Role of Selected Spectral Attributes in the Perception of Synthetic Vowels

This thesis is an experimental study regarding the identification and discrimination of vowels, studied using synthetic stimuli. The acoustic attributes of synthetic stimuli vary, which raises the question of how different spectral attributes are linked to the behaviour of the subjects. The spectral attributes used are formants and spectral moments (centre of gravity, standard deviation, skewness and kurtosis). Two types of experiments are used, related to the identification and discrimination of the stimuli, respectively. The discrimination is studied by using both the attentive procedures that require a response from the subject, and the preattentive procedures that require no response. Together, the studies offer information about the identification and discrimination of synthetic vowels in 15 different languages. Furthermore, this thesis discusses the role of various spectral attributes in the speech perception processes. The thesis is divided into three studies. The first is based only on attentive methods, whereas the other two concentrate on the relationship between identification and discrimination experiments. The neurophysiological methods (EEG recordings) reveal the role of attention in processing, and are used in discrimination experiments, while the results reveal differences in perceptual processes based on the language, attention and experimental procedure.

Brain Dopamine and Serotonin Receptors in the Perception of Pain. Positron Emission Tomography Studies in Healthy Subjects

The role of dopamine and serotonin in spinal pain regulation is well established. However, little is known concerning the role of brain dopamine and serotonin in the perception of pain in humans. The aim of this study was to assess the potential role of brain dopamine and serotonin in determining experimental pain sensitivity in humans using positron emission tomography (PET) and psychophysical methods. A total of 39 healthy subjects participated in the study, and PET imaging was performed to assess brain dopamine D2/D3 and serotonin 5-HT_1A receptor availability. In a separate session, sensitivity to pain and touch was assessed with traditional psychophysical methods, allowing the evaluation of potential associations between D2/D3 and 5-HT_1A binding and psychophysical responses. The subjects’ responses were also analyzed according to Signal Detection Theory, which enables separate assessment of the subject’s discriminative capacity (sensory factor) and response criterion (non-sensory factor). The study found that the D2/D3 receptor binding in the right putamen was inversely correlated with pain threshold and response criterion. 5-HT_1A binding in cingulate cortex, inferior temporal gyrus and medial prefrontal cortex was inversely correlated with discriminative capacity for touch. Additionally, the response criterion for pain and intensity rating of suprathreshold pain were inversely correlated with 5-HT_1A binding in multiple brain areas. The results suggest that brain D2/D3 receptors and 5-HT_1A receptors modulate sensitivity to pain and that the pain modulatory effects may, at least partly, be attributed to influences on the response criterion. 5-HT_1A receptors are also involved in the regulation of touch by having an effect on discriminative capacity.

Spatial and Spectral Separability of Grasslands in the inner Turku Archipelago using Landsat Thematic Mapper Satellite Imagery

The present study investigates the spatial and spectral discrimination potential for grassland patches in the inner Turku Archipelago using Landsat Thematic Mapper satellite imagery. The spatial discrimination potential was computed through overlay analysis using official grassland parcel data and a hypothetical 30 m resolution satellite image capturing the site. It found that Landsat TM imagery’s ability to retrieve pure or near-pure pixels (90% purity or more) from grassland patches smaller than 1 hectare was limited to 13% success, compared to 52% success when upscaling the resolution to 10 x 10 m pixel size. Additionally, the perimeter/area patch metric is proposed as a predictor for the suitability of the spatial resolution of input imagery. Regression analysis showed that there is a strong negative correlation between a patch’s perimeter/area ratio and its pure pixel potential. The study goes on to characterise the spectral response and discrimination potential for the five main grassland types occurring in the study area: recreational grassland, traditional pasture, modern pasture, fodder production grassland and overgrown grassland. This was done through the construction of spectral response curves, a coincident spectral plot and a contingency matrix as well as by calculating the transformed divergence for the spectral signatures, all based on training samples from the TM imagery. Substantial differences in spectral discrimination potential between imagery from the beginning of the growing season and the middle of summer were found. This is because the spectral responses for these five grassland types converge as the peak of the growing season draws nearer. Recreational grassland shows a consistent discrimination advantage over other grassland types, whereas modern pasture is most easily confused. Traditional pasture land, perhaps the most biologically valuable grassland type, can be spectrally discriminated from other grassland types with satisfactory success rates provided early growing season imagery is used.

Contextualizing entrepreneurial intentions : a multiple case study on entrepreneurial cognition and perception

Avhandlingen behandlar entreprenöriella intentioner och individens uppfattningar om entreprenörskap. Om vi vill främja entreprenörskap så räcker det inte att vi förstår vilken nytta samhället kan ha av entreprenörer (arbetsplatser, mera skatteinkomster osv.). Vi måste förstå varför entreprenörskap är intressant och attraktiv ur individens synvinkel. Just den frågan har varit central inom kognitiv entreprenörskapsforskning de senaste 10 åren har vår förståelse för entreprenörer ökat betydligt tack vare den forskningen. Problemet med existerande forskning är att uppfattad genomförbarhet och uppfattad attraktivitet, dvs. de attityder som sägs leda till entreprenöriella intentioner, beskriver enbart vilken attityd individen generellt har till entreprenörskap. Enligt tidigare forskningsresultat så är det skillnad på generella attityder till en handling och attityder till att genomföra just den handlingen. Vill vi veta om individen kan tänka sig starta och driva ett företag så måste vi alltså studera individens attityd till att utföra just den specifika handlingen. Enligt avhandlingens forskningsresultat så kan vi lära oss mera om attityder till entreprenörskap genom att studera också motivation och mål. På så sätt kan vi förstå varför en del väljer att bli entreprenörer medan andra väljer att låta bli, även om de utåt sett har samma möjligheter att bli entreprenörer.

Lifelong learning travels : single actors´ perception and talk of lifelong learning in a specific organizational context

I mars 2003 certifierades en finländsk advokatbyrå av den Europeiska kommissionen som den bästa i Europa inom specialkategorin livslångt lärande. Advokatbyrån var överraskad över utnämningen emedan de inte aktivt och/eller medvetet implementerat eller utövat en livslångt lärandestrategi i sin verksamhet bland sin personal. Byrån deltog i en tävling om bästa arbetsplats i Europa ("Best workplaces in Europe 2003") utan att vara medveten om den Europeiska kommissionens special- kategorier. Emedan advokatbyrån inte medvetet implementerat en livslångt lärandestrategi bland sin personal formar aktörerna, vars uppfattning och prat denna avhandling handlar om, sina föreställningar och sitt prat om livslångt lärande efter utnämningen. Översättningsprocessen av en idé utlöses sålunda i denna studie av en extern händelse. I sin avhandling beskriver Annica Isacsson hur och varför en idé (livslångt lärande) föds (på nytt) på en institutionell nivå, hur idén reser och förändras i en process av översättning, hur idén landar i två organisationer samt hur idén om livslångt lärande uppfattas och beskrivs av lokala aktörer i två olika organisationer. Fokus i studien ligger sålunda på enskilda aktörers uppfattning om ett kontroversiellt koncept i en lokal kontext. Teoretiskt möts och sammanlänkas teori om livslångt lärande, sociokulturella teorier om lärande och teorier om organisatoriskt lärande. Isacssons avhandling visar på hur livslångt lärande inte enbart, i en organisatorisk kontext, handlar om individuell kompetensutveckling utan också om organisatoriskt lärande i vilken lärande av andra organisationsmedlemmar och organisationer ingår. Studien visar vidare på hur enskilda aktörers prat påverkas av det institutionella fältet och av den tidsanda inom vilken diskursen livslångt lärande föds, rör sig och ingår.

Eating disorders, weight perception, and dieting in adolescence

Background: Eating disorders are serious psychiatric disorders, which usually have their onset in adolescence. Body dissatisfaction and dieting, both common among adolescents, are recognised risk factors for eating disorders. The aim of the present study was to assess the prevalence of eating disorders in the general adolescent population, assess the risk of developing eating disorders in subgroups of dieters, and analyse longitudinal concomitants of incorrect weight perception. Method: A prospective follow-up study on 595 adolescents, aged 15 at baseline, was conducted in western Finland. The study comprised questionnaires directed at the whole study population and subsequent personal interviews with adolescents found to be screen-positive for eating disorders, at both baseline and three-year follow-up. Results: The lifetime prevalence rates for 18 year old females were 2.6 % for anorexia nervosa, 0.4 for bulimia nervosa, and 9.0 % for eating disorder not otherwise specified (EDNOS). No prevalent case of DSM-IV eating disorders was found among the male participants. Eating disorders, as well as depressive symptoms, social anxiety, and low self-esteem, was more prevalent among females who perceived themselves as being overweight, despite being normal or underweight, when compared to females with a correct weight perception. An incorrect weight perception was associated in males with social anxiety. Female adolescents dieting due to psychological distress, rather than vanity or overweight, had a fifteen-fold risk of developing an eating disorder. Conclusions: Eating disorders are common among female adolescents, and adolescents choosing to diet due to psychological distress show a markedly increased risk of developing an eating disorder. Promotion of general well-being as well as the prevention of body dissatisfaction and misdirected dieting, accompanied by early detection and proper treatment of eating disorders, is needed to reduce the incidence of and facilitate recovery in adolescents suffering from eating disorders.