Early Attentional Modulation of the Neural Network Evoked with the Auditory Paired-click Paradigm: An MEG Study

AbstractAlthough numerous research studies have explored the functional attributes of the human duration perception, the spatio- temporal information on cortical networks underlying this process is still an open question. Moreover, the issue of possible differences in the nature of timing mechanisms responsible for perception of sub- and supra-second intervals requires the implementation of the functional brain imaging techniques with both high spatial and temporal resolution. Attention is very frequently used as a modulating factor for the perceived duration of a sensory stimulus. The non-attended stimuli appear to last shorter than the attended ones, increasing the perceived duration of a concurrent stimulus (Gorea, 2011). This study challenges the accepted model of early sensory responses, activated during the first 100ms after stimulus presentation, as preattentive, automatic processes which modulate the neural sensitivity to incoming stimuli (gating phenomena). We utilized Elekta Neuromag 306-channel whole-head system for magnetoencephalography (MEG) measurements and multi-dipole Calibrated Start Spatio Temporal (CSST) localization technique (Ranken et al., 2002) to investigate whether voluntary attention directed at the second tone of a pair in the standard paired-click paradigm could affect cortical networks underlying the gating out phenomenon. MEG recordings were obtained in a magnetically shielded room at the Biomagnetic Center in Jena, Germany. Two consecutive (ISI=500ms) identical short tonnes (S1 and S2; duration=20ms; f=1200Hz; ITI=8±1s) were used to evoke standard gating cortical responses in 19 healthy participants (21-38 years). In the second condition, the task was to direct attention toward the second tone and to respond to a rarely presented non-identical second tone of the pair (R=1300Hz, p(S1R)=0.3). MEG recordings showed transient early and middle latency responses with peak amplitudes over the temporo-parietal sensors followed by a peak of a sustained activity. Less prominent transient activity was recorded over the frontal sensors, accompanied with a more steady- state component from 100 until 400ms post-stimulus for both conditions. Preliminary results of the CSST spatio-temporal analyses revealed 4-6 brain regions activated during 20-500ms time interval including bilateral superior temporal gyrus (STG), bilateral and medial prefrontal (PF), bilateral parietal (PA) regions, and central motor cortex area. A cortical source underlying the steady-state component was identified in the left prefrontal region for S1 tone, and in central posterior regions (PA) for the repeated tone S2. During the standard paradigm the M50 gating suppression was observed only for bilateral STG sources while bilateral PF and PA sources did not show any reduction in the response during the first 100ms post-stimulus. Targeting the attention towards the second tone enhanced the M50 amplitude of the bilateral STG responses in respect to the repeated stimulus S2 and caused a change in the activated network evident by the emergence of a new generator in the medial PF area (orbitofrontal) instead of dorsolateral PF generators evoked in non-attended condition. These results demonstrate that voluntary attention can exert a topological and functional modulatory influence on the neural network even during early stages of auditory processing

Workshop: Hochschuldidaktische Konsequenzen aus zwei Semestern Krisenlehre

Die Umstellung des Lehrbetriebs an den Hochschulen auf Online-Lehre hat nicht nur technische, sondern vor allem auch didaktische Herausforderungen mit sich gebracht, die vielfältig – und zum Teil sehr unterschiedlich – beantwortet wurden. An einer systematischen hochschulübergreifenden Auswertung fehlt es bislang aber noch. Im hir dokumentierten Workshop wurde der aktuelle Stand exemplarisch vorgestellt und diskutiert, wie es gelingen kann, dass die wertvollen Erfahrungen dieser Zeit nicht mit der Rückkehr zur Präsenzlehre verloren gehen

Development of abstract mathematical reasoning: the case of algebra

Algebra typically represents the students’ first encounter with abstract mathematical reasoning and it therefore causes significant difficulties for students who still reason concretely. The aim of the present study was to investigate the developmental trajectory of the students’ ability to solve simple algebraic equations. 311 participants between the ages of 12 and 17 were given a computerized test of equation rearrangement. Equations consisted of an unknown and two other elements (numbers or letters), and the operations of multiplication/division. The obtained results showed that younger participants are less accurate and slower in solving equations with letters (symbols) than those with numbers. This difference disappeared for older participants (16-17 years), suggesting that they had reached an abstract reasoning level, at least for this simple task. A corresponding conclusion arises from the analysis of their strategies which suggests that younger participants mostly used concrete strategies such as inserting numbers, while older participants typically used more abstract, rule-based strategies. These results indicate that the development of algebraic thinking is a process which unfolds over a long period of time. In agreement with previous research, we can conclude that, on average, children at the age of 15-16 transition from using concrete to abstract strategies while solving the algebra problems addressed within the present study. A better understanding of the timing and speed of students’ transition from concrete arithmetic reasoning to abstract algebraic reasoning might help in designing better curricula and teaching materials that would ease that transition

Using the Rasch model to analyze the test of understanding of vectors

The test of understanding of vectors (TUV) is a multiple-choice test that was recently developed to assess student understanding of vector concepts required in introductory physics courses at the university level. In this study, the TUV was administered to 889 first-year students at the University of Zagreb. The Rasch model was used to evaluate the functioning of the TUV, and to determine the difficulty scale of vector concepts evaluated by this assessment instrument. The results of the Rasch analysis showed a good functioning of test items. However, the TUV was not well targeted to our sample of first-year engineering and science students in introductory physics courses. About half of the students had abilities outside the range of item difficulties, indicating that the TUV would benefit from including more difficult items that would help to better estimate the abilities of these students. Further analysis of the data from subpopulations in our sample showed that the TUV can be well targeted for certain student populations. Students’ scores suggest that the most difficult vector concept tested by the TUV is the unit vector, followed by the cross product, subtraction of vectors, dot product, and direction of a vector

Effect of representation format on conceptual question performance and eye-tracking measures

Previous studies have shown the important role of different representations in the teaching and learning of physics. In this study, we used eye tracking to investigate the effect of different representations on the process of answering conceptual questions. We compared students’ scores and eye-tracking measures on isomorphic questions which contained graphical, pictorial, and verbal representations. On average, in two-thirds of cases, students were consistent in their answers (correct or incorrect) across all three representations. There was no statistically significant difference in students’ scores for different representations. However, eye-tracking measures suggest that it was easiest for students to extract information from verbal representations and most difficult from pictorial representations for the conceptual questions used in this study. These results could be useful to teachers and researchers when creating conceptual questions and, more generally, when teaching with multiple representations

Analyzing high school students’ reasoning about polarization of light

Polarization of light is one of the topics in the Croatian high school physics curriculum. It is taught in the final year of high school education. Twenty-seven Croatian high-school students (aged 18–19 years) were interviewed after regular instruction about their understanding of polarization of light and the model of light itself. This paper reports on the observed students’ reasoning strategies and conceptual difficulties. Some of the reported difficulties correspond with previously identified difficulties, but some new difficulties were also found. Students often based their explanations on the remembered but misinterpreted common schematic representations of polarization. Explanations seemed to be created on the spot, suggesting the absence of prior models of polarization

Exploring digital signal processing using an interactive Jupyter notebook and smartphone accelerometer data

Digital signal processing is a valuable practical skill for the contemporary physicist, yet in physics curricula, its central concepts are often introduced either in method courses in a highly abstract and mathematics-oriented manner or in lab work with little explicit attention. In this paper, we present an experimental task in which we focus on a practical implementation of the discrete Fourier transform (DFT) in an everyday context of vibration analysis using data collected by a smartphone accelerometer. Students are accompanied in the experiment by a Jupyter notebook companion, which serves as an interactive instruction sheet and a tool for data analysis. The task is suitable for beyond-first-year university physics students with some prior experience in uncertainty analysis, data representation, and data analysis. Based on our observations the experiment is very engaging. Students have consistently reported interest in the experiment and they have found it a good demonstration of the DFT method.peerReviewe

DigiPhysLab : Digital Physics Laboratory Work for Distance Learning

Pursuing a broad range of learning objectives, effective physics laboratory courses need conducive-to-learning, motivating, and engaging experimental tasks. The Covid-19 pandemic has further increased the demand for quality experimental tasks which can also be used in online learning scenarios. The EU-funded DigiPhysLab-project meets this need by developing a set of 15 competence-centred experimental tasks which can be implemented by instructors effortlessly in their own lab courses, independent of whether they are held on-campus or in distance learning. For this, the project utilizes the broad availability of digital technologies like smartphones which allow an inexpensive data collection and analysis also outside a traditional laboratory. The developed tasks are characterized by a framework for design principles of experimental tasks derived from literature. In this conference proceedings, the general rationale and outline of the DigiPhysLab-project are described and exemplified by an experiment that is already developed, i.e., the Slamming Door experiment.peerReviewe