Visual-motor recalibration in geographical slant perception

An anti-inertial motion bias explains people discounting inertial motion of carried objects

In this paper we propose an anti-inertial motion (AIM) bias that can explain several intuitive physics beliefs including the straight-down belief and beliefs held concerning the pendulum problem. We show how the AIM bias also explains two new beliefs that we explore - a straight-up-and-down belief as well as a straight-out/backward bias that occurs for objects traveling in one plane that are then thrown in another plane, ostensibly affording a greater opportunity for perception of canonical motion. We then show how the AIM bias in general is invariant across perceived/imagined speed of the object carrier, only altering percentages of straight-out from backward responses, and why occluding the carrier once the object is released into a second plane does not result in more veridical perception. The AIM bias serves as a simple explanation for a family of beliefs including those in the current paper as well as those shown in previous work.

The experience of stereoblindness does not improve use of texture for slant perception

Stereopsis is an important depth cue for normal people, but a subset of people suffer from stereoblindness and cannot use binocular disparity as a cue to depth. Does this experience of stereoblindness modulate use of other depth cues? We investigated this question by comparing perception of 3D slant from texture for stereoblind people and stereo-normal people. Subjects performed slant discrimination and slant estimation tasks using both monocular and binocular stimuli. We found that two groups had comparable ability to discriminate slant from texture information and showed similar mappings between texture information and slant perception (biased perception toward frontal surface with texture information indicating low slants). The results suggest that the experience of stereoblindness did not change the use of texture information for slant perception. In addition, we found that stereoblind people benefitted from binocular viewing in the slant estimation task, despite their inability to use binocular disparity information. These findings are generally consistent with the optimal cue combination model of slant perception.

Size Perception of a Sport Target as a Function of Practice Success Conditions

Superior motor task success has been correlated with participants’ self-reports of a larger-than-actual size of a sport-related target. In the present study, we examined whether a putting practice condition with greater success would differentially impact participants’ self-reported perceptions of the size of the putting hole during acquisition and retention. We randomly assigned participants to one of three different practice conditions (success-early, success-late, and self-controlled success) and had them self-report their perceived size of the putting hole upon completion of each required putting distance (25, 50, 75, 100, 125, 150, 175, 200 cm). Although there were no statistically significant differences between motor task success in the acquisition or retention period for the practice conditions, self-reported perceptions of target size were impacted by practice condition. During the acquisition period, participants in the self-controlled success and success-late conditions self-reported that the putting hole was larger than did participants in the success-early condition. In the retention period, participants in the self-controlled success condition perceived the target as larger than those in the success-early condition. These findings are the first to show that practice condition, independent of task success, differentially impacted self-reported perception of a target size.

Mood Influences the Perception of the Sitting Affordance

This study tested the influence of mood on the perception of the sitting affordance in two experiments. The objective of Experiment 1 was to evaluate participants' perception of the sitting affordance, without mood induction. Forty-three participants assessed their maximum sitting height (SHmax) from different seat heights (perceptual SHmax) before performing the action (motor SHmax). They accurately perceived the sitting affordance, in body-scaled intrinsic units. Indeed, participants all perceived they could sit as long as the seat height did not exceed 82% (perceptual πc) of their total leg length (L), while the actual value of this intrinsic relationship was 83% (motor πc). In Experiment 2, forty participants were subjected to a mood induction procedure before performing the task employed in Experiment 1. Neutral participants accurately perceived the sitting affordance, as their perceptual πc was equivalent to their motor πc. However, both joyful and sad participants had their perceptual πc significantly lower than their motor πc. These differences between mood groups were not explained by a variation in maximal effective action capabilities. Indeed, participants had equivalent motor πc, whatever their mood. Two interpretations are offered to explain how joyful and sad moods could influence the accuracy of affordance perception. The first is based on their potential effect on organism's energy level. The second is related to the disruption of participants' attunement to optical variables relevant for action guidance and/or to perceptual-motor calibration.

Selective interference of hand posture with grasping capability estimation

Previous studies have shown that judgments about how one would perform an action are affected by the current body posture. Hence, judging one's capability to grasp an object between index and thumb is influenced by their aperture at the time of the judgment. This finding can be explained by a modification of the internal representation of one's hand through the effect of sensorimotor input. Alternatively, the influence of grip aperture might be mediated by a response congruency effect, so that a "less" vs. "more" open grip would bias the judgment toward a "less" vs. "more" capable response. To specify the role of sensorimotor input in prospective action judgments, we asked participants to estimate their capability to grasp circles between index and thumb while performing a secondary task that requires them to squeeze a ball with these two fingers (precision grip) or with a different hand configuration (palm grip). Experiment 1 showed that participants underestimated their grasping capability when the squeezing task involved the same grip as the judged action (precision grip) and their estimates were bound to the relative size of objects as revealed by size-contrast illusions (Ebbinghaus). Experiment 2 showed that the grip reduction caused by the squeezing task also interfered with the discrimination of large numbers in magnitude judgments, but this incongruency effect was only observed for the palm grip. The dissociated effects of the two grips in graspability and numerical judgments indicate that sensorimotor input may affect the perceived ability to grasp objects, independently of response congruency, by modifying the representation of the hand in action.

A day at the beach: Does visually perceived distance depend on the energetic cost of walking?

It takes less effort to walk from here to the Tiki Hut on the brick walkway than on the sandy beach. Does that influence how far away the Tiki Hut looks? The energetic cost of walking on dry sand is twice that of walking on firm ground (Lejeune et al., 1998). If perceived distance depends on the energetic cost or anticipated effort of walking (Proffitt, 2006), then the distance of a target viewed over sand should appear much greater than one viewed over brick. If perceived distance is specified by optical information (e.g., declination angle from the horizon; Ooi et al., 2001), then the distances should appear similar. Participants (N = 13) viewed a target at a distance of 5, 7, 9, or 11 m over sand or brick and then blind-walked an equivalent distance on the same or different terrain. First, we observed no main effect of walked terrain; walked distances on sand and brick were the same (p = 0.46), indicating that locomotion was calibrated to each substrate. Second, responses were actually greater after viewing over brick than over sand (p < 0.001), opposite to the prediction of the energetic hypothesis. This unexpected overshooting can be explained by the slight incline of the brick walkway, which partially raises the visually perceived eye level (VPEL) and increases the target distance specified by the declination angle. The result is thus consistent with the information hypothesis. We conclude that visually perceived egocentric distance depends on optical information and not on the anticipated energetic cost of walking.

Perception of maximum distance jumpable remains accurate after an intense physical exercise and during recovery

Earlier studies have revealed that changes in action capabilities due to fatigue or wearing a backpack have an effect on the perception of distance in meters or steepness in angles. Although these findings are interesting by themselves, they leave us uninformed about whether the accuracy of affordance perception is affected by fatigue. Are people still capable of accurately perceiving the maximum distance jumpable after an intense physical exercise? In the present experiment, this question is addressed. We found that after maximal exertion in a squatting task, the actual maximum jumping distance significantly decreased, but recovered quickly. Interestingly, on average, the participants accurately perceived their maximum jumping distance both before and after the squatting task. Apparently, the accuracy of the affordance perception remains intact after an intense physical exercise. The implications of this finding are discussed.

Physical fatigue and its effect on road crossing decisions: an examination of the embodied perception perspective

Road crossing is an everyday task that requires integration of information (e.g., speed and distance of an oncoming vehicle) to effectively guide behaviour. The embodied perception perspective suggests that individuals' perception of environmental stimuli is influenced by their psychophysiological state. Upon this premise, the current study examined whether acute physical fatigue influences visual perception and associated decision-making in road crossing. Using a between-subject design, 54 participants (healthy adults, aged 18-35) were divided into a fatigue and no-fatigue group. To manipulate fatigue, participants completed a vigorous cycling protocol (fatigue group) or a light cycling protocol (no-fatigue group) prior to completing a video-based examination of road crossing decisions (cross vs. not cross; action-based) and verbal judgments of speed and distance of an oncoming vehicle. Measures of heart rate, self-perceived recovery, and preferred walking speed indicated that fatigue was successfully induced (all p's < 0.03). Participants effectively distinguished between different speeds (30-50-70 km/h; p < 0.001), and distances (10-100 m in 10 m increments; p < 0.001). Moreover, both vehicle speed and distance (p's < 0.001) significantly influenced road crossing decisions. However, no significant effects of fatigue were observed for visual perception or road crossing decisions (all p's > 0.26). This study demonstrated that individuals are sensitive to changes in vehicle speed and distance and respond to these changes in making road crossing decisions. In contrast to the embodied perception perspective, however, physical fatigue did not alter perceptual judgments of vehicle speed and distance nor did it influence road crossing decisions in a video-simulated road crossing environment.

Subjective time compression induced by continuous action

Increasing evidence indicates that voluntary actions can modulate the subjective time experience of its outcomes to optimize dynamic interaction with the external environment. In the present study, using a temporal reproduction task where participants reproduced the duration of an auditory stimulus to which they were previously exposed by performing different types of voluntary action, we examined how the subjective time experience of action outcomes changed with voluntary action types. Two experiments revealed that the subjective time experience of action outcomes was compressed, compared with physical time, if the action was performed continuously (Experiment 1), possibly enhancing the experience of controlling the action outcome, or if the action was added an extra task-unrelated continuous action (Experiment 2), possibly reflecting different underlying mechanisms from subjective time compression induced by the task-related continuous action. The majority of prior studies have focused on the subjective time experience of action outcomes when actions were performed voluntarily or not, and no previous study has examined the effects of differences in voluntary action types on the subjective time experience of action outcomes. These findings may be useful in situations in which people wish to intentionally compress their own time experience of daily events through their voluntary actions.

Task Construal Influences Estimations of the Environment

People's characteristics can affect their perception of the physical environment, and the judgments and estimates they make about their surroundings. Estimates of the environment change based on observers' metabolic state, physical properties, and the potential effort they would need to exert for a certain action. The functional role of such scaling is to provide agents with information on possible actions and their energetic costs. Combining actions with costs facilitates both higher-level planning (e.g., choosing an optimal running speed on a marathon) as well as planning on lower levels of an action hierarchy, such as determining the best movement trajectories for energy-efficient action. Recently, some of the findings on reported effects of effort on perception have been challenged as arising from task demands-participants guessing the purpose of the experimental manipulation and adjusting their estimates as a result. Arguably however, the failed replications used overly distracting cover stories which may have introduced task demands of their own, and masked other effects. The current study tested the generality of effects of potential effort on height and distance perception, employing effective yet not distracting cover stories. Four experiments attempted to identify conditions under which anticipated effort may systematically change perceptual estimates. Experiment 1 found that height estimates were not influenced by the effort required to place objects of different weights onto surfaces of varying heights. Experiments 2, 3 used two different effort manipulations (walking vs. hopping; and carrying an empty vs. a heavy backpack, respectively) and found that these did not influence estimates of distance (to be) traveled. Experiment 4 also used backpack weight to manipulate effort but critically, unlike Exp. 1-3 it did not employ a cover story and participants did not traverse distances after giving estimates. In contrast with the first three experiments, distances in the final experiment were estimated as longer when participants were encumbered by a backpack. Combined, these results suggest that the measured effects on the estimation of distance were due to how participants construed the task rather than being of a perceptual nature.

Extraversion level predicts perceived benefits from social resources and tool use

Social baseline theory states that there are differences in how humans integrate social resources into their economy of action when they face environmental demands. However, although several authors suggested that extraversion may be an indicator of the social baseline, no study has demonstrated it. The present study aims to test this hypothesis and, in particular, examines whether extraversion is a specific indicator of the social baseline. In two experiments, participants were asked to move rolls either alone (with their hands), or with the help of a social resource (Experiment 1), or a tool (Experiment 2). Results showed that extraversion predicted the choice to use both types of resource. Specifically, the more participants were extraverted, the more they tended to consider the use of the social resource or the tool as beneficial. We argue that these results indicate that extraversion is not specifically an indicator of the social baseline, but rather an indicator of how individuals integrate technical and social resources into their economy of action. In addition, this study encourages future research endeavors to define what constitutes a resource and how it could fit into the Social Baseline Theory.

On the relevance of task instructions for the influence of action on perception

The present study explored how task instructions mediate the impact of action on perception. Participants saw a target object while performing finger movements. Then either the size of the target or the size of the adopted finger postures was judged. The target judgment was attracted by the adopted finger posture indicating sensory integration of body-related and visual signals. The magnitude of integration, however, depended on how the task was initially described. It was substantially larger when the experimental instructions indicated that finger movements and the target object relate to the same event than when they suggested that they are unrelated. This outcome highlights the role of causal inference processes in the emergence of action specific influences in perception.

Let Me Make You Happy, and I'll Tell You How You Look Around: Using an Approach-Avoidance Task as an Embodied Emotion Prime in a Free-Viewing Task

The embodied approach of human cognition suggests that concepts are deeply dependent upon and constrained by an agent's physical body's characteristics, such as performed body movements. In this study, we attempted to broaden previous research on emotional priming, investigating the interaction of emotions and visual exploration. We used the joystick-based approach-avoidance task to influence the emotional states of participants, and subsequently, we presented pictures of news web pages on a computer screen and measured participant's eye movements. As a result, the number of fixations on images increased, the total dwell time increased, and the average saccade length from outside of the images toward the images decreased after the bodily congruent priming phase. The combination of these effects suggests increased attention to web pages' image content after the participants performed bodily congruent actions in the priming phase. Thus, congruent bodily interaction with images in the priming phase fosters visual interaction in the subsequent exploration phase.

Enactive Pragmatism and Ecological Psychology

A widely cited roadblock to bridging ecological psychology and enactivism is that the former identifies with realism and the latter identifies with constructivism, which critics charge is subjectivist. A pragmatic reading, however, suggests non-mental forms of constructivism that simultaneously fit core tenets of enactivism and ecological realism. After advancing a pragmatic version of enactive constructivism that does not obviate realism, I reinforce the position with an empirical illustration: Physarum polycephalum, a communal unicellular organism that leaves slime trails that form chemical barriers that it avoids in foraging explorations. Here, environmental building and sensorimotor engagement are part of the same process with P. polycephalum coordinating around self-created, affordance-bearing geographies, which nonetheless exist independently in ways described by ecological realists. For ecological psychologists, affordances are values, meaning values are external to the perceiver. I argue that agent-enacted values have the same status and thus do not obviate ecological realism or generate subjectivism. The constructivist-realist debate organizes around the emphasis that enactivists and ecological theorists respectively place on the inner constitution of organisms vs. the structure of environments. Building on alimentary themes introduced in the P. polycephalum example and also in Gibson’s work, I go on to consider how environment, brain, visceral systems, and even bacteria within them enter perceptual loops. This highlights almost unfathomable degrees of mutually modulating internal and external synchronization. It also shows instances in which internal conditions alter worldly configurations and invert values, in Gibson’s sense of the term, albeit without implying subjectivism. My aim is to cut across the somatic focus of enactive constructivism and the external environment-oriented emphasis of ecological realism and show that enactivism can enrich ecological accounts of value.

Is the construction of spatial models multimodal? New evidences towards sensory-motor information involvement from temporary blindness study

Using new developments of interference paradigm, this paper addresses the raising question of the involvement of sensory-motor information in the construction of elaborate spatial models (Johnson-Laird in Mental models: towards a cognitive science of language, inference, and consciousness Cambridge University Press Cambridge, 1983). In two experiments, 112 participants had to explore and memorize the spatial arrangement of 12 objects, disposed on 3 tables. Participants were either sighted or blindfolded, leading to a visual or a more sensory-motor based exploration of the room. During exploration, participants were required to perform a classical verbal, a visuo-spatial dual task or none. In the second experiment, more exploratory, we draw on interference paradigm literature and its recent development in the embodied field to develop two original dual tasks meant to interfere directly with the acquisition of sensory-motor information (haptic and action). After this learning phase, five tasks addressing spatial memory and reasoning used in the construction of spatial models were performed. Results showed classical effects for both verbal and visuo-spatial tasks for sighted participants, but not for blindfolded sighted ones, suggesting that a temporary visual deprivation led participants to use other way to build their spatial models. Our second experiment confirmed this point by showing effect of both sensory-motor dual tasks, especially for blindfolded sighted participants. Taking together, our results support a multimodal view of spatial models, and that exploration modality will influence the information used to construct them. Moreover, this challenges the Baddeley's dualist view of working memory as a reference to theorize the construction of spatial models and provide new experimental evidences towards an embodied view of spatial models.

Functional Autonomy Affects Elderly Spatial Perception in Body-Centered Coordinates

According to the action-specific theory of perception, a person's dynamic ability to act in the environment affects her/his spatial perception. Empirical evidence shows that the elderly perceive distances as farther compared with younger adults and that the harder the ground surface to walk, the farther the perceived distance. Such results suggest a general perceptual readaptation promoted by the aging process that is fine-tuned with the decline of the motor resources. However, it is still unknown whether the elderly space perception is affected by interindividual differences in their functional autonomy (FA) and whether the decline of motor resources affects spatial categorization only when distances are judged with reference to the observer's own body or also when they are judged with reference to the body of another agent present in the scene. To this aim, a sample of elderly adults with preserved cognitive functions but different levels of FA, measured through the Instrumental Activity of Daily Living (IADL) scale, were enrolled and tested on the extrapersonal space categorization task. This task requires judging the position of a target as “Near” or “Far” with respect to different reference frames (RFs): centered on the observer's body (Self RF) or centered on external elements, like another body (Other RF) or an object (Object RF). Results indicated that the higher the level of FA, the wider the space categorized as “Near” when adopting as reference frame our own body or the body of another agent in the scene, but not a static object. In conclusion, the individual functional autonomy of elderly individuals, which is strongly influenced by motor resources and efficiency, modulates how the surrounding space is represented, but only when the distance judgment implies an agent body, thus providing new relevant data for recent embodied cognition models of aging.

Do not turn your head when estimating the distance: influence of head rotation on distance judgement

According to the mental number line (MNL) concept, people mentally represent numbers along a line with smaller values on the left and greater on the right. Embodied cognition theory assumes that MNL is activated by postural bias and in turn affects cognitive processes; for example, research shows that quantitative estimates are smaller when participants' bodies are leaning to the left than to the right. In this study, we tested whether distance estimation in the natural environment is influenced by head rotation. Outdoors, participants gave verbal reports about egocentric distances while keeping their head turned left, turned right, or in the straight-ahead position. Results showed that distance estimates were greater when participants rotated their head right as compared to left. Additionally, we tested whether the MNL is activated by camera-based image movement indicating that the camera is rotating left or right. Participants estimated distances in videos recorded with camera rotation, and the videos were viewed without any postural bias; estimates were similar for camera rotating left and right. The study thus demonstrates that proprioceptive information seems to be necessary for activation of the MNL, which in turn influences verbal distance estimation in the outdoor space.

Designing Urban Green Spaces for Older Adults in Asian Cities

Elderly populations in Asian countries are expected to increase rapidly in the next few decades. Older adults, particularly in high-density cities, spend a considerable amount of time in urban green spaces (UGSs). The World Health Organization noted that UGSs are key to improving the age-friendliness of neighborhoods. Thus, it is necessary to design UGSs for the promotion of healthy ageing to enhance preventive healthcare and relieve medical burdens. This study conducted interviews using a questionnaire with a sample size of 326 participants in the cities of Hong Kong (China) and Tainan (Taiwan region). The inter-relationships among the design of UGSs (e.g., spatial distribution and accessibility, characteristics of plants and UGSs), older adults' perceptions on safety and aesthetics quality of UGSs, and their self-reported health conditions (assessed by the self-reported SF-12v2 Health Survey) were investigated with bivariate Spearman rank correlation tests. The results indicate that the duration of visits to UGSs was positively associated with mental health and social functioning, two subscales evaluating health-related quality of life in SF 12v2. The statistical model (moderation analysis) showed that such a correlation was especially significant in women and those with low social support and social capital. A positive relationship was found between the physical health subscale and perceived safety in UGSs. This relationship was stronger among older adults living alone (moderation analysis). Furthermore, the color of plants and maintenance condition of UGSs were significant aspects affecting the subjective assessment of aesthetic quality. This study provides useful information regarding how to plan and design urban green spaces with certain characteristics that could improve the accessibility and aesthetic quality, which are preferred by older adults.

Embodied Cognition in Performance: The Impact of Michael Chekhov's Acting Exercises on Affect and Height Perception

Modern embodied approaches to cognitive science overlap with ideas long explored in theater. Performance coaches such as Michael Chekhov have emphasized proprioceptive awareness of movement as a path to attaining psychological states relevant for embodying characters and inhabiting fictional spaces. Yet, the psychology of performance remains scientifically understudied. Experiments, presented in this paper, investigated the effects of three sets of exercises adapted from Chekhov's influential techniques for actors' training. Following a continuous physical demonstration and verbal prompts by the actress Bonnie Eckard, 29 participants enacted neutral, expanding, and contracting gestures and attitudes in space. After each set of exercises, the participants' affect (pleasantness and arousal) and self-perceptions of height were measured. Within the limitations of the study, we measured a significant impact of the exercises on affect: pleasantness increased by 50% after 15 min of expanding exercises and arousal increased by 15% after 15 min of contracting exercises, each relative to the other exercise. Although the exercises produced statistically non-significant changes in the perceived height, there was a significant relation between perceived height and affect, in which perceived height increased with increases in either pleasantness, or arousal. These findings provide a preliminary support for Chekhov's intuition that expanding and contracting physical actions exert opposite effects on the practitioners' psychological experience. Further studies are needed to consider a wider range of factors at work in Chekhov's method and the embodied experience of acting in general.

Choosing efficient actions: Deciding where to walk

Humans evolved to be endurance animals. Our ancestors were persistence hunters; they would chase animals, including gazelles, until they ran them into exhaustion. Put simply, people evolved in an ecological niche that selected for endurance and efficiency of locomotion. To locomote to any destination, one could take countless different paths, each requiring different amounts of energy. Because the ground is typically not flat or homogeneous, the straight direct path is often not the most energetically efficient. For hills below 14°, the direct straight path up the hill is the most energetically efficient. However, for hills above 14°, walkers would minimize their absolute energy expenditure by taking a zigzagged path so that their gradient of ascension is 14° [1]. In three experiments, we assessed the degree to which people make bioenergetically efficient decisions about locomotion through path selection. In Experiment 1, people were immersed into a virtual environment and adjusted the angle of ascension of a virtual path up hills of various gradients so that when taking the path, they would expend the least amount of energy when they reached the top. The second experiment was of a similar design, but was conducted in the real word. In the last experiment, in a virtual environment, participants choose between two paths up hills of various gradient, where these paths varied in the energy required for ascent. Participants made these judgements both before and after motor experience with gradient climbing on an incline trainer. For steep hills, we found that people choose much straighter paths over the bioenergetically optimal zigzagged paths. Motor experience did lead to higher probability for choosing optimal paths for steep hills, but lead to less optimal paths for shallower ones. These results show clearly that individuals show a straight path bias when deciding how to ascend hills.

Spatial text processing: are estimates of time and distance influenced by the age of characters and readers?

It is widely accepted that, while hearing or reading a story, people continuously form and update mental representations of the characters, places and events being described, based on plausible spatial, temporal or intentional details. According to the embodied cognition approach, the mental representations that accompany text reading are grounded in each reader's own sensorimotor experiences. Two experiments were conducted to examine whether readers' estimates of time and distance are influenced by age, their own and that of the character being described. In Experiment 1, 182 young adults read the description of a route in a town being covered by a young or an elderly character. In Experiment 2, the same descriptions as in Experiment 1 were read by 121 young adults and 53 older people. To avoid a possible confound, a follow-up to Experiment 1 (Experiment 1a) repeated the study by removing from texts the adverbs describing the walking speed of characters. In all experiments, participants were asked to estimate: (a) the time the characters took to reach their destinations (time estimation task); and (b) the distance they covered (distance estimation task). The results showed that both characters' and readers' ages influenced the time estimated, whereas no effects were found on estimates of distance: the elderly character was estimated to take longer than the young character (Experiments 1, 1a and 2), and older readers estimated longer times than younger readers (Experiment 2). This prompts the conclusion that personal features of both the readers and the characters they read about were used to infer the temporal dimension of situations described in the narratives. The theoretical implications of the findings are discussed.

Impact of action planning on visual and body perception in a virtual grasping task

The present study examined mutual influences of visual and body-related signals during planning of an object-oriented action. Participants were to enclose a visual target object using two cursors controlled by the movements of their fingers. During movement preparation, they were asked to judge either the size of the object or a certain finger distance. Both types of judgments were systematically affected by the transformation of finger movements into the movements of visual cursors. We suggest that these biases are perceptual consequences of sensory integration of visual and body-related signals relating to the same external object.

Walking-related locomotion is facilitated by the perception of distant targets in the extrapersonal space

The Gibsonian notion of affordance has been massively employed in cognitive sciences to characterize the tight interdependence between hand-related actions, manipulable objects and peripersonal space. A behavioural facilitation effect, indeed, is observed for grasping actions directed to objects located in the ‘reachable’ peripersonal space. Relevantly, this relationship is supported by dedicated neural systems in the brain. The original notion of affordance, however, was directly inspired by real-time interactions between animals and their extended natural environment. Consistently, also the extrapersonal space representation can be significantly modulated by action-related factors, and the brain contains dedicated systems for the representation of topographical space and navigation. Here we examined whether a facilitation effect could be also described for a walking-related action in the far extrapersonal space. To this aim, we employed a go/no-go paradigm requiring subjects to execute a footstep ahead in response to pictures of a virtual reality environment containing objects located at different distances (near, far) and eccentricities (central, peripheral). A walking-related, facilitation effect for distant extrapersonal locations was found, suggesting an automatic trigger of walking by positions that preferentially guide spatial exploration. Based on the parallelism with the literature on micro-affordances, we propose that this effect can be described in terms of “macro-affordances”.

Thirst for Intention? Grasping a Glass Is a Thirst-Controlled Action

Every day and every hour, we feel we perform numerous voluntary actions, i.e., actions under the control of our will. Individual’s ability to initiate goal-directed movement is classically described as a hierarchical motor organization, from an intentional module, mostly considered as a black box, to muscular activity supporting action execution. The general focus is usually set on the triggering of action by intention, which is assumed to be the only entry to the action cascade, rather than on the preceding formation of intentions. If intentions play a key role in the specification of movement kinematic parameters, it remains largely unknown whether unconscious cognitive processes may also affect action preparation and unfolding. Recently, a seemingly irrelevant variable, thirst, was shown to modulate a simple arbitrary action such as key-pressing. Thirsty individuals were shown to produce stronger motor inhibition in no-go trials when a glass of water was present. In the present experiment, we intended to explore whether motor inhibition operates not only upstream from the action cascade but may also affect the unfolding of reaching movements, i.e., at a lower-level control. Thirsty vs. non-thirsty control subjects were asked to reach and grasp green (go trial) or red glasses (no-go trial) filled with either water or transparent gel wax with a central candlewick. Thirsty subjects were faster to initiate actions toward the water glasses. They also exhibited an earlier maximal grip aperture and a global reduction of movement time which was mostly explained by a shortening of deceleration time. The deceleration phase was correlated with individual’s thirst rating. In addition, no-go trial toward a glass of water tended to inhibit the next movement toward a glass filled with gel wax. Thus, our results show that an unintentional influence of an internal state can reorganize voluntary action structure not only at the decision-making level but also at the level of motor control. Although subjects explicitly paid more attention and were more cautious to glasses filled with water, they reported no explicit sensation of an increased urge to grasp it, further suggesting that these effects are controlled by covert mechanisms.

Warning against Critical Slopes in Agriculture: Comprehension of Targeted Safety Signs in a Group of Machinery Operators in Italy

Steep slopes are the main cause of rollover incidents in agriculture. Targeted safety signs have been developed to warn machinery operators against risky slopes. However, machinery user’s manuals and road signs report information regarding slope steepness in two different ways, by using the tilt angle in degrees and the slope percentage, respectively. In this study, we investigated the comprehension of safety signs depicting critical slopes, either in degrees or as percent values in a group of Italian agricultural machinery operators while considering the possible influence of previous experience with agricultural machinery, previous incidents, and on-farm occupation. Eighteen tractor and self-propelled machinery operators were administered graphical representations of seven slope angles in a randomized order and then were asked to estimate the slope steepness as both a tilt angle and a slope percentage. The participants tended to overestimate slope steepness in degrees, whereas the opposite was true for percentages. Farmers who were previously involved in a machinery-related incident were more accurate in their estimates. The present results raise some considerations regarding the need to redesign safety communication and to promote targeted training interventions.

Getting a grasp on action-specific scaling: A response to Witt (2017)

Can higher level cognition directly influence visual spatial perception? Many recent studies have claimed so, on the basis that manipulating cognitive factors (e.g., morality, emotion, action capacity) seems to directly affect perception. However, Firestone and Scholl (Behavioral and Brain Sciences, 39, 1–77, 2016) argued that such studies often fall prey to at least one of six pitfalls. They further argued that if an effect could be accounted for by any of these pitfalls, it is not a true demonstration of a top-down influence of cognition on perception. In response to Firestone and Scholl (Behavioral and Brain Sciences, 39, 1–77, 2016), Witt (Psychonomic Bulletin & Review, 24(4), 999–1021, 2017) discussed four action-specific scaling effects which, she argued, withstand all six pitfalls and thus demonstrate true perceptual changes caused by differences in action capacity. Her third case study was the influence of apparent grasping capacity on perceived object size. In this article, we provide new interpretations of previous findings and assess recent data which suggest that this effect is not, in fact, perceptual. Instead, we believe that many earlier studies showing this effect are subject to one or more of the pitfalls outlined by Firestone and Scholl (Behavioral and Brain Sciences, 39, 1–77, 2016). We substantiate our claims with recent empirical evidence from our laboratory which suggests that neither actual nor perceived grasping capacity directly influence perceived object size. We conclude that studies manipulating grasping capacity do not provide evidence for the action-specific account because variation in this factor does not directly influence size perception.

Comparison of two psychophysical methods across visual and haptic perception of stand-on-ability

Recent research (Hajnal et al. in Perception 45(7):768-786, 2016) found apparent differences between haptic and visual perception of the affordance of stand-on-ability. One reason for this discrepancy might be the imprecision of the measurement method. We compared the psychophysical method of adjustment with a dynamic staircase method of stimulus presentation in an affordance task. Three groups of participants either visually inspected a flat sturdy sloped ramp, placed one foot onto the ramp occluded from view, or placed one foot on the ramp while allowed to look at it, in the visual, haptic, or multimodal condition, respectively. Each trial was presented by moving the ramp up or down until the participant perceived the action boundary, i.e., the steepest slope that still afforded upright stance. After perceptual trials, we measured the actual action boundaries by allowing participants to attempt to stand on the ramp. The action boundary was the average between the lowest false alarm and steepest hit within a 1.5° margin of difference. Visual perception was found to be equivalent with haptic perception. Perceptual and action boundaries were indistinguishable, but only when employing the more precise staircase method. The results support the postulate of equivalence among perceptual systems proposed by Gibson (The senses considered as perceptual systems. Houghton Mifflin Company, Boston, 1966), and the idea of correspondence between perception and action which is the cornerstone of affordance theory.

No environmental context-dependent effect, but interference, of physical activity on object location memory

Research on context-dependent memory has addressed many external and internal types of contexts. However, whether the physical activity engaged in at the time of encoding and recall can act as an environmental context cue has been systematically investigated only in one study. The purpose of the present study was to replicate this; furthermore, given the effect of physical activity/effort on the way space is represented, we sought to extend the findings to object location memory. Using a 1-list paradigm (Experiment 1) and a 2-list paradigm (Experiment 2), participants had to learn the locations of objects on a grid and then recall them, while standing or walking on a health walker. No evidence of activity context effects was found. However, an interference effect of the motor task on location memory was detected, such that participants' performance was worse when walking, compared to standing, at encoding (Experiment 2) or recall (Experiment 1). Results are discussed based on the outshining hypothesis and the possible link between motor task and object location memory.

Contextual Effects in Face Lightness Perception Are Not Expertise-Dependent

Lightness judgments of face stimuli are context-dependent (i.e., judgments of face lightness are influenced by race classification). Here, we tested whether contextual effects in face lightness perception are modulated by expertise, exploiting well-known other race effects in face perception. We used a lightness-matching paradigm where Chinese and White observers were asked to adjust the lightness of a variable face to match that of a standard face. The context (i.e., race category) of the two faces could be the same or different. Our data indicated that both groups had the smallest matching errors in same-context trials, for which errors did not vary across different racial categories. For cross-context trials, observers made the largest (negative) errors when the reference face was Black, as compared to Chinese and White references, for which matching errors were no different from zero or trended positively. Critically, this pattern was similar for both groups. We suggest that contextual influences in lightness perception are unlikely to be guided by classical mechanisms that drive face perception. We instead speculate that such influences manifest in terms of an interaction between race assumptions (e.g., expected surface reflectance patterns) and traditional mechanisms for reflectance computations.

Matching optical flow to motor speed in virtual reality while running on a treadmill

We investigated how visual and kinaesthetic/efferent information is integrated for speed perception in running. Twelve moderately trained to trained subjects ran on a treadmill at three different speeds (8, 10, 12 km/h) in front of a moving virtual scene. They were asked to match the visual speed of the scene to their running speed-i.e., treadmill's speed. For each trial, participants indicated whether the scene was moving slower or faster than they were running. Visual speed was adjusted according to their response using a staircase until the Point of Subjective Equality (PSE) was reached, i.e., until visual and running speed were perceived as equivalent. For all three running speeds, participants systematically underestimated the visual speed relative to their actual running speed. Indeed, the speed of the visual scene had to exceed the actual running speed in order to be perceived as equivalent to the treadmill speed. The underestimation of visual speed was speed-dependent, and percentage of underestimation relative to running speed ranged from 15% at 8km/h to 31% at 12km/h. We suggest that this fact should be taken into consideration to improve the design of attractive treadmill-mediated virtual environments enhancing engagement into physical activity for healthier lifestyles and disease prevention and care.

Perceptual Modification of the Built Environment to Influence Behavior Associated with Physical Activity: Quasi-Experimental Field Studies of a Stair Banister Illusion

BACKGROUND

Re-engineering the built environment to influence behaviors associated with physical activity potentially provides an opportunity to promote healthier lifestyles at a population level. Here we present evidence from two quasi-experimental field studies in which we tested a novel, yet deceptively simple, intervention designed to alter perception of, and walking behavior associated with, stairs in an urban area.

OBJECTIVES

Our objectives were to examine whether adjusting a stair banister has an influence on perceptions of stair steepness or on walking behavior when approaching the stairs.

METHODS

In study 1, we asked participants (n = 143) to visually estimate the steepness of a set of stairs viewed from the top, when the stair banister was adjusted so that it converged with or diverged from the stairs (± 1.91°) or remained neutral (± 0°). In study 2, the walking behavior of participants (n = 36) was filmed as they approached the stairs to descend, unaware of whether the banister converged, diverged, or was neutral.

RESULTS

In study 1, participants estimated the stairs to be steeper if the banister diverged from, rather than converged with, the stairs. The effect was greater when participants were unaware of the adjustment. In study 2, walking speed was significantly slower when the banister diverged from, rather than converged with, the stairs.

CONCLUSIONS

These findings encourage us to speculate about the potential to economically re-engineer features of the built environment to provide opportunities for action (affordances) that invite physical activity behavior or even promote safer navigation of the environment.

Trapped in a tight spot: Scaling effects occur when, according to the action-specific account, they should not, and fail to occur when they should

The action-specific account of perception claims that what we see is perceptually scaled according to our action capacity. However, it has been argued that this account relies on an overly confirmatory research strategy—predicting the presence of, and then finding, an effect (Firestone & Scholl, 2014). A comprehensive approach should also test disconfirmatory predictions, in which no effect is expected. In two experiments, we tested one such prediction based on the action-specific account, namely that scaling effects should occur only when participants intend to act (Witt, Proffitt, & Epstein, 2005). All participants wore asymmetric gloves in which one glove was padded with extra material, so that one hand was wider than the other. Participants visually estimated the width of apertures. The action-specific account predicts that the apertures should be estimated as being narrower for the wider hand, but only when participants intend to act. We found this scaling effect when it should not have occurred (Exp. 1, for participants who did not intend to act), as well as no effect when it should have occurred (Exp. 2, for participants who intended to act but were given a cover story for the visibility and position of their hands). Thus, the cover story used in Experiment 2 eliminated the scaling effect found in Experiment 1. We suggest that the scaling effect observed in Experiment 1 likely resulted from demand characteristics associated with using a salient, unexplained manipulation (e.g., telling people which hand to use to do the task). Our results suggest that the action-specific account lacks predictive power.

The Effects of Social Support on Strenuous Physical Exercise

In humans, socio-environmental cues play an important role in determining adaptive psychophysiological states and behaviours. In sport and exercise, cues to cohesive groups and close, supportive relationships are ubiquitous, possibly because of their effects on neurobiological mechanisms underlying physical performance. Clinical research has shown that the presence of supportive others can lead to reductions in perceptions of pain, while research from sport and exercise science has shown that pain and physical fatigue occupy ranges on a single spectrum of physical discomfort, which works to regulate outputs during strenuous physical exertion. Given the similar neurobiological underpinnings of pain and fatigue, the involvement of both in the self-regulation of strenuous physical outputs, and the effects of social support on perceptions of pain and neurophysiological stress responses more generally, we hypothesised that perceptions of social support affect outputs during strenuous physical exercise by altering activity in self-regulatory mechanisms involved in perceptions of pain and fatigue. We used a between-subjects experimental design to test this hypothesis, varying participants' social support and measuring physical outputs and perceptions of physical discomfort and exertion during a series of maximum-effort cycling bouts. Analyses showed that participants in the social support condition produced greater initial outputs and steeper declines over time, compared to controls. This effect was moderated by participant neuroticism; an important predictor of how individuals react to social support. We discuss these findings in terms of proposed causal mechanisms linking supportive, cohesive social environments with self-regulation and physical performance.

From the Age of 5 Humans Decide Economically, Whereas Crows Exhibit Individual Preferences

Human societies greatly depend on tools, which spare us considerable time and effort. Humans might have evolved a bias to employ tools, using them even when they are unnecessary. This study aimed to investigate whether adult humans and a distantly related habitually tool-using vertebrate species, the New Caledonian crow (Corvus moneduloides), use tools depending on their necessity. In addition, children aged 3 to 5 years were examined to investigate the developmental pattern. The task involved choosing between using a body part (i.e. crows: beak; humans: hand) or a tool for retrieving a reward from a box. All subjects were tested in two conditions. In the Body+/Tool- condition, using the body was more efficient than using the tool, and conversely in the Body-/Tool+ condition. Our results suggest that the capacity to employ tools economically develops late in humans. Crows, however, failed to choose economically. At the individual level, some subjects exhibited striking individual preferences for either using a tool or their beak throughout the task. Whether such biases depend on individual experience or whether they are genetically determined remains to be investigated. Our findings provide new insights about tool use and its cognitive implementation in two outstanding tool-using taxa.

Higher levels of motor competence are associated with reduced interference in action perception across the lifespan

Action perception and action production are tightly linked and elicit bi-directional influences on each other when performed simultaneously. In this study, we investigated whether age-related differences in manual fine-motor competence and/or age affect the (interfering) influence of action production on simultaneous action perception. In a cross-sectional eye-tracking study, participants of a broad age range (N = 181, 20-80 years) observed a manual grasp-and-transport action while performing an additional motor or cognitive distractor task. Action perception was measured via participants' frequency of anticipatory gaze shifts towards the action goal. Manual fine-motor competence was assessed with the Motor Performance Series. The interference effect in action perception was greater in the motor than the cognitive distractor task. Furthermore, manual fine-motor competence and age in years were both associated with this interference. The better the participants' manual fine-motor competence and the younger they were, the smaller the interference effect. However, when both influencing factors (age and fine-motor competence) were taken into account, a model including only age-related differences in manual fine-motor competence best fit with our data. These results add to the existing literature that motor competence and its age-related differences influence the interference effects between action perception and production.

Counterpoint

Claims about alterations in perception based on manipulations of the energetics hypothesis (and other influences) are often framed as interesting specifically because they affect our perceptual experience. Many control experiments conducted on such perceptual effects suggest, however, that they are the result of attribution effects and other kinds of judgmental biases influencing the reporting process rather than perception itself. Schnall (2017, this issue), appealing to Heider's work on attribution, argues that it is fruitless to try to distinguish between perception and attribution. This makes the energetics hypothesis less interesting.

Does weight lifting improve visual acuity? A replication of Gonzalo-Fonrodona and Porras (2013)

Objective

A physical effort such as lifting up a weight affects our perception and cognition. A previous study reported in two experiments that weight lifting improves visual acuity. In the previous study, participants’ visual acuity was higher while lifting weights than while resting. Moreover, via a case study, that study further showed that the heavier the weight, the better the visual acuity. These experiments, although interesting, lacked methodological details and thorough statistical analyses. We thus conducted experiments similar to these two previous ones that mitigated these issues.

Results

Although our results of Experiment 1 echoed those of the previous study, the results of Experiment 2 did not support the latter case report. Thus, our results suggest that the bodily experience of weights improves visual acuity, but a gradual increase in weight does not seem to lead to a gradual increase in visual acuity.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2699-1) contains supplementary material, which is available to authorized users.

Does grasping capacity influence object size estimates? It depends on the context

Linkenauger, Witt, and Proffitt (Journal of Experimental Psychology: Human Perception and Performance, 37(5), 1432–1441, 2011, Experiment 2) reported that right-handers estimated objects as smaller if they intended to grasp them in their right rather than their left hand. Based on the action-specific account, they argued that this scaling effect occurred because participants believed their right hand could grasp larger objects. However, Collier and Lawson (Journal of Experimental Psychology: Human Perception and Performance, 43(4), 749–769, 2017) failed to replicate this effect. Here, we investigated whether this discrepancy in results arose from demand characteristics. We investigated two forms of demand characteristics: altering responses following conscious hypothesis guessing (Experiments 1 and 2), and subtle influences of the experimental context (Experiment 3). We found no scaling effects when participants were given instructions which implied the expected outcome of the experiment (Experiment 1), but they were obtained when we used unrealistically explicit instructions which gave the exact prediction made by the action-specific account (Experiment 2). Scaling effects were also found using a context in which grasping capacity could seem relevant for size estimation (by asking participants about the perceived graspability of an object immediately before asking about its size on every trial, as was done in Linkenauger et al., 2011; Experiment 2). These results suggest that demand characteristics due to context effects could explain the scaling effects reported in Experiment 2 of Linkenauger et al. (2011), rather than either hypothesis guessing, or, as proposed by the action-specific account, a change in the perceived size of objects.

Action ability modulates time-to-collision judgments

Time-to-collision (TTC) underestimation has been interpreted as an adaptive response that allows observers to have more time to engage in a defensive behaviour. This bias seems, therefore, strongly linked to action preparation. There is evidence that the observer’s physical fitness modulates the underestimation effect so that people who need more time to react (i.e. those with less physical fitness) show a stronger underestimation effect. Here we investigated whether this bias is influenced by the momentary action capability of the observers. In the first experiment, participants estimated the time-to-collision of threatening or non-threatening stimuli while being mildly immobilized (with a chin rest) or while standing freely. Having reduced the possibility of movement led participants to show more underestimation of the approaching stimuli. However, this effect was not stronger for threatening relative to non-threatening stimuli. The effect of the action capability found in the first experiment could be interpreted as an expansion of peripersonal space (PPS). In the second experiment, we thus investigated the generality of this effect using an established paradigm to measure the size of peripersonal space. Participants bisected lines from different distances while in the chin rest or standing freely. The results replicated the classic left-to-right gradient in lateral spatial attention with increasing viewing distance, but no effect of immobilization was found. The manipulation of the momentary action capability of the observers influenced the participants’ performance in the TTC task but not in the line bisection task. These results are discussed in relation to the different functions of PPS.

Bodily Effort Enhances Learning and Metacognition: Investigating the Relation Between Physical Effort and Cognition Using Dual-Process Models of Embodiment

Recent embodiment research revealed that cognitive processes can be influenced by bodily cues. Some of these cues were found to elicit disparate effects on cognition. For instance, weight sensations can inhibit problem-solving performance, but were shown to increase judgments regarding recall probability (judgments of learning; JOLs) in memory tasks. We investigated the effects of physical effort on learning and metacognition by conducting two studies in which we varied whether a backpack was worn or not while 20 nouns were to be learned. Participants entered a JOL for each word and completed a recall test. Experiment 1 (N = 18) revealed that exerting physical effort by wearing a backpack led to higher JOLs for easy nouns, without a notable effect on difficult nouns. Participants who wore a backpack reached higher recall scores. Therefore, physical effort may act as a form of desirable difficulty during learning. In Experiment 2 (N = 30), the influence of physical effort on JOL s and learning disappeared when more difficult nouns were to be learned, implying that a high cognitive load may diminish bodily effects. These findings suggest that physical effort mainly influences superficial modes of thought and raise doubts concerning the explanatory power of metaphor-centered accounts of embodiment for higher-level cognition.

It's out of my hands! Grasping capacity may not influence perceived object size

Linkenauger, Witt, and Proffitt (2011) found that the perceived size of graspable objects was scaled by perceived grasping capacity. However, it is possible that this effect occurred because object size was estimated on the same trial as grasping capacity. This may have led to a conflation of estimates of perceived action capacity and spatial properties. In 5 experiments, we tested Linkenauger et al.’s claim that right-handed observers overestimate the grasping capacity of their right hand relative to their left hand, and that this, in turn, leads them to underestimate the size of objects to-be-grasped in their right hand relative to their left hand. We replicated the finding that right handers overestimate the size and grasping capacity of their right hand relative to their left hand. However, when estimates of object size and grasping capacity were made in separate tasks, objects grasped in the right hand were not underestimated relative to those grasped in the left hand. Further, when grasping capacity was physically restricted, observers appropriately recalibrated their perception of their maximum grasp but estimates of object size were unaffected. Our results suggest that changes in action capacity may not influence perceived object size if sources of conflation are controlled for.

The action-specific account of perception suggests that an observer’s capacity for action scales how the environment appears to them and, specifically, how they perceive its spatial properties. However, contrary to the predictions of this account, the results of the present studies suggest that perceived object size is not influenced by either actual or perceived grasping capacity. First, although right handers perceived their right hand to be both larger and to have a greater grasping capacity than their left hand, size estimates for an object were not influenced by which hand was used to grasp that object. Second, in a stronger manipulation, we reduced both the actual and the perceived grasping capacity of one hand by taping its fingers together. Despite this causing a substantial reduction in action capacity, it did not influence estimates of object size. These results show that action capacity and spatial properties can be perceived independently.

Up, Down, Near, Far: An Online Vestibular Contribution to Distance Judgement

Whether a visual stimulus seems near or far away depends partly on its vertical elevation. Contrasting theories suggest either that perception of distance could vary with elevation, because of memory of previous upwards efforts in climbing to overcome gravity, or because of fear of falling associated with the downwards direction. The vestibular system provides a fundamental signal for the downward direction of gravity, but the relation between this signal and depth perception remains unexplored. Here we report an experiment on vestibular contributions to depth perception, using Virtual Reality. We asked participants to judge the absolute distance of an object presented on a plane at different elevations during brief artificial vestibular inputs. Relative to distance estimates collected with the object at the level of horizon, participants tended to overestimate distances when the object was presented above the level of horizon and the head was tilted upward and underestimate them when the object was presented below the level of horizon. Interestingly, adding artificial vestibular inputs strengthened these distance biases, showing that online multisensory signals, and not only stored information, contribute to such distance illusions. Our results support the gravity theory of depth perception, and show that vestibular signals make an on-line contribution to the perception of effort, and thus of distance.

Are Effects of Action on Perception Real? Evidence from Transformed Movements

It has been argued that several reported non-visual influences on perception cannot be truly perceptual. If they were, they should affect the perception of target objects and reference objects used to express perceptual judgments, and thus cancel each other out. This reasoning presumes that non-visual manipulations impact target objects and comparison objects equally. In the present study we show that equalizing a body-related manipulation between target objects and reference objects essentially abolishes the impact of that manipulation so as it should do when that manipulation actually altered perception. Moreover, the manipulation has an impact on judgements when applied to only the target object but not to the reference object, and that impact reverses when only applied to the reference object but not to the target object. A perceptual explanation predicts this reversal, whereas explanations in terms of post-perceptual response biases or demand effects do not. Altogether these results suggest that body-related influences on perception cannot as a whole be attributed to extra-perceptual factors.

Design of embodied interfaces for engaging spatial cognition

Aspects of spatial cognition, specifically spatial skills, are strongly correlated with interest and success in STEM courses and STEM-related professions. Because growth in STEM-related industries is expected to continue for the foreseeable future, it is important to develop evidence-based and theoretically grounded methods and interventions that can help train relevant spatial skills. In this article, we discuss research showing that aspects of spatial cognition are embodied and how these findings and theoretical developments can be used to influence the design of tangible and embodied interfaces (TEIs). TEIs seek to bring interaction with digital content off the screen and into the physical environment. By incorporating physical movement and tangible feedback in digital systems, TEIs can leverage the relationship between the body and spatial cognition to engage, support, or improve spatial skills. We use this knowledge to define a design space for TEIs that engage spatial cognition and illustrate how TEIs that are designed and evaluated from a spatial cognition perspective can expand the design space in ways that contribute to the fields of cognitive science and human computer interaction.

Sizing Up Objects: The Effect of Diminutive Forms on Positive Mood, Value, and Size Judgments

Language (e.g., structure, morphology, and wording) can direct our attention toward the specific properties of an object, in turn influencing the mental representation of that same object. In this paper, we examined this idea by focusing on a particular linguistic form of diminution used in many languages (e.g., in Polish, Spanish, and Portuguese) to refer to an object as being “smaller.” Interestingly, although objects are usually considered “better” when they are bigger in size, objects described with linguistic diminution can also refer to those that are emotionally positive. Across three experiments conducted in Polish, we examined this lexical ambiguity in terms of mood (Experiment 1), subjective quality and monetary value (Experiment 2), and choice selection (Experiment 3). Overall, we found that people evaluate objects differently depending on the linguistic form (i.e., with or without diminution) with which they are described, and that it was related to the perceptual representation of these objects, and not their affective status. Objects described with diminution are evaluated as less satisfying and of lesser value and this effect is attributed to the way participants represent the objects (i.e., encoded and memorized). The generalizability of these effects is discussed.

Do Individual Differences and Aging Effects in the Estimation of Geographical Slant Reflect Cognitive or Perceptual Effects?

Several individual differences including age have been suggested to affect the perception of slant. A cross-sectional study of outdoor hill estimation (N = 106) was analyzed using individual difference measures of age, experiential knowledge, fitness, personality traits, and sex. Of particular note, it was found that for participants who reported any experiential knowledge about slant, estimates decreased (i.e., became more accurate) as conscientiousness increased, suggesting that more conscientious individuals were more deliberate about taking their experiential knowledge (rather than perception) into account. Effects of fitness were limited to those without experiential knowledge, suggesting that they, too, may be cognitive rather than perceptual. The observed effects of age, which tended to produce lower, more accurate estimates of hill slant, provide more evidence that older adults do not see hills as steeper. The main effect of age was to lower slant estimates; such effects may be due to implicit experiential knowledge acquired over a lifetime. The results indicate the impact of cognitive, rather than perceptual factors on individual differences in slant estimation.

Fear Similarly Alters Perceptual Estimates of and Actions over Gaps

Previous research has demonstrated an influence of one's emotional state on estimates of spatial layout. For example, estimates of heights are larger when the viewer is someone typically afraid of heights (trait fear) or someone who, in the moment, is experiencing elevated levels of fear (state fear). Embodied perception theories have suggested that such a change in perception occurs in order to alter future actions in a manner that reduces the likelihood of injury. However, other work has argued that when acting, it is important to have access to an accurate perception of space and that a change in conscious perception does not necessitate a change in action. No one has yet investigated emotional state, perceptual estimates, and action performance in a single paradigm. The goal of the current paper was to investigate whether fear influences perceptual estimates and action measures similarly or in a dissociable manner. In the current work, participants either estimated gap widths (Experiment 1) or were asked to step over gaps (Experiment 2) in a virtual environment. To induce fear, the gaps were placed at various heights up to 15 meters. Results showed an increase in gap width estimates as participants indicated experiencing more fear. The increase in gap estimates was mirrored in participants' stepping behavior in Experiment 2; participants stepped over fewer gaps when experiencing higher state and trait fear and, when participants actually stepped, they stepped farther over gap widths when experiencing more fear. The magnitude of the influence of fear on both perception and action were also remarkably similar (5.3 and 3.9 cm, respectively). These results lend support to embodied perception claims by demonstrating an influence on action of a similar magnitude as seen on estimates of gap widths.

Manual anchoring biases in slant estimation affect matches even for near surfaces

People verbally overestimate hill slant by ~15°-25°, whereas manual estimates (e.g., palm board measures) are thought to be more accurate. The relative accuracy of palm boards has contributed to the widely cited theoretical claim that they tap into an accurate, but unconscious, motor representation of locomotor space. Recently, it was shown that a bias that stems from anchoring the hand at horizontal prior to the estimate can quantitatively account for the difference between manual and verbal estimates of hill slant. The present work extends this observation to manual estimates of near-surface slant, to test whether the bias derives from manual or visual uncertainty. As with far surfaces, strong manual anchoring effects were obtained for a large range of near-surface slants, including 45°. Moreover, correlations between participants' manual and verbal estimates further support the conclusion that both measures are based on the same visual representation.

Self-estimation of physical ability in stepping over an obstacle is not mediated by visual height perception: a comparison between young and older adults

Older adults tend to overestimate their step-over ability. However, it is unclear as to whether this is caused by inaccurate self-estimation of physical ability or inaccurate perception of height. We, therefore, measured both visual height perception ability and self-estimation of step-over ability among young and older adults. Forty-seven older and 16 young adults performed a height perception test (HPT) and a step-over test (SOT). Participants visually judged the height of vertical bars from distances of 7 and 1 m away in the HPT, then self-estimated and, subsequently, actually performed a step-over action in the SOT. The results showed no significant difference between young and older adults in visual height perception. In the SOT, young adults tended to underestimate their step-over ability, whereas older adults either overestimated their abilities or underestimated them to a lesser extent than did the young adults. Moreover, visual height perception was not correlated with the self-estimation of step-over ability in both young and older adults. These results suggest that the self-overestimation of step-over ability which appeared in some healthy older adults may not be caused by the nature of visual height perception, but by other factor(s), such as the likely age-related nature of self-estimation of physical ability, per se.

Can you experience 'top-down' effects on perception?: The case of race categories and perceived lightness

A recent surge of research has revived the notion that higher-level cognitive states such as beliefs, desires, and categorical knowledge can directly change what we see. The force of such claims, however, has been undercut by an absence of visually apparent demonstrations of the form so often appealed to in vision science: such effects may be revealed by statistical analyses of observers' responses, but you cannot literally experience the alleged top-down effects yourself. A singular exception is an influential report that racial categorization alters the perceived lightness of faces, a claim that was bolstered by a striking visual demonstration that Black faces appear darker than White faces, even when matched for mean luminance. Here, we show that this visually compelling difference is explicable in terms of purely low-level factors. Observers who viewed heavily blurred versions of the original Black and White faces still judged the Black face to be darker and the White face to be lighter even when these observers could not perceive the races of the faces, and even when they explicitly judged the faces to be of the same race. We conclude that the best subjectively appreciable evidence for top-down influences on perception does not reflect a genuinely top-down effect after all: instead, such effects arise from more familiar (if subtle) bottom-up factors within visual processing.