adulte pouvant jouer un rôle dans les apprentissages olfactifs. Nous nous sommes intéressés à son rôle dans un type d'apprentissage olfactif : l'apprentissage perceptif. Tout d'abord, l'enrichissement permet d'améliorer la discrimination d'odeurs proches : c'est l'apprentissage perceptif. En étudiant les effets de la suppression de la neurogenèse pendant l'enrichissement nous avons montré que la neurogenèse était nécessaire à l'apprentissage perceptif en modulant l'inhibition des cellules mitrales par les cellules granulaires. Ensuite, nous avons étudié le rôle de la noradrénaline dans cet apprentissage. La noradrénaline est nécessaire à l'apprentissage perceptif et suffisante pour en mimer les effets. De plus, nous avons montré que la neurogenèse bulbaire était essentielle à l'action de la noradrénaline pour permettre l'apprentissage perceptif. Enfin, nous nous sommes intéressés à l'effet du vieillissement sur l'apprentissage perceptif. Nous avons trouvé qu'il existait un défaut d'apprentissage perceptif chez la souris âgée en lien avec une diminution de la neurogenèse. En revanche, une stimulation noradrénergique permet de restaurer l'apprentissage perceptif sans modulation de la neurogenèse bulbaire suggérant l'existence de mécanismes compensatoires. L'apprentissage perceptif est sous-tendu par la neurogenèse bulbaire, via le système noradrénergique, pour permettre une hausse d'inhibition des cellules mitrales par les cellules granulaires améliorant la discrimination des odeurs proches. Avec l'âge, l'apprentissage perceptif peut être restauré suggérant une plasticité toujours présente dans un système olfactif vieillissant / The olfactory bulb is the target of a well described adult neurogenesis which has been involved in different kinds of learning. We focused on the role of adult neurogenesis on olfactory perceptual learning which consists on an improvement of olfactory discrimination after odor enrichment. We found that experience-driven improvement in olfactory discrimination (perceptual learning) requires the addition of newborn neurons in the olfactory bulb. More specifically, we showed that adult-born neurons are required for perceptual learning by modulating the inhibition of mitral cells by granule cells. Then, we studied the role of noradrenaline on perceptual learning. Direct manipulation of noradrenergic transmission significantly effect on adult-born neuron survival and perceptual learning. Finally, we investigated the effect of aging on perceptual learning. We found that perceptual learning was impaired by aging in line with an alteration of neurogenesis. However, noradrenergic stimulation restores perceptual learning without modulating neurogenesis suggesting compensatory mechanisms. Neural mechanisms underlying perceptual learning involve neurogenesis and noradrenergic system to allow an increase of mitral cell inhibition thanks to the granule cells leading to an improvement of odor discrimination. During aging, perceptual learning can be restored suggesting that the olfactory system is still plastic

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