Experiments in Computing : A Survey

Experiments play a central role in science. The role of experiments in computing is, however, unclear. Questions about the relevance of experiments in computing attracted little attention until the 1980s. As the discipline then saw a push towards experimental computer science, a variety of technically, theoretically, and empirically oriented views on experiments emerged. As a consequence of those debates, today's computing fields use experiments and experiment terminology in a variety of ways. This paper analyzes experimentation debates in computing. It presents five ways in which debaters have conceptualized experiments in computing: feasibility experiment, trial experiment, field experiment, comparison experiment, and controlled experiment. This paper has three aims: to clarify experiment terminology in computing; to contribute to disciplinary self-understanding of computing; and, due to computing's centrality in other fields, to promote understanding of experiments in modern science in general.Peer reviewe

Neuroanatomical correlates of speech and singing production in chronic post-stroke aphasia

A classical observation in neurology is that aphasic stroke patients with impairments in speech production can nonetheless sing the same utterances. This preserved ability suggests a distinctive neural architecture for singing that could contribute to speech recovery. However, to date, these structural correlates remain unknown. Here, we combined a multivariate lesion–symptom mapping and voxel-based morphometry approach to analyse the relationship between lesion patterns and grey matter volume and production rate in speech and singing tasks. Lesion patterns for spontaneous speech and cued repetition extended into frontal, temporal and parietal areas typically reported within the speech production network. Impairment in spontaneous singing was associated with damage to the left anterior–posterior superior and middle temporal gyri. Preservation of grey matter volume in the same regions where damage led to poor speech and singing production supported better performance in these tasks. When dividing the patients into fluent and dysfluent singers based on the singing performance from demographically matched controls, we found that the preservation of the left middle temporal gyrus was related to better spontaneous singing. These findings provide insights into the structural correlates of singing in chronic aphasia and may serve as biomarkers to predict treatment response in clinical trials using singing-based interventions for speech rehabilitation.Peer reviewe

Differential effects of ageing on the neural processing of speech and singing production

BackgroundUnderstanding healthy brain ageing has become vital as populations are ageing rapidly and age-related brain diseases are becoming more common. In normal brain ageing, speech processing undergoes functional reorganisation involving reductions of hemispheric asymmetry and overactivation in the prefrontal regions. However, little is known about how these changes generalise to other vocal production, such as singing, and how they are affected by associated cognitive demands.MethodsThe present cross-sectional fMRI study systematically maps the neural correlates of vocal production across adulthood (N=100, age 21–88 years) using a balanced 2x3 design where tasks varied in modality (speech: proverbs / singing: song phrases) and cognitive demand (repetition / completion from memory / improvisation).ResultsIn speech production, ageing was associated with decreased left pre- and postcentral activation across tasks and increased bilateral angular and right inferior temporal and fusiform activation in the improvisation task. In singing production, ageing was associated with increased activation in medial and bilateral prefrontal and parietal regions in the completion task, whereas other tasks showed no ageing effects. Direct comparisons between the modalities showed larger age-related activation changes in speech than singing across tasks, including a larger left-to-right shift in lateral prefrontal regions in the improvisation task.ConclusionThe present results suggest that the brains’ singing network undergoes differential functional reorganisation in normal ageing compared to the speech network, particularly during a task with high executive demand. These findings are relevant for understanding the effects of ageing on vocal production as well as how singing can support communication in healthy ageing and neurological rehabilitation

From intervention to perception : Speech and music in the post-stroke brain

Aivoverenkiertohäiriö (AVH) on maailmanlaajuisesti merkittävimpiä kielen ja auditiivisen havaitsemisen vaikeuksien aiheuttajia. Viime vuosikymmeninä musiikin ja kielen harjoittamisen on havaittu edistävän aivoissa paitsi modaliteetin sisäistä (kieli–kieli, musiikki–musiikki) havaitsemista myös siirtymävaikutusta erityisesti musiikista kielen havaitsemiseen. Tämä Pro Gradu -tutkielma selvitti äänikirjojen ja musiikin kuuntelun vaikutuksia varhaiseen puheen ja musiikin havaitsemiseen ensimmäisestä aivohalvauksesta toipuvissa aivoissa. Kontrolloituun tutkimusasetelmaan kuului kaksi interventioryhmää, joista toinen kuunteli päivittäin äänikirjoja ja toinen musiikkia ensimmäisten kahden kuukauden aikana aivohalvaukseen sairastumisesta; kontrolliryhmä ei saanut kuunneltavaa materiaalia. Potilaiden (N = 55) varhaista puheen ja musiikin havaitsemista aivoissa mitattiin äänisarjassa poikkeavan tavun (puhe) ja soinnun (musiikki) magneettisella poikkeavuusnegativisuusvasteella (magnetic mismatch negativity, MMNm) akuuttivaiheessa sekä seurantamittauksissa kolme ja kuusi kuukautta aivohalvaukseen sairastumisesta. Magnetoenkefalografisten (MEG) vasteiden lähteet aivoissa paikannettiin erotuskäyrien miniminormiestimaateilla (MNE) potilaiden yksilöllisissä, rakenteellisiin magneettiresonanssikuviin (MRI) perustuvissa aivomalleissa. Vasteiden lähteet rajoitettiin kuuteen puheen ja musiikin havaitsemisen kannalta keskeiseen alueeseen (keskimmäinen ja alempi otsalohkopoimu, ylempi ja keskimmäinen ohimolohkopoimu sekä supramarginaalinen ja kulmapoimu). Ryhmä- ja leesion hemisfäärin interaktiot analysoitiin tilastollisesti toistomittausten varianssianalyysillä näillä alueilla. Lisäksi interaktiotulokset korreloitiin (Pearson) neuropsykologiseen kuntoutumiseen verbaalisen muistin, työmuistin, kielen ja musiikin havaitsemisen osa-alueilla aivovasteiden laajemman osallisuuden selvittämiseksi auditiivisessa tiedonkäsittelyssä. Tutkimuksessa havaittiin, että äänikirjojen kuuntelu tehosti varhaista kielen havaitsemista vasemmanpuoleisilla otsalohkon alueilla kontrolliryhmään verrattuna; MMNm:n lateralisoituminen vasemmalle ilmeni kolme kuukautta aivohalvaukseen sairastumisesta ja oli lisäksi yhteydessä verbaalisen muistin paranemiseen äänikirjaryhmällä. Musiikin havaitseminen puolestaan herätti MMNm- ja P3a-komponentin yhdistelmän, jonka amplitudi vasemmalla alemmalla otsalohkopoimulla korreloi negatiivisesti työmuistin ja verbaalisen muistin paranemiseen kuusi kuukautta aivohalvaukseen sairastumisesta. Musiikin kuuntelu paransi suoriutumista, kun äänikirjojen kuuntelu oli yhteydessä kasvavaan amplitudiin ja heikkenevään työ- ja verbaaliseen muistiin; ilmiö todennäköisesti liittyy musiikin aikaansaamaan aktivaation levittäytymiseen aivoissa. Yhdessä tulokset viittaavat siihen, että äänikirjojen kuuntelu voi kehittää varhaista auditiivista havaitsemista kielimodaliteetin sisällä, joskaan se ei suoraan tue myöhempää, tarkkaavuuteen ja/tai musiikkimodaliteettiin liittyvää havaitsemista. Musiikin kuuntelu sen sijaan ei tue varhaista puheen havaitsemista suoraan, mutta voi edistää aivohalvauksen jälkeisiä plastisia muutoksia havaitsemisen ja verbaalisen muistin kannalta edullisemmalla tavalla

Viewpoints from Computing to the Epistemology of Experiments

Although experiments have been a core element of the scientific method since the 1600s, experiments per se only caught philosophers' interest in the 1980s. Since the 1980s dozens of philosophical analyses of experiments have been presented, based mostly on physics and biology. A number of philosophers of science have called for bottom-up, "naturalistic" investigations of experiments in various disciplines, especially fields other than physics. This paper presents an epistemological analysis of experiments in computing fields in terms of epistemological characteristics, research milieux, and epistemological features of results. Our analysis of experiments, based on how the term is operationalized in computer science papers, opens new critical viewpoints to the role of experiments in computing, as well as complementary viewpoints to the concept of experiment in the philosophy of science

Affective versus cognitive responses to musical chords: An ERP and behavioral study

Via electrophysiological methods, early neural responses to musical chords have been, on one hand, associated with feature encoding, feature change discrimination, rule violation processing, and conscious updating of musical expectations. On the other hand, late neural responses have been related to affective evaluation of sounds. The chronometric succession of these neural processes and their underlying psychological mechanisms related to cognitive and affective aspects of music listening have thus far remained unexplored. Here, the neural correlates of affective and cognitive processing of musical chords were contrasted by means of the event-related potential (ERP) technique and behavioral ratings. Adult subjects (N 24) performed an emotion judgment (affective) task and a correctness judgment (cognitive) task while listening to chord sequences ending in various major and minor final chords, which were either correctly tuned or mistuned. Enhanced negative ERPs during cadence listening preceding the affective ratings, relative to the cognitive ratings, suggest different neural preparation for these tasks. Furthermore, negatively rated (sad or incorrect) cadence endings in both tasks elicited early negative ERPs and later positive ERPs. These positivities, peaking at 500 ms, differed in scalp distribution between sad and incorrect stimuli. The present findings suggest a neural chronometry of music listening in which feature encoding and sensory memory processes are followed at a medium latency by affective classification, after which an evaluative stage takes place. This study provides a first look at the chronometric succession of electrophysiological brain responses in relation to emotion judgments of musical pitch as opposed to nonaffective correctness judgments

Differential effects of ageing on the neural processing of speech and singing production

Publisher Copyright: Copyright © 2023 Moisseinen, Särkämö, Kauramäki, Kleber, Sihvonen and Martínez-Molina.Background: Understanding healthy brain ageing has become vital as populations are ageing rapidly and age-related brain diseases are becoming more common. In normal brain ageing, speech processing undergoes functional reorganisation involving reductions of hemispheric asymmetry and overactivation in the prefrontal regions. However, little is known about how these changes generalise to other vocal production, such as singing, and how they are affected by associated cognitive demands. Methods: The present cross-sectional fMRI study systematically maps the neural correlates of vocal production across adulthood (N=100, age 21–88 years) using a balanced 2x3 design where tasks varied in modality (speech: proverbs / singing: song phrases) and cognitive demand (repetition / completion from memory / improvisation). Results: In speech production, ageing was associated with decreased left pre- and postcentral activation across tasks and increased bilateral angular and right inferior temporal and fusiform activation in the improvisation task. In singing production, ageing was associated with increased activation in medial and bilateral prefrontal and parietal regions in the completion task, whereas other tasks showed no ageing effects. Direct comparisons between the modalities showed larger age-related activation changes in speech than singing across tasks, including a larger left-to-right shift in lateral prefrontal regions in the improvisation task. Conclusion: The present results suggest that the brains’ singing network undergoes differential functional reorganisation in normal ageing compared to the speech network, particularly during a task with high executive demand. These findings are relevant for understanding the effects of ageing on vocal production as well as how singing can support communication in healthy ageing and neurological rehabilitation.Peer reviewe