INTRODUCTION: Food is a vital human need, and the human visual system is finely tuned to detect and respond to food cues in the environment. The omnipresence of food cues across various settings has been linked to the prevalence of obesity in susceptible populations. However, the influence of the post-prandial state on visual attention to food stimuli remains poorly understood. This study aimed to elucidate how a 12 hour fast affects visual attention to food and non-food stimuli in healthy, non-obese individuals. METHODS: Visual attention was assessed by measuring the total duration of visual fixations on stimuli presented on a computer screen, using a screen-based eye tracker (Tobii X2-60). Participants were divided into two groups: those who had fasted for 12 hours and those tested within two hours after consuming breakfast (satiated state). Additionally, performance on the Food Stroop task and electrodermal activity (EDA) responses were measured to evaluate attentional interference and physiological arousal, respectively. Salivary samples were also collected to assess levels of alpha-amylase and cortisol. RESULTS: Fasted participants exhibited a progressive decline in visual attention toward food stimuli compared to satiated individuals, reflecting a satiated state. This effect was independent of the palatability of the depicted food items and was not observed with stimuli representing non-food items. The Food Stroop task revealed no differences between fasting and satiated participants, indicating that the presence of food-related stimuli does not differentially impact attentional interference under varying hunger states. Moreover, no significant variations were observed in EDA responses across participant groups and stimulus types, suggesting that the modulation of visual attention to food cues by hunger is independent of physiological arousal. Interestingly, satiated subjects exhibited higher levels of salivary alpha-amylase, which was inversely related to their subjective hunger ratings. No differences in salivary cortisol levels were found between groups. DISCUSSION: The findings indicate a novel influence of mild hunger on the processing of visual food cues, independent of physiological arousal. The decline in visual attention to food stimuli in fasted individuals suggests that satiety modulates visual processing. The lack of differences in attentional interference and physiological arousal between fasting and satiated states further supports the notion that visual attention to food cues is primarily driven by hunger-related mechanisms rather than stress. Additionally, the inverse relationship between salivary alpha-amylase levels and hunger ratings implies that alpha-amylase may serve as a marker of satiety rather than stress.

• Klíčová slova
• EDA, Food Stroop test, Visual Analog Scale, eye-tracking, hunger, salivary cortisol and alpha-amylase, satiety, visual food cues,
• Publikační typ
• časopisecké články MeSH

Escape enables prey to avoid an approaching predator. The escape decision-making process has traditionally been interpreted using theoretical models that consider ultimate explanations based on the cost/benefit paradigm. Ultimate approaches, however, suffer from inseparable extra-assumptions due to an inability to accurately parameterize the model's variables and their interactive relationships. In this study, we propose a mathematical model that uses intensity of predator-mediated visual stimuli as a basic cue for the escape response. We consider looming stimuli (i.e. expanding retinal image of the moving predator) as a cue to flight initiation distance (FID; distance at which escape begins) of incubating Mallards (Anas platyrhynchos). We then examine the relationship between FID, vegetation cover and directness of predator trajectory, and fit the resultant model to experimental data. As predicted by the model, vegetation concealment and directness of predator trajectory interact, with FID decreasing with increased concealment during a direct approach toward prey, but not during a tangential approach. Thus, we show that a simple proximate expectation, which involves only visual processing of a moving predator, may explain interactive effects of environmental and predator-induced variables on an escape response. We assume that our proximate approach, which offers a plausible and parsimonious explanation for variation in FID, may serve as an evolutionary background for traditional, ultimate explanations and should be incorporated into interpretation of escape behavior.

• MeSH
• biologická evoluce * MeSH
• kachny fyziologie   MeSH
• podněty MeSH
• pozorování MeSH
• predátorské chování fyziologie   MeSH
• prostorové chování fyziologie   MeSH
• rozhodování fyziologie   MeSH
• teoretické modely * MeSH
• úniková reakce fyziologie   MeSH
• životní prostředí MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Seeing a person's mouth move for [ga] while hearing [ba] often results in the perception of "da." Such audiovisual integration of speech cues, known as the McGurk effect, is stable within but variable across individuals. When the visual or auditory cues are degraded, due to signal distortion or the perceiver's sensory impairment, reliance on cues via the impoverished modality decreases. This study tested whether cue-reliance adjustments due to exposure to reduced cue availability are persistent and transfer to subsequent perception of speech with all cues fully available. A McGurk experiment was administered at the beginning and after a month of mandatory face-mask wearing (enforced in Czechia during the 2020 pandemic). Responses to audio-visually incongruent stimuli were analyzed from 292 persons (ages 16-55), representing a cross-sectional sample, and 41 students (ages 19-27), representing a longitudinal sample. The extent to which the participants relied exclusively on visual cues was affected by testing time in interaction with age. After a month of reduced access to lipreading, reliance on visual cues (present at test) somewhat lowered for younger and increased for older persons. This implies that adults adapt their speech perception faculty to an altered environmental availability of multimodal cues, and that younger adults do so more efficiently. This finding demonstrates that besides sensory impairment or signal noise, which reduce cue availability and thus affect audio-visual cue reliance, having experienced a change in environmental conditions can modulate the perceiver's (otherwise relatively stable) general bias towards different modalities during speech communication.

• Klíčová slova
• Audiovisual integration, Cognitive adaptation, Cue reweighting, Speech perception,
• MeSH
• COVID-19 prevence a kontrola   MeSH
• dospělí MeSH
• fyziologická adaptace fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• masky * MeSH
• mladiství MeSH
• mladý dospělý MeSH
• odezírání * MeSH
• percepce řeči fyziologie   MeSH
• podněty * MeSH
• rozpoznání obličeje fyziologie   MeSH
• věkové faktory MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články 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

Laboratory and field studies have demonstrated that exposure to cues of intentional agents in the form of eyes can increase prosocial behavior. However, previous research mostly used 2-dimensional depictions as experimental stimuli. Thus far no study has examined the influence of the spatial properties of agency cues on this prosocial effect. To investigate the role of dimensionality of agency cues on fairness, 345 participants engaged in a decision-making task in a naturalistic setting. The experimental treatment included a 3-dimensional pseudo-realistic model of a human head and a 2-dimensional picture of the same object. The control stimuli consisted of a real plant and its 2-D image. Our results partly support the findings of previous studies that cues of intentional agents increase prosocial behavior. However, this effect was only found for the 3-D cues, suggesting that dimensionality is a critical variable in triggering these effects in a real-world settings. Our research sheds light on a hitherto unexplored aspect of the effects of environmental cues and their morphological properties on decision-making.

• MeSH
• lidé MeSH
• podněty MeSH
• rozhodování MeSH
• sociální chování MeSH
• sociální spravedlnost psychologie   MeSH
• světelná stimulace MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The active place avoidance task is used in the research of spatial cognition. Rats are trained on a rotating arena to avoid an aversive stimulus delivered in a part of the room while being transported toward it by the arena rotation. The task tests the ability of rats to navigate with respect to distal cues in the room and to ignore confusing cues on the arena. The demand for cue segregation makes the task suitable for studying neural mechanisms responsible for cognitive coordination. An incidental observation made in our laboratory implied that overtrained rats may be able to solve the task without the room-bound cues. The aim of this study was to test this observation. The room-bound cues were hidden by switching off the lights. Rats trained only in darkness did not learn the task at all. Rats that were initially pre-trained in light performed considerably better. In a few exceptional dark sessions they even reached the level of performance observed in light. The rats needed the aversive stimuli to keep off the to-be-avoided sector. Without them, they continued their behavior, but with no spatial relationship to the to-be-avoided sector. We conclude that rats are able to solve the place avoidance task without the room-bound cues, but not as efficiently as in their presence.

• Klíčová slova
• Avoidance behavior, Cognitive coordination, Idiothetic navigation, Spatial behavior,
• MeSH
• elektrický šok MeSH
• plnění a analýza úkolů MeSH
• podněty * MeSH
• potkani Long-Evans MeSH
• prostorové učení * MeSH
• psychologické testy MeSH
• tma MeSH
• učení vyhýbat se * MeSH
• zraková percepce MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Ground-nesting birds face many challenges to reproduce successfully, with nest predation being the main cause of reproductive failure. Visual predators such as corvids and egg-eating raptors, are among the most common causes of nest failure; thus, parental strategies that reduce the risk of visual nest predation should be favored by selection. To date, most research has focused on egg crypsis without considering adult crypsis, although in natural circumstances the eggs are covered by an incubating parent most of the time. Here we use a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus) as model species to experimentally test whether decoy parents influence nest predation. Using artificial nests with a male decoy, a female decoy or no decoy, we found that the presence of a decoy increased nest predation (N = 107 nests, p < 0.001). However, no difference was found in predation rates between nests with a male versus female decoy (p > 0.05). Additionally, we found that nests in densely vegetated habitats experienced higher survival compared to nests placed in sparsely vegetated habitats. Nest camera images, predator tracks and marks left on eggs identified the brown-necked raven (Corvus ruficollis) as the main visual nest predator. Our study suggests that the presence of incubating parents may enhance nest detectability to visual predators. However, parents may reduce the predation risk by placing a nest in sites where they are covered by vegetation. Our findings highlight the importance of nest site selection not only regarding egg crypsis but also considering incubating adult camouflage.

• MeSH
• ekosystém MeSH
• hnízdění fyziologie   MeSH
• hustota populace MeSH
• ovum fyziologie   MeSH
• predátorské chování fyziologie   MeSH
• pryskyřičné cementy chemie   MeSH
• ptáci fyziologie   MeSH
• rozmnožování fyziologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Crypsis dual-cure adhesive MeSH Prohlížeč
• pryskyřičné cementy MeSH

Multisensory stimuli provide organisms with information to assess the threat present in the surroundings. Olfactory cues show dominance over other sensory modalities in the aquatic environment. The impact of chemical predator cues combined with experiences gained (learning) in species without previous contact is not fully understood. We investigated the foraging and shelter-seeking behaviour of naïve and experienced marbled crayfish Procambarus virginalis juveniles in response to the chemical signals of pumpkinseed Lepomis gibbosus alone and in combination with alarm chemicals produced by preyed-upon conspecifics. Naïve and experienced (previously exposed to pumpkinseed predation) juveniles were stocked in an arena with shelter and feed and exposed (1) to water from a tank containing a predator actively feeding on conspecifics, (2) water from a tank with predator only and (3) water only as control. Crayfish exposed to the combined stimuli avoided the inlet zone and gravitated to shelter zone of the arena to a greater extent than did those exposed to predator-only cues and the control. Regardless of the treatment, experienced crayfish showed significantly reduced interest in feeding. Our findings imply that crayfish response to threat-associated odours with the greatest potency when visual or tactile cues are present, while previous encounters with predators may make them more cautious.

• Klíčová slova
• alarm cues, crayfish, fish, infochemicals, kairomones, predation,
• 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

We have studied the visual system of subterranean mole-rats of the rodent family Bathyergidae, for which light and vision seem of little importance. The eye diameter varies between 3.5mm in Bathyergus suillus and 1.3mm in Heterocephalus glaber. The small superficial eyes have features typical of sighted animals (clear optics, well-developed pupil and well-organized retina) and appear suited for proper image formation. The retinae are rod-dominated but possess rather high cone proportions of about 10%. The total number of retinal ganglion cells and optic nerve fibres ranges between 6000 in Bathyergus suillus and 2100 in Heliophobius argenteocinereus. Visual acuity (estimated from counts of peak ganglion cell density and axial length of the eye) is low, ranging between 0.3 and 0.5 cycles/degree. The retina projects to all the visual structures described in surface-dwelling sighted rodents. The suprachiasmatic nucleus is large and receives bilateral retinal input. All other visual nuclei are reduced in size and receive almost exclusively contralateral retinal projections of varying magnitude. The primary visual cortex is small and, in comparison to other rodents, displaced laterally. In conclusion, the African mole-rats possess relatively well-developed functional visual subsystems involved in photoperiodicity, form and brightness discrimination. In contrast, visual subsystems involved in coordination of visuomotor reflexes are severely reduced. This pattern suggests the retention of basic visual capabilities. Residual vision may enable subterranean mammals to localize breaches in the burrows that let in light thus providing a cue to enable mole-rats to reseal such entry points and to prevent entry of predators.

• MeSH
• colliculus superior anatomie a histologie   MeSH
• jádra thalamu MeSH
• metathalamus MeSH
• mikroftalmičtí podzemní hlodavci MeSH
• nucleus suprachiasmaticus MeSH
• retina anatomie a histologie   MeSH
• zrakové dráhy anatomie a histologie   MeSH
• zrakové korové centrum anatomie a histologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH