1. The complexity of caffeine’s effects on regular coffee consumersMateja Lesar, Jakob Sajovic, Dušanka Novaković, Maša Primožič, Eva Vetrih, Martin Sajovic, Anja Žnidaršič, Peter Rogelj, Andreas Daffertshofer, Zoran Levnajić, Gorazd Drevenšek, 2025, izvirni znanstveni članek Povzetek: Why does coffee wake us up? Is it because it contains caffeine, or because we are used to it waking us up after drinking it? To answer this question, we recruited twenty habitual coffee drinkers who received either caffeinated or decaffeinated coffee (placebo) in a double-blind, randomized fashion. The two substances were identical except for the presence of caffeine. We measured cognitive performance, cardiovascular responses, and whole-head EEG during rest and during an auditory-oddball task. The same measurements were done before and after ingestion. We expected to find significant differences between caffeine and placebo groups across the outcome measures. However, except for the resting-state alpha power, changes due to ingestion in physiological responses and in cognitive functioning were not significantly different between the two groups. Actually, only one of the three cognitive measures was found to be significantly altered by the ingestion. These findings suggest that regular coffee consumers respond to coffee-like beverages independently of the presence of caffeine.
Ključne besede: caffeine, decaffeine, ERP, event related potentials (ERP), electroencephalography (EEG), EEG, auditory odball, cognitive performance, resting state EEG
Objavljeno v DiRROS: 14.04.2026; Ogledov: 17; Prenosov: 6
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2. Distance deviation measure of contouring variabilityPeter Rogelj, Robert Hudej, Primož Petrič, 2013, izvirni znanstveni članek Povzetek: Background. Several methods that are currently used for contouring analysis have problems providing reliable and/ or meaningful results. In this paper a solution to these problems is proposed in a form of a novel measure, which was developed based on requirements defined for contouring studies. Materials and methods. The proposed distance deviation measure can be understood as an extension of the closest point measures in such a way that it does not measure only distances between points on contours but rather analyse deviation of distances to both/all contours from each image point/voxel. The obtained result is information rich, reliable and provided in a form of an image, enabling detailed topographic analysis. In addition to image representation, results can be further processed into angular representation for compact topographic analysis or into overall scalar estimates for quick assessment of contour disagreement. Results. Distance deviation method is demonstrated on a multi observer contouring example with complex contour shapes, i.e., with pronounced extremes and void interior. The results are presented using the three proposed methods. Conclusions. The proposed method can detect and measure contour variation irrespective of contour complexity and number of contour segments, while the obtained results are easy to interpret. It can be used in various situations, regarding the presence of reference contour or multiple test contours.
Ključne besede: contouring, contour comparison, distance transform
Objavljeno v DiRROS: 03.04.2024; Ogledov: 1277; Prenosov: 405
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