2,370 research outputs found
What does semantic tiling of the cortex tell us about semantics?
Recent use of voxel-wise modeling in cognitive neuroscience suggests that semantic maps tile the cortex. Although this impressive research establishes distributed cortical areas active during the conceptual processing that underlies semantics, it tells us little about the nature of this processing. While mapping concepts between Marr's computational and implementation levels to support neural encoding and decoding, this approach ignores Marr's algorithmic level, central for understanding the mechanisms that implement cognition, in general, and conceptual processing, in particular. Following decades of research in cognitive science and neuroscience, what do we know so far about the representation and processing mechanisms that implement conceptual abilities? Most basically, much is known about the mechanisms associated with: (1) features and frame representations, (2) grounded, abstract, and linguistic representations, (3) knowledge-based inference, (4) concept composition, and (5) conceptual flexibility. Rather than explaining these fundamental representation and processing mechanisms, semantic tiles simply provide a trace of their activity over a relatively short time period within a specific learning context. Establishing the mechanisms that implement conceptual processing in the brain will require more than mapping it to cortical (and sub-cortical) activity, with process models from cognitive science likely to play central roles in specifying the intervening mechanisms. More generally, neuroscience will not achieve its basic goals until it establishes algorithmic-level mechanisms that contribute essential explanations to how the brain works, going beyond simply establishing the brain areas that respond to various task conditions
The State of the Art in Cartograms
Cartograms combine statistical and geographical information in thematic maps,
where areas of geographical regions (e.g., countries, states) are scaled in
proportion to some statistic (e.g., population, income). Cartograms make it
possible to gain insight into patterns and trends in the world around us and
have been very popular visualizations for geo-referenced data for over a
century. This work surveys cartogram research in visualization, cartography and
geometry, covering a broad spectrum of different cartogram types: from the
traditional rectangular and table cartograms, to Dorling and diffusion
cartograms. A particular focus is the study of the major cartogram dimensions:
statistical accuracy, geographical accuracy, and topological accuracy. We
review the history of cartograms, describe the algorithms for generating them,
and consider task taxonomies. We also review quantitative and qualitative
evaluations, and we use these to arrive at design guidelines and research
challenges
Templates in chess memory: A mechanism for recalling several boards
This paper addresses empirically and theoretically a question derived from the chunking theory of memory (Chase & Simon, 1973): To what extent is skilled chess memory limited by the size of short-term memory (about 7 chunks)? This question is addressed first with an experiment where subjects, ranking from class A players to grandmasters, are asked to recall up to 5 positions presented during 5 seconds each. Results show a decline of percentage of recall with additional boards, but also show that expert players recall more pieces than is predicted by the chunking theory in its original form. A second experiment shows that longer latencies between the presentation of boards facilitate recall. In a third experiment, a Chessmaster gradually increases the number of boards he can reproduce with higher than 70% average accuracy to nine, replacing as many as 160 pieces correctly. To account for the results of these experiments, a revision of the Chase-Simon theory is proposed. It is suggested that chess players, like experts in other recall tasks, use long-term memory retrieval structures (Chase & Ericsson, 1982) or templates in addition to chunks in STM, to store information rapidly
Dynamic Responses in Brain Networks to Social Feedback: A Dual EEG Acquisition Study in Adolescent Couples
abstract: Adolescence is a sensitive period for the development of romantic relationships. During this period the maturation of frontolimbic networks is particularly important for the capacity to regulate emotional experiences. In previous research, both functional magnetic resonance imaging (fMRI) and dense array electroencephalography (dEEG) measures have suggested that responses in limbic regions are enhanced in adolescents experiencing social rejection. In the present research, we examined social acceptance and rejection from romantic partners as they engaged in a Chatroom Interact Task. Dual 128-channel dEEG systems were used to record neural responses to acceptance and rejection from both adolescent romantic partners and unfamiliar peers (N = 75). We employed a two-step temporal principal component analysis (PCA) and spatial independent component analysis (ICA) approach to statistically identify the neural components related to social feedback. Results revealed that the early (288 ms) discrimination between acceptance and rejection reflected by the P3a component was significant for the romantic partner but not the unfamiliar peer. In contrast, the later (364 ms) P3b component discriminated between acceptance and rejection for both partners and peers. The two-step approach (PCA then ICA) was better able than either PCA or ICA alone in separating these components of the brain's electrical activity that reflected both temporal and spatial phases of the brain's processing of social feedback.View the article as published at https://www.frontiersin.org/articles/10.3389/fncom.2017.00046/ful
Expectations and Beliefs in Immersive Virtual Reality Environments: Managing of Body Perception
Real and Perceived Feet Orientation Under Fatiguing and Non-Fatiguing Conditions in an Immersive Virtual Reality Environment
ABSTRACT
Lower limbs position sense is a complex yet poorly understood mechanism, influenced by many factors. Hence, we investigated the position sense of lower limbs through feet orientation with the use of Immersive Virtual Reality (IVR). Participants had to indicate how they perceived the real 1050 orientation of their feet by orientating a virtual representation of the feet that was shown in an IVR 1051 scenario. We calculated the angle between the two virtual feet (α-VR) after a high-knee step-in-1052 place task. Simultaneously, we recorded the real angle between the two feet (α-R) (T1). Hence, we 1053 assessed if the acute fatigue impacted the position sense. The same procedure was repeated after 1054 inducing muscle fatigue (T2) and after 10 minutes from T2 (T3). Finally, we also recorded the time 1055 needed to confirm the perceived position before and after the acute fatigue protocol. Thirty healthy 1056 adults (27.5 ± 3.8: 57% female, 43% male) were immersed in an IVR scenario with a representation 1057 of two feet. We found a mean difference between α-VR and α-R of 20.89° [95% CI: 14.67°, 27.10°] 1058 in T1, 16.76° [9.57°, 23.94°] in T2, and 16.34° [10.00°, 22.68°] in T3. Participants spent 12.59, 17.50 1059 and 17.95 seconds confirming the perceived position of their feet at T1, T2, T3, respectively. 1060 Participants indicated their feet as forwarding parallel though divergent, showing a mismatch in the 1061 perceived position of feet. Fatigue seemed not to have an impact on position sense but delayed the 1062 time to accomplish this task.The Effect of Context on Eye-Height Estimation in Immersive Virtual Reality: a Cross-Sectional Study
ABSTRACT
Eye-height spatial perception provides a reference to scale the surrounding environment. It is the result of the integration of visual and postural information. When these stimuli are discordant, the perceived spatial parameters are distorted. Previous studies in immersive virtual reality (IVR) showed that spatial perception is influenced by the visual context of the environment. Hence, this study explored how manipulating the context in IVR affects individualsâ eye-height estimation. Two groups of twenty participants each were immersed in two different IVR environments, represented by a closed room (Wall - W) and an open field (No Wall - NW). Under these two different conditions, participants had to adjust their virtual perspective, estimating their eye height. We calculated the perceived visual offset as the difference between virtual and real eye height, to assess whether the scenarios and the presence of virtual shoes (Feet, No Feet) influenced participantsâ estimates at three initial offsets (+100 cm, +0 cm, -100 cm). We found a mean difference between the visual 1679 offsets registered in those trials that started with 100 cm and 0 cm offsets (17.24 cm [8.78; 25.69]) 1680 and between 100 cm and -100 cm offsets (22.35 cm [15.65; 29.05]). Furthermore, a noticeable mean difference was found between the visual offsets recorded in group W, depending on the presence or absence of the virtual shoes (Feet VS No Feet: -6.12 [-10.29, -1.95]). These findings describe that different contexts influenced eye-height perception.Positive Expectations led to Motor Improvement: an Immersive Virtual Reality Pilot Study
ABSTRACT
This pilot study tested the feasibility of an experimental protocol that evaluated the effect of different positive expectations (verbal and visual-haptic) on anterior trunk flexion. Thirty-six participants were assigned to 3 groups (G0, G+ and G++) that received a sham manoeuvre while immersed in Immersive Virtual Reality (IVR). In G0, the manouvre was paired with by neutral verbal statement. In G+ and G++ the manouvre was paired with a positive verbal statement, but only G++ received a visual-haptic illusion. The illusion consisted of lifting a movable tile placed in front of the participants, using its height to raise the floor level in virtual reality. In this way, participants experienced the perception of touching the floor, through the tactile and the virtual visual afference. The distance between fingertips and the floor was measured before, immediately after, and after 5 minutes from the different manouvres. A major difference in anterior trunk flexion was found for G++ compared to the other groups, although it was only significant compared to G0. This result highlighted the feasibility of the present study for future research on people with mobility limitations (e.g., low back pain or kinesiophobia) and the potential role of a visual-haptic illusion in modifying the performance of trunk flexion
Regulating craving by anticipating positive and negative outcomes : a multivariate pattern analysis and network connectivity approach
During self-control, we may resist short-term temptations in order to reach a favorable future (e.g., resisting cake to stay healthy). The neural basis of self-control is typically attributed to âcold,â unemotional cognitive control mechanisms which inhibit affect-related regions via the prefrontal cortex (PFC). Here, we investigate the neural underpinnings of regulating cravings by mentally evoking the positive consequences of resisting a temptation (e.g., being healthy) as opposed to evoking the negative consequences of giving in to a temptation (e.g., becoming overweight). It is conceivable that when using these types of strategies, regions associated with emotional processing [e.g., striatum, ventromedial prefrontal cortex (vmPFC)] are involved in addition to control-related prefrontal and parietal regions. Thirty-one participants saw pictures of unhealthy snacks in the fMRI scanner and, depending on the trial, regulated their craving by thinking of the positive consequences of resisting, or the negative consequences of not resisting. In a control condition, they anticipated the pleasure of eating and thus, allowed the craving to occur (now-condition). In line with previous studies, we found activation of a cognitive control network during self-regulation. In the negative future thinking condition, the insula was more active than in the positive condition, while there were no activations that were stronger in the positive (> negative) future thinking condition. However, additionally, multivariate pattern analysis showed that during craving regulation, information about the valence of anticipated emotions was present in the vmPFC, the posterior cingulate cortex (PCC) and the insula. Moreover, a network including vmPFC and PCC showed higher connectivity during the positive (> negative) future thinking condition. Since these regions are often associated with affective processing, these findings suggest that âhot,â affective processes may, at least in certain circumstances, play a role in self-control
PENGARUH LATIHAN PSIKOLOGIS DAN KEBUGARAN JASMANI TERHADAP PENINGKATAN KINERJA WASIT JAWABARAT DALAM MEMIMPIN PERTANDINGAN SEPAKBOLA
Tujuan dari penelitian ini adalah untuk mengatahui apakah nilai rata-rata kinerja
wasit Jawa Barat dalam memimpin pertandingan sepakbola memiliki perbedaan
antara yang diberi latihan psikologis rileksasi, imagery, dan rileksasi-imagery
dengan kebugaran jasmani tinggi dan rendah serta apakah terdapat Interaksi antara
latihan psikologis dan Kebugaran Jasmani terhadap kinerja wasit Jawa Barat dalam
memimpin sepak bola. Penelitian ini dilakukan terhadap wasit Jawa Barat, dan
metode dalam penelitian adalah metode eksperimen dengan desain factorial 3 x 2.
Instrumen yang digunakan dalam penelitian ini menggunakan Fitness Test for
Referee untuk tes kebugaran jasmani dan Tes Kinerja Wasit menggunakan Aplikasi
Penilaian Kinerja wasit . Kesimpulan dalam penelitian ini adalah penilaian kinerja
wasit kelompok rileksasi-imagery dengan kemampuan kebugaran jasmani tinggi
mengalami peningatan paling tinggi nilai rata-ratanya dibandingan dengan
kelompok rileksasi dan kelompok Imagery, dan penilaian kinerja wasit kelompok
rileksasi dengan kemampuan kebugaran jasmani rendah mengalami peningatan
paling tinggi nilai rata-ratanya dibandingan dengan kelompok imagery dan
kelompok rileksasi-Imagery. Terdapat interaksi penerapan metode latihan
keterampil psikologis dan kebugaran jasmani terhadap kinerja wasit Jawa Barat
dalam memimpin sepakbola, wasit yang memiliki kebugaran jasmani tinggi lebih
tepat diberikan latihan psikologis rileksasi-imagery dan wasit yang memiliki
kebugaran jasmani rendah lebih tepat diberikan latihan psikologis rileksasi akan
tetapi keduanya bisa digunakan untuk meningkatkan kinerja wasit. Saran untuk
PSSI dan komisi wasit, agar memberikan latihan psikologis untuk meningkatkan
kinerja wasit dan tetap memelihara kebugaran jasmani pada setiap sesi latihan,
karena latihan psikologis dan kebugaran jasmani sangat penting untuk
meningkatkan kinerja wasit dalam memimpin pertandingan sepakbola.
The purpose of this study was to determine the average value of West Java refereesâ
performance in leading a football match had a difference between those who given
relaxation, imagery, and imagery-relaxation psychological exercises with high and low
physical fitness and whether there was a correlation between psychological exercise
and physical fitness on West Java refereesâ performance in leading football. This
research was conducted on West Java referees through an experimental method with a
3 x 2 factorial design. The instrument used in this study was physical fitness tests and
Referee Performance Assessment Application to assess the refereesâ performance. The
conclusion in this study is, the performance assessment of the relaxation-imagery group
referees with high physical fitness abilities experienced the highest improvement of
average value compared with the relaxation group and the Imagery group, and
performance assessment of the relaxation group referees with low physical fitness
abilities experienced the highest improvement in average scores. The average is
compared with the imagery group and the Imagery-relaxation group. There is a
correlation between the application of psychological skills training methods and
physical fitness on the performance of West Java referees in leading football, referees
who have high physical fitness are more appropriately given relaxation-imagery
psychological training, and referees who have low physical fitness are more
appropriately given relaxation psychological exercises, nevertheless, both can be used
to improve referee performance. Suggestions for PSSI and the referee commission, to
provide psychological skills training to improve referee performance and maintain
physical fitness at each training session because psychological skills training and
physical fitness are very important to improve referee performance in leading football
matches
Reviewing the Impact of the National Strategies Design and Technology Framework for Key Stage Three: A small-Ââscale evaluation of the Design and Technology Framework in England
Since the beginning of Design and Technology (D&T) in the English secondary school curriculum, the teaching of design has been identified as less effective than that of making. Research Questions: What are the experiences of pupils between the ages of 12 and 14 of design learning? Purpose of Study: In 2004 as part of the National Strategies, the D&T framework was launched, aiming to support the teaching of design skills. This is a small-Ââscale study, which begins to explore the experiences of pupils and teachers in four schools in the Northwest of England. Research Methods: The study used a mixed methods approach, gathering quantitative and qualitative data in a questionnaire with a convenience sample of school pupils. The questionnaire responses are analysed alongside qualitative interviews with D&T teachers from the schools. Findings: The findings indicate that many pupils had a clear understanding of the role of designing. However, some common assumptions of the nature of design activity centering on the act of sketching or drawing were evident. The majority of pupils were unable to accurately identify the names of many of the design activities introduced as part of the framework. Conclusions: Whilst some progress has been made in the teaching of design, through the use of design activities introduced in the D&T Framework, the support experienced by teachers was limited and were not sustained beyond the initial training. There are implications for initial teacher educators in supporting beginning teachers and balancing the tensions trainees experience whilst on placements in school. Key Words: Design, designing, pedagogy, teacher educatio
Biologically inspired distributed machine cognition: a new formal approach to hyperparallel computation
The irresistable march toward multiple-core chip technology presents currently intractable pdrogramming challenges. High level mental processes in many animals, and their analogs for social structures, appear similarly massively parallel, and recent mathematical models addressing them may be adaptable to the multi-core programming problem
Tapahtumasegmentaation aivovasteet hippokampuksessa ja aivokuorella ÀÀnitarinan kuuntelun aikana
Tapahtumasegmentaatio jÀsentÀÀ sekÀ arkista kokemustamme ettÀ muistiamme. Parhaillaan meneillÀÀn olevan tapahtuman hahmotus ja prosessointi tapahtuu todennÀköisesti aivokuorella, mutta ilman toimivaa hippokampusta tilanteesta ei voi syntyÀ pysyvÀÀ muistoa. On olennainen kysymys, missÀ kohtaa ja miten hippokampus osallistuu tapahtumien prosessointiin ja mieleen painamiseen. Aiemmin on magneettikuvaustutkimuksin osoitettu, ettÀ hippokampus reagoi tapahtumien vÀlisiin rajoihin aktivaatiopiikein. On ehdotettu, ettÀ ne ilmentÀisivÀt aistimodaliteetista riippumattoman tason prosessia, jossa hippokampus kokoaa yhteen ja vahvistaa koetun tilanteen kokonaisrepresentaation, jotta se voidaan painaa muistiin. Aiemmat tutkimukset on kuitenkin toteutettu yksinomaan audiovisuaalisilla ÀrsykkeillÀ, ja koska hippokampuksen tiedetÀÀn osallistuvan myös visuaaliseen prosessointiin, ei ole tÀysin selvÀÀ, etteivÀtkö havaitut aktivaatiot voisi selittyÀ alemman, aistitietoa kÀsittelevÀn tason prosesseilla.
TĂ€mĂ€n kysymyksen ratkaisemiseksi tĂ€ssĂ€ tutkimuksessa selvitettiin reagoiko hippokampus tapahtumarajoihin puhtaasti auditiivisessa Ă€rsykkeessĂ€. ĂrsykkeenĂ€ oli 71-minuuttinen tarinallinen ÀÀnikirja, jonka osallistujat kuuntelivat passiivisesti fMRI-rekisteröinnin aikana, ja jonka tapahtumarajat mÀÀriteltiin kokeellisesti erillisen koehenkilöryhmĂ€n avulla. Aivokuvausaineisto analysoitiin aivoalueittain sekĂ€ hippokampuksesta ettĂ€ eksploratiivisesti myös kaikilta aivokuoren alueilta.
Hippokampuksen havaittiin reagoivan tapahtumarajoihin aktivaatiopiikein. Aivokuorella voimakkaasti reagoivia alueita olivat mm. posteriorinen mediaalinen aivokuori, ventromediaalinen prefrontaalialue, parahippokampaalinen poimu sekÀ etummainen pihtipoimu. Monien nÀistÀ alueista uskotaan osallistuvan meneillÀÀn olevan tapahtuman mallintamiseen ja hahmottamiseen, ja osa mahdollisesti osallistuu huomion siirtÀmiseen sisÀisen ja ulkoisen vÀlillÀ. Etummaisen pihtipoimun tiedetÀÀn osallistuvan odotusten ja havaintojen vÀlisten konfliktien monitorointiin, mikÀ saattaisi tukea teoriaa, jonka mukaan segmentaatio olisi riippuvaista havaituista ennustevirheistÀ. TÀtÀ ei kuitenkaan tÀmÀn tutkimuksen perusteella voida varmasti pÀÀtellÀ, vaan asiaa tulisi tutkia tarkemmin.
TĂ€mĂ€n tutkimuksen tulokset tukevat nĂ€kemystĂ€, jonka mukaan hippokampuksen lisÀÀntynyt toiminta tapahtumarajoilla liittyy korkean tason abstraktiin segmentaatioon ja mahdollisesti episodisen muiston luomiseen. TĂ€mĂ€ prosessi mahdollisesti tapahtuu yhteistyössĂ€ aivokuoren aktiivisten alueiden kanssa, mutta kausaaliset suhteet ja informaation kulku nĂ€iden alueiden vĂ€lillĂ€ on selvitettĂ€vĂ€ myöhemmissĂ€ tutkimuksissa.Event segmentation structures our experience as well as our memories. The representation of the currently ongoing event is likely dependent on a network of cortical areas, but the ability to retain a memory of the event requires an intact hippocampus. It is thus a relevant question how and when this hippocampal episodic encoding happens. It has previously been shown that the hippocampus is sensitive to event boundaries and responds to them with transient fMRI activation peaks. It has been proposed that these hippocampal end-of-event activations represent a high-level, modality-independent process of sharpening or âprinting outâ of the memory trace of the situation. However, the studies reporting hippocampal peaks have been conducted on audio-visual stimuli, so it is unclear whether these results generalise to narratives without a visual component, as the hippocampus is known to support visual processing as well as episodic encoding.
In this study I aim to answer this question by analysing fMRI data from participants experiencing a purely auditory narrative. The stimulus was a 71-minute-long audio book, and it was segmented behaviourally by a separate group of participants with a naĂŻve intuitive segmentation paradigm. The data was analysed with a region of interest (ROI) analysis in the hippocampus, as well as in an exploratory manner on all areas from a cortical atlas.
The hippocampus was found to respond significantly to event boundaries in the story. Strong responses were also found in areas of the posterior medial cortex (PMC), as well as in ventromedial prefrontal cortex (vmPFC), parahippocampal gyrus, anterior cingulate (ACC) and the insula. Many of these are known to be involved in representing the event model, and some with switching between internal and external processing modes. ACC in particular is known to be involved in conflict monitoring â this might link with the proposal that segmentation in general is driven by prediction error and would merit further study.
I conclude that the hippocampus does detect and respond to event boundaries in a naturalistic auditory narrative, which is in line with the âprint outâ hypothesis and implies that these activations are related to domain-general episodic encoding. The increased hippocampal processing is likely to happen in collaboration with cortical areas involved in signalling change and representing the working event model. However, the causal connections between these areas during the boundary-related processing cascade needs to be elaborated in future studies
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