Minimalist surface-colour matching

Some theories of surface-colour perception assume that observers estimate the illuminant on a scene so that its effects can be discounted. A critical test of this interpretation of colour constancy is whether surface-colour matching is worse when the number of surfaces in a scene is so small that any illuminant estimate is unreliable. In the experiment reported here, observers made asymmetric colour matches between pairs of simultaneously presented Mondrian-like patterns under different daylights. The patterns had either 49 surfaces or a minimal 2 surfaces. No significant effect of number was found, suggesting that illuminant estimates are unnecessary for surface-colour matching.     

The binocular combination of chromatic contrast

How is chromatic contrast combined binocularly? One index of binocularity is the binocular contrast summation ratio (BCSR), which is the improvement in contrast sensitivity with binocular rather than monocular presentation. Simmons and Kingdom (1998, Vision Research 38 1063-1071) noted that BCSRs with some red-green isoluminant stimuli were suggestive of full linear summation. This suggestion was investigated further in four subjects by measuring binocular and monocular contrast thresholds for the detection of 0.5 cycle deg(1) isoluminant (red-green) and isochromatic (yellow-black) Gabor patches. These Gabor patches had either vertically or horizontally oriented carrier gratings and were either dichoptically in phase (same coloured bars in binocular correspondence) or in dichoptic anti-phase (opposite coloured bars in binocular correspondence). Full linear summation would be indicated by BCSRs of 2 for the in-phase and close to 0 for the anti-phase conditions. Mean BCSRs at isoluminance were 1.93 and 0.90, respectively, for the in-phase and anti-phase stimuli with horizontal carriers, the former being consistent with full linear summation, but the latter not. Despite these results, BCSRs obtained with isoluminant and isochromatic stimuli under similar conditions were not statistically distinguishable from each other, although there was a tendency for summation at isoluminance with in-phase stimuli to be higher and anti-phase stimuli to be lower. These data fall short of demonstrating full linear summation of chromatic contrast between the eyes under all presentation conditions, but they do indicate that there are strong binocular interactions at red-green isoluminance, which are similar to, and possibly even stronger than, those obtained with luminance stimuli.     

Gender Role Stereotyping of Parents in Children’s Picture Books: The Invisible Father

Previous studies reveal the reinforcement of gender stereotypes by picture books children read during the formative years. In these books, boys tend to be portrayed as active leaders, and girls as passive followers. Women and girls are under-represented. Men often exhibit career skills, and women perform traditional tasks in the home. Even when careers are nontraditional, personality characteristics and other qualities and behaviors are often stereotypical. Previous researchers emphasized the narrowly defined roles of women and children in picture books. In this study, we focused on the representation of mothers and fathers, and examined whether men are stereotyped as relatively absent or inept parents. A content analysis of the gender roles exhibited in 200 prominent childrens picture books demonstrated that fathers are largely under-represented, and, when they do appear, they are withdrawn and ineffectual parents. Further research could establish whether seriously deficient models of fatherhood in childrens literature affect the incidence of present, caring fathers in society.     

The training and transfer of real-world perceptual expertise

A hallmark of perceptual expertise is that experts classify objects at a more specific, subordinate level of abstraction than novices. To what extent does subordinate-level learning contribute to the transfer of perceptual expertise to novel exemplars and novel categories? In this study, participants learned to classify 10 varieties of wading birds and 10 varieties of owls at either the subordinate, species (e.g., "great blue crown heron,"eastern screech owl") or the family ("wading bird,"owl") level of abstraction. During training, the amount of visual exposure was equated such that participants received an equal number of learning trials for wading birds and owls. Pre- and posttraining performance was measured in a same/different discrimination task in which participants judged whether pairs of bird stimuli belonged to the same or different species. Participants trained in species-level discrimination demonstrated greater transfer to novel exemplars and novel species categories than participants trained in family-level discrimination. These findings suggest that perceptual categorization, not perceptual exposure per se, is important for the development and generalization of visual expertise.     

Affirmation of personal values buffers neuroendocrine and psychological stress responses

Stress is implicated in the development and progression of a broad array of mental and physical health disorders. Theory and research on the self suggest that self-affirming activities may buffer these adverse effects. This study experimentally investigated whether affirmations of personal values attenuate physiological and psychological stress responses. Eighty-five participants completed either a value-affirmation task or a control task prior to participating in a laboratory stress challenge. Participants who affirmed their values had significantly lower cortisol responses to stress, compared with control participants. Dispositional self-resources (e.g., trait self-esteem and optimism) moderated the relation between value affirmation and psychological stress responses, such that participants who had high self-resources and had affirmed personal values reported the least stress. These findings suggest that reflecting on personal values can keep neuroendocrine and psychological responses to stress at low levels. Implications for research on the self, stress processes, health, and interventions are discussed.     

Is developing scientific thinking all about learning to control variables?

Academically low-performing urban sixth graders engaged in inquiry activity received a suggestion that they focus their investigation on the role of a single factor. This suggestion had significant effects on their use of a superficially dissimilar strategy--controlling the variation of other factors. This latter strategy has received the lion's share of attention in research on the development of scientific reasoning. These results have implications, we propose, for what undergoes development with respect to scientific thinking and how this development can best be facilitated.     

Inhibition of return in children with Tourette's syndrome and comorbid forms: a preliminary study.

BACKGROUND: This study investigated the nature and functioning of the visual-spatial inhibition of return (IOR) phenomenon in children with "pure" Tourette's syndrome (TS), and those with comorbid forms of TS. METHOD: Children with TS-only and "TS + comorbid" (TS + ADHD +/- OCD) and matched controls performed the inhibition of return (IOR) task, which involved responding to left and right visual targets appearing on a computer screen that were preceded by congruent or incongruent exogenous visual cues. RESULTS: The TS-only group performed similarly on the IOR task to the controls. When the TS-only group was subdivided into children with mild and severe TS symptoms, a post hoc comparison between the controls and severe TS symptom children revealed that these TS children had a reduced magnitude of IOR for targets appearing in the right visual field. The comparison between the TS + comorbid and controls revealed an atypical IOR pattern for the TS + comorbid group. They displayed a loss of normal facilitatory and inhibitory effects for right visual field targets. CONCLUSIONS: The findings suggest abnormalities in attentional "disengage" and "move" mechanisms in TS when directing attention to the right visual field, which may reflect left posterior parietal, superior colliculus, and midbrain pathology.     

The relationship between age, processing speed, working memory capacity, and language comprehension

A total of 50 elderly individuals and 48 college students were tested on several measures of processing speed and of working memory capacity. Language processing was tested with an on-line measure of sentence processing efficiency, an end-of-sentence acceptability judgement task, and a paragraph comprehension test. Elderly individuals performed more poorly than college students on the speed of processing and working memory measures and had longer listening times overall on the sentence processing measures. Elderly individuals did not, however, have overall longer listening times at the most capacity-demanding regions of the harder sentence types. Correlational analyses failed to establish a relationship between the increase in syntactic processing load at the capacity-demanding region of the harder sentence type and the measures of working memory capacity, but did establish a relationship between paragraph comprehension and working memory capacity. The data are argued to provide evidence that the WM system used to structure sentences syntactically is separate from that used in other aspects of language comprehension.     

Study repetition and the rejection of conjunction lures

Four experiments were conducted to provide further support for a dual-process approach to conjunction errors in recognition memory over a single-process approach. In Experiments 1, 2a, and 2b study words were repeated once (2 presentations) or several times (8 or 16 presentations), and a response signal delay (RSD) was manipulated (short vs long). Short RSD groups produced lower hit rates but higher conjunction error rates compared to long RSD groups. Repetition effects on conjunction errors occurred for short RSD but not long RSD groups. In Experiment 3, additional judgements on new items were solicited to show that the "null" effects for long RSD groups in the earlier experiments were, in fact, illusory. Together, the experiments provide evidence for recollection-based rejections of conjunction lures and support a dual-process theory of recognition memory over a single-process model.     

Explicit Instruction With or Without High-<Emphasis Type="Italic">p</Emphasis> Sequences: Which is More Effective to Teach Multiplication Facts?

Basic fact acquisition is an important component for developing higher-order math skills. However, getting students with a history of academic noncompliance to engage in activities related to skills acquisition can be difficult. Prior research demonstrates that engagement increases when nonpreferred activities are preceded by a series of brief activities with a high probability of completion. This technique, called high-p task/request sequences, was not fully explored within the context of skill acquisition. The purpose of this study was to examine the effects of adding high-p sequences to explicit instruction on the math fact acquisition of three elementary-age students in a learning support classroom. Results showed no differences in fact acquisition between explicit instruction and explicit instruction with an added high-p component. However, the high-p sessions took nearly twice as long to complete when compared to explicit instruction alone. Implications for instructional efficiency and limitations of the high-p procedures for acquisition tasks are discussed.