Visual field inhomogeneous in brain-computer interfaces based on rapid serial visual presentation

Objective. Visual attention is not homogeneous across the visual field, while how to mine the effective EEG characteristics that are sensitive to the inhomogeneous of visual attention and further explore applications such as the performance of brain-computer interface (BCI) are still distressing explorative scientists. Approach. Images were encoded into a rapid serial visual presentation (RSVP) paradigm, and were presented in three visuospatial patterns (central, left/right, upper/lower) at the stimulation frequencies of 10Hz, 15Hz and 20Hz. The comparisons among different visual fields were conducted in the dimensions of subjective behavioral and EEG characteristics. Furthermore, the effective features (e.g. SSVEP, N2pc and P300) that sensitive to visual-field asymmetry were also explored. Results. The visual fields had significant influences on the performance of RSVP target detection, in which the performance of central was better than that of peripheral visual field, the performance of horizontal meridian was better than that of vertical meridian, the performance of left visual field was better than that of right visual field, and the performance of upper visual field was better than that of lower visual field. Furthermore, stimuli of different visual fields had significant effects on the spatial distributions of EEG, in which N2pc and P300 showed left-right asymmetry in occipital and frontal regions, respectively. In addition, the evidences of SSVEP characteristics indicated that there was obvious overlap of visual fields on the horizontal meridian, but not on the vertical meridian. Significance. The conclusions of this study provide insights into the relationship between visual field inhomogeneous and EEG characteristics. In addition, this study has the potential to achieve precise positioning of the target's spatial orientation in RSVP-BCIs.

Caffeine and attentional control: improved and impaired performance in healthy older adults and Parkinson’s disease according to task demands

Introduction Caffeine is frequently consumed to boost goal-directed attention. These procognitive effects may occur due to the adenosine-mediated enhancement of monoamines, such as dopamine, after caffeine administration. As such, caffeine’s beneficial effects may be altered in conditions such as Parkinson’s disease (PD). However, whether caffeine improves cognition, and at what cost, has not been experimentally established in patients with neurodegenerative disease. Methods Single-dose trials to probe cognitive effects of caffeine are often confounded by short-term caffeine abstinence which conflates caffeine’s effects with treatment of withdrawal. Using a placebo controlled, blinded, randomised trial design, we assessed the effect of 100 mg of caffeine across well-established tasks (Choice reaction time, Stroop Task and Rapid Serial Visual Presentation Task; RSVP) that probe different aspects of attention in PD patients (n = 24) and controls (n = 44). Critically, participants withdrew from caffeine for a week prior to testing to eliminate the possibility that withdrawal reversal explained any cognitive benefit. Results Caffeine administration was found to reduce the overall number of errors in patients and controls on the Stroop (p = .018, η2p = .086) and Choice reaction time (p < . 0001, η2p = .588) tasks, but there was no specific effect of caffeine on ignoring irrelevant information in the Stroop task. On the RSVP task, caffeine improved dual item accuracy (p = .037) but impaired single item accuracy (p = .044). Across all tasks, there was little evidence that caffeine has different effects in PD participants and controls. Conclusion When removing withdrawal effects as a factor, we demonstrate caffeine has beneficial effects on selective attention but is a double-edge sword for visual temporal attention and would need careful targeting to be clinically useful.

Modality Effects in Free Recall: A Retrieved-Context Account

The modality effect refers to the robust finding that memory performance differs for items presented aurally, as compared with visually. Whereas auditory presentation leads to stronger recency performance in immediate recall, visual presentation often produces better primacy performance (the inverse modality effect). To investigate and model these differences, we conducted two large-scale web-based immediate free recall experiments. In both experiments, participants studied visual and auditory word lists of varying lengths and rates of presentation. We observed typical modality and inverse modality effects, while also discovering that participants were more likely to initiate recall from recent items on auditory trials than on visual trials. However, modality effects persisted regardless of the first item recalled. Meanwhile, an analysis of intrusion errors revealed that participants were more likely on visual trials than on auditory trials to erroneously recall words from one list prior. Furthermore, words presented in the same modality as the present list intruded more often than those presented in a different modality. We next developed a retrieved-context account of the modality effect by fitting the Context Maintenance and Retrieval model to data across multiple list lengths. Through our simulations, we demonstrate that the modality effect can be explained by faster contextual drift and stronger context-to-item association formation during auditory presentation, relative to visual. Our modeling shows that modality effects can arise without hypothesizing distinct memory stores for recent and remote information. Finally, we propose that modality effects may derive primarily from the temporal dynamics of stimuli, rather than their modality.

Human EEG recordings for 1,854 concepts presented in rapid serial visual presentation streams

The neural basis of object recognition and semantic knowledge has been extensively studied but the high dimensionality of object space makes it challenging to develop overarching theories on how the brain organises object knowledge. To help understand how the brain allows us to recognise, categorise, and represent objects and object categories, there is a growing interest in using large-scale image databases for neuroimaging experiments. In the current paper, we present THINGS-EEG, a dataset containing human electroencephalography responses from 50 subjects to 1,854 object concepts and 22,248 images in the THINGS stimulus set, a manually curated and high-quality image database that was specifically designed for studying human vision. The THINGS-EEG dataset provides neuroimaging recordings to a systematic collection of objects and concepts and can therefore support a wide array of research to understand visual object processing in the human brain.

Implementasi Augmented Reality pada Mata Pelajaran Komputer dan Jaringan Dasar di SMK Nufa Citra Mandiri Berbasis Android

In the process of teaching and learning activities in schools, there are still many that only use learning media in the form of books. This causes boredom in the learning process. Especially in basic computer and network subjects, where in this subject there is a lot of visual recognition and developing forms of technology. Good visual presentation is very important to support the learning process. Augmented Reality (AR) is a learning medium that is currently still being used in the teaching and learning process. AR is an application that combines the real world with the virtual world in two-dimensional or three-dimensional forms which are projected in a real environment at the same time. AR technology is very appropriate to be implemented to support the visualization process in learning activities, because it can present visualization in 3-dimensional form. So that the visualization is more interactive and more interesting. In the learning process at SMK Nufa Citra Mandir, they still rely on books only, especially in computer and basic network subjects which really need visualization of the devices discussed. The application of AR technology to basic computer and network subjects at SMK Nufa Citra Mandiri is expected to help in the learning process. In its development, the design method used is the Extreme Programming (XP). Purpose of this research is to create software with AR technology on Android platform, so that students can better understand and get to know computer tools and computer network devices contained in basic computer and network subjects.

Implementasi Sistem Informasi untuk Pemantauan dan Evaluasi Efektivitas E-Learning

This study discusses the monitoring and evaluation of e-learning activities through the LMS (Learning Management System) application of Pamulang University. In the previous process, the system used could only display activities carried out by lecturers that were recorded in the e-learning log. The logs that are displayed only create, update, delete activity, and cannot provide information about the effectiveness of online learning. Other parameters are needed to measure the effectiveness of online learning. One of them is the number of activities lecturers have to do for each subject within a certain period. In each course, the lecturer activity frequency is called create. Create is intended to open discussion topics by providing questions and responses to students' answers. From the results of monitoring, the achievement of creation is not sufficient to determine the success of implementing e-learning at Pamulang University. So that several other restrictions are needed such as participation, intensity, and content suitability. However, problems that occur in other parameters cannot be monitored just by looking at the data from the e-learning log. From these problems, a visual presentation of the activities of lecturers and students is needed which allows Study Programs with low percentages to be identified as quickly as possible, and decision making can be determined. The results showed that the four parameters can be implemented in the system. The average value of student participation in discussion forums is 74.99%, the ratio of the intensity of the activeness of lecturers and students every day of the week during the implementation period is 49.40%. Then the content suitability obtained an average of 0.04% and an average value of 65.90% lecturer activity. The generating facility automatically shows the four parameters in cooperation with the final result considered to assess the effectiveness of e-learning.

Perceiving Destination Through Animated GIFs: A Mixed Method Design for Multifaceted Image Assessment

The notion of multifaceted image, composed of cognitive, affective, and sensory dimensions, has attracted growing scholarly interest in recent years. However, general understanding of the roles of the senses (i.e., sight, hearing, taste, smell, and touch) in image processing remains scarce. Little attention has also been paid to the effects of visual stimuli related to design features on the construction of multifaceted image. This study investigated viewers’ perceived multifaceted destination image upon exposure to different photo formats (i.e., animated vs. static). A mixed method approach was employed to collect data using a between-subjects experimental design. Findings revealed that moving visual presentation exert stronger impacts on three image dimensions in several aspects and associations were also observed between photo contents and sensory arousal. Results enrich the body of knowledge on destination image in terms of image structure and the features of visual stimuli. Practical implications are discussed as well.

Structural and Parametric Identification of Knowm Memristors

This paper proposes a novel identification method for memristive devices using Knowm memristors as an example. The suggested identification method is presented as a generalized process for a wide range of memristive elements. An experimental setup was created to obtain a set of intrinsic I–V curves for Knowm memristors. Using the acquired measurements data and proposed identification technique, we developed a new mathematical model that considers low-current effects and cycle-to-cycle variability. The process of parametric identification for the proposed model is described. The obtained memristor model represents the switching threshold as a function of the state variables vector, making it possible to account for snapforward or snapback effects, frequency properties, and switching variability. Several tools for the visual presentation of the identification results are considered, and some limitations of the proposed model are discussed.

Visualization of Web Spaces: State of the Art and Future Directions

The World Wide Web is a dominant global communication medium and knowledge repository. It is used by a great number of people with a variety of computer skills hence its usability is critical. As with many large information collections, the challenge with web usability is understanding the structure of a collection of information objects (web pages) to find relevant ones for satisfying a specific information need. Web sites are organized in a hyperlinked structure that somewhat addresses this challenge. However, this “connectedness” also causes the now well-known “lost in cyberspace” phenomenon where one may get confused within the complex organization of a web site. Meanwhile, information exploration on the web is not limited to browsing a web site. The problem of finding relevant information applies to a collection of pages that come from various web sites as in the case of the results of a “less than perfectly constructed” search query.<div><br>Information visualization has been proposed as a way to cope with these problems by taking advantage of people’s innate perceptual skills to support their cognitive skills. Many paradigms have been proposed for the visual presentation of web spaces (i.e. structured or unstructured collection of web pages). This study surveys these paradigms to provide a map of where the research in this field is, and what directions future research and practice can take. For this, we introduce a classification scheme to help in the systematic understanding of web visualization and for providing a framework for the development of<br>future visualizations.</div>

Visualization of Web Spaces: State of the Art and Future Directions

The World Wide Web is a dominant global communication medium and knowledge repository. It is used by a great number of people with a variety of computer skills hence its usability is critical. As with many large information collections, the challenge with web usability is understanding the structure of a collection of information objects (web pages) to find relevant ones for satisfying a specific information need. Web sites are organized in a hyperlinked structure that somewhat addresses this challenge. However, this “connectedness” also causes the now well-known “lost in cyberspace” phenomenon where one may get confused within the complex organization of a web site. Meanwhile, information exploration on the web is not limited to browsing a web site. The problem of finding relevant information applies to a collection of pages that come from various web sites as in the case of the results of a “less than perfectly constructed” search query.<div><br>Information visualization has been proposed as a way to cope with these problems by taking advantage of people’s innate perceptual skills to support their cognitive skills. Many paradigms have been proposed for the visual presentation of web spaces (i.e. structured or unstructured collection of web pages). This study surveys these paradigms to provide a map of where the research in this field is, and what directions future research and practice can take. For this, we introduce a classification scheme to help in the systematic understanding of web visualization and for providing a framework for the development of<br>future visualizations.</div>