Michał Wierzchoń

Jagiellonian University | UJ · Centre for Brain Research

Variations in mental imagery ability has been linked to various emotional, cognitive and personality measures. However, a comprehensive theoretical framework is missing to account for these associations and their link to mental health. Here, we present evidence for a model of mental imagery centered around a putative "inwardly focused" cognitive st...

A growing body of evidence indicates that spontaneous, moment-to-moment fluctuations of the EEG alpha activity (7-15 Hz) affect perception, with a lower amplitude of alpha oscillations right before the stimulus onset facilitating its detection and visibility. The present study aimed to determine whether alpha-band activity predicts perception also...

Whether attention is a prerequisite of perceptual awareness or an independent and dissociable process remains a matter of debate. Importantly, understanding the relation between attention and awareness is probably not possible without taking into account the fact that both are heterogeneous and multifaceted mechanisms. Therefore, the present study...

Objectives: Commercial systems for monitoring the depth of anesthesia (DoA) are often financially inaccessible to developing countries. As an alternative, a wearable single frontal electroencephalogram (EEG) device can be utilized. Nonetheless, most studies addressing DoA monitoring utilizing just one frontal EEG channel rely on nonlinear features...

Metacognition involves second-order judgments about first-order ones. It remains unclear whether an individual's confidence in being correct is generated by the same system across tasks (domain-generality) or whether it is computed independently in the context of each task (domain-specificity). Previous studies have focused on correlations across s...

Whether attention is a prerequisite of perceptual awareness or, conversely, an independent and dissociable process remains a matter of debate. Importantly, understanding the relation between attention and awareness is unlikely without taking into account that both are heterogeneous and multifaceted mechanisms. Therefore, the present study tested th...

Objective: Blindness deprives a person of a significant part of sensory information resulting in limited perceptual abilities and decreased quality of life. Although some aspects of visual information, like the shape of an object, can be conveyed by other senses, there is no easy way to perceive color without using sight. To address this issue, we...

Vision is inseparably connected to perceptual awareness which can be seen as the culmination of sensory processing. Studies on conscious vision reveal that object recognition is just one of the means through which our representation of the world is built. We propose an operationalization of subjective experience in the context of deep neural networ...

Objective: The driver fatigue detection using multi-channel electroencephalography (EEG) has been extensively addressed in the literature. However, the employment of a single prefrontal EEG channel should be prioritized as it provides users with more comfort. Furthermore, eye blinks from such channel can be analyzed as the complementary informatio...

The contribution of the prefrontal areas to visual awareness is critical for the Global Neuronal Workspace Theory and higher-order theories of consciousness. The goal of the present study was to test the potential engagement of the anterior medial prefrontal cortex (aMPFC) in visual awareness judgements. We aimed to temporarily influence the neuron...

Modern video streaming services require quality assurance of the presented audiovisual material. Quality assurance mechanisms allow streaming platforms to provide quality levels that are considered sufficient to yield user satisfaction, with the least possible amount of data transferred. A variety of measures and approaches have been developed to c...

Although detection of the driver fatigue using a single electroencephalography (EEG) channel has been addressed in literature, the gender differentiation for applicability of the model has not been investigated heretofore. Motivated accordingly, we address the detection of driver fatigue based the gender-segregated datasets, where each of them cont...

Background: Heautoscopy refers to a pathological experience of visual reduplication of one's body with an ambiguous sense of self-location and a disturbing sensation of owning the illusory body. It has been recognized to occur in the course of strikingly diverse psychiatric and neurological disorders, such as schizophrenia, space-occupying lesions...

p>Objective: Blindness deprives a person of a significant part of sensory information resulting in limited perceptual abilities and decreased quality of life. Although some aspects of visual information, like the shape of an object, can be conveyed by other senses, there is no easy way to perceive color without using sight. To address this issue, w...

p>Objective: Blindness deprives a person of a significant part of sensory information resulting in limited perceptual abilities and decreased quality of life. Although some aspects of visual information, like the shape of an object, can be conveyed by other senses, there is no easy way to perceive color without using sight. To address this issue, w...

Background: Mental disorders (MDx) comprise a heterogeneous group of conditions collectively characterized by abnormal patterns of feelings, thoughts, and behavior. Differential diagnosis is complicated by their varied and overlapping clinical presentations, which are shaped by a concerted interplay between hereditary risks and environmental exposu...

The notion of complexity currently receives significant attention in neuroscience, mainly through the popularity of the Integrated Information Theory (IIT). It has proven successful in research centred on discriminating states of consciousness, while little theoretical and experimental effort was directed toward studying the content. In this paper,...

Sensory substitution is thought to be a promising non-invasive assistive technology for people with complete loss of sight because it provides inaccessible visual information via a preserved modality. However, Sensory Substitution Devices (SSDs) are still rarely used by visually impaired persons, possibly due to a lack of structured and supervised...

Objective: Although a wide range of researches have shown the utility of electroencephalography (EEG) for the sleep monitoring, the majority of them reported a low sensitivity for classification of wakefulness from sleep stage I. This paper, therefore, validates a reliable nonlinear feature set for discriminating the wakefulness from sleep stage I...

Objective: Blink-related features derived from electroencephalography (EEG) have recently arisen as a meaningful measure of drivers cognitive state. Combined with band power features of low-channel prefrontal EEG data, blink-derived features enhance the detection of driver drowsiness. Yet, it remains unanswered whether synergy of combined blink an...

Imagia. Towards a neurocognitive theory of image (Francuz, 2013) defines art perception as a synthesis between acts of perception and visual imagination limited by attentional constraints. The majority of empirical evidence the author referred to in the book focuses on visual processing, attention, and aesthetic judgements. Nevertheless, other mech...

Although longitudinal studies are common in other disciplines, such as psychology, medicine, or User Experience, they are rarely used in Quality of Experience (QoE). However, observing users over time can provide useful information on the QoE and help to better understand its influencing factors. Here, we present a systematic review of the methodol...

The successful development of a system realizing color sonification would enable auditory representation of the visual environment. The primary beneficiary of such a system would be people that cannot directly access visual information—the visually impaired community. Despite the plethora of sensory substitution devices, developing systems that pro...

The Perceptual Awareness Scale (PAS) is often used to probe conscious experience, but the assumptions behind the scale and its validity are rarely tested. Using a continuous colour estimation task to assess perceptual quality, we focus on how well PAS follows perceptual quality and how the presence of the estimation task affects PAS ratings. We var...

The theoretical landscape of scientific studies of consciousness has flourished. Today, even multiple versions of the same theory are sometimes available. To advance the field, these theories should be directly compared to determine which are better at predicting and explaining empirical data. Systematic inquiries of this sort are seen in many subf...

Michel (The mismeasure of consciousness: a problem of coordination for the perceptual awareness scale. Philos Sci 2019;86:1239-49) claims that the Perceptual Awareness Scale (PAS) faces the problem of coordination (also known as validity). We argue that his claim holds only under certain theoretical assumptions which need to be made explicit as the...

Objective: Recent advances in development of low-cost single-channel electroencephalography (EEG) headbands have opened new possibilities for applications in health monitoring and brain-computer interface (BCI) systems. These recorded EEG signals, however, are often contaminated by eye blink artifacts that can yield the fallacious interpretation o...

VME-DWT algorithm for elimination of eye blink from short segment of single EEG channel

Transcranial magnetic stimulation (TMS) is used to make inferences about relationships between brain areas and their functions because, in contrast to neuroimaging tools, it modulates neuronal activity. The central aim of this article is to critically evaluate to what extent it is possible to draw causal inferences from repetitive TMS (rTMS) data....

Stimuli caused by self-initiated actions are perceived as less intense than those caused externally; this effect is called sensory attenuation (SA). In two experiments, we aimed to assess the impact of the amplitude of outcomes and its affective valence on SA and explicit ratings of sense of agency. This allowed us to test the predictions of the av...

Detecting characteristics of 3D scenes is considered one of the biggest challenges for visually impaired people. This ability is nonetheless crucial for orientation and navigation in the natural environment. Although there are several Electronic Travel Aids aiming at enhancing orientation and mobility for the blind, only a few of them combine passi...

In this study we tested the hypothesis that perceptual awareness judgments are sensitive to accuracy feedback about the previous action. We used a perceptual discrimination task in which participants reported their stimulus awareness. We created two conditions: No-feedback and Feedback (discrimination accuracy feedback was provided at the end of ea...

The influence of non-visual information on visual awareness judgments has recently gained substantial interest. Using single-pulse transcranial magnetic stimulation (TMS), we investigate the potential contribution of evidence from the motor system to judgment of visual awareness. We hypothesized that TMS-induced activity in the primary motor cortex...

People often claim seeing images completely despite performing poorly. This highlights an issue with conscious representations. We introduce an experimental manipulation aiming to disentangle two prevalent positions: Rich views posit that people virtually represent the external world with unlimited capacity; Sparse views state that representations...

Understanding how people rate their confidence is critical for the characterization of a wide range of perceptual, memory, motor and cognitive processes. To enable the continued exploration of these processes, we created a large database of confidence studies spanning a broad set of paradigms, participant populations and fields of study. The data f...

The influence of non-perceptual information on visual awareness has recently gained substantial interest. Here, we investigated a potential contribution of evidence from the motor system to visual awareness ratings using single-pulse Transcranial Magnetic Stimulation (sp-TMS). We hypothesized that TMS-induced activation of motor cortex will increas...

The influence of non-perceptual information on visual awareness has recently gained substantial interest. Here, we investigated a potential contribution of evidence from the motor system to visual awareness ratings using single-pulse Transcranial Magnetic Stimulation (sp-TMS). We hypothesized that TMS-induced activation of motor cortex will increas...

Understanding how people rate their confidence is critical for characterizing a wide range of perceptual, memory, motor, and cognitive processes. However, progress has been slowed by the difficulty of collecting new data and the unavailability of existing data. To address this issue, we created a large database of confidence studies spanning a broa...

Studies of perceptual awareness require sensitive measures reflecting subjective judgments of visibility. Two scales have been proposed for this purpose: the Continuous Scale (CS) and the Perceptual Awareness Scale (PAS). Here we compare the scales in the context of the Gabor patch orientation discrimination task and propose a Continuous Perceptual...

We aimed to distinguish electrophysiological signatures of visual awareness from other task-related processes through manipulating the level of processing of visual stimuli. During an event-related EEG experiment, 36 subjects performed either color (low-level condition) or magnitude (high-level condition) evaluations of masked digits. Participants...

Designing of color sonification systems provides a possibility of contribution to various fields ranging from rehabilitation of visually impaired through color perception, multisensory art experience to consciousness studies. The design process itself requires understanding and integrating knowledge from many difficult and inherently different bran...

This article discusses how the analysis of interactions between action and awareness allows us to better understand the mechanisms of visual awareness. We argue that action is one of several factors that influence visual awareness and we provide a number of examples. We also discuss the possible mechanisms that underlie these influences on both the...

In this study we tested the hypothesis that perceptual awareness judgments are sensitive to the accuracy feedback about previous behaviour. We used a perceptual discrimination task in which participants reported their stimulus awareness. We created two conditions: No-feedback and Feedback (discrimination accuracy feedback was provided at the end of...

Transcranial magnetic stimulation (TMS) is used to make inferences about relationships between brain areas and their functions because, in contrast to neuroimaging tools, it modulates neuronal excitability. In this poster, we critically evaluate to what extent it is possible to draw causal inferences from TMS data.

How can we assess the accuracy of our decisions? Recent theoretical and empirical work suggest that confidence in one's decision is influenced by the characteristics of motor response in a preceding decisional task. In this paper we present experiment designed to test whether decision itself can also inform confidence and therefore increase its acc...

Sense of agency (SoA) is the feeling of being the author of given actions and their effects. Recent works have investigated the cue integration approach to agency, according to which different predictive and inferential cues form SoA. In the current research we focus on how two such cues, i.e. accuracy of sensorimotor prediction and prior causal be...

How do we assess what we remember? Previous work on metacognition suggests that confidence judgements are more accurate when given after than before a response to a perceptual task. Here we present two experiments that investigate the influence of decision and response on metacognitive accuracy in a memory task so as to establish what kind of infor...

Identifying the neurobiological and cognitive mechanisms of consciousness is one of the biggest challenges of modern science. This task is difficult because we need to simultaneously describe the mechanisms that enable access to conscious content and cause the subjective nature of the experience of this content. Previously proposed scientific model...

Information that is normally accessed through a sensory modality (substituted modality, e.g., vision) is provided by sensory substitution devices (SSDs) through an alternative modality such as hearing or touch (i.e., substituting modality). SSDs usually support disabled users by replacing sensory inputs that have been lost, but they also offer a un...

Perception and action are tightly related, but what is the relation between perceptual awareness and action? In this study we tested the hypothesis that motor response influences perceptual awareness judgements. We design a procedure in which participants were asked to decide whether Gabor grating was oriented towards the left or the right. Present...

What is the relation between perceptual awareness and action? In this study we tested the hypothesis that motor response influences perceptual awareness judgements. We used a perceptual discrimination task in which presentation of the stimulus was immediately followed by a cue requiring a motor response that was irrelevant to the task but could be...

Fazekas and Overgaard ([1]) present a novel, multidimensional model that explains different ways in which conscious representations can be degraded. Moreover, the authors discuss possible mechanisms that underlie different kinds of degradation, primarily those related to attentional processing. In this letter, we argue that the proposed mechanisms...

Interoception provides information about the saliency of external or internal sensory events and thus may inform perceptual decision-making. Error in performance is an example of a motivationally significant internal event that evokes autonomic nervous system response resembling the orienting response: heart rate deceleration, increased skin conduc...

The rubber hand illusion (RHI) has been shown to alter the experience of pain, although studies have yielded inconsistent results. In this experiment we tested the influence of the RHI on the intensity of pain caused by electric stimuli. Electric stimuli were delivered to participants' experimental and control hands before RHI induction (control co...

Awareness can be measured by investigating the patterns of associations between discrimination performance (first-order decisions) and confidence judgments (knowledge). In a typical post-decision wagering (PDW) task, participants judge their performance by wagering on each decision made in a detection task. If participants are aware, they wager adv...

Both the multidimensional phenomenon and the polysemous notion of consciousness continue to prove resistant to consistent measurement and unambiguous definition. This is hardly surprising, given that there is no agreement even as regards the most fundamental issues they involve. One of the basic disagreements present in the continuing debate about...

Recent research suggests that the content of iconic memory (IM) and fragile visual short-term memory could be associated with a similar level of conscious accessibility as working memory (WM). The results of our studies, in which we used a subjective visibility scale in a partial-report change detection paradigm, indicate that it is possible to dis...

The present research investigated metacognitive awareness of emotional stimuli and its psychophysiological correlates. We used a backward masking task presenting participants with fearful or neutral faces. We asked participants for face discrimination and then probed their metacognitive awareness with confidence rating (CR) and post-decision wageri...

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Study Instructions. (DOCX)

Prospective and retrospective metacognitive judgments have been studied extensively in the field of memory; however, their accuracy has not been systematically compared. Such a comparison is important for studying how metacognitive judgments are formed. Here, we present the results of an experiment aiming to investigate the relation between perform...

The consciousness studies are unavoidably linked to the mind-body problem, as most of the researchers are trying to investigate how a physical system (namely the brain) generates mental property (consciousness). To get around this problem the researchers often seem to endorse physicalism and identity theory but it is not clear to what extent, if an...

Radical Plasticity Thesis proposed by Cleeremans (2011), claims that learning process plays a significant role in shaping conscious experience. In order to investigate this assumption we designed two experiments using binocular rivalry paradigm (BR). This paradigm enables experimental triggering of changes in the participants’ subjective experience...

1 Informacje wprowadzające Jak wskazano w poprzednich rozdziałach niniejszej ekspertyzy, mobilność polskich naukowców uzależniona jest od szeregu czynników natury ogólnej (sytuacja ekonomiczna, sposoby zatrudnienia) jak i inicjatyw mających bezpośrednio na celu promowanie mobil-ności. Może być ona również uzależniona od specyfi ki poszczególnych dz...