Urszula Górska

Chain Experiment competition inspires learning of physics

The Chain Experiment is an annual competition which originated in Slovenia in 2005 and later expanded to Poland in 2013. For the purpose of the event, each participating team designs and builds a contraption that transports a small steel ball from one end to the other. At the same time the constructed machine needs to use a number of interesting phenomena and physics laws. In the competitions finale, all contraptions are connected to each other to form a long chain transporting steel balls. In brief, they are all evaluated for qualities such as: creativity and advance in theoretical background, as well as the reliability of the constructed machine to work without human help. In this article, we present the contraptions developed by students taking part in the competition in order to demonstrate the advance in theoretical basis together with creativity in design and outstanding engineering skills of its participants. Furthermore, we situate the Chain Experiment in the context of other group competitions, at the same time demonstrating that—besides activating numerous group work skills—it also improves the ability to think critically and present ones knowledge to a broader audience. We discussed it in the context of problem based learning, gamification and collaborative testing.

Evidence Integration in Natural Acoustic Textures during Active and Passive Listening

Abstract Many natural sounds can be well described on a statistical level, for example, wind, rain, or applause. Even though the spectro-temporal profile of these acoustic textures is highly dynamic, changes in their statistics are indicative of relevant changes in the environment. Here, we investigated the neural representation of change detection in natural textures in humans, and specifically addressed whether active task engagement is required for the neural representation of this change in statistics. Subjects listened to natural textures whose spectro-temporal statistics were modified at variable times by a variable amount. Subjects were instructed to either report the detection of changes (active) or to passively listen to the stimuli. A subset of passive subjects had performed the active task before (passive-aware vs passive-naive). Psychophysically, longer exposure to pre-change statistics was correlated with faster reaction times and better discrimination performance. EEG recordings revealed that the build-up rate and size of parieto-occipital (PO) potentials reflected change size and change time. Reduced effects were observed in the passive conditions. While P2 responses were comparable across conditions, slope and height of PO potentials scaled with task involvement. Neural source localization identified a parietal source as the main contributor of change-specific potentials, in addition to more limited contributions from auditory and frontal sources. In summary, the detection of statistical changes in natural acoustic textures is predominantly reflected in parietal locations both on the skull and source level. The scaling in magnitude across different levels of task involvement suggests a context-dependent degree of evidence integration.

A validation of the Polish version of the Coma Recovery Scale-Revised (CRSR)

ABSTRACT Primary objective: The aim of this study was to determine the validity of the Polish version of the Coma Recovery Scale—Revised (CRS-R). Methods and design: Two trained raters, A and B, administered CRS-R on a group of 20 patients with severe brain injury (median age ± SD, 38.0 ± 14.39 years). Both rater A and rater B completed their assessment on day 1, and rater A repeated their assessment on day 2. Inter-rater and test-retest reliability were evaluated with an intra-class correlation coefficient and Spearman rank correlation. Internal consistency was estimated with Cronbach’s α. Agreement in diagnostic impression was determined using Cohen’s κ. Results: Inter-rater reliability for CRS-R total scores and test-retest reliability was excellent: (ρ = 0.76, p < 0.001) and (ρ = 0.92, p < 0.001), respectively. Inter-rater diagnostic agreement was good (κ = 0.72, p < 0.001). Inter-rater reliability for subscales was fair to excellent. Internal consistency was excellent (Cronbach’s α = 0.85). Conclusion: The Polish version of CRS-R can be administered reliably by trained raters and can successfully differentiate between vegetative state (VS), minimally conscious (MCS), and patients emerging from a minimally conscious state (EMCS).

40 hz auditory steady-state responses in patients with disorders of consciousness: Correlation between phase-locking index and coma recovery scale-revised score

OBJECTIVE We aimed to elucidate whether 40Hz auditory steady-state response (ASSR) could be sensitive to the state of patients with disorders of consciousness (DOC) as estimated with Coma Recovery Scale-Revised (CRS-R) diagnostic tool. METHODS Fifteen DOC patients and 24 healthy controls took part in the study. The 40Hz click trains were used to evoke ASSRs. Mean evoked amplitude (EA) and phase-locking index (PLI) within 38-42Hz window were calculated for 100ms bins, starting from -200 to 700ms relative to stimulus onset. RESULTS The PLI values from the patient group in the period of 200-500ms after the stimulus onset positively correlated with the CRS-R total score and with the scores of the Auditory and Visual subscales. CONCLUSIONS The phase-locking index of 40Hz auditory steady-state responses can be an indicator of the level of dysfunction of the central nervous system in DOC. SIGNIFICANCE Our results emphasize the role of central auditory system integrity in determining the level of functioning of DOC patients and suggest the possibility to use the ASSR protocol as an objective diagnostic method in DOC patients.