Structural analysis of fMRI data revisited: improving the sensitivity and reliability of fMRI group studies.

International audienceGroup studies of functional magnetic resonance imaging datasets are usually based on the computation of the mean signal across subjects at each voxel (random effects analyses), assuming that all subjects have been set in the same anatomical space (normalization). Although this approach allows for a correct specificity (rate of false detections), it is not very efficient for three reasons: i) its underlying hypotheses, perfect coregistration of the individual datasets and normality of the measured signal at the group level are frequently violated; ii) the group size is small in general, so that asymptotic approximations on the parameters distributions do not hold; iii) the large size of the images requires some conservative strategies to control the false detection rate, at the risk of increasing the number of false negatives. Given that it is still very challenging to build generative or parametric models of intersubject variability, we rely on a rule based, bottom-up approach: we present a set of procedures that detect structures of interest from each subject's data, then search for correspondences across subjects and outline the most reproducible activation regions in the group studied. This framework enables a strict control on the number of false detections. It is shown here that this analysis demonstrates increased validity and improves both the sensitivity and reliability of group analyses compared with standard methods. Moreover, it directly provides information on the spatial position correspondence or variability of the activated regions across subjects, which is difficult to obtain in standard voxel-based analyses

Behavioral and Neural Correlates of Communication via Pointing

Communicative pointing is a human specific gesture which allows sharing information about a visual item with another person. It sets up a three-way relationship between a subject who points, an addressee and an object. Yet psychophysical and neuroimaging studies have focused on non-communicative pointing, which implies a two-way relationship between a subject and an object without the involvement of an addressee, and makes such gesture comparable to touching or grasping. Thus, experimental data on the communicating function of pointing remain scarce. Here, we examine whether the communicative value of pointing modifies both its behavioral and neural correlates by comparing pointing with or without communication. We found that when healthy participants pointed repeatedly at the same object, the communicative interaction with an addressee induced a spatial reshaping of both the pointing trajectories and the endpoint variability. Our finding supports the hypothesis that a change in reference frame occurs when pointing conveys a communicative intention. In addition, measurement of regional cerebral blood flow using H2O15 PET-scan showed that pointing when communicating with an addressee activated the right posterior superior temporal sulcus and the right medial prefrontal cortex, in contrast to pointing without communication. Such a right hemisphere network suggests that the communicative value of pointing is related to processes involved in taking another person's perspective. This study brings to light the need for future studies on communicative pointing and its neural correlates by unraveling the three-way relationship between subject, object and an addressee

Neural correlates of egocentric and allocentric frames of reference combined with metric and non-metric spatial relations

Spatial relations (SRs: coordinate/metric vs categorical/non metric) and frames of reference (FoRs: egocentric/body vs allocentric/external element) represent the building blocks underlying any spatial representation. In the present 7-T fMRI study we have identified for the first time the neural correlates of the spatial representations emerging from the combination of the two dimensions. The direct comparison between the different spatial representations revealed a bilateral fronto-parietal network, mainly right sided, that was more involved in the egocentric categorical representations. A right fronto-parietal circuitry was specialized for egocentric coordinate representations. A bilateral occipital network was more involved in the allocentric categorical representations. Finally, a smaller part of this bilateral network (i.e. Calcarine Sulcus and Lingual Gyrus), along with the right Supramarginal and Inferior Frontal gyri, supported the allocentric coordinate representations. The fact that some areas were more involved in a spatial representation than in others reveals how our brain builds adaptive spatial representations in order to effectively react to specific environmental needs and task demands

PENGARUH PERSEPSI DAN SIKAP SISWA DALAM PENERAPAN MODEL PENILAIAN AUTENTIK TERHADAP HASIL BELAJAR MATEMATIKA SISWA KELAS VII SEKOLAH MENENGAH PERTAMA NEGERI KOTA CIREBON

ABSTRAK Penilaian autentik diterapkan sejalan diberlakukannya Kurikulum 2013. Kebijakan ini merupakan isu penting, karena akan membawa perubahan proses penilaian hasil belajar siswa. Perubahan tersebut diduga juga dapat mengantarkan sikap siswa pada kecenderungan tertentu, serta berdampak pada hasil belajar. Penelitian ini bertujuan untuk mengetahui pengaruh sikap siswa dalam penerapan penilaian autentik terhadap hasil belajar matematika, serta mengetahui faktor-faktor yang mempengaruhi sikap siswa dalam penerapan penilaian autentik berdasarkan pemodelan persamaan struktural. Sikap siswa dalam penerapan penilaian autentik diduga dipengaruhi oleh: pengalaman pribadi, emosional, berkembangnya inteligensi, orang yang dianggap penting (teman sebaya, guru, dan orang tua), lembaga pendidikan, dan media massa. Penelitian ini menggunakan metode penelitian hubungan kausal dengan pendekatan kuantitatif. Penelitian ini merupakan hasil modifikasi model yang mengonfirmasi pengaruh persepsi dan sikap siswa dalam penerapan penilaian autentik terhadap hasil belajar matematika. Metode analisis yang digunakan adalah Structural Equation Modelling (SEM). Sampel dalam penelitian ini adalah 361 siswa kelas VII SMP Negeri Kota Cirebon. Hasil analisis SEM menunjukkan bahwa 1) persepsi siswa tentang teman sebaya tidak memberikan pengaruh langsung terhadap sikap siswa dalam penerapan penilaian autentik dan juga tidak memberikan pengaruh langsung terhadap hasil belajar matematika, 2) persepsi siswa tentang kemampuan guru dan persepsi siswa tentang orang tua memberikan pengaruh langsung terhadap sikap siswa dalam penerapan penilaian autentik. Implikasi dari hasil penelitian ini, perlu upaya mempertahankan peran orang tua sebagai pendamping siswa selama proses penerapan penilaian autentik dan upaya meningkatkan kemampuan guru dalam penerapan penilaian autentik. Upaya-upaya tersebut juga akan berdampak langsung pentingnya peran orang tua dan kemampuan guru dalam penerapan penilaian autentik. Peran orang tua dan kemampuan guru sebagai faktor pemacu, sehingga siswa dapat memiliki sikap positif dalam penerapan penilaian autentik dan hasil belajar matematika. Kata kunci: Persepsi, Sikap, Penilaian, Autentik, Hasil Belajar ABSTRACT The implementation of authentic assessment is in line with the enactment of the 2013 Curriculum. This policy is an important issue since it will bring a change in the way of assessing student learning outcomes. These changes are thought to be able to lead students' attitudes to certain tendencies and have an impact on learning outcomes. This study aims to determine the effect of students' attitudes in the implementation of authentic assessment of mathematics learning outcomes. As well as knowing the factors that influence students' attitudes in the implementation of authentic assessment based on structural equation modeling. The students' attitudes in applying authentic assessment are thought to be influenced by: personal experience, emotional development, intelligence, people who are considered important (peers, teachers, and parents), educational institutions, and the mass media. This study uses a causal relationship research method with a quantitative approach. This research is the result of a modified model that confirms the influence of students' perceptions and attitudes in applying authentic assessment to mathematics learning outcomes. The analytical method used is Structural Equation Modeling (SEM). The samples of this study were 361 class VII students of SMP Negeri Cirebon City. The results of the SEM analysis show that 1) students' perceptions of peers do not have a direct influence on students' attitudes in the implementation of authentic assessment and also do not have a direct effect on mathematics learning outcomes, 2) students' perceptions of teacher abilities and students' perceptions of parents have a direct influence on student attitudes in the implementation of authentic assessment. The implication of this research is the importance of the role of parents and the ability of teachers to apply authentic assessment. The role of parents and the ability of the teacher as a driving factor, so that students can have a positive attitude in the implementation of authentic assessment and learning outcomes in mathematics. Keywords: Perception, Attitude, Assessment, Authentic, Learning Outcomes

Automatic Top-Down Processing Explains Common Left Occipito-Temporal Responses to Visual Words and Objects

Previous studies have demonstrated that a region in the left ventral occipito-temporal (LvOT) cortex is highly selective to the visual forms of written words and objects relative to closely matched visual stimuli. Here, we investigated why LvOT activation is not higher for reading than picture naming even though written words and pictures of objects have grossly different visual forms. To compare neuronal responses for words and pictures within the same LvOT area, we used functional magnetic resonance imaging adaptation and instructed participants to name target stimuli that followed briefly presented masked primes that were either presented in the same stimulus type as the target (word–word, picture–picture) or a different stimulus type (picture–word, word–picture). We found that activation throughout posterior and anterior parts of LvOT was reduced when the prime had the same name/response as the target irrespective of whether the prime-target relationship was within or between stimulus type. As posterior LvOT is a visual form processing area, and there was no visual form similarity between different stimulus types, we suggest that our results indicate automatic top-down influences from pictures to words and words to pictures. This novel perspective motivates further investigation of the functional properties of this intriguing region

Individual variation in brain network topology predicts emotional intelligence

BACKGROUND: Social cognitive ability is a significant determinant of functional outcome and deficits in social cognition are a disabling symptom of psychotic disorders. The neurobiological underpinnings of social cognition are not well understood, hampering our ability to ameliorate these deficits. Using ‘resting-state’ fMRI (functional magnetic resonance imaging) and a trans-diagnostic, data-driven analytic strategy, we sought to identify the brain network basis of emotional intelligence, a key domain of social cognition. METHODS: Subjects included 60 participants with a diagnosis of schizophrenia or schizoaffective disorder and 46 healthy comparison participants from three different sites: Beth Israel Deaconess Medical Center, Boston, MA, McLean Hospital, Belmont, MA, and University of Pittsburgh, Pittsburgh, PA. All participants underwent a structural T1/MPRAGE and resting-state fMRI scan. Emotional Intelligence was measured using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). A connectome-wide analysis of brain connectivity examined how each individual brain voxel’s connectivity correlated with emotional intelligence using multivariate distance matrix regression (MDMR). RESULTS: We identified a region in the left superior parietal lobule (SPL) where individual network topology predicted emotional intelligence. Specifically, the association of this region with the Default Mode Network (DMN) predicted higher emotional intelligence (r = 0.424, p < 0.001) and association with the Dorsal Attention Network (DAN) predicted lower emotional intelligence (r = -0.504, p < 0.001). This correlation was observed in both schizophrenia and healthy comparison participants. These results held true despite corrections for sex, age, race, medication dosage (chlorpromazine equivalents), and full scale IQ (FSIQ), and was replicable per site. Post-hoc analyses showed that membership of the left SPL was entirely within the DMN in high scorers and within the DAN in low scorers. This relationship was also shown to be specific to the identified left SPL region when compared to adjacent regions. Sulcal depth analysis of the left SPL revealed a correlation to emotional intelligence (r = 0.269, p = 0.0075). CONCLUSIONS: Previous studies have demonstrated individual variance in brain network topology but the cognitive or behavioral relevance of these differences was undetermined. We observe that the left SPL, a region of high individual variance at the cytoarchitectonic level, also demonstrates individual variance in its association with large scale brain networks and that network topology predicts emotional intelligence. This is the first demonstration of a clinical phenotype in individual brain network topology.2019-07-03T00:00:00

Brain activity underlying response induced by SNARC-congruent and SNARC-incongruent stimuli

At least three well‑documented phenomena indicate a relationship between numbers and the internal representation of space. They are shifting attention in accordance with the localization of numbers on the mental number line (MNL); the spatial‑numerical association of response codes (SNARC) effect, which manifests as faster responses to high numbers with the right hand than with the left, and vice versa for low numbers; and the processing of both numbers and space primarily in the parietal cortex. Some EEG studies have pointed to the response selection stage as a locus of this effect. However, this explanation has yet to be corroborated by the fMRI experiments.The goal of this study was to investigate the functional anatomy underlying response selection induced by SNARC‑congruent and SNARC-incongruent stimuli in a spatial visual cueing task. Healthy adult volunteers responded to a pair of target stimuli consisting of digits, non-digit symbols, or a mix of both. In each trial, the stimuli were preceded by a centrally presented numerical or non-numerical cue stimulus which was required to be memorized. One of the target stimuli that then appeared would be identical to the cue; the task was to determine which side it was presented on, within the pair. In the case of numerical stimuli, the side was congruent with its localization on the MNL in one‑half of the trials. In the other half of the trials, it was incongruent. The behavioral results revealed the SNARC effect, as well as a faster reaction to low numbers than to high numbers. The fMRI responses to the target stimuli showed engagement of regions implicated in number processing but also in sensory-motor areas. This suggests that the motor response selection or execution stage may be the locus of the SNARC effect. Yet, the activation pattern obtained in the congruent and incongruent conditions did not allow us to determine, indisputably, the neural correlates of the mechanisms involved in the SNARC effect. Moreover, we did not observe any stimulus-specific responses to cues