Cortical processing of speech and non-speech sounds in adults and newborns

Comprehension of a complex acoustic signal - speech - is vital for human communication, with numerous brain processes required to convert the acoustics into an intelligible message. In four studies in the present thesis, cortical correlates for different stages of speech processing in a mature linguistic system of adults were investigated. In two further studies, developmental aspects of cortical specialisation and its plasticity in adults were examined. In the present studies, electroencephalographic (EEG) and magnetoencephalographic (MEG) recordings of the mismatch negativity (MMN) response elicited by changes in repetitive unattended auditory events and the phonological mismatch negativity (PMN) response elicited by unexpected speech sounds in attended speech inputs served as the main indicators of cortical processes. Changes in speech sounds elicited the MMNm, the magnetic equivalent of the electric MMN, that differed in generator loci and strength from those elicited by comparable changes in non-speech sounds, suggesting intra- and interhemispheric specialisation in the processing of speech and non-speech sounds at an early automatic processing level. This neuronal specialisation for the mother tongue was also reflected in the more efficient formation of stimulus representations in auditory sensory memory for typical native-language speech sounds compared with those formed for unfamiliar, non-prototype speech sounds and simple tones. Further, adding a speech or non-speech sound context to syllable changes was found to modulate the MMNm strength differently in the left and right hemispheres. Following the acoustic-phonetic processing of speech input, phonological effort related to the selection of possible lexical (word) candidates was linked with distinct left-hemisphere neuronal populations. In summary, the results suggest functional specialisation in the neuronal substrates underlying different levels of speech processing. Subsequently, plasticity of the brain's mature linguistic system was investigated in adults, in whom representations for an aurally-mediated communication system, Morse code, were found to develop within the same hemisphere where representations for the native-language speech sounds were already located. Finally, recording and localization of the MMNm response to changes in speech sounds was successfully accomplished in newborn infants, encouraging future MEG investigations on, for example, the state of neuronal specialisation at birth.

Cortical processing of speech and non-speech sounds in autism and Asperger syndrome

Autism and Asperger syndrome (AS) are neurodevelopmental disorders characterised by deficient social and communication skills, as well as restricted, repetitive patterns of behaviour. The language development in individuals with autism is significantly delayed and deficient, whereas in individuals with AS, the structural aspects of language develop quite normally. Both groups, however, have semantic-pragmatic language deficits. The present thesis investigated auditory processing in individuals with autism and AS. In particular, the discrimination of and orienting to speech and non-speech sounds was studied, as well as the abstraction of invariant sound features from speech-sound input. Altogether five studies were conducted with auditory event-related brain potentials (ERP); two studies also included a behavioural sound-identification task. In three studies, the subjects were children with autism, in one study children with AS, and in one study adults with AS. In children with autism, even the early stages of sound encoding were deficient. In addition, these children had altered sound-discrimination processes characterised by enhanced spectral but deficient temporal discrimination. The enhanced pitch discrimination may partly explain the auditory hypersensitivity common in autism, and it may compromise the filtering of relevant auditory information from irrelevant information. Indeed, it was found that when sound discrimination required abstracting invariant features from varying input, children with autism maintained their superiority in pitch processing, but lost it in vowel processing. Finally, involuntary orienting to sound changes was deficient in children with autism in particular with respect to speech sounds. This finding is in agreement with previous studies on autism suggesting deficits in orienting to socially relevant stimuli. In contrast to children with autism, the early stages of sound encoding were fairly unimpaired in children with AS. However, sound discrimination and orienting were rather similarly altered in these children as in those with autism, suggesting correspondences in the auditory phenotype in these two disorders which belong to the same continuum. Unlike children with AS, adults with AS showed enhanced processing of duration changes, suggesting developmental changes in auditory processing in this disorder.

Cortical processing of musical pitch as reflected by behavioural and electrophysiological evidence

In a musical context, the pitch of sounds is encoded according to domain-general principles not confined to music or even to audition overall but common to other perceptual and cognitive processes (such as multiple pattern encoding and feature integration), and to domain-specific and culture-specific properties related to a particular musical system only (such as the pitch steps of the Western tonal system). The studies included in this thesis shed light on the processing stages during which pitch encoding occurs on the basis of both domain-general and music-specific properties, and elucidate the putative brain mechanisms underlying pitch-related music perception. Study I showed, in subjects without formal musical education, that the pitch and timbre of multiple sounds are integrated as unified object representations in sensory memory before attentional intervention. Similarly, multiple pattern pitches are simultaneously maintained in non-musicians' sensory memory (Study II). These findings demonstrate the degree of sophistication of pitch processing at the sensory memory stage, requiring neither attention nor any special expertise of the subjects. Furthermore, music- and culture-specific properties, such as the pitch steps of the equal-tempered musical scale, are automatically discriminated in sensory memory even by subjects without formal musical education (Studies III and IV). The cognitive processing of pitch according to culture-specific musical-scale schemata hence occurs as early as at the sensory-memory stage of pitch analysis. Exposure and cortical plasticity seem to be involved in musical pitch encoding. For instance, after only one hour of laboratory training, the neural representations of pitch in the auditory cortex are altered (Study V). However, faulty brain mechanisms for attentive processing of fine-grained pitch steps lead to inborn deficits in music perception and recognition such as those encountered in congenital amusia (Study VI). These findings suggest that predispositions for exact pitch-step discrimination together with long-term exposure to music govern the acquisition of the automatized schematic knowledge of the music of a particular culture that even non-musicians possess.

Koko talo soi : Klemetti-Opisto suomalaisen musiikkikulttuurin kehittäjänä 1953-1968

This study aims to examine the operations and significance of the Klemetti Institute (Klemetti-Opisto) as a developer of Finnish music culture from 1953 to 1968 during the term of office of the Institute s founder and first director, Arvo Vainio. The Klemetti Institute was originally established as a choir institute, but soon expanded to offer a wide range of music courses. In addition to providing courses for choir leaders and singers, the Institute began its orchestral activities as early as the mid-1950s. Other courses included ear training seminars as well as courses for young people s music instructors and in playing the kantele (a Finnish string instrument) and solo singing. More than 20 types of courses were offered over the 16-year period. The Klemetti Institute s courses were incorporated into the folk high school courses offered by the Orivesi Institute (Oriveden Opisto) and were organised during the summer months of June and July. In addition to funding based on the Folk High School Act, financial assistance was obtained from various foundations and funds, such as the Wihuri Foundation. This study is linked to the context of historical research. I examine the Klemetti Institute s operations chronologically, classifying instruction into different course types, and analyse concert activities primarily in the section on the Institute s student union. The source material includes the Klemetti Institute archives, which consist of Arvo Vainio s correspondence, student applications, register books and cards, journals and student lists, course albums and nearly all issues of the Klemettiläinen bulletin. In addition, I have used focused interviews and essays to obtain extensive data from students and teachers. I concentrate on primary school teachers, who accounted for the majority of course participants. A total of more than 2,300 people participated in the courses, nearly half of whom took courses during at least two summers. Primary school teachers accounted for 50% to 70% of the participants in most courses and constituted an even larger share of participants in some courses, such as the music instructor course. The Klemetti Institute contributed to the expansion throughout Finland of a new ideal for choral tone. This involved delicate singing which strives for tonal purity and expressiveness. Chamber choirs had been virtually unheard of in Finland, but the Klemetti Institute Chamber Choir popularised them. Chamber choirs are characterised by an extensive singing repertoire ranging from the Middle Ages to the present. As the name suggests, chamber choirs were originally rather small mixed choirs. Delicate singing meant the avoidance of extensive vibrato techniques and strong, heavy forte sounds, which had previously been typical of Finnish choirs. Those opposing and shunning this new manner of singing called it ghost singing . The Klemetti Institute s teachers included Finland s most prominent pedagogues and artists. As the focused essays, or reminiscences as I call them, show, their significance for the students was central. I examine extensively the Klemetti Institute s enthusiastic atmosphere, which during the early years was characterised by what some writers described as a hunger for music . In addition to distributing a new tonal ideal and choir repertoire, the Klemetti Institute also distributed new methods of music education, thus affecting the music teaching of Finnish primary schools, in particular. The Orff approach, which included various instruments, became well known, although some of Orff s ideas, such as improvisation and physical exercise, were initially unfamiliar. More important than the Orff approach was the in-depth teaching at the Klemetti Institute of the Hungarian ear training method known as the Kodály method. Many course participants were among those launching specialist music classes in schools, and the method became the foundation for music teaching in many such schools. The Klemetti Institute was also a pioneer in organising orchestra camps for young people. The Klemetti Institute promoted Finnish music culture and played an important role in the continuing music education of primary school teachers. Keywords: adult education, Grundtvigian philosophy, popular enlightenment, Klemetti Institute, Kodály method, choir singing, choir conducting, music history, music education, music culture, music camp, Orff approach, Orff-Schulwerk, Orivesi Institute, instrument teaching, free popular education, communality, solo singing, voice production

Effects of unilateral vocal fold paralysis treatment with fascia augmentation on airflow mechanics, tracheal sounds and voice acoustics

Data on the influence of unilateral vocal fold paralysis on breathing, especially other than information obtained by spirometry, are relatively scarce. Even less is known about the effect of its treatment by vocal fold medialization. Consequently, there was a need to study the issue by combining multiple instruments capable of assessing airflow dynamics and voice. This need was emphasized by a recently developed medialization technique, autologous fascia injection; its effects on breathing have not previously been investigated. A cohort of ten patients with unilateral vocal fold paralysis was studied before and after autologous fascia injection by using flow-volume spirometry, body plethysmography and acoustic analysis of breathing and voice. Preoperative results were compared with those of ten healthy controls. A second cohort of 11 subjects with unilateral vocal fold paralysis was studied pre- and postoperatively by using flow-volume spirometry, impulse oscillometry, acoustic analysis of voice, voice handicap index and subjective assessment of dyspnoea. Preoperative peak inspiratory flow and specific airway conductance were significantly lower and airway resistance was significantly higher in the patients than in the healthy controls (78% vs. 107%, 73% vs. 116% and 182% vs. 125% of predicted; p = 0.004, p = 0.004 and p = 0.026, respectively). Patients had a higher root mean square of spectral power of tracheal sounds than controls, and three of them had wheezes as opposed to no wheezing in healthy subjects. Autologous fascia injection significantly improved acoustic parameters of the voice in both cohorts and voice handicap index in the latter cohort, indicating that this procedure successfully improved voice in unilateral vocal fold paralysis. Peak inspiratory flow decreased significantly as a consequence of this procedure (from 4.54 ± 1.68 l to 4.21 ± 1.26 l, p = 0.03, in pooled data of both cohorts), but no change occurred in the other variables of flow-volume spirometry, body-plethysmography and impulse oscillometry. Eight of the ten patients studied by acoustic analysis of breathing had wheezes after vocal fold medialization compared with only three patients before the procedure, and the numbers of wheezes per recorded inspirium and expirium increased significantly (from 0.02 to 0.42 and from 0.03 to 0.36; p = 0.028 and p = 0.043, respectively). In conclusion, unilateral vocal fold paralysis was observed to disturb forced breathing and also to cause some signs of disturbed tidal breathing. Findings of flow volume spirometry were consistent with variable extra-thoracic obstruction. Vocal fold medialization by autologous fascia injection improved the quality of the voice in patients with unilateral vocal fold paralysis, but also decreased peak inspiratory flow and induced wheezing during tidal breathing. However, these airflow changes did not appear to cause significant symptoms in patients.

Seeing and hearing speech, sounds, and signs: functional magnetic resonance studies on fluent and dyslexic readers

Speech has both auditory and visual components (heard speech sounds and seen articulatory gestures). During all perception, selective attention facilitates efficient information processing and enables concentration on high-priority stimuli. Auditory and visual sensory systems interact at multiple processing levels during speech perception and, further, the classical motor speech regions seem also to participate in speech perception. Auditory, visual, and motor-articulatory processes may thus work in parallel during speech perception, their use possibly depending on the information available and the individual characteristics of the observer. Because of their subtle speech perception difficulties possibly stemming from disturbances at elemental levels of sensory processing, dyslexic readers may rely more on motor-articulatory speech perception strategies than do fluent readers. This thesis aimed to investigate the neural mechanisms of speech perception and selective attention in fluent and dyslexic readers. We conducted four functional magnetic resonance imaging experiments, during which subjects perceived articulatory gestures, speech sounds, and other auditory and visual stimuli. Gradient echo-planar images depicting blood oxygenation level-dependent contrast were acquired during stimulus presentation to indirectly measure brain hemodynamic activation. Lip-reading activated the primary auditory cortex, and selective attention to visual speech gestures enhanced activity within the left secondary auditory cortex. Attention to non-speech sounds enhanced auditory cortex activity bilaterally; this effect showed modulation by sound presentation rate. A comparison between fluent and dyslexic readers' brain hemodynamic activity during audiovisual speech perception revealed stronger activation of predominantly motor speech areas in dyslexic readers during a contrast test that allowed exploration of the processing of phonetic features extracted from auditory and visual speech. The results show that visual speech perception modulates hemodynamic activity within auditory cortex areas once considered unimodal, and suggest that the left secondary auditory cortex specifically participates in extracting the linguistic content of seen articulatory gestures. They are strong evidence for the importance of attention as a modulator of auditory cortex function during both sound processing and visual speech perception, and point out the nature of attention as an interactive process (influenced by stimulus-driven effects). Further, they suggest heightened reliance on motor-articulatory and visual speech perception strategies among dyslexic readers, possibly compensating for their auditory speech perception difficulties.

Word order and tonal shape in the production of focus in short Finnish utterances

This paper presents results from a study on the production of Finnish prosody. The effect of word order and the tonal shape in the production of Finnish prosody was studied as produced by 8 native Finnish speakers. Predictions formulated with regard to results from an earlier study pertaining to the perception of promi- nence were tested. These predictions had to do with the tonal shape of the utterances in the form of a flat hat pattern and the effect of word order on the so called top-line declination within an adver- bial phrase in the utterances. The results from the experiment give support to the following claims: the temporal domain of prosodic focus is the whole utterance, word order reversal from unmarked to marked has an effect on the production of prosody, and the pro- duction of the tonal aspects of focus in Finnish follows a basic flat hat pattern. That is the prominence of a word can be produced by an f 0 rise or a fall, depending on the location of the word in an utterance. The basic accentual shape of a Finnish word is then not a pointed rise/fall hat shape as claimed before since it can vary depending on the syllable structure and the position within an ut- terance.

Speech Rhythm in an Interlanguage Perspective : Finnish Adolescents Speaking English

Speech rhythm is an essential part of speech processing. It is the outcome of the workings of a combination of linguistic and non-linguistic parameters, many of which also have other functions in speech. This study focusses on the acoustic and auditive realization of two linguistic parameters of rhythm: (1) sentence stress, and (2) speech rate and pausing. The aim was to find out how well Finnish comprehensive school pupils realize these two parameters in English and how native speakers of English react to Finnish pupils English rhythm. The material was elicited by means of a story-telling task and questionnaires. Three female and three male pupils representing different levels of oral skills in English were selected as the experimental group. The control group consisted of two female and two male native speakers of English. The stories were analysed acoustically and auditorily with respect to interstress intervals, weak forms, fundamental frequency, pausing, and speech as well as articulation rate. In addition, 52 native speakers of English were asked to rate the intelligibility of the Finnish pupils English with respect to speech rhythm and give their attitudes on what the pupils sounded like. Results showed that Finnish pupils can produce isochronous interstress intervals in English, but that too large a proportion of these intervals contain pauses. A closer analysis of the pauses revealed that Finnish pupils pause too frequently and in inappropriate places when they speak English. Frequent pausing was also found to cause slow speech rates. The findings of the fundamental frequency (F0) measurements indicate that Finnish pupils tend to make a slightly narrower F0 difference between stressed and unstressed syllables than the native speakers of English. Furthermore, Finnish pupils appear to know how to reduce the duration and quality of unstressed sounds, but they fail to do it frequently enough. Native listeners gave lower intelligibility and attitude scores to pupils with more anomalous speech rhythm. Finnish pupils rhythm anomalies seemed to derive from various learning- or learner-related factors rather than from the differences between English and Finnish. This study demonstrates that pausing may be a more important component of English speech rhythm than sentence stress as far as Finnish adolescents are concerned and that interlanguage development is affected by various factors and characterised by jumps or periods of stasis. Other theoretical, methodological and pedagogical implications of the results are also discussed.

Preliminary Phonological Analysis of Denjongka of Sikkim

This thesis is a preliminary phonological description of the Tibetan-related Denjongka language of Sikkim, India. Because the language has not been much researched and the previous studies have focused on other issues than phonology, the present paper is the first of its kind. The data for this thesis was gathered in Gangtok, the capital of Sikkim, from March to May 2004. I had four language informants from four different locations in Sikkim who spoke different dialects of Denjongka. One of the informants, from whom I recorded c. 900 words and 530 sentences, was used as the main data source for the analysis. First, I will give some ethnographic background information on the people who speak Denjongka. Next, I will discuss first the segmental and then the suprasegmental phonology of the language, which were analysed much in line with American structuralism. I also used acoustic analysis enabled by the Praat-program. Eight vowel phonemes were found. The phonemic status of /E/, however, is still suspect. I present some preliminary evidence for roundedness, frontness and height assimilation among the vowels. In the interpretation adopted in this analysis, there are no diphthongs in Denjongka. Forty consonant phonemes were found: 17 plosives, 7 affricates, 5 fricatives, 5 nasals, 4 liquids and 2 approximants. Denjongka plosives and affricates have four-way aspiration/voicing distinction: voiceless aspirated, voiceless unaspirated, voiceless slightly aspirated (devoiced), and voiced unaspirated. Two voiceless nasals and two voiceless liquids were found. Two phonation types were found to be contrastive, lax/breathy and tense/creaky. Nasalisation and length in vowels are phonemic. Denjongka is an incipient tone language. Tonal phenomena, which involve mainly pitch and phonation type, are complex. Pitch is most of the time predictable from the initial consonant and the phonation type. In some cases, however, pitch is the only contrastive feature between words. The description of Denjongka in this paper differs from the traditional four-tone system, which has been used in many descriptions of Tibetan-related languages. In the four-tone system, pitch is contrastive both in the high and low register, whereas in the present analysis pitch has been established to contrast only in the high register. Lastly, the appendices include a comparative word list of the four Denjongka dialects studied in this thesis.

Principles of Pitch Organization in Béla Bartók's 'Duke Bluebeard's Castle'

The topic of my doctoral thesis is to demonstrate the usefulness of incorporating tonal and modal elements into a pitch-web square analysis of Béla Bartók's (1881-1945) opera, 'A kékszakállú herceg vára' ('Duke Bluebeard's Castle'). My specific goal is to demonstrate that different musical materials, which exist as foreground melodies or long-term key progressions, are unified by the unordered pitch set {0,1,4}, which becomes prominent in different sections of Bartók's opera. In Bluebeard's Castle, the set {0,1,4} is also found as a subset of several tetrachords: {0,1,4,7}, {0,1,4,8}, and {0,3,4,7}. My claim is that {0,1,4} serves to link music materials between themes, between sections, and also between scenes. This study develops an analytical method, drawn from various theoretical perspectives, for conceiving superposed diatonic spaces within a hybrid pitch-space comprised of diatonic and chromatic features. The integrity of diatonic melodic lines is retained, which allows for a non-reductive understanding of diatonic superposition, without appealing to pitch centers or specifying complete diatonic collections. Through combining various theoretical insights of the Hungarian scholar Ernő Lendvai, and the American theorists Elliott Antokoletz, Paul Wilson and Allen Forte, as well as the composer himself, this study gives a detailed analysis of the opera's pitch material in a way that combines, complements, and expands upon the studies of those scholars. The analyzed pitch sets are represented on Aarre Joutsenvirta's note-web square, which adds a new aspect to the field of Bartók analysis. Keywords: Bartók, Duke Bluebeard's Castle (Op. 11), Ernő Lendvai, axis system, Elliott Antokoletz, intervallic cycles, intervallic cells, Allen Forte, set theory, interval classes, interval vectors, Aarre Joutsenvirta, pitch-web square, pitch-web analysis.

Suomen rautakautiset kulkuset, kellot ja kelloriipukset : äänimaiseman arkeologiaa

The thesis addresses the problem of Finnish Iron Age bells, pellet bells and bell pendants, previously unexplored musical artefacts from 400–1300 AD. The study, which contributes to the field of music archaeology, aims to provide a gateway to ancient soundworlds and ideas of music making. The research questions include: Where did these metal artefacts come from? How did they sound? How were they used? What did their sound mean to the people of the Iron Age? The data collected at the National Museum of Finland and at several provincial museums covers a total of 486 bells, pellet bells and bell pendants. By means of a cluster analysis, each category was divided into several subgroups. The subgroups, which all seem to have a different dating and geographical distribution, represent a spread of both local and international manufacturing traditions. According to an elemental analysis, the material varies from iron to copper-tin, copper-lead and copper-tin-lead alloys. Clappers, pellets and pebbles prove that the bells and pellet bells were indisputably instruments intended for sound production. Clusters of small bell pendants, however, probably produced sound by jingling against each other. Spectrogram plots reveal that the partials of the still audible sounds range from 1 000 to 19 850 Hz. On the basis of 129 inhumation graves, hoards, barrows and stray finds, it seems evident that the bells, pellet bells and bell pendants were fastened to dresses and horse harnesses or carried in pouches and boxes. The resulting acoustic spaces could have been employed in constructing social hierarchies, since the instruments usually appear in richly furnished graves. Furthermore, the instruments repeatedly occur with crosses, edge tools and zoomorphic pendants that in the later Finnish-Karelian culture were regarded as prophylactic amulets. In the Iron Age as well as in later folk culture, the bell sounds seem to have expressed territorial, social and cosmological boundaries.

Lumometsän syli : Anni Swanin satusymbolismi 1896-1923

Lumometsän syli, Anni Swanin satusymbolismi 1896-1923 on suomenkielisen satukirjallisuuden poetiikkaa ja 1900-luvun alun modernia naiseutta selvittävä feministiseen tutkimustraditioon liittyvä tutkimus. Sen kohteena ovat lasten- ja nuortenkirjailija Anni Swanin (1875-1958) satukokoelmat vuosilta 1901-1923 ja Uusi Suometar -lehden sadunomaiset novellit vuosilta 1896-1904. Tutkimus tuo uutta tietoa lastenkirjallisuuden osalta 1900-luvun alun modernin ihmisen problematiikasta. Se sisältää naissubjektin kehityskaaren ja sisäisen kasvun kohti naistaiteilijuutta. Yksityiskohtaisen tarkastelun kohteina ovat sadut Veli ja sisar (1917), Ihmekukka (1905), Marjaanan helmikruunu (1912), Aaltojen salaisuus (1901), Jääkukka (1905), Tyttö ja kuolema (1917), Merenkuningatar ja hänen poikansa (1905), Lumolinna (1905) ja Tarina Kultasirkasta (1901). Tutkimuksessa tarkastellaan Swanin satujen poeettista kieltä ja naiseuden tematiikkaa ranskalaisen postmodernin ajan feministisen viitekehyksen valossa. Siinä keskeisiä ovat Julia Kristevan psykoanalyyttispohjaiset näkemykset ja Hélène Cixous´n sekä Luce Irigarayn ajatukset feminiinisestä kirjoituksesta. Sadut kontekstualisoidaan ajankohdan symbolistiseen taidevirtaukseen ja Suomen taiteen kultakauteen. Satuja tulkitaan naiskirjailijan lajina ja erityisenä naisen metaforisen ilmaisun muotona. Satujen feministinen lukutapa purkaa perinteisiä lukemiskonventioita ja merkitsee satutekstin lukemista "toisin". Se avaa varhaista modernia naiseutta ja sille ominaista naisen ilmaisukielen erityisyyttä sekä mykkää ei-kielellistä, melankolian ilmaisua. Tutkimus tuo esiin uudenlaisen naiskirjailijan aistimusvoimaisen kielen. Swanin satusymbolismi on luonnon kauneuden synesteettista ja aistimusvoimaista kerrontaa, jolle on luonteenomaista aistiestetiikka, metaforisuus, metonymisyys ja metamorfoosit. Swan vahvistaa osaltaan naisen sankaruutta, omaa ilmaisukieltä ja ääntä. Tuloksena paljastuu satuperinteeseen verrattuna uudenlaisia tyttöyden, äitiyden, naistaiteilijuuden ja perheen malleja ja niiden representaatioita. Satumallit osoittautuvat aikanaan moderneiksi tyttösankareiksi, osin ambivalenteiksi uudenlaista naiseutta ja suhteessa oloa heijastaviksi ja ovat siten varhaisia feministisen sadun tunnusmerkkejä. Tutkimus selvittää, miten Swan rakentaa omaperäisen satusymboliikan. Satumetsä on luonnonkauniin suomalaismetsän symbolinen mielenmaisema ja samanaikaisesti sadun myyttis-symbolinen topos. Swanin luontokäsitys sisältää luonnonsuojelun ja varhaisen ekokriittisen näkemyksen. Tutkimus osoittaa Swanin satujen kytkeytyvän 1900-luvun alun modernismiin ja Suomen taiteen kultakauteen. Swan on suomenkielisen symbolistisen taidesadun kehittäjä ja feministisen sadun aloittaja.

Pitch discrimination in optimal and suboptimal acoustic environments: electroencephalographic, magnetoencephalographic, and behavioral evidence

Pitch discrimination is a fundamental property of the human auditory system. Our understanding of pitch-discrimination mechanisms is important from both theoretical and clinical perspectives. The discrimination of spectrally complex sounds is crucial in the processing of music and speech. Current methods of cognitive neuroscience can track the brain processes underlying sound processing either with precise temporal (EEG and MEG) or spatial resolution (PET and fMRI). A combination of different techniques is therefore required in contemporary auditory research. One of the problems in comparing the EEG/MEG and fMRI methods, however, is the fMRI acoustic noise. In the present thesis, EEG and MEG in combination with behavioral techniques were used, first, to define the ERP correlates of automatic pitch discrimination across a wide frequency range in adults and neonates and, second, they were used to determine the effect of recorded acoustic fMRI noise on those adult ERP and ERF correlates during passive and active pitch discrimination. Pure tones and complex 3-harmonic sounds served as stimuli in the oddball and matching-to-sample paradigms. The results suggest that pitch discrimination in adults, as reflected by MMN latency, is most accurate in the 1000-2000 Hz frequency range, and that pitch discrimination is facilitated further by adding harmonics to the fundamental frequency. Newborn infants are able to discriminate a 20% frequency change in the 250-4000 Hz frequency range, whereas the discrimination of a 5% frequency change was unconfirmed. Furthermore, the effect of the fMRI gradient noise on the automatic processing of pitch change was more prominent for tones with frequencies exceeding 500 Hz, overlapping with the spectral maximum of the noise. When the fundamental frequency of the tones was lower than the spectral maximum of the noise, fMRI noise had no effect on MMN and P3a, whereas the noise delayed and suppressed N1 and exogenous N2. Noise also suppressed the N1 amplitude in a matching-to-sample working memory task. However, the task-related difference observed in the N1 component, suggesting a functional dissociation between the processing of spatial and non-spatial auditory information, was partially preserved in the noise condition. Noise hampered feature coding mechanisms more than it hampered the mechanisms of change detection, involuntary attention, and the segregation of the spatial and non-spatial domains of working-memory. The data presented in the thesis can be used to develop clinical ERP-based frequency-discrimination protocols and combined EEG and fMRI experimental paradigms.