Ground truth annotation of traffic video data

This paper presents a software application to generate ground-truth data on video files from traffic surveillance cameras used for Intelligent Transportation Systems (IT systems). The computer vision system to be evaluated counts the number of vehicles that cross a line per time unit intensity-, the average speed and the occupancy. The main goal of the visual interface presented in this paper is to be easy to use without the requirement of any specific hardware. It is based on a standard laptop or desktop computer and a Jog shuttle wheel. The setup is efficient and comfortable because one hand of the annotating person is almost all the time on the space key of the keyboard while the other hand is on the jog shuttle wheel. The mean time required to annotate a video file ranges from 1 to 5 times its duration (per lane) depending on the content. Compared to general purpose annotation tool a time factor gain of about 7 times is achieved.This work was funded by the Spanish Government project MARTA under the CENIT program and CICYT contract TEC2009-09146.Mossi García, JM.; Albiol Colomer, AJ.; Albiol Colomer, A.; Oliver Moll, J. (2014). Ground truth annotation of traffic video data. Multimedia Tools and Applications. 1-14. https://doi.org/10.1007/s11042-013-1396-xS114Albiol A et al (2011) Detection of parked vehicles using spatiotemporal maps. IEEE Trans Intell Transport Syst 12(4):1277–1291Blunsden SJ, Fisher R (2010) The BEHAVE video dataset: ground truthed video for multi-person behavior classification. Annal British Mach Vis Assoc 4:1–12Bradski G, Kaehler A (2008) Learning OpenCV: Computer vision with the OpenCV library. O'Reilly Media, IncorporatedBrooke J. SUS: a “quick and dirty” usability scale. Usability evaluation in industry. Taylor and FrancisBrostow GJ et al (2009) Semantic object classes in video: a high-definition ground truth database. Pattern Recognit Lett 30(2):88–97Buch N et al (2011) A review of computer vision techniques for the analysis of urban traffic. IEEE Trans Intell Transp Syst 12(3):920–939D’Orazio T et al. (2009) A semi-automatic system for ground truth generation of soccer video sequences. Advanced Video and Signal Based Surveillance, 2009. AVSS’09. Sixth IEEE International Conference on (Sep. 2009), 559–564Dollar P et al (2012) Pedestrian detection: an evaluation of the state of the art. IEEE Trans Pattern Anal Mach Intell 34(4):743–761Faro A et al (2011) Adaptive background modeling integrated with luminosity sensors and occlusion processing for reliable vehicle detection. IEEE Trans Intell Transport Syst 12(4):1398–1412Giro-i-Nieto X et al (2010) GAT: a graphical annotation tool for semantic regions. Multimed Tool Appl 46(2–3):155–174i-LIDS. Image Library for Intelligent Detection Systems: www.ilids.co.uk . Home Office Scientific Development Branch, United Kingdom. Last Accessed February 2013Kasturi R et al (2009) Framework for performance evaluation of face, text, and vehicle detection and tracking in video: data, metrics, and protocol. IEEE Trans Pattern Anal Mach Intell 31(2):319–336Laganière R (2011) OpenCV 2 computer vision application programming cookbook. Packt Pub LimitedLorist MM et al (2000) Mental fatigue and task control: planning and preparation. Psychophysiology 37(5):614–625Russell B et al (2008) LabelMe: a database and web-based tool for image annotation. Int J Comput Vis 77(1):157–173Serrano M, Gracía J, Patricio M, Molina J (2010). Interactive video annotation tool. Distributed Computing and Artificial Intelligence, 325–332Traffic City Cameras. Ajuntament de València, Spain. http://camaras.valencia.es . Last Accessed February 2013TREC video retrieval evaluation. http://www-nlpir.nist.gov/projects/trecvid/Vezzani R, Cucchiara R (2010) Video Surveillance Online Repository (ViSOR): an integrated framework. Multimed Tool Appl 50(2):359–380ViPER: the video performance evaluation resource: http://viper-toolkit.sourceforge.net/Volkmer T et al. (2005) A web-based system for collaborative annotation of large image and video collections: an evaluation and user study. Proceedings of the 13th annual ACM international conference on Multimedia (New York, NY, USA, 2005), 892–901Zhang HB, Li SA, Chen SY, Su SZ, Duh DJ, Li SZ (2012) Adaptive photograph retrieval method. Multimedia Tools and Applications, Published online September 2012.Zou Y et al (2011) Traffic incident classification at intersections based on image sequences by HMM/SVM classifiers. Multimed Tool Appl 52(1):133–14

Why are we not flooded by involuntary thoughts about the past and future? Testing the cognitive inhibition dependency hypothesis

© The Author(s) 2018In everyday life, involuntary thoughts about future plans and events occur as often as involuntary thoughts about the past. However, compared to involuntary autobiographical memories (IAMs), such episodic involuntary future thoughts (IFTs) have become a focus of study only recently. The aim of the present investigation was to examine why we are not constantly flooded by IFTs and IAMs given that they are often triggered by incidental cues while performing undemanding activities. One possibility is that activated thoughts are suppressed by the inhibitory control mechanism, and therefore depleting inhibitory control should enhance the frequency of both IFTs and IAMs. We report an experiment with a between-subjects design, in which participants in the depleted inhibition condition performed a 60-min high-conflict Stroop task before completing a laboratory vigilance task measuring the frequency of IFTs and IAMs. Participants in the intact inhibition condition performed a version of the Stroop task that did not deplete inhibitory control. To control for physical and mental fatigue resulting from performing the 60-min Stroop tasks in experimental conditions, participants in the control condition completed only the vigilance task. Contrary to predictions, the number of IFTs and IAMs reported during the vigilance task, using the probe-caught method, did not differ across conditions. However, manipulation checks showed that participants’ inhibitory resources were reduced in the depleted inhibition condition, and participants were more tired in the experimental than in the control conditions. These initial findings suggest that neither inhibitory control nor physical and mental fatigue affect the frequency of IFTs and IAMs.Peer reviewedFinal Published versio

Fatigue-induced changes of impedance and performance in target tracking

Kinematic variability is caused, in part, by force fluctuations. It has been shown empirically and numerically that the effects of force fluctuations on kinematics can be suppressed by increasing joint impedance. Given that force variability increases with muscular fatigue, we hypothesized that joint impedance would increase with fatigue to retain a prescribed accuracy level. To test this hypothesis, subjects tracked a target by elbow flexion and extension both with fatigued and unfatigued elbow flexor and extensor muscles. Joint impedance was estimated from controlled perturbations to the elbow. Contrary to the hypothesis, elbow impedance decreased, whereas performance, expressed as the time-on-target, was unaffected by fatigue. Further analysis of the data revealed that subjects changed their control strategy with increasing fatigue. Although their overall kinematic variability increased, task performance was retained by staying closer to the center of the target when fatigued. In conclusion, the present study reveals a limitation of impedance modulation in the control of movement variability

A ‘spoon full of sugar’ helps the medicine go down: how a participant friendly version of a psychophysics task significantly improves task engagement, performance and data quality in a typical adult sample

Few would argue that the unique insights brought by studying the typical and atypical development of psychological processes are essential to building a comprehensive understanding of the brain. Often, however, the associated challenges of working with non-standard adult populations results in the more complex psychophysical paradigms being rejected as too complex. Recently we created a child (and clinical group) friendly implementation of one such technique – the reverse correlation Bubbles approach and noted an associated performance boost in adult participants. Here, we compare the administration of three different versions of this participant-friendly task in the same adult participants to empirically confirm that introducing elements in the experiment with the sole purpose of improving the participant experience, not only boost the participant’s engagement and motivation for the task but results in significantly improved objective task performance and stronger statistical results

Superior Inhibitory Control and Resistance to Mental Fatigue in Professional Road Cyclists

Purpose: Given the important role of the brain in regulating endurance performance, this comparative study sought to determine whether professional road cyclists have superior inhibitory control and resistance to mental fatigue compared to recreational road cyclists. Methods: After preliminary testing and familiarization, eleven professional and nine recreational road cyclists visited the lab on two occasions to complete a modified incongruent colour-word Stroop task (a cognitive task requiring inhibitory control) for 30 min (mental exertion condition), or an easy cognitive task for 10 min (control condition) in a randomized, counterbalanced cross-over order. After each cognitive task, participants completed a 20-min time trial on a cycle ergometer. During the time trial, heart rate, blood lactate concentration, and rating of perceived exertion (RPE) were recorded. Results: The professional cyclists completed more correct responses during the Stroop task than the recreational cyclists (705±68 vs 576±74, p = 0.001). During the time trial, the recreational cyclists produced a lower mean power output in the mental exertion condition compared to the control condition (216±33 vs 226±25 W, p = 0.014). There was no difference between conditions for the professional cyclists (323±42 vs 326±35 W, p = 0.502). Heart rate, blood lactate concentration, and RPE were not significantly different between the mental exertion and control conditions in both groups. Conclusion: The professional cyclists exhibited superior performance during the Stroop task which is indicative of stronger inhibitory control than the recreational cyclists. The professional cyclists also displayed a greater resistance to the negative effects of mental fatigue as demonstrated by no significant differences in perception of effort and time trial performance between the mental exertion and control conditions. These findings suggest that inhibitory control and resistance to mental fatigue may contribute to successful road cycling performance. These psychobiological characteristics may be either genetic and/or developed through the training and lifestyle of professional road cyclists

Basal ganglia correlates of fatigue in young adults

Although the prevalence of chronic fatigue is approximately 20% in healthy individuals, there are no studies of brain structure that elucidate the neural correlates of fatigue outside of clinical subjects. We hypothesized that fatigue without evidence of disease might be related to changes in the basal ganglia and prefrontal cortex and be implicated in fatigue with disease. We aimed to identify the white matter structures of fatigue in young subjects without disease using magnetic resonance imaging (MRI). Healthy young adults (n = 883; 489 males and 394 females) were recruited. As expected, the degrees of fatigue and motivation were associated with larger mean diffusivity (MD) in the right putamen, pallidus and caudate. Furthermore, the degree of physical activity was associated with a larger MD only in the right putamen. Accordingly, motivation was the best candidate for widespread basal ganglia, whereas physical activity might be the best candidate for the putamen. A plausible mechanism of fatigue may involve abnormal function of the motor system, as well as areas of the dopaminergic system in the basal ganglia that are associated with motivation and reward

Alterations in cognitive performance during passive hyperthermia are task dependent

The objectives of this study were to (1) assess the effect of passive heating upon attention and memory task performance, and (2) evaluate the effectiveness of the application of cold packs to the head on preserving these functions. Using a counterbalance design 16 subjects underwent three trials: a control (CON, 20°C, 40% rH), hot (HOT, 50°C, 50% rH) and hot with the head kept cool (HHC). In each condition, three attention tests and two memory tests were performed. Mean core, forehead and tympanic temperatures were all significantly higher (p< 0.05) during HOT (38.6° ±0.1°, 39.6° ±0.2° and 38.8°±0.1°C, respectively) and HHC (38°±0.2, 37.7°±0.3° and 37.7°C, respectively) than in CON (37.1°±0.6°, 33.3° ±0.2° and 35.9°±0.3°C, respectively). Results indicate that there was impairment in working memory with heat exposure (p < 0.05) without alteration in attentional processes. The regular application of cold packs only prevented the detrimental effect of hyperthermia on short-term memory. Our results show that impairments in cognitive function with passive hyperthermia and the beneficial effect of head cooling are task dependent and suggests that exposure to a hot environment is a competing variable to the cognitive processes