Formation and disruption of tonotopy in a large-scale model of the auditory cortex.

There is ample experimental evidence describing changes of tonotopic organisation in the auditory cortex due to environmental factors. In order to uncover the underlying mechanisms, we designed a large-scale computational model of the auditory cortex. The model has up to 100 000 Izhikevich's spiking neurons of 17 different types, almost 21 million synapses, which are evolved according to Spike-Timing-Dependent Plasticity (STDP) and have an architecture akin to existing observations. Validation of the model revealed alternating synchronised/desynchronised states and different modes of oscillatory activity. We provide insight into these phenomena via analysing the activity of neuronal subtypes and testing different causal interventions into the simulation. Our model is able to produce experimental predictions on a cell type basis. To study the influence of environmental factors on the tonotopy, different types of auditory stimulations during the evolution of the network were modelled and compared. We found that strong white noise resulted in completely disrupted tonotopy, which is consistent with in vivo experimental observations. Stimulation with pure tones or spontaneous activity led to a similar degree of tonotopy as in the initial state of the network. Interestingly, weak white noise led to a substantial increase in tonotopy. As the STDP was the only mechanism of plasticity in our model, our results suggest that STDP is a sufficient condition for the emergence and disruption of tonotopy under various types of stimuli. The presented large-scale model of the auditory cortex and the core simulator, SUSNOIMAC, have been made publicly available.

Rotation-based schedules in elementary schools to prevent COVID-19 spread: a simulation study.

Rotations of schoolchildren were considered as a non-pharmacological intervention in the COVID-19 pandemic. This study investigates the impact of different rotation and testing schedules.We built an agent-based model of interactions among pupils and teachers based on a survey in an elementary school in Prague, Czechia. This model contains 624 schoolchildren and 55 teachers and about 27 thousands social contacts in 10 layers. The layers reflect different types of contacts (classroom, cafeteria, etc.) in the survey. On this multi-graph structure we run a modified SEIR model of covid-19 infection. The parameters of the model are calibrated on data from the outbreak in the Czech Republic in spring 2020. Weekly rotations of in-class and distance learning are an effective preventative measure in schools reducing the spread of covid-19 by 75-81% . Antigen testing twice a week or PCR once a week significantly reduces infections even when using tests with a lower sensitivity. The structure of social contacts between pupils and teachers strongly influences the transmission. While the density of contact graphs for older pupils is 1.5 times higher than for younger pupils, the teachers' network is an order of magnitude denser. Teachers moreover act as bridges between groups of children, responsible for 14-18% of infections in the secondary school compared to 8-11% in the primary school. Weekly rotations with regular testing are a highly effective non-pharmacological intervention for the prevention of covid-19 spread in schools and a way to keep schools open during an epidemic.

To Quiz or to Shoot When Practicing Grammar? Catching and Holding the Interest of Child Learners: A Field Study.

Learning grammar requires practice and practicing grammar can be boring. We examined whether an instructional game with intrinsically integrated game mechanics promotes this practice: compared to rote learning through a quiz. We did so "in the field." Tens of thousands children visited, in their leisure time, a public website with tens of attractive online games for children during a 6-week-long period. Of these children, 11,949 picked voluntarily our grammar training intervention. Thereafter, unbeknown to them, they were assigned either to the game or the quiz condition. By means of learning analytics, we examined variables related to participants' persistence and performance. The results showed large participant drop-out before completing the first level in both conditions (42.2%), confirming the boringness of the topic. More children completed at least one level in the game compared to the quiz (61.8 vs. 53.6%). However, more children completed the intervention (all six levels) with the quiz (6.0 vs. 4.3%). In the game, children answered fewer questions correctly (36.3 vs. 47.4) and made more errors compared to the quiz (16.1 vs. 13.1). These findings suggest that even if a game initially catches user attention, it may not hold it. Plus, even if it is a minimalistic game with intrinsic integration of learning and playing, it may be distractive. We conclude that persistence in practicing grammar may be driven by other means than by a game's shooting mechanics; for instance, by a desire to learn the topic and a feeling of achievement or by quizzing mechanics.

Extrinsically Integrated Instructional Quizzes in Learning Games: An Educational Disaster or Not?

Instructional quizzes are frequently used in educational games. When they present correct answers after learners have responded, these quizzes can be used on their own for teaching new factual and conceptual knowledge (no additional learning materials are needed). In games, these quizzes are often unrelated to gameplay: gameplay can be viewed as a reward for answering quiz questions. This has been criticized in game-based learning literature as a "chocolate-covered-broccoli" approach. However, is it really a bad approach? Theories offer conflicting predictions concerning the instructional efficiency of in-game quizzes relative to bare quizzes (i.e., not embedded in games) and empirical literature is lacking. Here, we present a within-subject design study (N = 69), in which 10-12-year-olds learn from both an in-game quiz and a bare quiz and undergo immediate and 2-3 weeks delayed post-test on the quiz questions. A modest difference in learning outcomes favoring the bare quiz was found in the immediate post-tests (d = 0.46), but not in the 2-3 weeks delayed post-tests (d = 0.09). Children enjoyed the game more than the bare quiz (d z = 0.65) and 59 preferred the game in the free-choice period. The findings suggest that both a bare quiz and a quiz within a game have their place at the table for useful educational interventions: the bare quiz should be preferred in schooling contexts; whereas, the game in leisure time situations as a voluntary activity. In the latter case, it should be considered how the game and the quiz are integrated.

A virtual reality task based on animal research - spatial learning and memory in patients after the first episode of schizophrenia.

OBJECTIVES: Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models, we designed a virtual analog of the Morris water maze (MWM), the virtual Four Goals Navigation (vFGN) task. METHODS: Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM) session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP) session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions. RESULTS: Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to the healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and a similar deficit in spatial bias in the probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. The age affected spatial performance only in healthy controls. CONCLUSIONS: Despite some limitations of the study, our results correspond well with the previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in comparative research.