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The human visual system has the remarkable capacity to transform spatio-temporal patterns of light into structured units of perception. Much research has focused on how the visual system integrates information around the perimeter of closed contours to form the perception of shape. This dissertation extends previous work by investigating how the perception of curvature along closed-contour shapes is affected by the presence of additional shapes that appear close to the target shape in space and/or time. Chapter 2 examined the ability of shape mechanisms at representing low frequency curvature in the presence of a higher frequency component along contours in multi-shape displays. We found that additions of high amplitude, high frequency curvature along a contour path can modulate the strength of interaction observed between shapes, and thus attenuates the contribution of low frequency components in interactions between neighbouring contours. Chapter 3 examined what curvature features are of importance in modulating phase dependent interactions between shapes. Results revealed that phase-dependent masking does not depend on curvature frequency, but is related to sensitivity for phase shifts in isolated contours, and is affected by both positive and negative curvature extrema. Computational simulations aimed at modelling the population responses evoked in intermediate shape processing areas (i.e., V4) suggest sensitivity to shifts in phase of shapes is not well captured by such a population code, and therefore alternative explanations are required. Chapter 4 examined how sensitivity to curvature deformations along the contour of a closed shape changes as a function of polar angle, angular frequency, and spatial uncertainty. Results show that human observers are, at first approximation, uniformly sensitivity to curvature deformations across all polar angles tested, and this result holds despite changes in angular frequency and spatial uncertainty. Chapter 5 examined whether the strength of spatial masking between shapes is affected by the presentation of a temporal mask. Our results demonstrate that a temporal mask affected spatial masking only when it preceded the target-mask stimulus by 130-180ms. Furthermore, the effects of a temporal mask on spatial masking are approximately additive, suggesting that separate components contribute to spatial and temporal interactions between shapes. / Thesis / Doctor of Philosophy (PhD)

Yes / There is increasing concern with protecting quiet and tranquil areas from intrusive noise. Noise reduction at source and barriers to transmission are mitigation measures often considered. An alternative is to attempt to mask or distract attention away from the noise source. The masking or distracting sound source should be pleasant so that it does not add to any irritation caused by the noise source alone. The laboratory measurements described in this paper consisted of capturing under controlled conditions the third octave band spectra of water falling onto water, gravel, bricks and small boulders and various combinations. These spectra were then matched with typical traffic noise spectra to assess the degree of masking that could be expected for each option. Recordings were also taken during each measurement and these were used later to enable the subjective assessment of the tranquility of the sounds. It was found that there were differences between water sounds both in terms of masking and their subjective impact on tranquility.

A recent study by Polka, Rvachew, and Molnar (2008) found that 6- to 8-month-old infants do not discriminate a simple native consonant-vowel contrast when familiarized to it in the presence of distraction noise (i.e., recordings of crickets and birds chirping), even when testing was conducted in quiet. Because the distraction noise did not overlap with the phonemes' frequencies, failure to encode the familiarization phoneme could be due more to a disruption in infant attention than to direct masking effects. Given that infants learn speech under natural conditions involving noise and distraction, it is important to identify factors that may 'protect' their speech perception under non-ideal listening conditions. The current study investigated three possible factors: speech register, face information, and speaker gender. Six-month-old infants watched a video of a female speaker producing a native phoneme in either an adult-directed or infant-directed manner accompanied by the same background noise as in Polka et al. (2008). After habituation, infants were tested with alternating trials of the familiar phoneme and a novel phoneme in quiet. Phoneme discrimination was measured by recording infants' heart rate and looking times during familiar and novel trials. Discrimination was poor in infants who viewed a female speaker using adult-directed speech but was significantly improved (as seen in both dependent measures of attention) when the female speaker used infant-directed speech. Results indicate that common factors in the typical environment of infants can promote speech perception abilities in noise. / Master of Science

I denna uppsats har filmljudet i krigsfilmerna Apocalypse Now och Saving Private Ryan undersökts. Detta har gjorts för att försöka bidra med ökad förståelse för filmljudets användningsområde och funktioner, främst för filmerna i fråga, men även för krigsfilm rent generellt. Filmljud i denna kontext omfattar allt det ljud som finns i film, men utesluter dock all ickediegetisk musik. Båda filmerna har undersökts genom en audio-visuell analys. En sådan analys görs genom att detaljgranska båda filmernas ljud- och bildinnehåll var för sig, för att slutligen undersöka samma filmsekvens som helhet då ljudet och bilden satts ihop igen. Den audio-visuella analysmetod som nyttjats i uppsatsen är Michel Chions metod, Masking. De 30 minuter film som analyserades placerades sedan i olika filmljudzoner, där respektive filmljudzons ljudinnehåll bland annat visade vilka främsta huvudfunktioner somfilmljudet hade i dessa filmer. Dessa funktioner är till för att bibehålla åskådarens fokus och intresse, att skapa närhet till rollkaraktärerna, samt att tillföra en hög känsla av realism och närvaro. Intentionerna med filmljudet verkade vara att flytta åskådaren in i filmens verklighet, att låta åskådaren bli ett med filmen. Att återspegla denna känsla av realism, närvaro, fokus samt intresse, visade sig också vara de intentioner som funnits redan i de båda filmernas förproduktionsstadier. Detta bevisar att de lyckats åstadkomma det de eftersträvat. Men om filmljudet använts på samma sätt eller innehar samma funktioner i krigsfilm rent genrellt går inte att säga.I have for this bachelor’s thesis examined the movie sound of the classic warfare movies Apocalypse Now and Saving Private Ryan. This is an attempt to contribute to a more profound comprehension of the appliance and importance of movie sound. In this context movie sound implies all kinds of sounds within the movies, accept from non-diegetic music. These two movies have been examined by an audio-visual analysis. It's done by auditing the sound and picture content separately, and then combined to audit the same sequence as a whole. Michel Chion, which is the founder of this analysis, calls this method Masking. The sound in this 30 minute sequence was then divided into different zones, where every zone represented a certain main function. These functions are provided to create a stronger connection to the characters, sustain the viewers interest and bring a sense of realism and presence. It seems though the intention with the movies sound is to bring the viewers to the scene in hand, and let it become their reality. To mirror this sense of realism, presence, focus and interest, proves to be the intention from an early stage of the production. This bachelor’s thesis demonstrates a success in their endeavours. Although it can’t confirm whether the movie sound have been utilized in the same manner or if they posess the same functions to warefare movies in general.

Die bipolare Störung ist eine in depressiven und manischen Phasen verlaufende psychiatrische Erkrankung. Zwischen diesen Phasen kehren die Betroffenen zu einer ausgeglichenen Stimmungslage zurück. Dennoch verschlechtert sich der kognitive Allgemeinzustand der Patienten mit zunehmender Erkrankungsdauer und Anzahl der durchlittenen Episoden, was auch in euthymen Phasen erkennbar ist. Lithium ist das Medikament erster Wahl, das zur Behandlung der bipolaren Störung eingesetzt wird. Es zeichnet sich durch seine antimanische, antisuizidale und phasenprophylaktische Wirkung aus. In Zell- und Kleintierstudien konnte zudem gezeigt werden, dass Lithium sich positiv auf die Resilienz von Neuronen auswirkt und eine Zellen-erhaltende Wirkung hat. Im Rahmen dieser multizentrischen Querschnittstudie soll gezeigt werden, dass die neuroprotektiven Eigenschaften von Lithium sich bei einer Langzeitbehandlung auch schützend auf die kognitive Leistungsfähigkeit bipolarer Patienten auswirkt. Um diesen Effekt zu belegen, verglichen wir 3 Gruppen: Patienten mit einer bipolaren Störungvon einer minimalen Erkrankungsdauer von 10 Jahren und minimal 5 Erkrankungsepisoden mit (akut, seit mindestens 2 Jahren) und ohne (insgesamt maximal 3 Monate, vor mindesten 2 Jahren) Lithium-Langzeitbehandlung und gesunde Kontrollprobanden miteinander. Im Rahmen dieser Studie wurden folgende Daten erhoben: Hippokampusvolumen gemessen mit MRT, NAA-Konzentration im DLPFC gemessen mit MRS, Lebensqualität gemessen mit Quality of Well-Being Scale, allgemeine Intelligenz gemessen mit der HAWIE Testbatterie, verbales Lernen und Merkfähigkeit gemessen mit CVLT und frühe visuelle Informationsverarbeitung sowie Reaktionsgeschwindigkeit gemessen mit VBMT. Im Rahmen dieser Dissertation wurden die Ergebnisse der VBMT ausgewertet und interpretiert. Insgesamt wurden die Daten von 142 Studienteilnehmern ausgewertet, von denen 31 Patienten ohne Lithiumbehandlung, 58 mit Lithiumbehandlung und 53 gesunde Kontrollprobanden waren. Entgegengesetzt zur Studienhypothese, schnitten Patienten mit einer Lithiumbehandlung bezüglich Reaktionsgeschwindigkeit und Fehlerquote schlechter bei der VBMT ab, als gesunde Kontrollprobanden, aber auch als Patienten mit einer bipolaren Störung ohne Lithiumbehandlung. Bei der Untersuchung von allgemeiner Intelligenz und verbaler Lern- und Merkfähigkeit konnte kein signifikanter Unterschied zwischen den drei Gruppen gefunden werden. Dennoch wird bei Betrachtung der absoluten Zahlen deutlich, dass auch bei diesen Untersuchungen Patienten schlechter abschneiden als Gesunde und dass Lithiumpatienten tendenziell schlechter abschneiden als Patienten ohne Lithiumbehandlung. Andererseits ergaben die hirnphysiologischen Untersuchungen dieser Studie, dass sowohl die NAA-Konzentration, als neuronaler Marker, und auch das Volumen des Hippokampus bei Patienten mit Lithiumbehandlung größer war, als bei Patienten ohne Lithiumbehandlung. Zwischen den Volumina und den NAA-Levels der Lithiumpatienten und gesunder Probanden gab es keinen Unterschied. Aus diesen Ergebnissen lässt sich schlussfolgern, dass Lithium auch beim Menschen einen Zell-erhaltenden Effekt hat, der sich jedoch nur physiologisch messen lässt und sich nicht auf die neurokognitive Fähigkeit auswirkt. Patienten mit einer Lithiumbehandlung scheinen zwar eine bessere Resilienz ihrer neuronalen Zellen aufzuweisen, haben aber größere kognitive Defizite. Ob diese Defizite kausal mit der Lithiumbehandlung zusammenhängen, lässt sich bei einem einmaligen Messzeitpunkt nicht aussagen. Des Weiteren ist der kognitive Defizit deutlicher bei der Testung der frühen visuellen Informationsverarbeitung und Reaktionsgeschwindigkeit, gemessen mit der VBMT, als bei Merkfähigkeit und allgemeiner Intelligenzleistung zu erkennen. Dies deutet darauf hin, dass die Hirnregionen, welche bei der frühen visuellen Informationsverarbeitung und psychomotorischer Steuerung beteiligt sind, bei bipolaren Patienten stärker als bei Gesunden, und bei Lithiumpatienten stärker als bei Nicht-Lithiumpatienten beeinträchtigt sind.:Liste der Abkürzungen 6 1. EINLEITUNG 8 1.1 DIE BIPOLAR AFFEKTIVE STÖRUNG 8 1.1.1 Diagnostik und Klassifikation 9 1.1.2.1 Depression 9 1.1.2.2 Manie 10 1.1.2.3 Klassifikation nach ICD-10 und DSM-IV 11 1.1.2 Epidemiologie 12 1.1.3 Verlauf und Behandlung 13 1.1.3.1 Verlauf 13 1.1.3.2 Behandlung 14 1.1.4 Hirnphysiologische Veränderungen bei bipolaren Patienten 17 1.1.4.1 Volumetrische Veränderungen 17 1.1.4.2 Funktionale Veränderungen 21 1.1.4.3 Biochemische Veränderungen 23 1.1.5 Beeinträchtigung kognitiver Funktionen 23 1.2 VISUAL BACKWARD MASKING (VBM) 24 1.2.1 Theoretischer Hintergrund zum VBM 24 1.2.2 Studienergebnisse durch VBM bei psychiatrischen Erkrankungen 28 Vulnerabilitätsfaktor oder Krankheitssymptom 28 Defizite in euthymen und bipolaren Phasen 29 1.3 EFFEKTE DER LITHIUMTHERAPIE 30 1.5.1 Die Lithiumtherapie 30 1.5.2 Potentielle Wirkmechanismen 31 1.5.3 Neuroprotektive Effekte der Lithiumtherapie 33 Bcl-2 33 GSK-3 33 PKC 33 BDNF 34 Weitere neuroprotektive Effekte 34 1.5.4 Effekte von Lithium auf frühe visuelle Informationsverarbeitung 34 1.5.5 Effekte von Lithium auf die kognitive Leistung 35 1.5.6 Effekte von Lithium auf die Neuroanatomie 36 1.5.7 Effekte von Lithium auf Funktion und Biochemie 36 2. HYPOTHESEN 37 2.1 PRIMÄRE HYPOTHESE 37 2.2 SEKUNDÄRE HYPOTHESEN 37 3. METHODEN UND MATERIALIEN 38 3.1 STUDIENDESIGN 38 3.2 TEILNEHMER 38 3.3 STUDIENABLAUF 41 3.4 METHODEN ZUR TESTUNG DER HYPOTHESEN 42 Visual Backward Masking Task (VBMT) 42 3.5 FALLZAHLBERECHNUNG UND STATISTISCHE ANALYSE 43 3.5.1 Fallzahlberechnung 43 3.5.2 Statistische Analyse 44 4. ERGEBNISSE 45 4.1 SOZIODEMOGRAFISCHE DATEN 45 4.2 KLINISCHE DATEN 46 4.3 VBMT 48 5. DISKUSSION 52 VERWERFUNG DER HYPOTHESEN 52 GLOBALERE UNTERSCHIEDE ZWISCHEN LITHIUM UND NICHT-LITHIUM PATIENTEN 54 ZUSAMMENHANG ZWISCHEN ZELLERHALT UND KOGNITIVER LEISTUNG 57 LIMITATIONEN 59 ZUKÜNFTIGE STUDIEN: 61 6. SCHLUSSFOLGERUNG 61 ZUSAMMENFASSUNG 62 SUMMARY 64 LITERATURVERZEICHNIS 66 ABBILDUNGSVERZEICHNIS 86

Background: In certain masking paradigms, the masker can have two components, energetic and informational. Energetic masking is the traditional peripheral masking, whereas informational masking involves confusions (uncertainty) between the signal and masker that originate more centrally in the auditory system. Sperry et al (1997) used Northwestern University Auditory Test No. 6 (NU-6) words in multitalker babble to study the differential effects of energetic and informational masking using babble played temporally forward (FB) and backward (BB). The FB and BB are the same except BB is void of the contextual and semantic content cues that are available in FB. It is these informational cues that are thought to fuel informational masking. Sperry et al found 15% better recognition performance (∼3 dB) on BB than on FB, which can be interpreted as the presence of informational masking in the FB condition and not in the BB condition (Dirks and Bower, 1969). The Words-in-Noise Test (WIN) (Wilson, 2003; Wilson and McArdle, 2007) uses NU-6 words as the signal and multitalker babble as the masker, which is a combination of stimuli that potentially could produce informational masking. The WIN presents 5 or 10 words at each of seven signal-to-noise ratios (S/N, SNR) from 24 to 0 dB in 4 dB decrements with the 50% correct point being the metric of interest. The same recordings of the NU-6 words and multitalker babble used by Sperry et al are used in the WIN. Purpose: To determine whether informational masking was involved with the WIN. Research Design: Descriptive, quasi-experimental designs were conducted in three experiments using FB and BB in various paradigms in which FB and BB varied from 4.3 sec concatenated segments to essentially continuous. Study Sample: Eighty young adults with normal hearing and 64 older adults with sensorineural hearing losses participated in a series of three experiments. Data Collection and Analysis: Experiment 1 compared performance on the normal WIN (FB) with performance on the WIN in which the babble segment with each word was reversed temporally (BB). Experiment 2 examined the effects of continuous FB and BB segments on WIN performance. Experiment 3 replicated the Sperry et al (1997) experiment at 4 and 0 dB S/N using NU-6 words in the FB and BB conditions. Results: Experiment 1-with the WIN paradigm, recognition performances on FB and BB were the same for listeners with normal hearing and listeners with hearing loss, except at the 0 dB S/N with the listeners with normal hearing at which performance was significantly better on BB than FB. Experiment 2-recognition performances on FB and BB were the same at all SNRs for listeners with normal hearing using a slightly modified WIN paradigm. Experiment 3-there was no difference in performances on the FB and BB conditions with either of the two SNRs. Conclusions: Informational masking was not involved in the WIN paradigm. The Sperry et al results were not replicated, which is thought to be related to the way in which the Sperry et al BB condition was produced.

The present dissertation aims to evaluate the phenomenon of visual masking as a tool for studying visual awareness focusing on two-alternative forced choice (2AFC) discrimination tasks. Two existing theories of masking - Bachmann's (1984) perceptual retouch theory and Marcel's (1983) recovery theory - are discussed along with the global neuronal workspace theory of awareness (Baars. 1989; Dehaene, Kerszberg, & Changeux, 1998). Performance accuracy on Semantic discrimination is compared to that on Orthographic discrimination as an indication of a potential difference between semantic and orthographic processing of masked word stimuli presented for 40 ms and 50 ms. This is further compared to an e-detection task previously used as an indicator of awareness in some masked priming experiments. Together, these tasks are further evaluated in terms of their relationship with participants' subjective reports collected in the form of confidence ratings. The implications and predictions drawn from the theories of masking and visual awareness as well as the notion of partial awareness (Kouider & Dupoux, 2001) are assessed taking into account the data obtained in the current experiments.The relevance of these data for masked priming is determined by performing a comparison between 2AFC discrimination and detection tasks, and the lexical decision task. An ERP study is also presented, in which Semantic and Orthographic discrimination as well as e-detection are paired with confidence ratings and electrophysiological recordings in search of an ERP component that can be correlated with both subjective (confidence) and objective (performance) measures of awareness. A binding account of visual awareness with special attention paid to visual masking is proposed and compared to the three existing theories.

Time-Frequency (TF) masking is an audio processing technique useful for isolating an audio source from interfering sources. TF masking has been applied and studied in monaural and binaural applications, but has only recently been applied to distributed microphone arrays. This work focuses on evaluating the TF masking technique's ability to isolate human speech and improve speech intelligibility in an immersive "cocktail party" environment. In particular, an upper-bound on TF masking performance is established and compared to the traditional delay-sum and general sidelobe canceler (GSC) beamformers. Additionally, the novel technique of combining the GSC with TF masking is investigated and its performance evaluated. This work presents a resource-efficient method for studying the performance of these isolation techniques and evaluates their performance using both virtually simulated data and data recorded in a real-life acoustical environment. Further, methods are presented to analyze speech intelligibility post-processing, and automated objective intelligibility measurements are applied alongside informal subjective assessments to evaluate the performance of these processing techniques. Finally, the causes for subjective/objective intelligibility measurement disagreements are discussed, and it was shown that TF masking did enhance intelligibility beyond delay-sum beamforming and that the utilization of adaptive beamforming can be beneficial.

La théorie dominante suggérant une séparation entre une vision consciente pour la perception et une vision non consciente pour l'action au sein du système visuel fut particulièrement discutée au cours des dernières décennies. La thèse défendue ici se positionne dans le cadre d'une approche alternative reposant sur une évaluation conjointe des réponses motrice et perceptive en présence de stimuli au seuil perceptif. Les travaux réalisés dans ce contexte ont initialement porté sur les temps de réaction et ont contribué au développement d'un modèle psychophysique postulant que les réponses perceptives et motrices dépendraient d'un signal sensoriel unique mais de seuils de décision spécifiques. Les trois études réalisées au cours de cette thèse ont permis de tester ces propositions à partir de travaux portant sur le contrôle moteur manuel. Tout en confirmant une forte association entre les traitements visuels pour la perception et pour l'action, ces travaux ont permis de mettre en évidence un rôle important des conditions expérimentales (par exemple le contraste des stimuli et la présence ou non d'un masque visuel) dans les résultats obtenus. Les résultats se sont révélés compatibles avec les modèles neurophysiologiques du masquage visuel qui postulent que la réponse neurale à une stimulation visuelle est constituée d'une vague d'activation feedforward associée à la présence physique de la stimulation et de boucles de rétroaction liées à la perception consciente de celle-ci. Nos travaux ont également permis d'adapter au contrôle moteur manuel le modèle de décision à signal unique initialement développé dans le cadre des études portant sur les temps de réaction. / The dominant position of a separation between a conscious vision for perception and an unconscious vision for action within the visual system has been particularly discussed in the last decades. The present dissertation is to be placed in the context of an alternative approach consisting in evaluating jointly both perceptual and motor responses in the presence of near-treshold visual stimuli. Previous work within this framework, which have mainly concerned reaction times, have contributed to develop a psychophysical model in which perceptual and motor decision are taken relatively to the same single incoming signal but are based on different tresholds. The three studies conducting during this PhD aimed to testing these proposals in experiments involving manual motor control. While confirming the strong link between perceptual and motor processing within the visual system, the results obtained in these studies underlined the importance of experimental parameters such as the contrast of the stimuli and the presence of visual masks. These results are congruent with neurophysiological models of visual masking, which postulate that the neural response to a visual stimulus is composed of a transient feedforward sweep of activation related to the presence of as stimulus and recurrent feedback loops linked to the conscious perception of this stimulus. Our work also led to the adaptation to manual motor control of the single signal decisional model initially developed on the basis of reaction time studies.