ABSTRACTHumans are social beings that often interact in multi-individual environments. As such, we are frequently confronted with nonverbal social signals, including eye-gaze direction, from multiple individuals. Yet, the factors that allow for the prioritisation of certain gaze cues over others are poorly understood. Using a modified conflicting gaze paradigm, we tested the hypothesis that fearful gaze would be favoured amongst competing gaze cues. We further hypothesised that this effect is related to the increased sclera exposure, which is characteristic (...) of fearful expressions. Across three experiments, we found that fearful, but not happy, gaze guides observers’ attention over competing non-emotional gaze. The guidance of attention by fearful gaze appears to be linked to increased sclera exposure. However, differences in sclera exposure do not prioritise competing gazes of other types. Thus, fearful gaze guides attention among competing cues and this effect is facilitated by increased sclera exposure... (shrink)

The phenomenon of size constancy is defined as the apparent perceptual invariance of the linear dimensions of a seen object as this approaches the eye or recedes from it. It has been interpreted as resulting from the application by the brain of a size correction, made possible by the subject's apprehension of distance cues present in the image. We present several observations which, by dissociating accommodation from distance of the seen object and by suppressing the optic effects (...) of accommodation on the visual image itself, show that this interpretation is incorrect, and that in fact the size correction of the visual image is a function of the central effort of accommodation, not of the distance of the seen object. (shrink)

Our ability to rapidly distinguish new from already stored information is important for behavior and decision making, but the underlying processes remain unclear. Here, we tested the hypothesis that contextual cues lead to a preselection of information and, therefore, faster recognition. Specifically, on the basis of previous modeling work, we hypothesized that recognition time depends on the amount of relevant content stored in long-term memory, i.e., set size, and we explored possible age-related changes of this relationship in older (...) humans. In our paradigm, subjects learned by heart four different word lists written in different colors. On the day of testing, a color cue indicated with a probability of 50% that a subsequent word might be from the corresponding list or from a list of new words. The old/new status of the word had to be distinguished via button press. As a main finding, we can show in a sample of n = 49 subjects, including 26 younger and 23 older humans, that response times increased linearly and logarithmically as a function of set size in both age groups. Conversely, corrected hit rates decreased as a function of set size with no statistically significant differences between both age groups. As such, our findings provide empirical evidence that contextual information can lead to a preselection of relevant information stored in long-term memory to promote efficient recognition, possibly by cyclical top-down and bottom-up processing. (shrink)

ABSTRACTRemembering to perform a behaviour in the future, prospective memory, is essential to ensuring that people fulfil their intentions. Prospective memory involves committing to memory a cue to action, and later recognising and acting upon the cue in the environment. Prospective memory performance is believed to be influenced by the emotionality of the cues, however the literature is fragmented and inconsistent. We conducted a systematic search to synthesise research on the influence of emotion on prospective memory. Sixty-seven effect sizes (...) were extracted from 17 articles and hypothesised effects tested using three meta-analyses. Overall, prospective memory was enhanced when positively-valenced rather than neutral cues were presented. In contrast, negatively-valenced cues did not enhance prospective memory overall, but this effect was moderated by the timing of the emotional manipulation. Prospective memory performance was improved when negatively-valenced... (shrink)

The current study assessed potential relationships among childhood wayfinding experience, navigational style, and adult wayfinding anxiety in the Faroe Islands. The Faroe Islands are of interest because they have an unusual geography that may promote the use of an orientational style of navigation (e.g., use of cardinal directions). Faroese adults completed questionnaires assessing (1) their permitted childhood range sizes, (2) the types of navigational strategies they use, and (3) the amount of anxiety they experience when navigating in adulthood. Males had (...) more childhood wayfinding experience, used the orientation strategy at a higher rate, and showed lower levels of wayfinding anxiety. When compared with other cultures, both Faroese women and men appear to embrace orientation strategies at an unusually high rate. Childhood experience was not conclusively linked to later wayfinding anxiety. However, the current findings raise the possibility that children who have particularly small ranges in childhood may be especially anxious when navigating in adulthood. (shrink)

Asif A. Ghazanfar,1,3,* Hjalmar K. Turesson,1,3 statistical pattern recognition [16, 17] and psychophys- Joost X. Maier,1 Ralph van Dinther,2 ics [13, 18–23] have suggested that formants are signif- Roy D. Patterson,2 and Nikos K. Logothetis1 icant contributors to these indexical cues. It is likely, 1Max Planck Institute for Biological Cybernetics then, that detecting formants could have provided 72076 Tuebingen ancestral primates with indexical cues necessary for Germany navigating the complex social interactions that are the 2Centre for the Neural (...) Basis of Hearing essence of primate societies. One important indexical Department of Physiology cue is body size. Formant cues related to body size University of Cambridge could be used by monkeys to determine the sex (in sex- CB2 3EG Cambridge ually dimorphic species), degree of potential threat (e.g., United Kingdom whether a competitor is larger or smaller), and/or age of an individual, as such cues do for human listeners [13, 18, 20, 21]. Summary Formants are the result of acoustic filtering by the supralaryngeal vocal tract—the nasal and oral cavities Vocal-tract resonances (or formants) are acoustic sigabove the vocal folds. During vocal production, pulses natures in the voice and are related to the shape and of air generated by the rapid movement of the vocal length of the vocal tract. Formants play an important folds produce an acoustic signal. The frequency of these role in human communication, helping us not only to pulses—the glottal-pulse rate—determines the fundadistinguish several different speech sounds [1], but mental frequency of the signal, which in turn is perceived also to extract important information related to the as pitch. As the signal passes through the supralaryngphysical characteristics of the speaker, so-called ineal vocal tract, it excites resonances, resulting in the dexical cues. How did formants come to play such an enhancement of particular frequency bands; these are important role in human vocal communication? One the formants.. (shrink)

Cue labels are useful during multimedia learning. According to spatial contiguity principle, people learn more when related words and pictures are displayed spatially near one another. Well-arranged labels of multimedia material can greatly facilitate learning. This study used eye tracking to examine the joint influence of label size and color on multimedia learning. The results revealed that larger labels led to better retention test performance and a higher AOI glance count, but no cueing effect was found for color. (...) class='Hi'>Cues have a certain attention-leading function that promotes the learner remembering the content. These findings suggest that salient labels that provide explanatory information can guide learners’ attention and facilitate learning, though a combination of label size and color salience did not demonstrate a superior cueing effect. (shrink)

Recently, there has been a growing interest in the effect of perceptual features of learning materials on adults’ memory and metamemory. Previous studies consistently have found that adults use font size as a cue when monitoring their learning, judging that they will remember large font size words better than small font size words. Most studies have not demonstrated a significant effect of font size on adults’ memory, but a recent meta-analysis of these studies revealed a subtle (...) memory advantage for large font words. The current study extended this investigation to elementary school children. First and fifth–sixth graders studied words for a free recall test presented in either large or small font and made judgments of learning (JOLs) for each word. As did adults, children predicted they would remember large font size words better than small font size words and, in fact, actually remembered the large font size words better. No differences were observed between the two age groups in the effect of font size on memory or metamemory. These results suggest that the use of font size as a cue when monitoring one’s own learning is robust across the life span and, further, that this cue has at least some validity. (shrink)

Expansive body posture is the most commonly studied and widely described in psychological literature. For many years, expansive posture was universally identified as a pose of power, but more recent research has revealed that the link between expansive posture and power may be moderated by gender, culture or even contextual cues. Our findings show that with little variation added to expansive posture it does not necessarily lead to the sense of power, and may actually trigger the opposite effect: a (...) feeling of submissiveness. In three studies, persons assuming their body in a standing-at-attention posture were perceived as being more obedient, thus participants who expanded their body in a standing-at-attention manner displayed greater compliance to requests and declared greater submissiveness toward social norms. We discuss how the cultural and interpersonal context imprinted in specific body posture can modify the feedback of innate and universal body states. (shrink)

Previous research found that application of eyeshadow on the upper eyelids induces overestimation of eye size. The present study examined whether this eyeshadow illusion is dependent on or independent of viewpoint. We created a three-dimensional model of a female face and manipulated the presence/absence of eyeshadow and face orientation around the axis of yaw (Experiment 1) or pitch (Experiment 2) rotation. Using the staircase method, we measured perceived eye size for each face stimulus. Results showed that the eyeshadow (...) illusion occurred regardless of face orientation around axes of both yaw and pitch rotations. Crucially, the illusion’s magnitude did not vary across face orientations; lack of interaction between the illusion’s magnitude and face orientation was confirmed by small values of Bayes factors. These findings ruled out the hypothesis that eyeshadow serves as a depth cue and leads to overestimation of eye size due to size-distance scaling. Alternatively, the present findings suggest that the eyeshadow illusion can be well explained by the assimilation between the eyes and eyeshadow, which also facilitates assimilation between the eyes and eyebrows. Practical implications and the present findings’ generalizability are also discussed. (shrink)

The much larger appearance of the moon near horizon than the perceived size of the moon at zenith has motivated many scientists to develop theories that aim at explaining this puzzling phenomenon. Considering that the size of retinal images of the moon in these positions are very similar, the explanation of difference in their apparent sizes has relied on perceptual cues of distance embedded in the retinal image of their respective contexts. Although this account of the moon (...) illusion is quite popular, it does not explain all aspects of this phenomenon. The theoretical formulation of the moon illusion based on other factors such as size contrast later may have had some advantages but has also created some new problems. Although the moon is perceived in a three-dimensional (3D) environment, the present analysis proposes that an explanation of the moon illusion based on two-dimensional (2D) cues can remove some of the unnecessary problems. The empty space and size contrast that have already been considered in explaining classic geometric-optical illusions play a parallel role in explaining the moon illusion. In other words, the role of open space in interaction with the image of the moon and different objects near horizon, all reflected on the retina, are considered as the main explaining factors. The advantages of this approach will be discussed and some of the facts pertaining to the moon illusion will be explained within this theoretical framework. (shrink)

Humans have undergone a long evolutionary history of violent agonistic exchanges, which would have placed selective pressures on greater body size and the psychophysical systems that detect them. The present work showed that greater body size in humans predicted increased knockout power during combative contests (Study 1a-1b: total N = 5,866; Study 2: N = 44 openweight fights). In agonistic exchanges reflective of ancestral size asymmetries, heavier combatants were 200% more likely to win against their lighter counterparts (...) because they were 200% more likely to knock them out (Study 2). Human dominance judgments (total N = 500 MTurkers) accurately tracked the frequency with which men (N = 516) knocked out similar-sized adversaries (Study 3). Humans were able to directly perceive a man’s knockout power because they were attending to cues of a man’s body size. Human dominance judgments—which are important across numerous psychological domains, including attractiveness, leadership, and legal decision-making—accurately predict the likelihood with which a potential mate, ally, or rival can incapacitate their adversaries. (shrink)

Perceived size is a function of viewing distance, retinal images size, and various contextual cues such as linear perspective and the size and location of neighboring objects. Recently, we demonstrated that illusion magnitudes of classic visual size illusions may be greatly enhanced or reduced by adding dynamic elements. Specifically, a dynamic version of the Ebbinghaus illusion (classically considered a “size contrast” illusion) led to a greatly enhanced illusory effect, whereas a dynamic version of the (...) Corridor illusion (a “size constancy” illusion) led to a greatly diminished illusory effect. Although these differences may arise from the different processes underlying these illusions (size contrast vs. size constancy), the dynamic variants we tested in our previous work also differed in the nature of the dynamic elements; specifically, whereas the Dynamic Ebbinghaus included a moving target and inducers that changed size and position, the Dynamic Corridor only included a moving target on a static background. Here, we explore further dynamic versions of the Ebbinghaus illusion and the Corridor and Ponzo illusions by separately manipulating three types of dynamic elements: target motion, context translation, and dynamic changes in context. Across five experiments examining 21 dynamic illusory configurations, adding target motion or a dynamically changing context separately resulted in little-to-no illusory effect. In contrast, the combination of target motion and a dynamically changing context led to a robust size illusion, consistent with an interactive effect. However, illusory effects that exceeded the matched classic, static illusory configuration were only observed for the dynamic versions of the Ebbinghaus illusion and the Revealed Ponzo illusions, in which the contextual elements changed size. We conclude that the combination of target motion and a dynamically changing context are necessary to produce dynamic size illusions, but that enhancement above and beyond static illusions may be largely specific to size contrast effects. Our results have important implications for the integration of motion signals, a ubiquitous environmental stimulus, in the perception of object size. (shrink)

A wide array of species throughout the animal kingdom has shown the ability to distinguish between quantities. Aside from being important for optimal foraging decisions, this ability seems to also be of great relevance in group-living animals as it allows them to inform their decisions regarding engagement in between-group conflicts based on the size of competing groups. However, it is often unclear whether these animals rely on numerical information alone to make these decisions or whether they employ other (...) class='Hi'>cues that may covary with the differences in quantity. In this study we used a touch screen paradigm to investigate the quantity discrimination abilities of two closely related group-living species, wolves and dogs, using a simultaneous visual presentation paradigm. Both species were able to successfully distinguish between stimuli of different quantities up to 32 items and ratios up to 0.80, and their results were in accordance with Weber's law (which predicts worse performances at higher ratios). However, our controls showed that both wolves and dogs may have used continuous, non-numerical cues, such as size and shape of the stimuli, in conjunction with the numerical information to solve this task. In line with this possibility, dogs' performance greatly exceeded that which they had shown in other numerical competence paradigms. We discuss the implications these results may have on these species' underlying biases and numerical capabilities, as well as how our paradigm may have affected the animals' ability to solve the task. (shrink)

The pupils of the eyes reflexively constrict in light and dilate in dark to optimize retinal illumination. Non-visual cognitive factors, like attention, arousal, decision-making, etc., also influence pupillary light response. During passive viewing, the eccentricity of a stimulus modulates the pupillary aperture size driven by spatially weighted corneal flux density, which is the product of luminance and the area of the stimulus. Whether the scope of attention also influences PLR remains unclear. In this study, we contrasted the pupil dynamics (...) between diffused and focused attentional conditions during decision-making, while the global CFD remained the same in the two conditions. A population of 20 healthy humans participated in a pair of forced choice tasks. They distributed attention to the peripheral decision cue in one task, and concentrated at the center in the other to select the target from four alternatives for gaze orientation. The location of this cue did not influence participants’ reaction time. However, the magnitude of constriction was significantly less in the task that warranted attention to be deployed at the center than on the periphery. We observed similar pupil dynamics when participants either elicited or canceled a saccadic eye movement, which ruled out pre-saccadic obligatory attentional orientation contributing to PLR. We further addressed how the location of attentional deployment might have influenced PLR. We simulated a biomechanical model of PLR with visual stimulation of different strengths as inputs corresponding to the two attentional conditions. In this homeomorphic model, the computational characteristic of each element was derived from the physiological and/or mechanical properties of the corresponding biological element. The simulation of this model successfully mimicked the observed data. In contrast to common belief that the global ambient luminosity drives pupillary response, the results of our study suggest that the effective CFD determined via the luminance multiplied by the size of the stimulus at the location of deployed attention in the visual space is critical for the magnitude of pupillary constriction. (shrink)

Findings suggest a positive impact of bilingualism on cognition, including the later onset of dementia. However, it is not clear to what extent these effects are influenced by variations in attentional control demands in response to specific task requirements. In this study, 20 bilingual and 20 monolingual older adults performed a task-switching task under explicit task-cuing vs. memory-based switching conditions. In the cued condition, task switches occurred in random order and a visual cue signaled the next task to be performed. (...) In the memory-based condition, the task alternated after every second trial in a predictable sequence without presenting a cue. The performance of bilinguals did not vary across experimental conditions, whereas monolinguals experienced a pronounced increase in response latencies and error rates in the cued condition. Both groups produced similar switch costs and mixing costs, but bilinguals produced them with lower response latencies. The cognitive benefits of bilingualism seem not to apply to executive functions per se but to affect specific cognitive processes that involve task-relevant context processing. The present results suggest that lifelong bilingualism could promote in older adults a flexible adjustment to environmental cues, but only with increased task demands. However, due to the small sample size, the results should be interpreted with caution. (shrink)

ABSTRACTThe eyes reveal important social messages, such as emotions and whether a person is aroused and interested or bored and fatigued. A growing body of research has also shown that individuals with large pupils are generally evaluated positively by observers, while those with small pupils are perceived negatively. Here, we examined whether observed pupil size influences approach-avoidance tendencies. Participants performed an Approach-Avoidance Task using faces with large and small pupil sizes. Results showed that pupil size influences the accuracy (...) of arm movements. Specifically, individuals were less prone to approach a face with small pupils than a face with large pupils. Conversely, participants were less prone to avoid a face with large pupils than a face with small pupils. Collectively, these findings suggest that perceivers attend to a facial cue – pupil size – when interacting with others. (shrink)

Given the complexity of human social life, it is astonishing to observe how quickly children adapt to their social environment. To be accepted by the other members, it is crucial to understand and follow the rules and norms shared by the group. How and from whom do young children learn these social rules? In the experiments, based on the crucial role of affective social learning and dominance hierarchies in simple rule understanding, we showed 15-to-23-month-olds and 3-to-5-year-old children videos where the (...) agents’ body size and affective cues were manipulated. In the dominant rule-maker condition, when a smaller protagonist puts an object in one location, a bigger agent reacts with a positive reaction; on the contrary, when the smaller protagonist puts an object in another location, the bigger agent displays a negative reaction. In the subordinate rule-maker condition, the roles are shifted but the agents differ. Toddlers expect the protagonist to follow the rules (based on anticipatory looks), independent of the dominant status of the rule-making agent. Three-to-five-year-old pre-schoolers overall perform at the chance level but expect the protagonist to disobey a rule in the first trial, and obey the rule in the second trial if the rule-maker is dominant. (shrink)

Previous research has successfully used feature integration theory to operationalise the predictions of Perceptual Load Theory, while simultaneously testing the predictions of both models. Building on this work, we test the extent to which these models hold up in a 3D world. In two experiments, participants responded to a target stimulus within an array of shapes whose apparent depth was manipulated using a combination of monoscopic and stereoscopic cues. The search task was designed to test the predictions of feature (...) integration theory, as the target was identified by a single feature or a conjunction of features and embedded in search arrays of varying size, and perceptual load theory, as the task included congruent and incongruent distractors presented alongside search tasks imposing high or low perceptual load. Findings from both experiments upheld the predictions of feature integration theory, regardless of 2D/3D condition. Longer search times in conditions with a combination of monoscopic and stereoscopic depth cues suggests that binding features into three-dimensional objects requires greater attentional effort. This additional effort should have implications for perceptual load theory, yet our findings did not uphold its predictions; the effect of incongruent distractors did not differ between conjunction search trials and feature search trials. Individual differences in susceptibility to the effects of perceptual load were evident and likely explain the absence of load effects. Overall, our findings suggest that feature integration theory may be useful for predicting attentional performance in a 3D world. (shrink)

Current cognitive models of addiction imply that speeded detection and increased distraction from substance cues might both independently contribute to the persistence of addictive behavior. Speeded detection might lower the threshold for experiencing craving, whereas increased distraction might further increase the probability of entering a bias-craving-bias cycle, thereby lowering the threshold for repeated substance use. This study was designed to examine whether indeed both attentional processes are involved in substance use disorders. Both attentional processes were indexed by an Odd-One-Out (...) visual search task in individuals diagnosed with alcohol use disorder and cannabis use disorder. To test whether the detection and/or the distraction component are characteristic for AUD and CUD, their indices were compared with matched individuals without these diagnoses. Individuals with CUD showed speeded detection of cannabis cues; the difference in detection between AUD and the comparison group remained inconclusive. Neither the AUD nor the CUD group showed more distraction than the comparison groups. The sample size of the CUD group was relatively small. In addition, participants made relatively many errors in the attentional bias task, which might have lowered its sensitivity to detect ABs. The current study provided no support for the proposed role of increased distraction in CUD and AUD. The findings did, however, provide support for the view that speeded detection might be involved in CUD. Although a similar trend was evident for AUD, the evidence was weak and remained therefore inconclusive. (shrink)

Human listeners are assumed to apply different strategies to improve speech recognition in background noise. Young listeners with normal hearing, e.g., have been shown to follow the voice of a particular speaker based on the fundamental and formant frequencies, which are both influenced by the gender, age, and size of the speaker. However, the auditory and cognitive processes that underlie the extraction and discrimination of these voice cues across speakers may be subject to age-related decline. The present study (...) aimed to examine the utilization of F0 and formant cues for voice discrimination in older adults with hearing expected for their age. Difference limens for VD were estimated in 15 healthy older adults and 35 young adults using only F0 cues, only formant frequency cues, and a combination of F0 + formant frequencies. A three-alternative forced-choice paradigm with an adaptive-tracking threshold-seeking procedure was used. Wechsler backward digit span test was used as a measure of auditory working memory. Trail Making Test was used to provide cognitive information reflecting a combined effect of processing speed, mental flexibility, and executive control abilities. The results showed that the mean VD thresholds of the older adults were poorer than those of the young adults for all voice cues, although larger variability was observed among the older listeners; both age groups found the formant cues more beneficial for VD, compared to the F0 cues, and the combined cues resulted in better thresholds, compared to each cue separately; significant associations were found for the older adults in the combined F0 + formant condition between VD and TMT scores, and between VD and hearing sensitivity, supporting the notion that a decline with age in both top-down and bottom-up mechanisms may hamper the ability of older adults to discriminate between voices. The present findings suggest that older listeners may have difficulty following the voice of a specific speaker and thus implementing doing so as a strategy for listening amid noise. This may contribute to understanding their reported difficulty listening in adverse conditions. (shrink)

Transplantation experiments have shown that developing metazoan organs carry intrinsic information about their size and shape. Organ and body size are also sensitive to extrinsic cues provided by the environment, such as the availability of nutrients. The genetic and molecular pathways that contribute to animal size and shape are numerous, yet how they cooperate to control growth is mysterious. The recent identification and characterization of several mutations affecting growth in Drosophila melanogaster promises to provide insights. Many (...) of these mutations affect the extrinsic control of animal size; others affect the organ‐intrinsic control of pattern and size. In this review, we summarize the characteristics of some of these mutations and their roles in growth and size control. In addition, we speculate about possible connections between the extrinsic and intrinsic pathways controlling growth and pattern. BioEssays 24:54–64, 2002. © 2002 John Wiley & Sons, Inc. (shrink)

Despite its theoretical importance, little is known about how semantic memory structure facilitates and constrains creative idea generation. We examine whether the semantic richness of a concept has both benefits and costs to creative idea generation. Specifically, we tested whether cue set size—an index of semantic richness reflecting the average number of elements associated with a given concept—impacts the quantity (fluency) and quality (originality) of responses generated during the Alternate Uses Task (AUT). Across four studies, we show that low-association, (...) sparse, AUT cues benefit originality at the cost of fluency compared to high-association, rich, AUT cues. Furthermore, we found an interaction with individual differences in fluid intelligence in the low-association AUT cues, suggesting that constraints of sparse semantic knowledge can be overcome with top-down intervention. Our findings indicate that semantic richness differentially impacts the quality and quantity of generated ideas, and that cognitive control processes can facilitate idea production when conceptual knowledge is limited. (shrink)

In studying how lay people evaluate arguments, psychologists have typically focused on logical form and content. This emphasis has masked an important yet underappreciated aspect of everyday argument evaluation: social cues to argument strength. Here we focus on the ways in which observers evaluate arguments by the reaction they evoke in an audience. This type of evaluation is likely to occur either when people are not privy to the content of the arguments or when they are not expert enough (...) to appropriately evaluate it. Four experiments explore cues that participants might take into account in evaluating arguments from the reaction of the audience. They demonstrate that participants can use audience motivation, expertise, and size as clues to argument quality. By contrast we find no evidence that participants take audience diversity into account. (shrink)

A meta-analysis and an experiment show that the degree of compression of the in-depth dimension of visual space relative to the frontal dimension increases quickly as a function of the distance between the stimulus and the observer at first, but the rate of change slows beyond 7 m from the observer, reaching an apparent asymptote of about 50 %. In addition, the compression of visual space is greater for monocular and reduced cue conditions. The pattern of compression of the in-depth (...) dimension as a function of distance is similar to the ratio of in-depth to frontal visual angles of stimuli, but is not as extreme as this ratio would suggest, implying that observers are incapable of fully ignoring size information provided by cues to depth. Size and distance judgments may be described by an Affine transformation of physical space; however, the compression parameter in this model changes as a function of distance from the observer and other experimental conditions. (shrink)

Sexually signalling animals must trade off the benefits of attracting mates with the consequences of attracting predators. For male guppies, predation risk depends on their behaviour, colouration, environmental conditions and changing intensity of predation throughout the day. Theoretically, this drives diel patterns of display behaviour in native Trinidadian populations, where males display more under low-light conditions when their most dangerous predator is less active. Here, we observed Australian guppies in a laboratory setting to investigate their diel display pattern, and if (...) this pattern is controlled by ambient light intensity. We also quantified individual variation in both the daily frequency and diel pattern of displays, and if such variation relates to body size, colouration and a non-sexual behaviour. Under a typical daily light regime, male guppies displayed mostly in the first hour of observation. Extending the duration of dawn-like lighting, however, resulted in an extended period of high display, demonstrating that light intensity per se is an important cue for this behaviour. These findings mirror those obtained for Trinidadian populations, suggesting that male courtship timing is likely shaped by broad, potentially generalizable features of guppy ecology. The effect of acclimation to captive conditions on male behaviour is also discussed. Whereas the temporal pattern of display appeared consistent, individuals varied in their daily display frequency, and this was correlated with variation in colour phenotype and a measure of non-sexual risk acceptance behaviour. Such relationships pose promising avenues for integrating behavioural and sensory ecology with contemporary work on behavioural syndromes and animal personality. (shrink)

Although disoriented young children reorient themselves in relation to the shape of the surrounding surface layout, cognitive accounts of this ability vary. The present paper tests three theories of reorientation: a snapshot theory based on visual image-matching computations, an adaptive combination theory proposing that diverse environmental cues to orientation are weighted according to their experienced reliability, and a modular theory centering on encapsulated computations of the shape of the extended surface layout. Seven experiments test these theories by manipulating four (...) properties of objects placed within a cylindrical space: their size, motion, dimensionality, and distance from the space’s borders. Their findings support the modular theory and suggest that disoriented search behavior centers on two processes: a reorientation process based on the geometry of the 3D surface layout, and a beacon-guidance process based on the local features of objects and surface markings. Ó 2010 Elsevier Inc. All rights reserved. (shrink)

Evidence from visual-search experiments is discussed that indicates that there is spatially parallel encoding based on three-dimensional (3-D) spatial relations between complex image features. In one paradigm, subjects had to detect an odd part of cube-like figures, formed by grouping of corner junctions. Performance with cube-like figures was unaffected by the number of corner junctions present, though performance was affected when the corners did not configure into a cube. It is suggested from the data that junctions can be grouped to (...) form 3-D shapes in a spatially parallel manner. Further, performance with cube-like figures was more robust to noncollinearity between junctions than was performance when junctions grouped to form two-dimensional planes. In the second paradigm, subjects searched for targets defined by their size. Performance was affected by a size illusion, induced by linear-perspective cues from local background neighbourhoods. Search was made more efficient when the size illusion was consistent with the real size difference between targets and nontargets, and it was made less efficient when the size illusion was inconsistent with the real size difference. This last result occurred even though search was little affected by the display size in a control condition. We suggest that early, parallel visual processes are influenced by 3-D spatial relations between visual elements, that grouping based on 3-D spatial relations is relatively robust to noncollinearity between junctions, and that, at least in some circumstances, 3-D relations dominate those coded in two-dimensions. (shrink)

The perceptual system estimates distal conditions based upon proximal sensory input. It typically exploits information from multiple cues across and within modalities: it estimates shape based upon visual and haptic cues; it estimates depth based upon convergence, binocular disparity, motion parallax, and other visual cues; and so on. Bayesian models illuminate the computations through which the perceptual system combines sensory cues. I review key aspects of these models. Based on my review, I argue that we should (...) posit co-referring perceptual representations corresponding to distinct sensory cues. For example, the perceptual system represents a distal size using a representation canonically linked with vision and a distinct representation canonically linked with touch. Distinct co-referring perceptual representations represent the same denotation, but they do so under different modes of presentation. Bayesian cue combination models demonstrate that psychological explanation of perception should attend to mode of presentation and not simply to denotation. (shrink)

Research on automatic attention to emotional faces offers mixed results. Therefore we examined validity effects for facial expressions of different emotions with a dot-probe paradigm in seven studies. Systematic variations of type of emotion, CTI, task, cue size, and masking allow for a differentiated assessment of attentional capture by emotions and possible moderating factors. Results indicate a general absence of emotional validity effects as well as a lack of significant interactions with either of the manipulated factors, indicating that facial (...) expressions of emotions do not capture attention in a fully automatic fashion. These findings suggest that situational and contextual factors have to be taken into account when investigating attentional capture of emotional faces. (shrink)

Children often refer to things ambiguously but learn not to from responding to clarification requests. We review and explore this learning process here. In Study 1, eighty-four 2- and 4-year-olds were tested for their ability to request stickers from either (a) a small array with one dissimilar distracter or (b) a large array containing similar distracters. When children made ambiguous requests, they received either general feedback or specific questions about which of two options they wanted. With training, children learned to (...) produce more complex object descriptions and did so faster in the specific feedback condition. They also tended to provide more information when requesting stickers from large arrays. In Study 2, we varied only distracter similarity during training and then varied array size in a generalization test. Children found it harder to learn in this case. In the generalization test, 4-year-olds were more likely to provide information (a) when it was needed because distracters were similar to the target and (b) when the array size was greater (regardless of need for information). We discuss how clear cues to potential ambiguity are needed for children to learn to tailor their referring expression to context and how several cues of heuristic value (e.g., more distracters > say more) can promote the efficiency of communication while language is developing. Finally, we consider whether it would be worthwhile drawing on the human learning process when developing algorithms for the production of referring expressions. (shrink)

Sex differences in reproductive strategy and the sexual division of labor resulted in selection for and maintenance of sexual dimorphism across a wide range of characteristics, including body size, hormonal physiology, behavior, and perhaps spatial abilities. In laboratory tasks among undergraduates there is a general male advantage for navigational and mental-rotation tasks, whereas studies find female advantage for remembering item locations in complex arrays and the locations of plant foods. Adaptive explanations of sex differences in these spatial abilities have (...) focused on patterns of differential mate search and routine participation in distinct subsistence behaviors. The few studies to date of spatial ability in nonindustrial populations practicing subsistence lifestyles, or across a wider age range, find inconsistent results. Here we examine sex- and age-based variation in one kind of spatial ability related to navigation, dead-reckoning, among Tsimane forager horticulturalists living in lowland Bolivia. Seventy-three participants (38 male) aged 6–82 years pointed a handheld global positioning system (GPS) unit toward the two nearest communities and the more distant market town. We find no evidence of sex differences in dead reckoning (p = 0.47), nor do we find any evidence of age-related decline in dead-reckoning accuracy (p = 0.28). Participants were significantly more accurate at pointing toward the market town than toward the two nearest villages despite its being significantly farther away than the two nearest communities. Although Tsimane do show sexual dimorphism in foraging tasks, Tsimane women have extensive daily and lifetime travel, and the local environment lacks directional cues that typically enhance male navigation. This study raises the possibility that greater similarity in mobility patterns because of overlapping subsistence strategies and activities may result in convergence of some male and female navigation abilities. (shrink)

A new hypothesis is proposed to explain the perennially enlarged breasts of human females. The nubility hypothesis proposes that hominid females evolved protruding breasts because the size and shape of breasts function as an honest signal of residual reproductive value. Hominid females with greater residual reproductive value were preferred by males once reliable cues to ovulation were lost and long-term bonding evolved. This adaptation was favored because female-female competition for investing males increased once hominid males began to provide (...) valuable resources. (shrink)

In this article, we consider the problem of a discrepancy between, on the one hand, lay prescriptive judgments on the necessity of altruistic actions and, on the other, attributing moral worth to these actions. Based on Kantian theory of morality, we hypothesized that lay attributions of the moral worth of altruistic actions would be inversely related to normative ought-judgments according to which these actions should be performed, as having positive evolutionary-based utilitarian externalities for the actors. To test this general hypothesis, (...) we conducted two experiments using the same set of vignettes that were constructed based on systematically varying such factors as relatedness, reciprocity, the size of donation, and probability of meeting in the future. The results provide overall confirmation of our assumption, as evaluative judgments about the moral worth were inversely dependent on information provided about possible contributions from such consequentialist, payoff-based mechanisms as kinship and expected reciprocity, while prescriptive judgments were positively influenced by such information cues. (shrink)