The accuracy of ‘haptically’ measured geographical slant perception

In two recent issues of Acta, the widely accepted view of Proffitt (2006), that ‘haptic’ measures of perceived geographical slant are generally accurate, and dissociated from explicit overestimates, came under intense scrutiny (Durgin, Hajnal, Li, Tonge, and Stigliani, 2010; 2011). Durgin and colleagues' challenge to this account centred on the claim that Proffitt's haptic’ measure of geographical slant, the palm-board, may be accidently accurate due to restricted movements available at the wrist. Two experiments reported here compare the accuracy of Proffitt's palm-board with an alternative measure of geographical slant perception, the Palm-Controlled Inclinometer (PCI), which allows participants to use wrist, elbow and shoulder movements to match slant with their hand. Participants (N = 320) made slant judgements using both measures, across five hills and five staircases with 32 participants for each stimulus angle (4.5°–31°). Results for the palm-board replicated those of Proffitt and co-workers, overestimation at shallow angles (≤ 14°), contrasted with underestimation at steeper angles (≥ 23°), whereas estimates made using the PCI had a greater degree of accuracy for steeper slopes. A follow-up experiment tested the accuracy of the palm-board and PCI for surfaces in near space to repeat the design of Durgin et al. (2010, experiment 1). Participants (N = 20) used the palm-board and PCI to judge the angle of slanted blocks (25°, 30°). As with traversable slopes, PCI judgements did not differ from the actual angle of the blocks whereas the palm-board measure underestimated. ‘Haptic’ measures of geographical slant perception can be accurate for relatively steep slopes, in both near and far space.     

Summarizing slant perception with words and hands; an empirical alternative to correlations in Shaffer,McManama, Swank,Williams & Durgin (2014)

The paper by Shaffer, McManama, Swank, Williams & Durgin (2014) uses correlations between palm-board and verbal estimates of geographical slant to argue against dissociation of the two measures. This paper reports the correlations between the verbal, visual and palm-board measures of geographical slant used by Proffitt and co-workers as a counterpoint to the analyses presented by Shaffer and colleagues. The data are for slant perception of staircases in a station (N = 269), a shopping mall (N = 229) and a civic square (N = 109). In all three studies, modest correlations between the palm-board matches and the verbal reports were obtained. Multiple-regression analyses of potential contributors to verbal reports, however, indicated no unique association between verbal and palm-board measures. Data from three further studies (combined N = 528) also show no evidence of any relationship. Shared method variance between visual and palm-board matches could account for the modest association between palm-boards and verbal reports.     

Design,data, and theory regarding a digital hand inclinometer: a portable device for studying slant perception

Palm boards are often used as a nonverbal measure in human slant perception studies. It was recently found that palm boards are biased and relatively insensitive measures, and that an unrestricted hand gesture provides a more sensitive response (Durgin, Hajnal, Li, Tonge, & Stigliani, Acta Psychologica, 134, 182-197, 2010a). In this article, we describe an original design for a portable lightweight digital device for measuring hand orientation. This device is microcontroller-based and uses a micro inclinometer chip as its inclination sensor. The parts are fairly inexpensive. This device, used to measure hand orientation, provides a sensitive nonverbal method for studying slant perception, which can be used in both indoor and outdoor environments. We present data comparing the use of a free hand to palm-board and verbal measures for surfaces within reach and explain how to interpret free-hand measures for outdoor hills.     

What do hands know about hills? Interpreting Taylor-Covill and Eves (2013) in context

Hills appear much steeper than they are. Although near surface slant is also exaggerated, near surfaces appear much shallower than equivalently slanted hills. Taylor-Covill and Eves (2013) propose a new type of palm orientation measuring device that provides outputs that accurately reflect the physical slants of stairs and hills from 19 to 30° and also seems to accurately reflect the slants of near surfaces (25–30°). They question the validity of the observations of Durgin, Hajnal, Li, Tonge & Stigliani (2010), who observed that palm boards grossly underestimated near surfaces. Here I review our recent work on the visual and haptic perception of near surface orientation in order to place Taylor-Covill and Eves' arguments in context. I note in particular that free hand measures of real surfaces in near space show excellent calibration, but free hand measures show gross exaggeration for hills. This leads to the question of the grounds for preferring a mechanical device to a freely wielded hand. In addition I report an investigative replication of the crucial observations that led to our concerns about the value of palm boards as measures of perception and note the specific methodological details that we have accounted for in our procedures. Finally, I propose some testable hypotheses regarding how better-than-expected haptic matches to hills may arise.     

Explicit and motoric dependent measures of geographical slant are dissociable: A reassessment of the findings of Durgin, Hajnal, Li, Tonge, and Stigliani (2010)

Durgin et al. (2010) argued that the apparent accuracy of the palmboard measure of geographical slant is accidental and reflects limitations in wrist flexion that reduce palmboard adjustments by just the right amount given the perceptual overestimations upon which they are based. This account is inconsistent with findings that verbal reports and palmboard adjustments are dissociable. In addition to previous evidence found for such dissociation, Durgin et al. also found verbal/palmboard dissociations in Experiment 2. Experiments 1 and 3 of Durgin et al. lacked verbal reports and instead compared palmboard adjustments to free-hand estimates in the context of small wooden surfaces. These experiments are not relevant to the issue of verbal/palmboard dissociability. Across studies, the accuracy of Durgin et al.'s palmboard implementation is far less than that found by others (Feresin & Agostini, 2007). The design of Durgin et al.'s Experiment 5 misrepresented the experimental conditions of Creem and Proffitt (1998), and consequently, the findings of this study have no bearing on the issue at hand.     

An effect of mood on the perception of geographical slant

Previous research has shown that hills appear steeper to those who are fatigued, encumbered, of low physical fitness, elderly, or in declining health (Bhalla & Proffitt, 1999; Proffitt, Bhalla, Gossweiler, & Midgett, 1995). The prevailing interpretation of this research is that observers' perceptions of the environment are influenced by their capacity to navigate that environment. The current studies extend this programme by investigating more subtle embodied effects on perception of slant; namely those of mood. In two studies, with two different mood manipulations, and two estimates of slant in each, observers in a sad mood reported hills to be steeper. These results support the role of mood and motivational factors in influencing spatial perception, adding to the previous work showing that energetic potential can influence perception.     

An effect of mood on the perception of geographical slant

Previous research has shown that hills appear steeper to those who are fatigued, encumbered, of low physical fitness, elderly, or in declining health (Bhalla & Proffitt, 1999; Proffitt, Bhalla, Gossweiler, & Midgett, 1995). The prevailing interpretation of this research is that observers’ perceptions of the environment are influenced by their capacity to navigate that environment. The current studies extend this programme by investigating more subtle embodied effects on perception of slant; namely those of mood. In two studies, with two different mood manipulations, and two estimates of slant in each, observers in a sad mood reported hills to be steeper. These results support the role of mood and motivational factors in influencing spatial perception, adding to the previous work showing that energetic potential can influence perception.     

Is there any Proffitt in stair climbing? A headcount of studies testing for demographic differences in choice of stairs

The apparent slope of a hill, termed geographical slant perception, is overestimated in explicit awareness. Proffitt (2006) argued that overestimation allows individuals to manage their locomotor resources. Increasing age, fatigue, and wearing a heavy back pack will reduce the available resources and result in steeper reports for a particular hill. In contrast, Durgin and colleagues have proposed an alternative explanation for these effects based on experimental design—particularly, the potential effects of experimental demand. Proffitt’s resource-based model would predict that pedestrians with reduced resources should avoid climbing a hill that would further deplete their resources if the opportunity arose. Within the built environment, stairs are the man-made equivalent of relatively steep hills (20°–30°). In many public access settings, pedestrians can avoid climbing the stairs by opting for an adjacent escalator. Observations of pedestrian behavior in shopping malls reveal that 94.5 % do so. This article summarizes the effects of demographic grouping on avoidance of stairs in public health research. Observations in shopping malls (n = 355,069) and travel contexts (n = 711,867) provide data consistent with Proffitt’s resource model. Women, the old, and those carrying excess body weight or large bags avoid the stairs more than do their comparison groups. Discussion focuses on differences in physiology that may underlie avoidance of stair climbing in order to highlight the pedestrian behavior that psychology needs to explain.     

Affordances matter in geographical slant perception

We argue that the experimental conditions in the Durgin et al. (2009) study were so different from those in Bhalla and Proffitt (1999) that the results of the former study cannot be generalized to the latter. The participants in the Durgin et al. study viewed a 2-m-long ramp; those in Bhalla and Proffitt viewed expansive hills. When drawing generalizations from one study to another, equating experimental conditions is always important; moreover, from an embodied perspective on perception, equating the opportunities for action also matters.     

Introduction to the special section on the neural substrate of analogical reasoning and metaphor comprehension

The special section on the neural substrate of relational reasoning includes 4 articles that address the processes and brain regions involved in analogical reasoning (Green, Kraemer, Fugelsang, Gray, & Dunbar, 2011; Maguire, McClelland, Donovan, Tillman, & Krawczyk, 2011) and in metaphor comprehension (Chettih, Durgin, & Grodner, 2011; Prat, Mason, & Just, 2011). We see this work as an example of how neuroscience approaches to cognition can lead to increased understanding of cognitive processes. In this brief introduction, we first situate the 4 articles in the context of prior cognitive neuroscience work on relational reasoning. We then highlight the main issues explored in these articles: different sources of complexity and difficulty in relational processing, potential differences between the roles of the 2 hemispheres, and the impact of individual differences in various cognitive abilities. The 4 articles illustrate a range of methodologies, including functional magnetic resonance imaging (fMRI; Green et al., 2011; Prat et al., 2011), event-related potentials (ERPs; Maguire et al., 2011), and different types of semantic priming (Chettih et al., 2011; Prat et al., 2011). They highlight the connections between research on analogy and on metaphor comprehension and suggest, collectively, that a cognitive neuroscience approach to relational reasoning can lead to converging conclusions.     

How little do we need for 3-D shape perception?

How little do we need to perceive 3-D shape in monocular natural images? The shape-from-texture and shape-from-shading perspectives would motivate that 3-D perception vanishes once low-level cues are disrupted. Is this the case in human vision? Or can top-down influences salvage the percept? In this study we probe this question by employing a gauge-figure paradigm similar to that used by Koenderink et al (1992, Perception & Psychophysics 52 487-496). Subjects were presented degraded natural images and instructed to make local assessments of slant and tilt at various locations thereby quantifying their internal 3-D percept. Analysis of subjects' responses reveals recognition to be a significant influence thereby allowing subjects to perceive 3-D shape at high levels of degradation. Specifically, we identify the 'medium-blur' condition, images approximately 32 pixels on a side, to be the limit for accurate 3-D shape perception. In addition, we find that degradation affects the perceived slant of point-estimates making images look flatter as degradation increases. A subsequent condition that eliminates texture and shading but preserves contour and recognition reveals how bottom-up and top-down cues can combine for accurate 3-D shape perception.     

Estimates of shape by eye, or, The little invariant that could

Five experiments were conducted to test the hypothesis that observers apprehend specific constancies under change in perspective. The constancies were projective properties of ellipses pictured to slant and tilt in depth. Observers were asked to reproduce the static upright view of a moving pair of ellipses, using a computer graphics display and interface. Projective invariants for pairs of conics were computed on the observers’ productions. A few experimental conditions revealed near-perfect performance. When pairs of coplanar ellipses were viewed under dynamic transformation in perspective, then invariants calculated on the observers’ productions were a match – in value on average – to the invariants of the transforming ellipse pairs. It is proposed that measures of projective properties afford a family of techniques that can be applied to gauge acuity for complex shapes in the study of visual form perception.     

The effect of texture relief on perception of slant from texture

Texture can be an effective source of information for perception of slant and curvature. A computational assumption required for some texture cues is that texture must be flat along a surface. There are many textures which violate this assumption, and have some sort of texture relief: variations perpendicular to the surface. Some examples include grass, which has vertical elements, or scattered rocks, which are volumetric elements with 3-D shapes. Previous studies of perception of slant from texture have not addressed the case of textures with relief. The experiments reported here test judgments of slant for textures with various types of relief, including textures composed of bumps, columns, and oriented elements. The presence of texture relief was found to affect judgments, indicating that perception of slant from texture is not robust to violations of the flat-texture assumption. For bumps and oriented elements, slant was underestimated relative to matching flat textures, while for columns textures, which had visible flat top faces, perceived slant was equal or greater than for flat textures. The differences can be explained by the way different types of texture relief affect the amount of optical compression in the projected image, which would be consistent with results from previous experiments using cue conflicts in flat textures. These results provide further evidence that compression contributes to perception of slant from texture.     

Perceiving virtual geographical slant: action influences perception

In 4 experiments, the authors varied the extent and nature of participant movement in a virtual environment to examine the influence of action on estimates of geographical slant. Previous studies showed that people consciously overestimate hill slant but can still accurately guide an action toward the hill (D. R. Proffitt, M. Bhalla, R. Gossweiler, & J. Midgett, 1995). Related studies suggest that one's potential to act may influence perception of slant and that distinct representations may independently inform perceptual and motoric responses. The authors found that in all conditions, perceptual judgments were overestimated and motoric adjustments were more accurate. The virtual environment allowed manipulation of the effort required to walk up simulated hills. Walking with the effort appropriate to the visual slant led to increased perceptual overestimation of slant compared with active walking with the effort appropriate to level ground, while visually guided actions remained accurate.     

Texture gradient effectiveness in the perception of surface slant

To assess the development of monocular slant perception as well as the relative effectiveness of different sources of information, children in first, third, and fifth grades and college adults were asked to make judgments of surface slant on the basis of monocular texture gradient information. Accuracy of judgment increased with increasing age. In addition, differences in gradient effectiveness were found. Compression gradients were relatively ineffective sources of information, whereas perspective and multiple gradients resulted in greater accuracy. The results suggest limitations on the specificity of certain forms of gradients.     

An imputed dissociation might be an artifact: Further evidence for the generalizability of the observations of Durgin et al. 2010

We recently showed that palm board measures are systematically inaccurate for full-cue surfaces within reach of one's hand, whereas free-hand gestures and reaching actions are quite accurate for such surfaces (Durgin, Hajnal, Li, Tonge, & Stigliani, 2010). Proffitt and Zadra (2010) claim that our demonstration that palm boards are highly inaccurate is irrelevant to interpreting past and present findings concerning dissociations between verbal reports and palm board estimates. In their paper they offer a theoretical representation of the findings of Bhalla and Proffitt (1999) and argue that our analysis is incompatible with their account. We offer here an alternative account of the findings of Bhalla and Proffitt, based on their actual data (which are fully compatible with our original analysis). We further show how our account generalizes to more recent studies that continue (1) to mistakenly describe null statistical effects on (insensitive) palm boards as evidence of a “dissociation” from (more sensitive) verbal measures that show a similar relative magnitude of change and (2) to introduce uncontrolled demand characteristics.     

Individual differences in women's perceptions of other women's dominance

Recent research on men's dominance perception suggests that the extent to which men perceive masculine men to be more dominant than relatively feminine men is negatively correlated with measures of their own dominance. In the current studies, we investigated the relationship between indices of women's own dominance and their perceptions of other women's facial dominance. Women's own height and scores on a dominance questionnaire were negatively correlated with the extent to which they perceived masculine women to be more dominant than relatively feminine women. In follow‐up studies, we observed similar individual differences when (i) women separately judged other women's social and physical dominance, suggesting that individual differences in women's dominance perceptions generalize across two different types of dominance judgment and (ii) we assessed the perceivers' dominance indirectly by using a questionnaire that measures the extent to which women view interactions with other women in competitive terms. These findings present new evidence that the extent to which people perceive masculine individuals to be more dominant than relatively feminine individuals is negatively correlated with measures of their own dominance and suggest that competition and conflict among women may have shaped individual differences in women's dominance perception. Copyright © 2011 John Wiley & Sons, Ltd.     

坡度知觉及其影响因素的研究进展

人们对于地表斜坡的知觉是非常不准确的,通常表现为对坡度估计过高。但是,研究发现,在以行为的方式对坡度进行模拟时,所模拟的坡度值却与实际坡度基本一致。这种面对同一视觉线索出现的视知觉与行为不一致的现象即为坡度知觉中的“知觉-行为分离”。本文回顾了影响坡度知觉的各种因素,涉及视觉线索、认知判断、感觉通道、生理状态以及报告方式等方面的研究,并对坡度知觉的未来研究进行了展望。     

Perceiving Aggression from Facial Structure: Further Evidence for a Positive Association with Facial Width‐to‐Height Ratio and Masculinity,but not for Moderation by Self‐Reported Dominance

Recent work has indicated that individual differences in facial structure are linked to perceptions of aggressiveness. In particular, the relative width of a face [facial width‐to‐height ratio (fWHR)] has been suggested to be a reliable cue to aggressive behaviour, at least in men. Additionally, facial masculinity has been associated with perceptions of dominance, a close proxy of aggressiveness. In two studies, we assessed the robustness of this link using faces transformed along these vectors in men (Studies 1 and 2) and women (Study 2). Additionally, we examined whether individual differences in self‐reported dominance of perceivers moderated this association in order to extend previous work indicating that own dominance affects perception of such behaviour in others. Results indicated that both male and female faces with increased fWHR and increased facial masculinity were perceived as more aggressive. However, we found no systematic evidence for moderating effects of self‐reported dominance on the perception of aggression in others. Taken together, these results further support the robustness of fWHR and facial masculinity as cues to aggressiveness but question whether observers' own dominance moderates their perception of these cues in others. Copyright © 2013 European Association of Personality Psychology