Visual attention modulates the firing rate of neurons in many primate cortical areas. In V4, a cortical area in the ventral visual pathway, spatial attention has also been shown to reduce the tendency of neurons to fire closely separated spikes (burstiness). A recent model proposes that a single mechanism accounts for both the firing rate enhancement and the burstiness reduction in V4, but this has not been empirically tested. It is also unclear if the burstiness reduction by spatial attention is found in other visual areas and for other attentional types. We therefore recorded from single neurons in the medial superior temporal area (MST), a key motion-processing area along the dorsal visual pathway, of two rhesus monkeys while they performed a task engaging both spatial and feature-based attention. We show that in MST, spatial attention is associated with a clear reduction in burstiness that is independent of the concurrent enhancement of firing rate. In contrast, feature-based attention enhances firing rate but is not associated with a significant reduction in burstiness. These results establish burstiness reduction as a widespread effect of spatial attention. They also suggest that in contrast to the recently proposed model, the effects of spatial attention on burstiness and firing rate emerge from different mechanisms.

• Klíčová slova
• attention, burstiness, monkey neurophysiology, visual cortex,
• MeSH
• biologické hodiny fyziologie   MeSH
• Macaca mulatta MeSH
• mozkové vlny fyziologie   MeSH
• nervová síť fyziologie   MeSH
• pozornost fyziologie   MeSH
• vnímání prostoru fyziologie   MeSH
• zraková pole fyziologie   MeSH
• zrakové korové centrum fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In a complex choice reaction time experiment, patterned stimuli without luminance change were presented, and pattern-specific visual evoked potentials to lower half-field stimulation were recorded. Two experimental conditions were used. The first was the between-field selection, where square patterns were presented in either the lower or the upper half of the visual field. In a given stimulus run one of the half-fields was task-relevant, and the subjects' task was to press a microswitch to stimuli of higher duration value (GO stimuli), while they had to ignore shorter ones, i. e. stimuli of lower apparent spatial contrast (NOGO stimuli). They had to ignore the stimuli appearing in the irrelevant half-field (IRR stimuli). In order to ensure proper fixation, the subjects had to press another microswitch at the onset of a dim light at the fixation point (CRT stimuli). Our second experimental condition was the within-field selection, where the GO, NOGO, and IRR stimuli appeared in the lower half of the visual field. GO and NOGO were square patterns while IRR stimuli were constructed of circles, or vice versa. (The CRT stimuli were the same as in the previous condition.) Three pattern-specific visual evoked potential components were identified, i. e. CI (70 ms latency), CII (100 ms latency), and CIII (170 ms latency). There were marked selective attention effects on both the CI-CII and CII-CIII peak-to-peak amplitudes. In both experimental conditions, responses with the highest amplitude were evoked by the GO type of stimuli, while the IRR stimuli evoked the smallest responses. According to these results, attention effects on the pattern-specific visual evoked potentials in the first 200 ms cannot be attributed to a simple stimulus set kind of selection.

• MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• pozornost fyziologie   MeSH
• reakční čas MeSH
• rozpoznávání obrazu fyziologie   MeSH
• zraková pole MeSH
• zrakové evokované potenciály * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

A preliminary report is given concerning phasic heart rate responses in hypertensive individuals. There is some evidence, that the expected accelerative drive appears under visual attention conditions. That is demonstrated in two typical reactions of a hypertensive and a normotensive subject and in a marked higher acceleration at several points of the response curves for the hypertensive group. Z-scores of heart periods are discussed as the appropriate measurement of phasic HR-changes from rest to stimulus conditions.

• MeSH
• dospělí MeSH
• hypertenze patofyziologie   psychologie   MeSH
• lidé MeSH
• pozornost fyziologie   MeSH
• srdeční frekvence * MeSH
• zraková percepce fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Existing research indicates that the shape of various facial regions is linked to perceived attractiveness and perceived formidability. Interestingly, little evidence shows that people directly focus on these specific facial regions during judgments of attractiveness and formidability, and there is little support for the notion that the levels of attractiveness and formidability affect raters' visual attention. We employed eye-tracking to examine visual attention (the number of fixations and dwell time) in 40 women and 37 men, while they assessed 45 male faces in life-sized photographs for attractiveness and formidability. The facial photographs were grouped by varying levels of attractiveness and formidability (low, medium, and high). Our results showed that regardless of the characteristics rated, both men and women paid the most visual attention to the eyes, nose, mouth, and forehead regions. We found statistically discernible variation in visual attention in relation to the rater's sex or target's attractiveness levels for other facial features (the chin, cheeks, or ears), but these differences may not be substantial enough to have practical implications. We suggest that the eyes, the nose, and the mouth regions play a central role in the evolution of face perception as regions most salient to the acquisition of informative cues about others. Further, during both attractiveness and formidability judgments, men looked longer at the stimuli than women did, which may hint at increased difficulty of this task for men, possibly because they compare themselves with the stimuli. Additionally, irrespective of sex, raters looked marginally longer at faces with a medium level of formidability than at those with a high formidability level, which may reflect ambiguity of these stimuli and uncertainty regarding assessment. We found no other significantly relationships between the target's attractiveness and formidability levels and the rater's visual attention to whole faces.

• Klíčová slova
• Attractiveness, Eye-tracking, Formidability, Intersexual selection, Intrasexual selection,
• MeSH
• dospělí MeSH
• krása MeSH
• lidé MeSH
• mínění MeSH
• mladý dospělý MeSH
• obličej * MeSH
• pozornost * fyziologie   MeSH
• rozpoznání obličeje fyziologie   MeSH
• technologie sledování pohybu očí MeSH
• výběrové chování fyziologie   MeSH
• zraková percepce fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Throughout human evolutionary history, snakes have been associated with danger and threat. Research has shown that snakes are prioritized by our attentional system, despite many of us rarely encountering them in our daily lives. We conducted two high-powered, pre-registered experiments (total N = 224) manipulating target prevalence to understand this heightened prioritization of threatening targets. Target prevalence refers to the proportion of trials wherein a target is presented; reductions in prevalence consistently reduce the likelihood that targets will be found. We reasoned that snake targets in visual search should experience weaker effects of low target prevalence compared to non-threatening targets (rabbits) because they should be prioritized by searchers despite appearing rarely. In both experiments, we found evidence of classic prevalence effects but (contrasting prior work) we also found that search for threatening targets was slower and less accurate than for nonthreatening targets. This surprising result is possibly due to methodological issues common in prior studies, including comparatively smaller sample sizes, fewer trials, and a tendency to exclusively examine conditions of relatively high prevalence. Our findings call into question accounts of threat prioritization and suggest that prior attention findings may be constrained to a narrow range of circumstances.

• Klíčová slova
• Affective feature, Negative valence, Snake, Threat detection, Visual feature, Visual search,
• MeSH
• biologická evoluce MeSH
• hadi MeSH
• králíci MeSH
• Lagomorpha * MeSH
• lidé MeSH
• pozornost MeSH
• reakční čas MeSH
• strach * MeSH
• zraková percepce MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Previous research on cross-cultural differences in visual attention has been inconclusive. Some studies have suggested the existence of systematic differences in global and local attention and context sensitivity, while others have produced negative or mixed results. The objective in this study was to examine the similarities and differences in holistic and analytic cognitive styles in a sample of Czech and Taiwanese university students. Two cognitive tasks were conducted: a Compound Figures Test and a free-viewing scene perception task which manipulated several focal objects and measured eye-movement patterns. An analysis of the reaction times in the Compound Figures Test showed no clear differences between either sample. An analysis of eye-movement metrics showed certain differences between the samples. While Czechs tended to focus relatively more on the focal objects measured by the number of fixations, the Taiwanese subjects spent more time fixating on the background. The results were consistent for scenes with one or two focal objects. The results of a correlation analysis of both tasks showed that they were unrelated. These results showed certain differences between the samples in visual perception but were not as systematic as the theory of holistic and analytic cognitive styles would suggest. An alternative model of cross-cultural differences in cognition and perception is discussed.

• MeSH
• Asijci MeSH
• běloši MeSH
• kognice fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• oční fixace fyziologie   MeSH
• pohyby očí fyziologie   MeSH
• pozornost fyziologie   MeSH
• reakční čas fyziologie   MeSH
• srovnání kultur MeSH
• studenti MeSH
• univerzity MeSH
• zrak fyziologie   MeSH
• zraková percepce fyziologie   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Taiwan MeSH

The present research was motivated by the routine digital media practice of producing page layouts as composite images that include several unrelated pictures. We investigated whether or how visually highlighting affective and positional components of pictures in a viewer's field of vision might influence viewer perception and evaluation of the composite image. We examined combinations of visual, spatial, and affective features of cues in composite images to learn whether they affected the viewer's attentional capture of other affective information in the composite image and viewer's affective evaluations. The manipulation check of the feature combinations (positive/negative affect, presence/absence of highlighted color, central/peripheral position) showed significant effects of these features and their interactions on viewers' eye movements. On the other hand, we observed only a small effect on viewers' affective evaluations. Our results suggested that media page layout designers might manipulate the viewer's attention by visual and positional adjustments of affective components in composite images. Future researchers might use this study's design to better understand the human perception of real media images.

• Klíčová slova
• affective evaluation, eye tracking, media design, viewer perceptions, visual attention,
• MeSH
• afekt fyziologie   MeSH
• arousal fyziologie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• podněty * MeSH
• pohyby očí fyziologie   MeSH
• pozornost fyziologie   MeSH
• světelná stimulace MeSH
• učení fyziologie   MeSH
• zraková percepce fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

UNLABELLED: Single cases may lead to unexpected hypotheses in psychology. We retrospectively analyzed single case studies that suggested organizational principles along the early visual pathway, which have remained unanswered until now. FIRST CASE: In spite of the inhomogeneity of sensitivity, paradoxically the visual field on the subjective level appears to be homogeneous; constancy of brightness of supra-threshold stimuli throughout the visual field is claimed to be responsible for homogeneity; specific summation properties of retinal ganglion cells are hypothesized to guarantee this effect. SECOND CASE: With a brain-injured patient having suffered a partial visual field loss it can be shown that color induction is a retinal phenomenon; lateral inhibitory processes at the level of amacrine cells are hypothesized as neural network. Third case: In a patient having suffered a bilateral occipital lobe infarction, some functional recovery has been demonstrated; divergence and convergence of projection in the ascending neural pathway are suggested as a structural basis for recovery. Slowed down binocular rivalry discloses a sequential mechanism in the construction of a visual percept. Fourth case: The pre-wired projection of the retina to the visual cortex in spite of a severe squint of one eye is confirmed, but paradoxically some local neuroplasticity is also suggested. Fifth case: Using habituation of local sensitivity in the visual field and its resetting by interhemispheric interactions as an experimental paradigm, it is suggested that spatial attention is controlled at the midbrain level. Sixth case: Observations on residual vision or "blindsight" support the hypothesis that the visual cortex is the one and only structure responsible for visual perception on a conscious level. The unifying principle of these retrospective analyses is that subjective visual phenomena can lead to unexpected but testable hypotheses of neural processing on the structural and functional level in the early visual pathway.

• Klíčová slova
• attentional control, binocular rivalry, blindsight, brightness perception, color perception, consciousness, eccentricity effect, habituation, neuroplasticity, restitution of function,
• MeSH
• lidé MeSH
• metathalamus fyziologie   MeSH
• mozkový infarkt patofyziologie   MeSH
• poranění mozku patofyziologie   MeSH
• pozornost fyziologie   MeSH
• retina fyziologie   MeSH
• retrospektivní studie MeSH
• slepota patofyziologie   MeSH
• světelná stimulace MeSH
• vnímání barev MeSH
• zraková pole * MeSH
• zrakové dráhy fyziologie   MeSH
• zrakové korové centrum fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

• MeSH
• časové faktory MeSH
• fyziologický stres MeSH
• krátkodobá paměť MeSH
• lidé MeSH
• percepce * MeSH
• pozornost * MeSH
• zraková percepce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Event related potentials (ERPs) provide an insight into sensory and cognitive processes in health and disease. Studies of an ERP negative amplitude deflection elicited by a change in a series of auditory stimuli is known as mismatch negativity (MMN). The generation of MMN is impaired in schizophrenia. Its deficit is associated with lower everyday functioning and may be also interpreted as the marker of progression in schizophrenia. MMN elicited by visual stimuli (vMMN) was described by several research teams, but it has not been investigated in schizophrenia as yet. Using a motion-direction paradigm, we elicited visual MMN in 24 patients with schizophrenia and schizoaffective disorder. The vMMN was computed as differences in areas under curve of visual ERPs to standard and deviant motion-direction stimuli recorded from midline derivations at the interval of 100-200 ms. They were compared between groups of patients with schizophrenia and healthy controls. The significantly smaller vMMN indicated an impaired generation of mismatch negativity in patients with schizophrenia. In secondary analyses there was an association of vMMN impairment among patients with higher dose of medication, lower level of functioning and the presence of deficit syndrome. This impairment appears analogous to the impairment of MMN in the auditory domain and is probably related to early visual information processing. Its relationship to cognitive functioning of patients with schizophrenia deserves further attention.

• MeSH
• dospělí MeSH
• elektroencefalografie statistika a číselné údaje   MeSH
• funkční lateralita fyziologie   MeSH
• kognitivní poruchy diagnóza   patofyziologie   MeSH
• kontrolní skupiny MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozek fyziologie   MeSH
• neuropsychologické testy MeSH
• paměť fyziologie   MeSH
• plocha pod křivkou MeSH
• pozornost fyziologie   MeSH
• průřezové studie MeSH
• psychotické poruchy diagnóza   patofyziologie   MeSH
• reakční čas fyziologie   MeSH
• schizofrenie (psychologie) MeSH
• schizofrenie diagnóza   patofyziologie   MeSH
• světelná stimulace metody   MeSH
• vnímání pohybu fyziologie   MeSH
• zraková percepce fyziologie   MeSH
• zrakové dráhy fyziologie   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH