Gyula Kovacs
Friedrich-Schiller-Universität Jena, Psychology, Faculty Member
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Most artists who create abstract paintings place the pictorial elements not at random, but arrange them intentionally in a specific artistic composition. This arrangement results in a pattern of image properties that differs from image... more
Most artists who create abstract paintings place the pictorial elements not at random, but arrange them intentionally in a specific artistic composition. This arrangement results in a pattern of image properties that differs from image versions in which the same pictorial elements are randomly shuffled. In the article under discussion, the original abstract paintings of the author’s image set were rated as more ordered and harmonious but less interesting than their shuffled counterparts. The authors tested whether the human brain distinguishes between these original and shuffled images by recording electrical brain activity in a particular paradigm that evokes a so-called visual mismatch negativity. The results revealed that the brain detects the differences between the two types of images fast and automatically. These findings are in line with models that postulate a significant role of early (low-level) perceptual processing of formal image properties in aesthetic evaluations.
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doi: 10.3389/fpsyg.2012.00566 Face distortion aftereffects evoked by featureless first-order stimulus configurations
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S – ORAL PRESENTATIONS 1 FACE PROCESSING IN SOCIAL ANXIETY: INTER-INDIVIDUAL DIFFERENCES IN CORTICAL NETWORKS WITHIN AND BEYOND THE CLASSICAL VISUAL HIERARCHY
The recognition of facial identity is essential for social interactions. Despite extensive prior fMRI and EEG/MEG research on the neural representations of familiar faces, we know little about the spatio-temporal dynamics of face identity... more
The recognition of facial identity is essential for social interactions. Despite extensive prior fMRI and EEG/MEG research on the neural representations of familiar faces, we know little about the spatio-temporal dynamics of face identity information. Therefore, we applied a novel multimodal approach by fusing the neuronal responses recorded in an fMRI and an EEG experiment. We analyzed the neural responses to naturally varying famous faces and traced how face identity emerges over time in different areas of the brain. We found that image invariant face identity information prevails over an extended time period (from 150 to 810 ms after stimulus onset) in the representational geometry of a broadly distributed network of parietal, temporal, and frontal areas with overlapping temporal profiles. These results challenge the current hierarchical models of face perception and suggest instead concerted and parallel activation of multiple nodes in the brain’s identity coding network while p...
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ABSTRACT Individuals with developmental prosopagnosia are unable to identify familiar people via their faces, despite normal low-level vision and intellect and in the absence of any obvious damage of the central nervous system. Previous... more
ABSTRACT Individuals with developmental prosopagnosia are unable to identify familiar people via their faces, despite normal low-level vision and intellect and in the absence of any obvious damage of the central nervous system. Previous results suggested the existence of different types of prosopagnosia, however to date the selective role of the perceptual, and memory factors in face recognition processes formally never been tested in this disorder. Additionally, the reliable evaluation of the possible subtypes was impossible in most prior studies due to the small number of participants. To this end we have recruited a group of developmental prosopagnosics (n=26) and individually matched neurotypical participants (n=26) to analyse various aspects of the impairment. Our results suggest the existence of two different subtypes in developmental prosopagnosia, one related to impaired memory and associative, while the other to impaired perceptual functions. Our findings help us to understand the heterogeneity of previous results and may also provide better tools for developing efficient training techniques in prosopagnosia. [ This work was supported by the Hungarian Scientific Research Fund (OTKA) PD 101499 (MZ) and by the Deutsche Forschungsgemeinschaft (KO 3918/1-1) (GK). ]
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In our everyday life, we continuously get to know people, dominantly through their faces. Several neuroscientific experiments showed that familiarization changes the behavioral processing and underlying neural representation of faces of... more
In our everyday life, we continuously get to know people, dominantly through their faces. Several neuroscientific experiments showed that familiarization changes the behavioral processing and underlying neural representation of faces of others. Here, we propose a model of the process of how we actually get to know someone. First, the purely visual familiarization of unfamiliar faces occurs. Second, the accumulation of associated, nonsensory information refines person representation, and finally, one reaches a stage where the effortless identification of very well-known persons occurs. We offer here an overview of neuroimaging studies, first evaluating how and in what ways the processing of unfamiliar and familiar faces differs and, second, by analyzing the fMRI adaptation and multivariate pattern analysis results we estimate where identity-specific representation is found in the brain. The available neuroimaging data suggest that different aspects of the information emerge gradually...
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The occipital face area (OFA) is hierarchically one of the first stages of the face processing network. It has originally been thought to be involved in early, structural processing steps, but currently more and more studies challenge... more
The occipital face area (OFA) is hierarchically one of the first stages of the face processing network. It has originally been thought to be involved in early, structural processing steps, but currently more and more studies challenge this view and propose that it also takes part in higher face processing, such as identification and recognition. Here we tested whether the OFA is involved in the initial steps of recognition memory and plays a causal role in the differential processing of familiar and unfamiliar faces. We used an offline, inhibitory continuous theta-burst stimulation (cTBS) protocol over the right OFA and the vertex as control site. An electroencephalographic (EEG) recording of event-related potentials (ERPs), elicited by visually presented familiar (famous) and unfamiliar faces was performed before and after stimulation. We observed a difference in ERPs for famous and unfamiliar faces in a time-window corresponding to the N250 component. Importantly, this difference ...
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In recent years, several functional magnetic resonance imaging (fMRI) studies showed that correct stimulus predictions reduce the neural responses when compared to surprising events (Egner et al., 2010). Further, it has been shown that... more
In recent years, several functional magnetic resonance imaging (fMRI) studies showed that correct stimulus predictions reduce the neural responses when compared to surprising events (Egner et al., 2010). Further, it has been shown that such fulfilled expectations enhance the magnitude of repetition suppression (RS, i.e. a decreased neuronal response after the repetition of a given stimulus) in face selective visual cortex as well (Summerfield et al., 2008). Current MEG and neuroimaging studies suggest that the underlying mechanisms of expectation effects are independent from these of RS (Grotheer and Kovács, 2015; Todorovic and Lange, 2012). However, it is not clear as of today how perceptual expectations modulate the neural responses: is the difference between correctly predicted and surprising stimuli due to a genuine response reduction for correctly predicted stimuli or is it due to an increased response for surprising stimuli? Therefore, here we used a modified version of the pa...
Research Interests: Psychology, Cognitive Science, Perception, Facial Recognition, Neuroimaging, and 15 moreMagnetic Resonance Imaging, Medicine, Pergamon, Brain Mapping, Brain, Humans, Functional Magnetic Resonance Imaging, Female, Male, Oxygen, Neuropsychologia, Neurosciences, Functional Laterality, Neuropsychological Tests, and photic stimulation
Previous studies have suggested that the human visual system processes faces and bodies holistically—that is, the different body parts are integrated into a unified representation. However, the time course of this integrative process is... more
Previous studies have suggested that the human visual system processes faces and bodies holistically—that is, the different body parts are integrated into a unified representation. However, the time course of this integrative process is less known. In the present study, we investigated this issue by recording event-related potentials evoked by a face and two hands presented simultaneously and in different configurations. When the hands were rotated to obtain a biologically implausible configuration, a reduction of the P2 amplitude was observed relative to the condition in which the face and hands were retained in their veridical configuration and were supplemented with visual cues to highlight further the overall body posture. Our results show that the P2 component is sensitive to manipulations affecting the configuration of face and hand stimuli and suggest that the P2 reflects the operation of perceptual mechanisms responsible for the integrated processing of visually presented bo...
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Visual adaptation and spatial frequency content are known to have an effect on face processing. The slope in the log-log plots of the Fourier power spectrum of an image is a relative measure for the energy in low and high spatial... more
Visual adaptation and spatial frequency content are known to have an effect on face processing. The slope in the log-log plots of the Fourier power spectrum of an image is a relative measure for the energy in low and high spatial frequencies. To investigate whether adaptation to noise with different image statistics as compared to a target face affects face processing differentially, we studied the effect of different Fourier power spectrum slopes in an adaptation paradigm. We used a gray image as a control, and noise images with five different slopes in the Fourier power spectrum. These possessed either the same slope as the face images (matching condition), two different steeper slopes (lower spatial frequencies enhanced) or two different shallower slopes (higher spatial frequencies enhanced). In a block design, participants were first adapted to noise images with one of the five slopes (or a gray image) for three minutes, followed by trials, in which an oval cut-out face appeared on a noise (or gray) image that remained on the screen. We measured event-related potentials (ERPs) for the faces while participants performed an age categorization task. ERP results showed that adaptation to noise images compared to the uniform gray control condition enhances face processing. This was evident by an increase of the N170 and a decrease of the P200 component amplitudes in all noise conditions when compared to the gray condition. Moreover, in the P200 time window, adaptation to shallower slopes increased the signal-to-noise ratio more than to steeper slopes, with the matching condition yielding to intermediate results. In conclusion, our data suggest that adaptation to noise images, especially with enhanced high spatial frequencies, facilitates the neural processing of faces. Meeting abstract presented at VSS 2015.
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Prosopagnosia (PA) is a syndrome where various aspects of face perception are impaired. A specific and quite rare type of PA is the so-called congenital prosopagnosia (CP) which is inherited and occurs without any visible damage to the... more
Prosopagnosia (PA) is a syndrome where various aspects of face perception are impaired. A specific and quite rare type of PA is the so-called congenital prosopagnosia (CP) which is inherited and occurs without any visible damage to the neural system. In our current experiments we studied the neural bases of CP in three patients of the same family (a 56 year- old father, his daughter [23 years] and his son [25 years]), as well in healthy, age- and IQ matched control subjects (n=22), using combined neuropsychological, electrophysiological and functional magnetic resonance imaging (fMRI) methods. Neuropsychological tests (Cambridge Famous Face and Face Memory Tests; Philadelphia Face Perception Battery) demonstrated significant impairments of face perception and recognition in each patient. To reveal the magnitude and category-selectivity of the blood oxygen level dependent (BOLD) signal in the core areas of the face processing cortical network we presented faces and nonsense objects i...
Congenital prosopagnosia is a life-long disorder of face perception. To study the neural backgrounds of congenital prosopagnosia we measured the blood oxygen level-dependent response of congenital prosopagnosic participants, using... more
Congenital prosopagnosia is a life-long disorder of face perception. To study the neural backgrounds of congenital prosopagnosia we measured the blood oxygen level-dependent response of congenital prosopagnosic participants, using functional magnetic resonance imaging. We tested three persons of the family (father, daughter and son), having symptoms of congenital prosopagnosia, as well as healthy controls, using combined neuropsychological and functional magnetic resonance imaging methods. To reveal the neural correlates of the impairments, blood oxygen level-dependent responses within the occipito-temporal cortex were measured to faces and nonsense object images in a block-design experiment. Neuropsychological tests demonstrated significant impairments of face perception/recognition in each subject. We found that the activity of the fusiform and occipital face areas as well as of the lateral occipital cortex was significantly reduced in congenital prosopagnosic participants when compared to controls. Analysis of the hemodynamic response function revealed a lower peak response, but also a significantly faster and stronger decay of the blood oxygen level-dependent response in the occipito-temporal areas in congenital prosopagnosic participants when compared to controls. Our results emphasize the dysfunction of the core face processing system, as well as the lateral occipital complex, in congenital prosopagnosia. Further, the functional impairment of these areas is signalled best by the altered hemodynamic response function, showing abnormally low initial peak and stronger and faster decay in the later parts of the blood oxygen level-dependent response.
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Az élő rendszerek egyik alapvető tulajdonsága - mely a környezetükhöz való alkalmazkodás és így a túlélés fontos eleme - az alkalmazkodás vagy adaptáció. A központi idegrendszeri neuronok adaptációját a perceptuálisan megfigyelhető... more
Az élő rendszerek egyik alapvető tulajdonsága - mely a környezetükhöz való alkalmazkodás és így a túlélés fontos eleme - az alkalmazkodás vagy adaptáció. A központi idegrendszeri neuronok adaptációját a perceptuálisan megfigyelhető utóhatások megjelenése mutatja. Az utóbbi időkben az egyszerű vizuális ingerekhez való adaptációra kialakuló utóhatások mellett egyre többet vizsgálják a komplex alakokra, többek közt az emberi arcokra megfigyelhető utóhatásokat is. Tanulmányunkban ezeket az újonnan leírt utóhatásokat foglaljuk össze, különös tekintettel arra, hogyan vetítenek fényt ezek az eredmények az emberi agy tárgy- és arcreprezentációjára.
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Az emberi arcfelismerés neurális korrelátumait számos elektro- és pszichofizikai kísérlet keresi. Elektrofiziológiai vizsgálatok leírták, hogy az okcipito-temporális területek felől elvezethető egy nagy negatív hullám, mely latenciája... more
Az emberi arcfelismerés neurális korrelátumait számos elektro- és pszichofizikai kísérlet keresi. Elektrofiziológiai vizsgálatok leírták, hogy az okcipito-temporális területek felől elvezethető egy nagy negatív hullám, mely latenciája miatt az N170 nevet kapta. Számos tanulmány szerint az N170 speci_
Research Interests: Humanities and Art
Since its introduction in 1959 tolperisone hydrochloride (Mydeton) is still one of the leading products of Gedeon Richter Ltd. It has been successfully applied for treating different painful muscle spasms. The compound is successfully... more
Since its introduction in 1959 tolperisone hydrochloride (Mydeton) is still one of the leading products of Gedeon Richter Ltd. It has been successfully applied for treating different painful muscle spasms. The compound is successfully marketed also by several foreign, mostly Japanese, pharmaceutical companies, as a central muscle relaxant agent. The present summary overviews the pharmacology of tolperisone, with special emphasize on its still partly understood way of action. Data from the scientific literature as well as our own experimental results strongly support the hypothesis that inhibition of voltage gated sodium channels is a major component of the mechanism of action of tolperisone. The paper also summarizes the clinical results with tolperisone and the perspectives of the therapeutic use of centrally acting muscle relaxants.
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Congenital prosopagnosia (CP) is a life-long disorder of face perception. We investigated the neural bases of CP in three patients of a family (father, daughter and son), as well in healthy, age-matched controls, using combined... more
Congenital prosopagnosia (CP) is a life-long disorder of face perception. We investigated the neural bases of CP in three patients of a family (father, daughter and son), as well in healthy, age-matched controls, using combined neuropsychological, electrophysiological and functional magnetic resonance imaging (fMRI) methods. Neuropsychological tests demonstrated significant impairments of face perception/recognition in each patient. To reveal the impairments of the core face processing network we presented faces and nonsense objects in a block-design experiment to the patients and to a control group in the fMRI scanner. We found that the activity of the fusiform and occipital face areas (FFA, OFA) was reduced, when compared to controls, but remained category-selective. Analysis of the hemodynamic response function, however, revealed a significantly faster and stronger adaptation in all areas (FFA, OFA and the lateral occipital cortex) in the CP patients when compared to controls. Ou...
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Research Interests: Neuroscience, Chemistry, Chronic Pain, Neuropharmacology, Drug interactions, and 15 moreMedicine, Animals, Male, Antagonist, Frequency Dependence, Analysis of Variance, Benzoxazoles, Central Sensitization, Action Potentials, Neurosciences, Dorsal Horn, Glutamate Receptor, Excitatory Postsynaptic Potentials, Electric stimulation, and Nerve fibers
Windup, the frequency dependent build-up of spinal neuronal responses is an electrophysiological model of the development of the central sensitization in the chronic pain states. NR2B subunit containing NMDA-type glutamate receptors are... more
Windup, the frequency dependent build-up of spinal neuronal responses is an electrophysiological model of the development of the central sensitization in the chronic pain states. NR2B subunit containing NMDA-type glutamate receptors are implicated in the windup of dorsal horn neurons, while their role at the motoneuronal level is controversial. The cumulative motoneuronal depolarization in hemisected rat spinal cord preparation is
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Az utóbbi időben egyre több tanulmány születik a szaglás és a vizuális rendszer egymásra hatásáról. Kutatásunkban férfi nemi hormonszerű anyag (5-α-androgenst-16-en-3-one) szaglásának hatását vizsgáltuk egészséges heteroszexuális férfiak... more
Az utóbbi időben egyre több tanulmány születik a szaglás és a vizuális rendszer egymásra hatásáról. Kutatásunkban férfi nemi hormonszerű anyag (5-α-androgenst-16-en-3-one) szaglásának hatását vizsgáltuk egészséges heteroszexuális férfiak arcpercepciójára. Kísérleti paradigmánk kétalternatívás nemi diszkriminációs feladat volt, ahol a személyeknek a bemutatott vizuális ingerekről kellett eldönteniük, hogy női vagy férfi arcok voltak-e, miközben olfaktorosan férfi nemi hormonszerű anyagot, illetve kontrollként vizet mutattunk be nekik. Eredményeink szerint ugyanazon arcot férfi nemi hormonszerű anyag szaglása közben nagyobb valószínűséggel ítélték a kísérleti személyek férfinak, mint a kontroll esetben. A kapott hatás hasonló mértékben változtatta meg a férfi és női arcok nemi diszkriminációját. Eredményeink megerősítik azt a tényt, miszerint az arcok nemi diszkriminációját a szex hormonszerű anyagok szaglása a bemutatott arc nemétől függetlenül képes megváltoztatni, vagyis a kemoszen...
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Research Interests: Neuroscience, Psychology, Medicine, Color Perception, Brain Mapping, and 15 moreMacaca, Factor analysis, Population, Cerebral Cortex, Animals, Cluster Analysis, Neurons, Inferotemporal Cortex, Brain and cognitive sciences, Macaque, Neuronal Activity, Action Potentials, Macaque Monkey, Cell count, and photic stimulation
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Research Interests: Psychology, Cognitive Psychology, Perception, Decision Making, Plasticity, and 15 moreAdaptation, Face, Medicine, Face perception, Humans, Discrimination Learning, Female, Ambiguity, Male, Neuronal Plasticity, Adult, Analysis of Variance, photic stimulation, Psychology and Cognitive Sciences, and Medical and Health Sciences
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Research Interests: Psychology, Psychophysics, Psychometrics, Sex, Face, and 15 moreFacial expression, Medicine, Visual Processing, Vision, Humans, Form perception, Female, Face processing, Adult, Time Factors, Visual Evoked Potentials, photic stimulation, Psychology and Cognitive Sciences, Medical and Health Sciences, and Translation Invariant
It has been proposed that perceptual decision making involves a task-difficulty component, which detects perceptual uncertainty and guides allocation of attentional resources. It is thought to take place immediately after the early... more
It has been proposed that perceptual decision making involves a task-difficulty component, which detects perceptual uncertainty and guides allocation of attentional resources. It is thought to take place immediately after the early extraction of sensory information and is specifically reflected in a positive component of the event related potentials, peaking at ∼220 ms after stimulus onset. However, in the previous research, neural processes associated with the monitoring of overall task difficulty were confounded by those associated with the increased sensory processing demands as a result of adding noise to the stimuli. Here we dissociated the effect of phase noise on sensory processing and overall decision difficulty using a face gender categorization task. Task difficulty was manipulated either by adding noise to the stimuli or by adjusting the female/male characteristics of the face images. We found that it is the presence of noise and not the increased overall task difficulty ...
Research Interests: Neuroscience, Psychology, Perception, Decision Making, Magnetic Resonance Imaging, and 15 moreAttention, Electroencephalography, Categorization, Medicine, Brain Mapping, Humans, Noise, Female, Male, Oxygen, Adult, Analysis of Variance, Neuropsychological Tests, photic stimulation, and Medical and Health Sciences
Recently, there has been an increased interest on the neural mechanisms underlying perceptual decision making. However, the effect of neuronal adaptation in this context has not yet been studied. We begin our study by investigating how... more
Recently, there has been an increased interest on the neural mechanisms underlying perceptual decision making. However, the effect of neuronal adaptation in this context has not yet been studied. We begin our study by investigating how adaptation can bias perceptual decisions. We considered behavioral data from an experiment on high-level adaptation-related aftereffects in a perceptual decision task with ambiguous stimuli on humans. To understand the driving force behind the perceptual decision process, a biologically inspired cortical network model was used. Two theoretical scenarios arose for explaining the perceptual switch from the category of the adaptor stimulus to the opposite, nonadapted one. One is noise-driven transition due to the probabilistic spike times of neurons and the other is adaptation-driven transition due to afterhyperpolarization currents. With increasing levels of neural adaptation, the system shifts from a noise-driven to an adaptation-driven modus. The beha...