Повесть Н.В. Гоголя «Заколдованное место»: Опыт прочтения

Multisensory integration is essential for our perception of the world. Multisensory illusion provide a unique opportunity to study the integration process. In particular, the double-flash paradigm – in which a single flash, paired with two auditory beeps causes perception of an illusory second flash – has often been used as a test bed for multisensory integration. The research reported here examines the effect of situational, stimulus driven and pre-stimulus brain state influence on the phenomenon to cast light on (i) whether we can have control over the integration (ii) what mechanisms account for the dominance of one modality (in this case auditory) and can the dominance change (iii) do ongoing changes in brain activity not related to the stimuli predict the rate of the illusion. Chapter 3 tests whether impairment of cognitive influences through working memory load alters illusion rates. In chapter 4 the reliability of the auditory stimuli were reduced to see if modality dominance might switch. Chapter 5 examines whether incentives for correct responses using paid feedback can alter illusion rates. Working memory load had no effect on rates of illusion. Paid feedback did, however, produce a resistance to the illusion. The resistance appeared to be learned. When auditory reliability was reduced, an auditory illusion was detected, alongside the standard visual illusion. EEG data for the visual illusion with near threshold sound was consistent with previous literature for full intensity sound. For the auditory illusion, EEG interaction was found to occur later than in the standard paradigm. These findings suggest that, firstly, multisensory interaction takes place early in sensory processing, too early to be affected by top down attentional processes. However, it does not appear to be immune to adaption or learning, as evidenced by the reduction in illusions and change in multisensory ERP components when participants are paid for correct answers. Secondly, reduction in auditory reliability does not appear to change the visual illusion in terms of illusion rate or ERP profile. It does however produce a simultaneous auditory illusion with apparently different neural mechanisms which occur later. Finally, ongoing changes in pre-stimulus activity appear to be associated with perception of the illusion.

Experiential phenomena (EP), such as illusions and complex hallucinations, are vivid experiences created in one's mind. They can occur spontaneously as epileptic auras or can be elicited by electrical brain stimulation (EBS) in patients undergoing presurgical evaluation for drug-resistant epilepsy. Previous work suggests that EP arise from activation of different nodes within interconnected neural networks mainly in the temporal lobes. Yet, the anatomical extent of these neural networks has not been described and the question of lateralization of EP has not been fully addressed. To this end, an extended number of brain regions in which electrical stimulation elicited EP were studied to test whether there is a lateralization propensity to EP phenomena. A total of 19 drug-resistant focal epilepsy patients who underwent EBS as part of invasive presurgical evaluation and who experienced EP during the stimulation were included. Spatial dispersion of visual and auditory illusions and complex hallucinations in each hemisphere was determined by calculation of Euclidean distances between electrodes and their centroid in common space, based on (x, y, z) Cartesian coordinates of electrode locations. In total, 5857 stimulation epochs were analyzed; 917 stimulations elicited responses, out of which 130 elicited EP. Complex visual hallucinations were found to be widely dispersed in the right hemisphere, while they were tightly clustered in the occipital lobe of the left hemisphere. Visual illusions were elicited mostly in the occipital lobes bilaterally. Auditory illusions and hallucinations were evoked symmetrically in the temporal lobes. These findings suggest that complex visual hallucinations arise from wider spread in the right compared to the left hemisphere, possibly mirroring the asymmetry in the white matter organization of the two hemispheres. These results offer some insights into lateralized differences in functional organization and connectivity that may be important for functional mapping and planning of surgical resections in patients with epilepsy.

Stimuli received beyond a very short timeframe, known as temporal binding windows (TBWs), are perceived as separate events. In previous audio-visual multisensory integration (McGurk effect) studies, widening of TBWs has been observed in people with schizophrenia. The present study aimed to determine if dexamphetamine could increase TBWs in unimodal auditory and unimodal visual illusions that may have some validity as experimental models for auditory and visual hallucinations in psychotic disorders. A double-blind, placebo-controlled, counter-balanced crossover design with permuted block randomisation for drug order was followed. Dexamphetamine (0.45mg/kg, PO, q.d.) was administered to healthy participants. Phantom word illusion (speech illusion) and visual-induced flash illusion/VIFI (visual illusion) tests were measured to determine if TBWs were altered as a function of delay between stimuli presentations. Word emotional content for phantom word illusions was also analysed. Dexamphetamine significantly increased the total number of phantom words/speech illusions (p<0.01) for pooled 220-1100ms ISIs in kernel density estimation and the number of positive valence words heard (beta=2.20, 95% CI [1.86, 2.55], t=12.46, p<0.001) with a large effect size (std. beta=1.05, 95% CI [0.89, 1.22]) relative to placebo without affecting the TBWs. For the VIFI test, kernel density estimation for pooled 0-801ms ISIs showed a significant difference (p<0.01) in the data distributions of number of target flash (es) perceived by participants after receiving dexamphetamine as compared with placebo. Overall, healthy participants who were administered dexamphetamine (0.45mg/kg, PO, q.d.) experienced increases in auditory and visual illusions in both phantom word illusion and VIFI tests without affecting their TBWs.

Auditory illusions will be demonstrated, and their relevance to prehistoric cave art and Stonehenge revealed. In the ancient past, when the wave characteristics of sound were not understood, virtual sound effects arising from complex sound wave interactions (echoes, reverberations, interference patterns, etc.) were misinterpreted as invisible beings (echo spirits, thunder gods, sound absorbing bodies, etc.) as described in ancient myths around the world. In this session, live hands-on demonstrations will be given to small groups of students who can experience for themselves these types of auditory illusions. Participants will get to experience various sounds and will be given the task of interpreting what the sounds are, first blindfolded, then with visual cues. (Previous student reactions have included “Whoa!,” “Wow!,” “Amazing!,” “Cool!,” and “What??.”) These scientifically conducted experiments show how various ambiguous sounds can be interpreted in more than one way—like optical illusions—and thus can help in understanding our ancestors’ reactions to sounds they considered mysterious and spooky. These discoveries are just a few examples of research findings that are springing from the new field of Archaeoacoustics. See https://sites.google.com/site/rockartacoustics/ for further examples.

Occult binding and unbinding: A New Testament perspective In view of the recent upsurge in attention given to practices of “spiritual warfare” like “demonic binding/unbinding”, “exorcism” and “mapping”, a study is made of various New Testament references to the devil and evil spirits, their influence and how these influences were dealt with. Conclusions are drawn concerning the legitimacy, character and possible practice of a present-day (Reformed) ministry dealing with demonic influences on the life of Christians.

Multiple sensory illusions are evoked during the course of proton therapy

Sleep in patients with epilepsy.

It has long been known that sound fields rotating around a stationary, blindfolded observer can elicit self-motion illusions (circular vection) in 20--60% of participants. Here, we investigated whether auditory circular vection might depend on whether participants sense and know that actual motion is or impossible. Although participants in auditory vection studies are often seated on moveable seats to suspend the disbelief of self-motion, it has never been investigated whether this does, in fact, facilitate vection. To this end, participants were seated on a hammock chair with their feet either on solid ground (movement impossible condition) or suspended (movement possible condition) while listening to individualized binaural recordings of two sound sources rotating synchronously at 60°/s. In addition, hardly noticeable vibrations were applied in half of the trials. Auditory circular vection was elicited in 8/16 participants. For those, adding vibrations enhanced vection in all dependent measures. Not touching solid ground increased the intensity of self-motion and the feeling of actually rotating in the physical room. Vection onset latency and the percentage of trials where vection was elicited were only marginally significantly (p

Phonological features, auditory objects, and illusions

The interpretive cortex has in it a mechanism for instant reactivation of the detailed record of the past. It has a mechanism also for the production of interpretive signals. Such signals could only be significant if past records are scanned and relevant experiences are selected for comparison with present experience. This is a subconscious process. But it may well be that this scanning of past experience and selection from it also renders the relevant past available for conscious consideration as well. Thus, the individual may refer to the record as he employs other circuits of the brain. Access to the record of the past seems to be as readily available from the temporal cortex of one side as from that of the other. Auditory illusions (or interpretations of the distance, loudness, or tempo of sounds) have been produced by stimulation of the temporal cortex of either side. The same is true of illusional emotions, such as fear and disgust. But, on the contrary, visual illusions (interpretations of the distance, dimension, erectness, and tempo of things seen) are only produced by stimulation of the temporal cortex on the nondominant (normally, right) side of the brain. Illusions of recognition, such as familiarity or strangeness, were also elicited only from the nondominant side, except in one case.

Many recent studies have investigated whether visual (spatial) illusions affect visual (spatio-temporal) action control, with results that are far from simple. The present study asks the analogous question with regard to auditory temporal perception and action timing. The auditory illusion chosen for this particular study is the effect of increasing or decreasing the intensity of a tone in a sequence (i.e., accentuation or deaccentuation) on its perceived relative time of occurrence. The motor task is sensorimotor synchronization (finger tapping), specifically the automatic phase correction response to an advanced or delayed tone in a sequence. The strong hypothesis was that (de)accentuation would affect perceptual judgments of the tone's relative time of occurrence, but would have no effect at all on the phase correction response. The results of two experiments, if averaged across participants, confirm these predictions and furthermore suggest that individual perceptual and sensorimotor effects of (de)accentuation are uncorrelated. It is argued that perception and motor control in this case probably rely on different kinds of temporal information: relative versus absolute time of occurrence. Two unexpected findings complicate the results, however: the perceptual illusion was asymmetric, occurring only for delayed tones; and many individual participants did show significant differences in their phase correction response to accented and deaccented tones, although the direction of that difference varied.

Paramethoxymethamphetamine (Mitsubishi turbo) abuse: Case report and literature review

Appreciating a sensory illusion requires first hand experience with the stimulus. While visual and auditory illusions can be rendered using commonly available hardware, hap-tic illusions often require dedicated mechanical systems. This work introduces a series of haptic illusions and demonstrations that can be fabricated using any FDM 3D printer and assembled by hand. This is a step forward in increasing the accessibility of tactile illusions for educational purposes.

Our studies with children suffering from congenital heart disease were inspired by the observations made with adult patients with cardiac defects. Many authors report consistently that a certain number of adult patients show a psychotic reaction after cardiac surgery in the pattern of the “exogener Reaktionstyp Bonhoeffer” [4, 5, 7, 8]. This postoperative delirium or “cardiac psychosis” presents mainly as a syndrome of disorientation, visual and auditory illusions and hallucinations, and paranoid ideas. In addition Meyendorf [8] enumerates the following characteristics: 1. The delirium normally occurs between the 3rd and 6th day after operation. 2. Its duration normally varies between 3 and 7 days. 3. It occurs significantly more often after open-(26%) than after closed-heart surgery (17.4%).

Illusions provide a window into the brain’s perceptual strategies. In certain illusions, an ostensibly task-irrelevant variable influences perception. For example, in touch as in audition and vision, the perceived distance between successive punctate stimuli reflects not only the actual distance but curiously the inter-stimulus time. Stimuli presented at different positions in rapid succession are drawn perceptually toward one another. This effect manifests in several illusions, among them the startling cutaneous rabbit, in which taps delivered to as few as two skin positions appear to hop progressively from one position to the next, landing in the process on intervening areas that were never stimulated. Here we provide an accessible step-by-step exposition of a Bayesian perceptual model that replicates the rabbit and related illusions. The Bayesian observer optimally joins uncertain estimates of spatial location with the expectation that stimuli tend to move slowly. We speculate that this expectation – a Bayesian prior – represents the statistics of naturally occurring stimuli, learned by humans through sensory experience. In its simplest form, the model contains a single free parameter, tau: a time constant for space perception. We show that the Bayesian observer incorporates both pre- and post-dictive inference. Directed spatial attention affects the prediction-postdiction balance, shifting the model’s percept toward the attended location, as observed experimentally in humans. Applying the model to the perception of multi-tap sequences, we show that the low-speed prior fits perception better than an alternative, low-acceleration prior. We discuss the applicability of our model to related tactile, visual, and auditory illusions. To facilitate future model-driven experimental studies, we present a convenient freeware computer program that implements the Bayesian observer; we invite investigators to use this program to create their own testable predictions.