When two pure tones of slightly different frequency are presented separately to each ear, the listener perceives a third single tone with amplitude variations at a frequency that equals the difference between the two tones; this perceptual illusion is known as the binaural auditory beat (BB). There are anecdotal reports that suggest that the binaural beat can entrain EEG activity and may affect the arousal levels, although few studies have been published. There is a need for double-blind, well-designed studies in order to establish a solid foundation for these sounds, as most of the documented benefits come from self-reported cases that could be affected by placebo effect. As BBs are a cheap technology (it even exists a free open source programmable binaural- beat generator on the Internet named Gnaural), any achievement in this area could be of public interest. The aim in our research was to explore the potential of BBs in a particular field: tasks that require focus and concentration. In order to detect changes in the brain waves that could relate to any particular improvement, EEG recordings of a small sample of individuals were also obtained. In this study we compare the effect of different binaural stimulation in 7 EEG frequency ranges. 78 participants were exposed to 20-min binaural beat stimulation. The effects were obtained both quali- tative with cognitive test and quantitative with EEG analysis. Results suggest no significant statistical improvement in 20-min stimulation.
The propagation of EEG activity during the Continuous Attention Test (CAT) was determined by means of Short-time Directed Transfer Function (SDTF). SDTF supplied the information on the direction, spectral content and time evolution of the propagating EEG activity. The differences in propagation for target and non-target conditions were found mainly in the frontal structures of the brain.
Studies based on the most common diagnostic categories do not bring conclusive results concerning the overlapping and distinctive features of anxiety and depression, especially in the areas of attentional functioning, structure of affect, and cognitive emotion regulation. However, a new typology has been proposed which treats anxiety and depression as personality types (Fajkowska, 2013). These types – arousal and apprehension anxiety as well as valence and anhedonic depression – are constructed based on two criteria: specific structure and functions (reactive or regulative). The present paper critically examines the empirical evidence related to this approach. The data mostly confirmed the prediction that the similarities and differences in attentional and affective functioning among the anxiety and depression types would be related to their shared and specific structural and functional characteristics. The new typology turned out to be suitable for integrating the existing research findings by relating them to the structure and functions of anxiety and depression. As a result, it is useful in explaining some of the inconsistencies in literature, as it allows to identify the overlapping and distinctive features of the anxiety and depression types. It also helps to understand the mechanisms contributing to the development and maintenance of anxiety and depression, which might be useful in diagnosis and treatment. However, even though Fajkowska’s approach is an important contribution to the understanding of anxiety and depression, it is not exhaustive. Its limitations are discussed, along with proposed modifications of the theory, as well as further research directions.
This study presents the consequences of incidental affect when performing a letter search in a complex visual field. Participants were exposed to two superficially unrelated tasks in succession. First, they had to read and remember as much as possible from among 135 emotional words chosen to enable manipulation of two affective factors, valence and origin of emotional state, in a 3x3 factorial design with alignment of other variables, such as arousal, concreteness, frequency of appearance and length. The second task was based on a visual search paradigm. Participants viewed a display of six letters and responded if at least one of two target letters was present. Analysis of reaction latencies for correct responses showed that valence of the words read in the first task had no effect on visual search effectiveness. The origin of the affective state elicited by the words in the first task did influence response latencies: latencies were longer when the first task involved reading words eliciting emotions of automatic origin rather than words eliciting emotions of reflective origin. This study provides further evidence that valence effects found in earlier studies could be accounted for by other dimensions, especially origin of emotional state.
Simultaneous perception of audio and visual stimuli often causes concealment or misrepresentation of information actually contained in these stimuli. Such effects are called the "image proximity effect" or the "ventriloquism effect" in the literature. Until recently, most research carried out to understand their nature was based on subjective assessments. The authors of this paper propose a methodology based on both subjective and objectively retrieved data. In this methodology, objective data reflect the screen areas that attract most attention. The data were collected and processed by an eye-gaze tracking system. To support the proposed methodology, two series of experiments were conducted - one with a commercial eye-gaze tracking system Tobii T60, and another with the Cyber-Eye system developed at the Multimedia Systems Department of the Gdańsk University of Technology. In most cases, the visual-auditory stimuli were presented using a 3D video. It was found that the eye-gaze tracking system did objectivize the results of experiments. Moreover, the tests revealed a strong correlation between the localization of a visual stimulus on which a participant's gaze focused and the value of the "image proximity effect". It was also proved that gaze tracking may be useful in experiments which aim at evaluation of the proximity effect when presented visual stimuli are stereoscopic.