Discrimination and memory for symmetry in young children.

Conducted 3 experiments to assess the development of symmetry perception in children between the ages of 4 and 6 yrs. Exp I employed a learning task in which 72 Ss were asked at different times to discriminate vertically symmetrical, obliquely symmetrical, and horizontally symmetrical holistic patterns from asymmetrical ones. Results reveal a developmental progression: 4-yr-olds discriminated only vertical; 5-yr-olds, vertical and horizontal; and 6-yr-olds, vertical, horizontal, and oblique. Exp II retested the 18 6-yr-olds with fragmented patterns of the different symmetries; these Ss regressed to the performance level of 4-yr-olds and only discriminated vertical. Exp III, conducted with 18 Ss, used a memory-production task with new vertical, oblique, horizontal, and asymmetrical patterns constructed to 4, 5, or 6 elements. Measures of the goodness and accuracy of Ss' reproductions were consistent with data from the discrimination-learning experiments in terms of age, stimulus orientation, and stimulus complexity. These studies support the view that vertical symmetry is special perceptually and developmentally and that, after vertical, horizontal predominates, followed by oblique. The role of symmetry in early perceptual development and the value of child–adult perceptual comparisons are discussed. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination of shape reflections and shape orientations by Columba livia..

By using a free-operant instrumental discrimination procedure, it was demonstrated that pigeons find two-dimensional mirror-image visual forms more difficult to distinguish than otherwise similar forms. Variations in orientation of the discriminanda exacerbated the relative confusability of mirror images. No significant difference was found in the pigeons' performance whether the birds were discriminating vertically or horizontally reflected mirror-image pairs. Mirror images of shapes were also shown to be less discriminable than upside-down versions of shapes. The similarity of mirror-image patterns is discussed in relation to the generalized recognition of bilaterally symmetrical forms by pigeons. Pigeons found an orientation discrimination task involving a 45° tilt comparatively hard. A second experiment with a discrete-trial conditional paradigm confirmed that discriminations of shape orientations can be difficult for these birds. The addition of shape cues improved the performance on the orientation discrimination task, more so when arbitrary shapes were employed than when mirror images were used, which indicates again that the latter were more difficult to discriminate than the former. The relative insensitivity to shape orientations is ascribed to normal ecological demands on pigeons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unexceptional spatial memory in an exceptional memorist.

Rajan Mahadevan evidences an exceptional memory for arrays of digits. The authors tested whether Rajan's spatial memory was likewise exceptional. Eight control Ss and Rajan were instructed to remember the position and orientation of 48 images of common objects shown either to the left or the right of fixation and facing either left or right. Rajan's accuracy for judging whether the position and orientation of these pictures had changed when they were shown in a different sequence was lower than that of control Ss for both judgments. Rajan's exceptional memory capacity apparently does not extend to spatial relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The understanding of invariance by very young children.

Conducted 3 conservation experiments with a total of 164 3-6 yr. olds to determine whether young children understand the invariance of quantity. Results show that (a) even 3-yr-olds were able to transfer a quantity judgment over a perceptual transformation very well, (b) Ss only failed to make this kind of transfer when the judgments normally produced by the pre- and post-transformation displays were in direct conflict, and (c) training that some cues provide a more reliable basis for quantity judgments than others enabled Ss to transfer quantity judgments over perceptual transformations much more effectively than they had previously. It is concluded that very young children have a basic understanding of invariance, and that their real difficulty in quantity tasks is in distinguishing between a correct and an incorrect basis for quantity judgments. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional focus and locus of performance causality as determinants of equity behavior.

168 undergraduates divided reward between themselves and a competitor following performance on a task in which they were either responsible or not responsible for the results. While receiving performance feedback and allocating reward, Ss either faced a mirror (self-focused condition) or a nonreflecting surface (not-self-focused condition). The equity norm was followed when Ss were responsible for their performance, although the degree of differentiation between recipients was much more extreme among self-focused allocators than among not-self-focused allocators. The equality norm was followed when Ss were not responsible for their performance, regardless of their attentional focus. Results show that equity behavior is exacerbated by self-awareness when the Ss sees himself or herself as responsible for relative performance differences. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Consensus information and fundamental attribution error: The role of development and in-group versus out-group knowledge.

24 4-yr-olds, 24 9-yr-olds, and 24 undergraduates watched a target actor select an item from an array, and other actors either agreed (high consensus) or disagreed (low consensus) with the choice. Actors were either peers or nonpeers of the Ss, and the target's choice did or did not match the S's own preference. Ss were asked why the actor liked the chosen object best. Ss in all age groups appropriately used the consensus information. Nine-year-olds and adults, however, were much less likely to use the consensus information when judging peers than when judging nonpeers, suggesting the use of self-provided consensus information. Four-yr-olds made greater entity attributions when they agreed with the target actor's choice than when they disagreed, suggesting that young children use self-reference as a basis for normative expectancies. There was also a developmental shift in general attributional bias. Nine-year-olds and adults had a person bias for peer targets, but they had no attribution bias for nonpeer targets. Four-year-olds had an entity bias for both peer and nonpeer targets. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using mother as a spatial landmark: Evidence against egocentric coding in infancy.

30 9-mo-old infants learned to turn one way to view a visual event. In a transfer task, they were rotated 180°. The mothers of half the Ss moved with them as in previous procedures, and the other mothers remained in a fixed position throughout training and testing. Ss made more turns to the same spatial location when their mothers did not move. Thus, Ss used their mother's position as a cue to their spatial response. Results suggest that even in situations in which young infants were judged egocentric, they may have been using objective, nonegocentric information. Thus, even apparent errors do not preclude the presence of objective representation. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early postnatal X-irradiation of the hippocampus and discrimination learning in adult rats.

Trained Long-Evans rats with X-irradiation produced degranulation of the hippocampal dentate gyrus in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze in 3 experiments. The experiments employed the same treatment, apparatus, and procedure but varied in task difficulty. In the brightness and roughness discriminations, the irradiated Ss were not handicapped in acquiring or reversing discriminations of low or low-moderate task difficulty. However, these Ss were handicapped in acquiring and reversing discriminations of moderate and high task difficulty. In a Black/White discrimination in which the stimuli were restricted to the goal-arm walls, the irradiated Ss were handicapped in the acquisition (low task difficulty) and reversal (moderate task difficulty) phases of the task. Results suggest that the irradiated Ss were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. Results are consistent with the hypothesis that rats with hippocampal damage are inattentive due to hyperactivity. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parallel perceptual/cognitive functions in humans and rats: Space and time.

Examined 24 dark- (DR) and 24 light-reared (LR) male rats' ability to learn discriminations involving location of sounds or lights. Auditory signals were more effective and more salient in terms of establishing stimulus-response associations. Visually inexperienced DR Ss learned initial discriminations as rapidly as their LR controls except under ipsilateral response conditions with light signals. Visually naive DR Ss failed to demonstrate as much cross-modal transfer as did visually experienced LR Ss. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reference frame and effects of orientation on finding the tops of rotated objects.

Investigated effects of stimulus orientation across trial blocks and the spatial reference frame with a task in which Ss, with their heads upright or tilted, judged a dot to be near the top or the bottom of rotated line drawings of objects. Objects used in this task were also named. Response times from the 1st block of trials increased linearly for objects rotated from 0 to 120° from the upright. Across blocks, orientation effects diminished for naming but remained the same for top–bottom discriminations. Practice with top–bottom discriminations diminished orientation effects when the same objects were subsequently named. The spatial reference frame for top–bottom discrimination was midway between retinal and environmental coordinates. Specifying the location of object features is of greater importance for top–bottom discriminations than for naming and underlies orientation effects in these tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imprinting: Monocular and binocular cues in object discrimination.

Conducted 2 experiments with a total of 200 Peking ducklings (Anas platyrhyncos) which predicted that under monocular conditions an imprinted preference for a 3-dimensional object should be eliminated or reduced. Results show that binocular viewing was not essential for the establishment of imprinted preferences, contrary to expectations raised by the failure to imprint the Ss to 2-dimensional images. It is suggested that ducklings rely on a hierarchy of cues when making discriminations and that the order within the hierarchy may vary from one situation to the next. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading and generating normal and transformed sentences.

Three experiments (108 undergraduates) examined the relative contributions made in skilled and unskilled processing by data driven and conceptually driven processes. In Exp I, Ss recalled nouns and complete sentences after having read and generated meaningful and anomalous sentences. Generated and transformed sentences were better recalled than normal sentences if they were meaningful, but not if they were anomalous. Exp II used the same sentences as Exp I, except they were displayed in 3 typographies: normal orientation, mirror transformed, or rotated 180°. Results show that reading the transformed typography increased semantic interword organization. In Exp III, Ss had to generate sentences and read transformed typography. Results duplicate those in Exps I and II. It is concluded that a decrease in the efficiency of data driven processing causes an increase in semantic interword organization. (French abstract) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contrasting effects of lateral striate and superior colliculus lesions on visual discrimination performance in rhesus monkeys.

Tested 3 rhesus monkeys with lesions of lateral striate cortex (LSC), 4 monkeys with superior colliculus (SC) lesions, and 3 unoperated monkeys for retention of a preoperatively acquired pattern discrimination. The 3 groups of monkeys were then tested in 2-choice, color discrimination tests, 1 involving varying degrees of stimulus–response (S–R) separation and the other, administered several months later, involving various directions of S–R separation. Ss were also tested in a series of 2-choice pattern discriminations, following each of which they were tested for relearning when the patterns were masked with bars or circles. LSC lesioned Ss were moderately retarded in retention of the pattern discrimination, whereas those with SC lesions were not. SC lesioned Ss, but not those with LSC lesions, were impaired in both S–R separation tests, which demonstrates that their deficit was not transient or solely due to a difficulty in shifting the gaze in 1 direction. The LSC Ss, unlike those with SC lesions, were deficient in relearning discriminations between masked patterns. Findings suggest that SC and LSC may be involved in 2 different aspects of attention, respectively: shifting attention (and orientation) from 1 spatial locus to another and maintaining attention on fixated stimuli. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-awareness and transgression in children: Two field studies.

Two field studies explored the relationship between self-awareness and transgressive behavior. 363 Halloween trick-or-treaters (children) were instructed to take only 1 candy. Self-awareness induced by the presence of a mirror placed behind the candy bowl decreased transgression rates for Ss who had been individuated by asking them their name and address but did not affect the behavior of Ss left anonymous. Self-awareness influenced older but not younger Ss. Naturally occurring standards instituted by the behavior of the 1st child to approach the candy bowl in each group were shown to interact with the experimenter's verbally stated standard. The behavior of 349 children in the 2nd study replicated the findings of the 1st study. Additionally, when no standard was stated by the experimenter, Ss took more candy when not self-aware than when self-aware. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Naive statics: Current misconceptions on equilibrium.

Studied common concepts regarding the equilibrium of objects in 3 experiments, using a total of 85 17–45 yr old Ss. Groups of Ss (including some experts in statics) were asked to solve problems like finding the resting position of objects suspended either by their center of gravity or at some point more or less removed from the center of gravity. Results show that, with few exceptions, Ss confused neutral equilibrium with the stable equilibrium that is assumed when the object is symmetrical with its vertical axis. This error is explained, together with the errors found in tasks in which objects were not suspended by their center of gravity, by the hypothesis that Ss conceive equilibrium as an equaling of the potential energy of gravity. The possibility that Ss' mistakes may be due to an impression of equilibrium connected to conditions of perfect symmetry is discussed, as is the hypothesis of the coexistence of naive and objective concepts in the human system of knowledge. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term effects of a school-based secondary prevention program for young maladapting children.

Assessed the current status of 61 4th–6th graders seen 2–5 yrs earlier in an intervention program for children experiencing school adjustment problems. Based on comparisons of teacher ratings of Ss' problems and competencies at 3 time points (referral, termination, and follow-up), program Ss were found to have maintained initial intervention gains. At follow-up, they were significantly better adjusted than a demographically comparable, teacher-identified group of current problem children (n?=?61), but not as well adjusted as a randomly selected, demographically matched "never-seen" group (n?=?27). The 3 groups did not differ systematically on measures of self-esteem or academic achievement. The absolute placement of the seen sample on those measures was at the midpoint of the normal range. Thus, the immediate gains shown by young, maladjusted Ss seen through the early intervention program endured over time. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigating the orientation effect on the water-level task: Who? When? and Why?

Four experiments with adults on Piaget's (J. Piaget & B. Inhelder, 1956) water-level task investigated previous reports that containers tilted at larger angles produce more error than those tilted at smaller angles. Exp 1 found that this orientation effect occurred in both male and female Ss when the angles were manipulated between Ss but was absent in male Ss when manipulated within Ss. Exps 2 and 3 indicated that male, and to a lesser degree female Ss, appear to benefit from exposure to easier (less-tilted) stimulus trials and, as a result, perform more accurately on subsequent difficult trials. Exp 4 implicated mental rotation processes in the orientation effect by demonstrating that accuracy varied as a function of how far Ss needed to mentally rotate the container from its initial position to its test position. A developmental sequence is proposed in which relevant spatial abilities are assumed to facilitate acquisition of the principle that liquids are invariantly horizontal, which in turn leads to more accurate performance on the task. Differences in cognitive strategies may be responsible for the Gender X Orientation interaction observed under some conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inferior temporal lesions do not impair discrimination of rotated patterns in monkeys.

Ablation of inferior temporal cortex in the rhesus monkey produces a visual discrimination learning deficit. The severity of this deficit has often been found to be a function of task difficulty. The present paper reports 2 experiments with 25 Macaca mulatta and M. fascicularis on a type of visual discrimination problem that, although difficult, is not sensitive to inferior temporal lesions. Ss with anterior, posterior, and complete inferior temporal lesions were repeatedly unimpaired or only slightly impaired in learning to discriminate a pattern from the same pattern rotated 90° or 180°; yet they were very severely impaired in learning equally or more difficult discriminations of 2 different patterns. This demonstration that discrimination of orientation of patterns is relatively spared after inferior temporal lesions helps specify the pattern-rcognition processes that require inferior temporal cortex. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Features of style classification: A multivariate experimental analysis of children's responses to drawings.

Investigated the sensitivity of 48 children (aged 6–11 yrs) to the formal or stylistic properties of line drawings. Particular emphasis was placed on a detailed analysis of Ss' classifications through the use of multidimensional scaling and multiple-regression analyses. Ss were asked to judge the similarity of 12 line drawings that were specially prepared to vary along 3 dimensions (thickness, amount of shading, and expressiveness), which were shown to be salient in 12 adults' discriminations. The scaling and regression analyses confirmed that the youngest Ss were able to make systematic stylistic comparisons utilizing the 3 dimensions of line variation contained in the drawings. The significance of this finding is discussed in relation to research on children's perception of multidimensional relations. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)