Browsing by Subject "REPRESENTATIONS"

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  • Lin, Hai; Li, Wei-ping; Carlson, Synnöve (2019)
    Top-down modulation is engaged during multiple stages of working memory (WM), including expectation, encoding, and maintenance. During WM maintenance period, an "incidental cue" can bring one of the two items into a privileged state and make the privileged item be recalled with higher precision, despite being irrelevant to which one to be probed as the target. With regard to the different representational states of WM, it's unclear whether there is top-down modulation on earth sensory cortical areas. Here, We used this behavioral paradigm of "incidental cue" and event-related fMRI to investigate whether there were a privileged WM state and top-down modulation for complex stimuli including faces and natural scenes. We found that faces, not scenes, could enter into the privileged state with improved accuracy and response time of WM task. Meanwhile, cue-driven baseline activity shifts in fusiform face area (FFA) were identified by univariate analysis in the recognition of privileged faces, compared to that of nonprivileged ones. In addition, the functional connectivity between FFA and right inferior frontal junction (IFJ), middle frontal gyrus (MFG), inferior frontal gyrus, right intraparietal sulcus (IPS), right precuneus and supplementary motor area was significantly enhanced, corresponding to the improved WM performance. Moreover, FFA connectivity with IFJ and IPS could predict WM improvements. These findings indicated that privileged WM state and potential top-down modulation existed for faces, but not scenes, during WM maintenance period.
  • Kukkonen, Anna; Stoddart, Mark CJ; Ylä-Anttila, Tuomas (2021)
    In this paper, we examine the centrality of policy actors and moral justifications in media debates on Arctic climate change in Finland and Canada from 2011?2015. We take a network approach on the media debates by analysing relations between the actors and justifications, using discourse network analysis on a dataset of 745 statements from four newspapers. We find that in both countries, governments and universities are the most central actors, whereas business actors are the least central. Justifications that value environmental sustainability and scientific knowledge are most central and used across actor types. However, ecological justifications are sometimes in conflict with market justifications. Government actors emphasize new economic possibilities in the Arctic whereas environmental organizations demand greater protection of the vulnerable Arctic. Ecological justifications and justifications that value international cooperation are more central in the Finnish debate, whereas justifications valuing sustainability and science, as well as those valuing national sovereignty, are more central in the Canadian debate. We conclude that in addition to the centrality of specific policy actors in media debates, the use of different types of moral justifications also reflects political power in the media sphere.
  • Rodriguez-Becerra, Jorge; Cáceres-Jensen, Lizethly; Díaz, Tatiana; Druker, Sofía; Bahamonde Padilla, Victor; Pernaa, Johannes; Aksela, Maija (2020)
    The purpose of this descriptive case study was to develop pre-service chemistry teachers’ Technological Pedagogical Science Knowledge (TPASK) through novel computational chemistry modules. The study consisted of two phases starting with designing a computational chemistry based learning environment followed by a case study where students’ perceptions towards educational computational chemistry were explored. First, we designed an authentic research-based chemistry learning module that supported problem-based learning through the utilization of computational chemistry methods suitable for pre-service chemistry education. The objective of the learning module was to promote learning of specific chemistry knowledge and development of scientific skills. Systematic design decisions were made through the TPASK framework. The learning module was designed for a third-year physical chemistry course taken by pre-service chemistry teachers in Chile. After the design phase, the learning module was implemented in a course and students’ perceptions were gathered using semi-structured group interviews. The sample consisted of 22 pre-service chemistry teachers. Data were analyzed through qualitative content analysis using the same TPASK framework employed in the learning module design. Based on our findings, pre-service chemistry teachers first acquired Technological Scientific Knowledge (TSK) and then developed some elements of their TPASK. In addition, they highly appreciated the combination of student-centred problem-based learning and the use of computational chemistry tools. Students felt the educational computational learning environment supported their own knowledge acquisition and expressed an interest in applying similar learning environments in their future teaching careers. This case study demonstrates that learning through authentic real-world problems using educational computational methods offers great potential in supporting pre-service teachers’ instruction in the science of chemistry and pedagogy. For further research in the TPASK framework, we propose there would be significant benefit from developing additional learning environments of this nature and evaluating their utility in pre-service and in-service chemistry teacher’s education.
  • Ylinen, Sari; Junttila, Katja; Laasonen, Marja; Iverson, Paul; Ahonen, Lauri; Kujala, Teija (2019)
    Dyslexia is characterized by poor reading skills, yet often also difficulties in second-language learning. The differences between native- and second-language speech processing and the establishment of new brain representations for spoken second language in dyslexia are not, however, well understood. We used recordings of the mismatch negativity component of event-related potential to determine possible differences between the activation of long-term memory representations for spoken native- and second-language word forms in Finnish-speaking 9-11-year-old children with or without dyslexia, studying English as their second language in school. In addition, we sought to investigate whether the bottleneck of dyslexic readers' second-language learning lies at the level of word representations or smaller units and whether the amplitude of mismatch negativity is correlated with native-language literacy and related skills. We found that the activation of brain representations for familiar second-language words, but not for second-language speech sounds or native-language words, was weaker in children with dyslexia than in typical readers. Source localization revealed that dyslexia was associated with weak activation of the right temporal cortex, which has been previously linked with word-form learning. Importantly, the amplitude of the mismatch negativity for familiar second-language words correlated with native-language literacy and rapid naming scores, suggesting a close link between second-language processing and these skills.
  • Kujala, Miiamaaria; Kujala, Jan; Carlson, Synnove; Hari, Riitta (2012)
  • Kliuchko, Marina; Brattico, Elvira; Gold, Benjamin P.; Tervaniemi, Mari; Bogert, Brigitte; Toiviainen, Petri; Vuust, Peter (2019)
    Learning, attention and action play a crucial role in determining how stimulus predictions are formed, stored, and updated. Years-long experience with the specific repertoires of sounds of one or more musical styles is what characterizes professional musicians. Here we contrasted active experience with sounds, namely long-lasting motor practice, theoretical study and engaged listening to the acoustic features characterizing a musical style of choice in professional musicians with mainly passive experience of sounds in laypersons. We hypothesized that long-term active experience of sounds would influence the neural predictions of the stylistic features in professional musicians in a distinct way from the mainly passive experience of sounds in laypersons. Participants with different musical backgrounds were recruited: professional jazz and classical musicians, amateur musicians and non-musicians. They were presented with a musical multi-feature paradigm eliciting mismatch negativity (MMN), a prediction error signal to changes in six sound features for only 12 minutes of electroencephalography (EEG) and magnetoencephalography (MEG) recordings. We observed a generally larger MMN amplitudes-indicative of stronger automatic neural signals to violated priors-in jazz musicians (but not in classical musicians) as compared to non-musicians and amateurs. The specific MMN enhancements were found for spectral features (timbre, pitch, slide) and sound intensity. In participants who were not musicians, the higher preference for jazz music was associated with reduced MMN to pitch slide (a feature common in jazz music style). Our results suggest that long-lasting, active experience of a musical style is associated with accurate neural priors for the sound features of the preferred style, in contrast to passive listening.
  • Pesonen, Henri; Itkonen, Tiina; Saha, Mari; Nordahl-Hansen, Anders (2021)
    Purpose Media play a significant role in the process of raising public awareness about autism spectrum disorder (ASD). Despite an increase in ASD media coverage, there is scarcity of research that examines how the actual frame is constructed and how the news stories are narrated. This study aims to examine the extent to which Finnish print media papers extend medical and societal narration of ASD to other issue domains and the extent to which newspaper stories use a positive, negative or neutral narrative. Design/methodology/approach The authors analyzed 210 full newspaper reports from the largest daily appearing newspaper by circulation in Finland from 1990 to 2016. The authors used the newspaper's electronic database to conduct a systematic papers search. The authors then used coding scheme about news story framing, which was followed by a detailed content analysis of the papers. Findings Approximately two-thirds of the papers consisted of a straightforward informational or clinical lens to educate the public (n= 110). This is in line with international studies. However, the authors' analysis revealed four additional themes of medical and societal ASD reporting. Social implications The study increases understanding about how the media can shape the public perception of ASD, which in turn might influence how autistic individuals are accepted in the society, as well as how they feel that they belong. Originality/value While ASD itself is at the center of neutral news reporting, this study's results imply how to construct ASD from new paradigms. Linking ASD to a culture, and thus extending it to the more commonly accepted notion of deafness as a culture, might shape the public's perceptions about ASD.
  • Ye, Chaoxiong; Xu, Qianru; Liu, Xinyang; Astikainen, Piia; Zhu, Yongjie; Hu, Zhonghua; Liu, Qiang (2021)
    Previous studies have associated visual working memory (VWM) capacity with the use of internal attention. Retrocues, which direct internal attention to a particular object or feature dimension, can improve VWM performance (i.e., retrocue benefit, RCB). However, so far, no study has investigated the relationship between VWM capacity and the magnitudes of RCBs obtained from object-based and dimension-based retrocues. The present study explored individual differences in the magnitudes of object- and dimension-based RCBs and their relationships with VWM capacity. Participants completed a VWM capacity measurement, an object-based cue task, and a dimension-based cue task. We confirmed that both object- and dimension-based retrocues could improve VWM performance. We also found a significant positive correlation between the magnitudes of object- and dimension-based RCB indexes, suggesting a partly overlapping mechanism between the use of object- and dimensionbased retrocues. However, our results provided no evidence for a correlation between VWM capacity and the magnitudes of the object- or dimension-based RCBs. Although inadequate attention control is usually assumed to be associated with VWM capacity, the results suggest that the internal attention mechanism for using retrocues in VWM retention is independent of VWM capacity.
  • Vainio, Lari; Tiainen, Mikko (2018)
    Past studies have revealed connections in directional programming between hands. The present study investigated whether there could also be interaction in programming proximal and distal components of a prehensile hand action. In Experiment 1, the participants performed simultaneously either a push or pull response with the left hand and the grip closure or opening with the right hand. In Experiment 2, the push and pull responses of the left hand were performed together with the precision or power grip responses of the right hand. The participants showed preference, measured in reaction times, to couple the push response with the grip opening and the precision grip, whereas the pull response was associated with the grip closure and the power grip. The study shows for the first time a systematic interaction in proximal and distal prehensile components between two hands. We propose that these effects reflect inter- and intra-limb connections between the representations that prepare the arm extension for the outward reaching, the finger extension for the grip opening, and the motor processes that prepare the precision grip. Conversely, there appear to be connections between the representations that prepare the arm flexion for the inward directed hand movements, the flexion of the thumb and the fingers for the grip closure, and flexion of four fingers for the power grip.
  • Bubba, Tatiana A.; Kutyniok, Gitta; Lassas, Matti; März, Maximilian; Samek, Wojciech; Siltanen, Samuli; Srinivasan, Vignesh (2019)
    The high complexity of various inverse problems poses a significant challenge to model-based reconstruction schemes, which in such situations often reach their limits. At the same time, we witness an exceptional success of data-based methodologies such as deep learning. However, in the context of inverse problems, deep neural networks mostly act as black box routines, used for instance for a somewhat unspecified removal of artifacts in classical image reconstructions. In this paper, we will focus on the severely ill-posed inverse problem of limited angle computed tomography, in which entire boundary sections are not captured in the measurements. We will develop a hybrid reconstruction framework that fuses model-based sparse regularization with data-driven deep learning. Our method is reliable in the sense that we only learn the part that can provably not be handled by model-based methods, while applying the theoretically controllable sparse regularization technique to the remaining parts. Such a decomposition into visible and invisible segments is achieved by means of the shearlet transform that allows to resolve wavefront sets in the phase space. Furthermore, this split enables us to assign the clear task of inferring unknown shearlet coefficients to the neural network and thereby offering an interpretation of its performance in the context of limited angle computed tomography. Our numerical experiments show that our algorithm significantly surpasses both pure model- and more data-based reconstruction methods.
  • Härkki, Tellervo; Seitamaa-Hakkarainen, Pirita; Hakkarainen, Kai (2018)
    While sketching has an established role in professional design, its benefits and role in design education are subjects that invite research and opinions. We investigated how undergraduates studying to become design educators and textile teachers used sketching to generate and develop design solutions in a collaborative setting. The students were given an authentic design assignment involving three detailed tasks, one of which was 2D visualisation by sketching. Adopting a micro-analytical approach, we analysed the video-recorded visualisation session to understand how teams used sketching to collaborate and to generate and develop design solutions. To that end, we set three research questions: (1) What ways of collaborative working are reflected in actions of sketching? (2) In what ways do sequences of collaborative sketching contribute to designing? (3) What kinds of collaborative sequences of sketching advance designing? Our analysis identified three collaborative ways of sketching (co-ordinated, collective and disclosed) and confirmed that sketching is an important facilitator of mutual appropriation, adaption and adoption. Next, we identified three ways of contributing to designing, as well as three functions and six capacities for advancing designing. Our analysis shows that sketching can lead to invaluable advances in designing, although each team had its own way of using and benefiting from sketching. We further consider that the teams' diverse sketching processes and rich content owed, at least in part, to the task structure and imposed constraints. We continue to see sketching as an important design tool, one among many.
  • Tiainen, Mikko; Tiippana, Kaisa; Paavilainen, Petri; Vainio, Martti; Vainio, Lari (2017)
    Manual actions and speech are connected: for example, grip execution can influence simultaneous vocalizations and vice versa. Our previous studies show that the consonant [k] is associated with the power grip and the consonant [t] with the precision grip. Here we studied whether the interaction between speech sounds and grips could operate already at a pre-attentive stage of auditory processing, reflected by the mismatch-negativity (MMN) component of the event-related potential (ERP). Participants executed power and precision grips according to visual cues while listening to syllable sequences consisting of [ke] and [te] utterances. The grips modulated the MMN amplitudes to these syllables in a systematic manner so that when the deviant was [ke], the MMN response was larger with a precision grip than with a power grip. There was a converse trend when the deviant was [te]. These results suggest that manual gestures and speech can interact already at a pre-attentive processing level of auditory perception, and show, for the first time that manual actions can systematically modulate the MMN. (C) 2017 Elsevier B.V. All rights reserved.
  • Virtala, P.; Talola, S.; Partanen, E.; Kujala, T. (2020)
    Whereas natural acoustic variation in speech does not compromise phoneme discrimination in healthy adults, it was hypothesized to be a challenge for developmental dyslexics. We investigated dyslexics’ neural and perceptual discrimination of native language phonemes during acoustic variation. Dyslexics and non-dyslexics heard /æ/ and /i/ phonemes in a context with fo variation and then in a context without it. Mismatch negativity (MMN) and P3a responses to phoneme changes were recorded with electroencephalogram to compare groups during ignore and attentive listening. perceptual phoneme discrimination in the variable context was evaluated with hit-ratios and reaction times. MMN/N2bs were diminished in dyslexics in the variable context. Hit-ratios were smaller in dyslexics than controls. MMNs did not differ between groups in the context without variation. These results suggest that even distinctive vowels are challenging to discriminate for dyslexics when the context resembles natural variability of speech. This most likely reflects poor categorical perception of phonemes in dyslexics. Difficulties to detect linguistically relevant invariant information during acoustic variation in speech may contribute to dyslexics’ deficits in forming native language phoneme representations during infancy. Future studies should acknowledge that simple experimental paradigms with repetitive stimuli can be insensitive to dyslexics’ speech processing deficits.
  • Savec, Vesna Ferk; Urankar, Bernarda; Aksela, Maija; Devetak, Iztok (2017)
    The main purpose of this paper is to present Slovenian and Finnish prospective chemistry teachers' perceptions of their future profession, especially with regard to their understanding of the role of the triple nature of chemical concepts (macro, submicro and symbolic) and their representations in chemistry learning. A total of 19 prospective teachers (10 Slovenian, 9 Finnish) at master's level in chemical education participated in the research. The prospective teachers' opinions were gathered using an electronic questionnaire comprising six open-ended questions. The study revealed many parallels between Slovenian and Finnish prospective chemistry teachers' perceptions of their future profession and their understanding of the role of the triple nature of chemical concepts, especially particle representations, in chemistry learning. The majority of the prospective teachers from both countries believe that personal characteristics are the most important attribute of a successful chemistry teacher. Thus, they highly value teachers' enthusiasm for teaching and the use of contemporary teaching approaches in chemistry. The prospective teachers displayed an adequate understanding of the role of the triple nature of chemical concepts (i.e., particle representations) in the planning and implementation of a specific chemistry lesson.
  • Salmela, Viljami R.; Ölander, Kaisu; Muukkonen, Ilkka; Bays, Paul M. (2019)
    Many studies of visual working memory have tested humans' ability to reproduce primary visual features of simple objects, such as the orientation of a grating or the hue of a color patch, following a delay. A consistent finding of such studies is that precision of responses declines as the number of items in memory increases. Here we compared visual working memory for primary features and high-level objects. We presented participants with memory arrays consisting of oriented gratings, facial expressions, or a mixture of both. Precision of reproduction for all facial expressions declined steadily as the memory load was increased from one to five faces. For primary features, this decline and the specific distributions of error observed, have been parsimoniously explained in terms of neural population codes. We adapted the population coding model for circular variables to the non-circular and bounded parameter space used for expression estimation. Total population activity was held constant according to the principle of normalization and the intensity of expression was decoded by drawing samples from the Bayesian posterior distribution. The model fit the data well, showing that principles of population coding can be applied to model memory representations at multiple levels of the visual hierarchy. When both gratings and faces had to be remembered, an asymmetry was observed. Increasing the number of faces decreased precision of orientation recall, but increasing the number of gratings did not affect recall of expression, suggesting that memorizing faces involves the automatic encoding of low-level features, in addition to higher-level expression information.
  • Bytsenko, A. A.; Chaichian, M. (2016)
    In this paper we analyze the quantum homological invariants (the Poincare polynomials of the sI(N) link homology). In the case when the dimensions of homologies of appropriate topological spaces are precisely known, the procedure of the calculation of the Kovanov-Rozansky type homology, based on the Euler-Poincare formula can be appreciably simplified. We express the formal character of the irreducible tensor representation of the classical groups in terms of the symmetric and spectral functions of hyperbolic geometry. On the basis of Labastida-Marino-Ooguri-Vafa conjecture, we derive a representation of the Chern-Simons partition function in the form of an infinite product in terms of the Ruelle spectral functions (the cases of a knot, unknot, and links have been considered). We also derive an infinite-product formula for the orthogonal Chem-Simons partition functions and analyze the singularities and the symmetry properties of the infinite-product structures. (C) 2016 The Authors. Published by Elsevier B.V.
  • Muukkonen, Ilkka; Ölander, Kaisu; Numminen, Jussi Kustaa; Salmela, Viljami (2020)
    The temporal and spatial neural processing of faces has been investigated rigorously, but few studies have unified these dimensions to reveal the spatio-temporal dynamics postulated by the models of face processing. We used support vector machine decoding and representational similarity analysis to combine information from different locations (fMRI), time windows (EEG), and theoretical models. By correlating representational dissimilarity matrices (RDMs) derived from multiple pairwise classifications of neural responses to different facial expressions (neutral, happy, fearful, angry), we found early EEG time windows (starting around 130 ​ms) to match fMRI data from primary visual cortex (V1), and later time windows (starting around 190 ​ms) to match data from lateral occipital, fusiform face complex, and temporal-parietal-occipital junction (TPOJ). According to model comparisons, the EEG classification results were based more on low-level visual features than expression intensities or categories. In fMRI, the model comparisons revealed change along the processing hierarchy, from low-level visual feature coding in V1 to coding of intensity of expressions in the right TPOJ. The results highlight the importance of a multimodal approach for understanding the functional roles of different brain regions in face processing.
  • Chen, Tsao-Hsien; Vilonen, Kari; Xue, Ting (2018)
    In this paper we establish Springer correspondence for the symmetric pair (SL(N); SO(N)) using Fourier transform, parabolic induction functor, and a nearby cycle sheaf construction. As an application of our results we see that the cohomology of Hessenberg varieties can be expressed in terms of irreducible representations of Hecke algebras of symmetric groups at q = -1. Conversely, we see that the irreducible representations of Hecke algebras of symmetric groups at q = -1 arise in geometry.