Alexander Pastukhov

• Kandidat Nauk (equivalent to PhD)
• Akademischer Rat (~Assistant Professor) at University of Bamberg

To clarify the relation between attention and microsaccades, we monitored microsaccades while observers performed tasks with different attentional demand. In four high-demand conditions, observers shifted attention covertly to a peripheral location, or focused attention at fixation. Three corresponding low-demand conditions on physically identical...

Planar motion flows can induce the illusory appearance of a volume rotating in depth ("depth from motion"; G. Sperling, & B. A. Dosher 1994). This appearance changes spontaneously from time to time, reversing simultaneously its depth and its direction of rotation. We investigated asymmetric illusory volumes, which reverse more frequently at some an...

We investigated the relation between perception and sensory memory of multi-stable structure-from-motion displays. The latter is an implicit visual memory that reflects a recent history of perceptual dominance and influences only the initial perception of multi-stable displays. First, we established the earliest time point when the direction of an...

In ambiguous or conflicting sensory situations, perception is often ‘multistable’ in that it perpetually changes at irregular intervals, shifting abruptly between distinct alternatives. The interval statistics of these alternations exhibits quasi-universal characteristics, suggesting a general mechanism. Using binocular rivalry, we show that many a...

We investigated how changes in dynamic spatial context influence visual perception. Specifically, we reexamined the perceptual coupling phenomenon when two multistable displays viewed simultaneously tend to be in the same dominant state and switch in accord. Current models assume this interaction reflecting mutual bias produced by a dominant percep...

Graph and network visualization supports exploration, analysis and communication of relational data arising in many domains: from biological and social networks, to transportation and powergrid systems. With the arrival of AI-based question-answering tools, issues of trustworthiness and explainability of generated answers motivate a greater role fo...

Hypersexuality and impulsivity are regarded as risk factors for sexual offending against children. Studies exploring these factors in undetected men who offended or are at risk of offending are rare. This study aims to investigate hypersexuality and impulsivity in treatment-seeking men with and without a diagnosis of (exclusive) pedophilia who comm...

In this work, we used a modified version of the Geistesblitz game to investigate how prior history primes speed of responses in a visual search task. In the game, players must identify a target among the game objects based on a subset of objects present in the trial attention set. An attention set can be direct when the target object is the only ob...

Perceptual multistability is well-known and mostly visually demonstrated: Common examples are Necker's cube or Rubin's face-vase that produce qualitatively different percepts continuously oscillating between the solutions despite physically stable stimuli. We lack knowledge about similar phenomena in other domains, for instance in linguistics, wher...

When multistable displays are presented intermittently with long blank intervals, their onset perception is determined by perceptual memory of multistable displays. We investigated when and how it is formed using a reverse correlation method and bistable kinetic depth effect displays. Each experimental block consisted of interleaved fully ambiguous...

Multistability - spontaneous switches of perception when viewing a stimulus compatible with several percepts - is often characterized by the distribution of durations of dominance phases. For continuous viewing conditions, these distributions are similar for various multistable displays and share two characteristic features: a Gamma-like distributi...

Although there is an agreement about a general definition of a saccade, the more specific details are harder to agree upon. Therefore, there are numerous algorithms that extract saccades based on various heuristics, which differ in the assumptions about velocity, acceleration, etc. The package uses these methods to label individual samples and then...

R package to import eye tracking recording generated by SR Research EyeLink eye tracker from EDF-files. It includes options to import events and/or recorded samples and extract individual events such as saccades, fixations, blinks, and recorded variables. Use install.package("eyelinkReader") and read instructions at https://github.com/alexander-pa...

Presenting pictures of people with and without facial masks, we employed a 6-AFC paradigm (emotional states happy, angry, fearful, sad, disgusted, and neutral), accompanied by a confidence rating of the own recognition performance. Simultaneously, we recorded participants’ gaze via an eye tracker and their facial expression via a HD video camera to...

When multistable displays are presented intermittently with a long blank interval, they become stabilized via perceptual memory. However, we still lack an understanding of perceptual memory’s role in daily vision, its mechanisms, and even the conditions that lead to its formation. Therefore, we used a reverse correlation method to recover a biasing...

During the COVID-19 pandemic social consequences in day-to-day decisions might not have been salient to the decider and thus egoistic. How can prosocial intentions be increased? In an experimental vignette study with N = 206, we compared the likelihood that parents send sick children to kindergarten after four interventions (general information abo...

A package to compute a cumulative history for time-series of perceptual dominance in bistable displays. Estimates cumulative history, an estimate of accumulating adaptation/prediction error for the dominant percept, for time-series for continuously viewed bistable perceptual rivalry displays. Computes cumulative history via a homogeneous first orde...

Advancements in user interface technologies and demands of design engineering led to increasing implementation of large and mostly flat interactive surfaces in automotive. Recent discussions in the context of in-vehicle usage of touchscreens advocate for the use of haptic feedback to restore the explore- and feel-qualities typically experienced in...

During the COVID-19 pandemic social consequences in day-to-day decisions might not have been salient to the decider and thus egoistic. How can prosocial intentions be increased? In an experimental vignette study with N = 206, we compared the likelihood that parents send sick children to kindergarten after four interventions (general information abo...

When several multistable displays are viewed simultaneously, their perception is synchronized, as they tend to be in the same perceptual state. Here, we investigated the possibility that perception may reflect embedded statistical knowledge of physical interaction between objects for specific combinations of displays and layouts. We used a novel di...

Fits 2D and 3D geometric transformations via 'Stan' probabilistic programming engine. Returns posterior distribution for individual parameters of the fitted distribution. Allows for computation of LOO and WAIC information criteria (Vehtari A, Gelman A, Gabry J (2017) <doi:10.1007/s11222-016-9696-4>) as well as Bayesian R-squared (Gelman A, Goodrich...

Sometimes, we do not notice big changes in our environment, if these changes occur while we perform eye movements or external events interrupt our perception. This striking phenomenon is known as "change blindness." Research on chimpanzees, macaques, and pigeons suggests that change blindness may not be unique to humans, but our understanding is li...

Multistable perception is produced by stimuli that are consistent with two or more different comparably likely perceptual interpretations. After the initial perception is resolved in favor of one of the interpretations, continued viewing leads to fluctuating subjective experience, as perception spontaneously switches between alternative states. Mul...

We investigated the influence of perceived protective value for the public, perceived self-protective value, and perceived cost of the behavior on the adoption of protective behavior during the COVID-19 pandemic. In a pilot study conducted when the lockdown was put in place in Germany, we investigated perceptions of the protective value and use of...

With the present study, we tested whether generosity changes dependent on money or time being shared. During the experiment, participants N = 371 (MAge = 37.5 years, 38.8% female) completed questionnaires measuring social value orientation, moral identity centrality, and honesty-humility. The opportunity cost of time spent on a real effort task was...

Electrostatic friction modulation can be used to augment virtual user interface elements via haptic feedback, for example to highlight interactive elements like a button. This might be especially useful in a seamless user interface, such as a display or control panel, that requires both high aesthetic quality and safe-to-use interactions. However,...

Multistable perception – spontaneous switches of perception when viewing a stimulus compatible with several distinct interpretations – is often characterized by the distribution of durations of individual dominance phases. For continuous viewing conditions, these distributions look remarkably similar for various multistable displays and are typical...

In ambiguous or conflicting sensory situations, perception is often 'multistable' in that it changes abruptly at irregular intervals, shifting perpetually between distinct alternatives. Intriguingly, the interval statistics of these alternations exhibits quasi-universal characteristics, suggesting a general mechanism. Here we show that the stereoty...

We investigated the perception and the frequency of various protective behavior measures against COVID-19. Although our sample (German general public, N = 419, age = 38.07 (15.67) years, female = 71.1 % (diverse = 0.5%), students = 34.37%) consisted mostly of prosocially oriented individuals, we found that, above all, participants used protective m...

When multistable displays—stimuli that are compatible with several comparably likely perceptual interpretations—are presented intermittently, the perceptual state at the stimulus onset shows a complex dependence on the duration of the preceding blank interval. Specifically, perception is maximally destabilized for interruptions that are approximate...

Is dominance in face rivalry driven by low level image properties (contour, contrast, local features , etc.) or by high level face properties (gender, age, emotions, etc.)? Perceptual dominance in face rivalry mostly reflects low level image features, rather than high level face properties.

When continuously viewing multistable displays, which are compatible with several comparably likely interpretations, perception perpetually switches between available alternatives. Prior studies typically report the lack of consistent individual switch rates across different displays. However, this comparison is based on an assumption that neural r...

R package to import eye tracking recording generated by SR Research Eyelink eye tracker from EDF-files. It includes options to import events and/or recorded samples and extract individual events such as saccades, fixations, blinks, and recorded variables. Install from github respository: library("devtools"); options(devtools.install.args = "--n...

Package to calculate the bidimensional regression between two 2D configurations following the approach by Tobler (1965). Provides fits and statistics for Eucledian, affine, and projective transformation. Individual fits can be compared via ANOVA.

Abstract When two bi-stable structure-from-motion (SFM) spheres are presented simultaneously, they tend to rotate in the same direction. This effect reflects a common state bias that is present for various multistable displays. However, it was also reported that when two spheres are positioned so that they touch each other, they tend to counterrota...

Art history claims that Western art shows light from the top left, which has been repeatedly shown with narrow image sets and simplistic research methods. Here we employed a set of 10,000 pictures for which participants estimated the direction of light plus their confidence of estimation. From 1420 A.D., the onset of Early Renaissance, until 1900 A...

Our brain constantly tries to anticipate the future by using a variety of memory mechanisms. Interestingly, studies using the intermittent presentation of multistable displays have shown little perceptual persistence for interruptions longer than a few hundred milliseconds. Here we examined whether we can facilitate the perceptual stability of bist...

In win–win solutions, all parties benefit more from the solution than they would if they each pursued their own individual goals. Such solutions are beneficial at individual and collective levels and thus represent optimal solutions. Win–win solutions are desirable but often difficult to find. To allow the study of individual differences and situat...

We investigated how various grouping factors altered subjective disappearances of the individual targets in the motion-induced blindness display. The latter relies on a moving mask to render highly salient static targets temporarily subjectively invisible. Specifically, we employed two extrinsic grouping factors, the connectedness and the common re...

Devyatko and Pastukhov—Ethical approval. (PDF)

Our visual system combines sensory evidence with prior knowledge to produce a representation of an outside world. Here, we explored the limits of the feedforward computation using an ambiguously rotating human biological motion. Specifically, we investigated whether an overall rotation, which was added to all the displays used in the study, would b...

Supplementary Video 2. Upright walker display. Please ensure that video is looped.

Supplementary Video 1. Scrambled static display, please ensure that video is looped.

Supplementary Video 3. Inverted walker display. Please ensure that video is looped.

Supplementary Video captions

Supplementary Video 4. Scrambled dynamic display. Please ensure that video is looped.

Unlabelled: The timing of perceptual decisions depends on both deterministic and stochastic factors, as the gradual accumulation of sensory evidence (deterministic) is contaminated by sensory and/or internal noise (stochastic). When human observers view multistable visual displays, successive episodes of stochastic accumulation culminate in repeat...

Here, we characterize the duration of exogenously triggered perceptual switches in an ambiguously rotating structure-from-motion display and demonstrate their independence on visual awareness. To this end, we triggered a perceptual reversal by inverting the on-screen motion and systematically varied the posttrigger presentation duration, while coll...

This library provides a simple interface to import contents of the EDF files generated by Eyelink eye-tracker into Matlab (if you don’t know what are EDF fi les generated by Eyelink - you don’t need this library). It imports events and/or samples, automatically parsing them into separate trials. In addition to that, several post-processing function...

Retinal input is riddled with abrupt transients due to self-motion, changes in illumination, object-motion, etc. Our visual system must correctly interpret each of these changes to keep visual perception consistent and sensitive. This poses an enormous challenge, as many transients are highly ambiguous in that they are consistent with many alternat...

Multi-stable displays are ambiguous visual displays that have several comparably plausible interpretations. When presented continuously, their appearance reverses spontaneously from time to time. When presented intermittently (blank intervals >1 s), the appearance stabilizes, revealing the existence of an implicit visual memory ("sensory memory") f...

Perceptual adaptation destabilizes the phenomenal appearance of multistable visual displays. Prolonged dominance of a perceptual state fatigues the associated neural population, lowering the likelihood of renewed perception of the same appearance (Nawrot & Blake in Perception & Psychophysics, 49, 230–44, 1991). Here, we used a selective adaptation...

When multistable displays (stimuli consistent with two or more equally plausible perceptual interpretations) are presented intermittently, their perceptions are stabilized by sensory memory. Independent memory traces are generated not only for different types of multistable displays (Maier, Wilke, Logothetis, & Leopold, Current Biology 13:1076-1085...

Background / Purpose: Visual perception exhibits numerous cooperative phenomena suggestive of attractor dynamics, such as order-disorder transitions or hysteresis. Here we ask whether the perception of coherent motion in random-dot kinematograms (RDK) is consistent with the dynamics of a cortical network model, specifically, with an input-depende...

Far from being “memoryless”, the phenomenal appearance of an ambiguous display depends in complex ways on the recent history of similar perceptions. Given several possible appearances, the continued dominance of one appearance mitigates against its renewed dominance at a later time. This “negative priming" effect is likely caused by neural adaptati...

Perceptual priming can stabilize the phenomenal appearance of multistable visual displays (Leopold, Wilke, Maier, & Logothetis, Nature Neuroscience, 5, 605-609, 2002). Prior exposure to such displays induces a sensory memory of their appearance, which persists over long intervals and intervening stimulation, and which facilitates renewed perception...

We report that multi-stable perception operates in a consistent, dynamical regime, balancing the conflicting goals of stability and sensitivity. When a multi-stable visual display is viewed continuously, its phenomenal appearance reverses spontaneously at irregular intervals. We characterized the perceptual dynamics of individual observers in terms...

We compared the spatial and temporal allocation of attention as revealed by microsaccades. Observers viewed several concurrent "rapid serial visual presentation" (RSVP) streams in the periphery while maintaining fixation. They continually attended to, and discriminated targets in one particular, cued stream. Over and above this continuous allocatio...

In the structure-from-motion paradigm, physical motion on a screen produces the vivid illusion of an object rotating in depth. Here, we show how to dissociate illusory depth and illusory rotation in a structure-from-motion stimulus using a rotationally asymmetric shape and reversals of physical motion. Reversals of physical motion create a conflict...

Multiple dots moving independently back and forth on a flat screen induce a compelling illusion of a sphere rotating in depth (structure-from-motion). If all dots simultaneously reverse their direction of motion, two perceptual outcomes are possible: either the illusory rotation reverses as well (and the illusory depth of each dot is maintained), o...

Forced ambiguous switch: small pairing distance favours constant illusory motion. For most observers the sphere appears to retain initial direction of the illusory rotation for the entire trial. The moment of the forced ambiguous switch may be perceived as a brief “hesitation” in the illusory motion. See text for further details. (MOV)

Structure-from-motion display also referred to as kinetic-depth effect or depth-from-motion. A planar flow is perceived as an illusory sphere rotating in depth. Due to an ambiguous illusory depth, the front surface can be perceived as moving left or right. Perception will spontaneously change between alternatives during continuous viewing (please e...

Forced ambiguous switch: large pairing distance favours illusory motion reversals. For most observers the sphere appears to reverse its direction of the illusory rotation during the presentation. See text for further details. (MOV)

In the structure-from-motion paradigm, physical motion on a screen produces the vivid illusion of an object rotating in depth. Here, we show how to dissociate illusory depth and illusory rotation in a structure-from-motion stimulus using a rotationally asymmetric shape and reversals of physical motion. Reversals of physical motion create a conflict...

Binocular rivalry in childhood has been poorly investigated in the past. Information is scarce with respect to infancy, and there is a complete lack of data on the development of binocular rivalry beyond the first 5–6 years of age. In this study, we are attempting to fill this gap by investigating the developmental trends in binocular rivalry in pr...

Neural adaptation plays an important role in multistable perception, but its effects are difficult to discern in sequences of perceptual reversals. Investigating the multistable appearance of kinetic depth and binocular rivalry displays, we introduce cumulative history as a novel statistical measure of adaptive state. We show that cumulative histor...

We investigated whether visual selective attention contributes to the reversals of phenomenal appearance that characterize multi-stable displays. We employed a rotating-ring display that reverses appearance only at certain phases of its rotation (i.e., when in full-frontal view). During this critical window of time, observers were required to perfo...

When an ambiguous pattern is viewed once, it may be perceived in two equally compelling ways. When viewed repeatedly, its perception is biased by priming effects: (i) An unambiguous pattern negatively primes a subsequent ambiguous pattern, which is less often perceived in the same way. This “flash suppression” [1] may reflect habituation of the pri...