Errors towards the perpendicular in children's copies of angular figures: a test of the bisection interpretation

Children distort angular figures so that the constituent angles are nearer 90 degrees than they should be. This could be due to a perpendicular bias or a bisection bias, or to both. A study is reported which was designed to establish whether a perpendicular bias would appear independently of bisection. Twenty four-year-old children were tested on two types of angular figure: (i) a baseline with another line joining at the end at 45 degrees, 90 degrees, or 135 degrees and (ii) a baseline with another line joining at the middle at 45 degrees or 90 degrees. Perpendicular errors were obtained both for 'end' and for 'middle' figures, but overall more strongly for 'middle' figures. However, while 90 degrees 'middle' figures were copied more accurately than 45 degrees/135 degrees figures, this effect was only obtained for vertical and horizontal presentations of 'end' figures, and was reversed for oblique presentations. Also, for 'end' figures, directional errors varied with subtended-line orientation, whereas for 'middle' figures they varied with baseline orientation. It is concluded that although errors towards the perpendicular do occur with single-angle figures, angle equalisation may take place when there are two adjacent angles in the figure. One interpretation of the differing orientation effects is that in 'middle' figures strong internal relational forces produce a distortion that varies with the angle at which the figure is viewed, whereas in 'end' figures the absence of relational forces within the figure leads to a stronger influence from external cues.     

Breakdown of spatial parallel coding in children's drawing

When drawing real scenes or copying simple geometric figures young children are highly sensitive to parallel cues and use them effectively. However, this sensitivity can break down in surprisingly simple tasks such as copying a single line where robust directional errors occur despite the presence of parallel cues. Before we can conclude that this directional bias is a limiting case it needs to be shown that any given parallel cues are indeed being processed. We achieved this by using a texture-defined contour where parallel cues are integral to the stimulus and thus cannot be ignored. Here we report that even when prolific parallel cues must have been processed, young children make robust directional errors when copying single lines. This finding demonstrates a major constraint on young children's spatial parallel coding.     

How to keep a reversible figure from reversing: teasing out top-down and bottom-up processes

The nature of processes underlying our perception of reversible figures was examined through two experiments investigating the effects of prior exposure conditions on an observer's report of figural reversal. In experiment 1, observers were adapted over several minutes to an unambiguous version of a rotating Necker cube prior to the presentation of the standard ambiguous figure. Results indicated that adaptation produced an immediate bias to perceive the ambiguous figure in the opposite configuration (ie reverse bias) and to reduce reports of reversal over the test period. The introduction of a brief delay between the adaptation and test periods revealed that this bias is a highly transient effect and is only clearly evident when the adaptation and test figures are matched in size. In experiment 2, observers were primed with an unambiguous figure for a few seconds prior to the presentation of the standard ambiguous figure. In this case, the obtained bias strongly favored the observer's reporting the ambiguous figure to be in the same configuration as the adapting figure (ie positive bias); and neither introducing a delay period nor changing figure size had any effect. We conclude that these experiments reveal the distinct roles of transient, retinally localized neural processes as well as more stable, global processes under specifiable conditions.     

Symmetry brings an impression of familiarity but does not improve recognition memory

Studies have shown that symmetric stimuli are recognized better than asymmetric stimuli but evidence suggests that this advantage may result from a familiarity bias induced by symmetry. We used a classic episodic memory paradigm to test this bias and see if it truly accounts for the symmetry advantage. Subjects first encoded symmetric and asymmetric figures. During a subsequent recognition phase, they discriminated the encoded (old) figures from new intermixed figures. The recognition rate of old figures was higher with symmetric figures than asymmetric figures. However, the tendency to falsely recognize new figures was also higher when they were symmetric, meaning that the higher recognition rate for symmetric figures was artificially inflated by a response bias. Three other experiments further tested this finding and examined the influence of some variables (rotation in virtual 3D space, stimulus meaningfulness, and redundancy of information) on the bias. A fifth experiment with photo stimuli confirmed that the response bias also applies to objects that we regularly encounter in everyday life. In conclusion, our results show that symmetry does not enhance mnemonic processes but instead induces a response bias leading individuals to judge such stimuli as having been seen.     

Representational bias does not affect bisection of lines with a pictorially or semantically defined top by patients with left hemispatial neglect

Normal subjects may have both representational and visual-based components determining bias in bisection of horizontal, vertical, and radial lines. The influence of these components is less clear in patients with neglect. We asked 25 patients with right hemisphere stroke and clinical features of neglect to bisect lines oriented horizontally, vertically, and radially above and below eye level. Objects including human silhouette figures, arrowheads, and the words 'TOP' and 'BOTTOM' were placed at either end of each line. These figures were presented either upright or upside down in some orientations, and presented rightward and leftward in other orientations, to pictorially or semantically define a "top" to each line independent of the actual top of the visual field. Patients demonstrated a rightward bias on all horizontal line bisections, with similar bias and greater magnitude than normal subjects. Patients also demonstrated visual-based biases on some of the vertical, radial down, and radial up lines presented. However, patients did not demonstrate a significant representational bias with any of the visual cues presented on any of the line orientations. Patients with acute right hemisphere stroke demonstrate a rightward bias when asked to perform line bisection in the horizontal line orientation, as well as an upward bias in vertical line bisection. The lack of representational bias in patients with neglect may be due to a greater degree of visual-based neglect as compared to representational neglect, or it may be due to an absence of representational bias in patients with right hemisphere stroke.     

Expanding angles? Systematic distortions of space involving angular figures

Using simple, single angular figures, including figures containing only one line, we have shown systematic misestimations of distance defined by these figures. These misestimations are not related to the absolute distance per se, but are related both to the size of the angle defining the distance, and to the part of the angle defining it. Some implications of these findings are discussed.     

Mental rotation performance in primary school age children: Are there gender differences in chronometric tests?

In contrast to the well documented male advantage in psychometric mental rotation tests, gender differences in chronometric experimental designs are still under dispute. Therefore, a systematic investigation of gender differences in mental rotation performance in primary-school children is presented in this paper. A chronometric mental rotation task was used to test 449 second and fourth graders. The children were tested in three separate groups each with different stimulus material (animal drawings, letters, or cube figures). The results show that chronometric mental rotation tasks with cube figures – even rotated in picture plane only – were too difficult for children in both age groups. Further analyses with animal drawings and letters as stimuli revealed an overall gender difference in response time (RT) favoring males, an increasing RT with increasing angular disparity for all children, and faster RTs for fourth graders compared to second graders. This is the first study which has shown consistent gender differences in chronometric mental rotation with primary school aged children regarding reaction time and accuracy while considering appropriate stimuli.     

Obesity Bias in Children: The Role of Actual and Perceived Body Size

The aim of this study was to examine how children perceive their body size and whether their actual or perceived body size can explain their anti‐fat views. Four hundred and fourteen 5–6, 7–8 and 9–10‐year‐old children were read short vignettes depicting two characters, one possessing a positive and the other a negative quality. Following each vignette, participants were asked to pick the story characters among thin, average and obese figures. Obesity bias was defined as the attribution of the positive quality to the thin or average figure and the corresponding negative one to the obese. Body mass index determined children's actual body size. Perceived body size was determined with the use of Collins' (1991) figures of increasing size. The results showed that actual body size affected the accuracy of perceived body size. While the majority of average children were accurate at identifying their body size, most overweight and obese children tended to underestimate it. The accuracy of body size perception improved with age. Obesity bias did not relate to children's actual but to their perceived body size: Those who perceived themselves as heavier exhibited less bias. The implications of the findings are discussed in relation to children's developing identity, and suggestions are made for future research. Copyright © 2014 John Wiley & Sons, Ltd.     

Decrement in the horizontal-vertical illusion: are subjects aware of their increased accuracy?

47 subjects adjusted the extended vertical lines of 20 inverted-T figures to make them appear equal to a horizontal line and rated the confidence in their accuracy after each trial. One group viewed figures of varying sizes, a second group viewed figures of standard size, and a third group viewed figures of standard size but received feedback on their accuracy immediately after completing Trial 5. Except for a significant increase in accuracy on Trial 6 for the Feedback Group, there were no differences in performance among groups. Subjects made the vertical line significantly shorter than the horizontal line on initial trials but their accuracy improved over trials. In contrast, there was no consistent increase in confidence, and several analyses indicated that confidence ratings were unrelated to accuracy. These results suggest that the subjects were unaware of the decrement in illusion that occurred over trials.     

Development of the ability to judge relative areas: Role of the procedure of placing one object on another

This study examined the role of the cognitive procedure of superimposition in the development of an area concept. Forty-five children from age 4 to 6 were presented with target squares or rectangles and asked to choose one that was equal to two standard rectangles in area. In the perceptual judgment condition, children compared these figures just by looking; whereas, in the manipulative judgment condition, they placed the standard figures on the targets. Children were also asked to compare the sizes of geometric figures, and their spontaneous strategies were observed. The children performed better under the manipulative judgment condition than under the perceptual judgment condition, and their performance was facilitated when one target could be overlapped completely with the standard figures. Each of these facilitating effects was found independently of the other only in children who used the strategy of superimposition spontaneously for comparing sizes.     

Cognitive Bias for Pictorial and Linguistic Threat Cues in Children

The present study was designed to test the conditions under which threat-related cognitive bias can be observed in anxious children. Measures of cognitive bias for threatening words and pictures were obtained from spider fearful children (N = 55) and non-fearful children (N = 58) aged 8–11 in the first experiment, and from spider fearful children (N = 44), and two control groups (N = 41; N = 36) aged 8 in the second experiment. Cognitive bias was assessed by the emotional Stroop task. In line with our previous findings, all children aged 8 showed a bias for spider words, but not for spider pictures. However, a relation between spider fear and bias was observed when age was taken into account: bias for spider words decreased with age in the non-fearful children whereas this bias maintained in the fearful group. This differential age effect too replicated earlier findings (Kindt, Bierman, & Brosschot, 1997). It is suggested that a bias for threat words is a normal characteristic in children aged 8. During development, normal children learn to inhibit this processing bias, whilst fearful children fail to learn this ability.     

完美主义者对不完美图形的注意偏好研究

本研究通过两组点探测任务实验,考察高完美主义者和低完美主义者对不完美图形的注意模式。两组实验都表明,当不完美图形与完美图形成对出现时,高完美主义的个体倾向于回避不完美图形,而低完美主义的个体对不完美图形表现出一定的注意倾向。图形不完美的程度对被试的注意偏好模式也有影响。被试比较容易从对中度不完美图形的注意中抽离出来。研究者推断：不完美图形能够唤起完美主义者的“不完美焦虑”,产生注意俘获效应,使其比非完美主义者更难从对这类图形的注意中抽离。     

Nonholistic processing in mental rotation: Some suggestive evidence

A series of experiments, using a modification of the Shepard and Metzler mental rotation task, was performed to investigate Shepard’s “holistic rotation” hypothesis. Effective figural complexity was manipulated in the experiments in two distinct ways. In one manipulation, blocks were added to the standard 10-blockfigures. In the other manipulation, the figures used and the direction of angular rotation were restricted so that some featural information in the figures was redundant, that is, unnecessary for the discrimination task at hand. There were two major conclusions. First, when figural complexity is effectively manipulated, it has a powerful effect on the “speed of mental rotation,” as measured by the slope of the curve relating reaction time to angular disparity. Second, it is possible, by ignoring featural redundancy, to construct experimental paradigms in which “complexity” of figures is apparently manipulated but has no effect on speed of mental rotation. This fact provides a possible explanation of why some previous experiments have failed to find a complexity effect in mental rotation.     

数字线和离散物体任务训练对儿童整数偏向的影响

通过数字线任务和离散物体任务对81名拥有错误整数偏向的儿童进行干预,再进行分数比较任务,以考查不同干预对错误整数偏向的影响以及分数在心理数字线上的表征方式。结果表明：（1）离散物体组儿童在干预任务中表现较好,在分数比较任务中得分也显著高于数字线组儿童,但反应时要慢于数字线组儿童。（2）正确比较分数时,两组均出现正确整数偏向,但错误的整数偏向依然存在,二者在整数系统扩展到有理数系统这个过渡期同时存在。     

The role of structural components in the Mueller-Lyer illusion

In order to assess the role of the structural components of the Mueller-Lyer illusion, subjects reproduced the central extent of standard Mueller-Lyer figures and configural variations. Illusory magnitude of the underestimated wings-in and overestimated wings-out figures was examined with selective amputations of the oblique wings and central line segment (shaft). Variations were presented at 0, 45, 90, and 135 deg from vertical. Orientation had no reliable effect on illusory magnitude. Elimination of the shaft effected a decrease in the apparent extent for all variations, presumably due to the addition of the filled-unfilled space illusory effect to the standard Mueller-Lyer effect. A second study corroborated this finding The decrease in apparent extent consequent to shaft removal occurred independently of any response factor. Selective wing removal differentially decreased the illusory magnitude of the standard Mueller-Lyer figures; this was discussed with regard to a dual-illusion hypothesis. Finally, variations that contained no intersecting lines produced a significant illusion in the direction of the standard Mueller-Lyer figures, suggesting the involvement of higher level, nonperipheral distortion mechanisms.     

Angular induction as a function of contact and target orientation

The Poggendorff effect is seen as misalignment of two obliques, or misprojection of one, when the obliques are placed outside a set of parallel lines. To understand better the mechanisms behind this effect, the orientation of the lines which are normally parallel was systematically manipulated. The results indicate that projection bias is affected by the orientation of either line, is at a minimum where the line is orthogonal to the oblique, and is maximal at small angles. This is in line with classic theories which attribute the illusion to misperception of angular size. However, such explanations presuppose that in order to be effective the induction line must be proximal to the oblique so that an angle can be formed. Results are reported which show that the angle formed by the oblique and a line placed at a distance from the oblique, serving as the target of the projection, follows an angular rule of effectiveness similar to what is seen when the line is placed directly in contact with the oblique. The underlying process is described as 'angular induction'.     

Factors influencing perceived angular velocity.

The assumption that humans are able to perceive and process angular kinematics is critical to many structure-from-motion and optical flow models. The current studies investigate this sensitivity, and examine several factors likely to influence angular velocity perception. In particular, three factors are considered: (1) the extent to which perceived angular velocity is determined by edge transitions of surface elements, (2) the extent to which angular velocity estimates are influenced by instantaneous linear velocities of surface elements, and (3) whether element-velocity effects are related to three-dimensional (3-D) tangential velocities or to two-dimensional (2-D) image velocities. Edge-transition rate biased angular velocity estimates only when edges were highly salient. Element velocities influenced perceived angular velocity; this bias was related to 2-D image velocity rather than 3-D tangential velocity. Despite these biases, however, judgments were most strongly determined by the true angular velocity. Sensitivity to this higher order motion parameter was surprisingly good, for rotations both in depth (y-axis) and parallel to the line of sight (z-axis).     

Assessing anti-fat bias in preschoolers: a comparison of a computer generated line-drawn figure array and photographic figure array

This study examined differences in preschoolers' ratings of anti-fat bias and identification of current body size depending on the realism of the figure array used: computer generated line-drawn or photographic. Children reported strong anti-fat bias with both arrays. However, less extreme bias was elicited with the photographic figure array. In addition, children were inaccurate reporters of their current body size when both figure arrays were used. However, children were consistent in their selection of figures that were thinner than their actual body size. Children's consistent selection of thinner figures as representative of their current body size may be an additional indicator of anti-fat bias. Overall, these results suggest that some of the anti-fat bias observed in preschoolers is attributable to less realistic figure arrays. Therefore, photographic figure arrays are proposed as a better measurement tool in the assessment of anti-fat bias in preschoolers.     

Factors influencing perceived angular velocity

The assumption that humans are able to perceive and process-angular kinematics is critical to many structure-from-motion and optical flow models. The current studies investigate this sensitivity, and examine several factors likely to influence angular velocity perception. In particular, three factors are considered: (1) the extent to which perceived angular velocity is determined by edge transitions of surface elements, (2) the extent to which angular velocity estimates are influenced by instantaneous linear velocities of surface elements, and (3) whether element-velocity effects are related to three-dimensional (3-D) tangential velocities or to two-dimensional (2-D) image velocities. Edge-transition rate biased angular velocity estimates only when edges were highly salient. Element velocities influenced perceived angular velocity; this bias was related to 2-D image velocity rather than 3-D tangential velocity. Despite these biases, however, judgments were most strongly determined by the true angular velocity. Sensitivity to this higher order motion parameter was surprisingly good, for rotations both in depth (y-axis) and parallel to the line of sight (z-axis).     

Maternal Expectancy Versus Objective Measures of Child Skill: Evidence for Absence of Positive Bias in Mothers’ Expectations of Children with Internalizing Disorders

Parents of anxious children are thought to be more attuned to threat, which might translate into less positive bias in parental report of child coping and ability, unlike parents of non-anxious children. Maternal expectancy bias was examined in a sample of 43 clinically anxious (51 % female), 30 clinically anxious/depressed (50 % female), and 44 non-clinical control children (46 % female), 8–14 years of age. When compared to an objective observer’s ratings of the children, mothers of non-clinical children demonstrated a positive bias (i.e., over-rated their children’s performance) for both ratings of expected speech performance in absolute terms and relative to peers. Mothers in the clinical groups did not exhibit this positive expectancy bias. Moreover, mothers of clinical children reported lower expectations in absolute terms and relative to peers than mothers of non-clinical children. The data suggest that mothers of clinical children held accurate expectations for child performance when compared to the gold standard of an objective observer.