Letter-naming time as a function of set familiarity and symbol distinctiveness

Two symbol-naming experiments were conducted assessing the dependence of Fitts and Switzer's set-familiarity effect upon symbol distinctiveness. Sixty college males named printed letters presented in a strobotron tachistoscope, the letter always being selected from a preannounced set of three. A voice key detected the response. Experiment I found the Fitts and Switzer finding to be a joint effect: response latency for naming the symbol B in the unfamiliar but distinctive set, VBO, was intermediate to that for the familiar distinctive set, ABC, and the unfamiliar, homolographic set, PBE, the two sets used by Fitts and Switzer. Experiment II, a factorial combination of set familiarity and symbol distinctiveness yielded a significant interaction such that with homolographic symbols, set familiarity was associated with an increase in reaction time. The results were interpreted as consistent with an hypothesis that the set-familiarity effect relates to symbol-identification time as opposed to response-identification time.     

Are there qualitative differences in reading behavior between dyslexics and normal readers?

This study asked whether the reading behavior of dyslexics differs qualitatively from that of normal children. Thirty-seven children who had been identified is dyslexic (mean age 11 years, 9 months) were matched with 37 normal readers (mean age 8,6) on ability to read regular words. The dyslexics' and normals' levels of performance on nonsense words and exception words were strikingly close. Also, patterns of individual differences were similar for the two groups. The results suggest that these dyslexics are delayed in the development of both spelling-sound rules and word specific associations. They do not support the view that dyslexics have a specific deficit in the use of spelling-sound rules, or that dyslexics show more extreme individual differences than do normal readers.     

Motherhood in the Context of Normative Discourse: Birth Stories of Mothers of Children with Down Syndrome

Using birth stories as our object of inquiry, this article examines the ways in which normative discourses about gender, disability and Down syndrome construct the birth stories of three mothers of children with Down syndrome. Their stories are composed of the mothers’ recollections of the first hours after birth as a time when their infants are separated from them and their postpartum needs are ignored. Together, their stories illustrate socio-cultural tropes that position Down syndrome as a dangerous form of the “other” and mothers who give birth to children with Down syndrome as implicated in transgressing cultural norms.     

Serial dependence in position occurs at the time of perception

Observers perceive objects in the world as stable over space and time, even though the visual experience of those objects is often discontinuous and distorted due to masking, occlusion, camouflage, or noise. How are we able to easily and quickly achieve stable perception in spite of this constantly changing visual input? It was previously shown that observers experience serial dependence in the perception of features and objects, an effect that extends up to 15 seconds back in time. Here, we asked whether the visual system utilizes an object’s prior physical location to inform future position assignments in order to maximize location stability of an object over time. To test this, we presented subjects with small targets at random angular locations relative to central fixation in the peripheral visual field. Subjects reported the perceived location of the target on each trial by adjusting a cursor’s position to match its location. Subjects made consistent errors when reporting the perceived position of the target on the current trial, mislocalizing it toward the position of the target in the preceding two trials (Experiment 1). This pull in position perception occurred even when a response was not required on the previous trial (Experiment 2). In addition, we show that serial dependence in perceived position occurs immediately after stimulus presentation, and it is a fast stabilization mechanism that does not require a delay (Experiment 3). This indicates that serial dependence occurs for position representations and facilitates the stable perception of objects in space. Taken together with previous work, our results show that serial dependence occurs at many stages of visual processing, from initial position assignment to object categorization.     

The interaction of observational learning with overt practice: effects on motor skill learning

This study explored various methods of combining observational learning via demonstration with the effects of overt practice for learning a discrete action pattern. Three groups were compared that varied by the timing of demonstration in relation to practice. An all-pre-practice demonstration group viewed 10 pre-practice videotape demonstrations of an expert performing the skill, and then engaged in practice. An interspersed demonstration group viewed one pre-practice demonstration, then initiated practice on the skill. Every three attempts, practice was halted while participants viewed another demonstration, with this pattern repeated throughout acquisition. A combination demonstration group experienced elements of each schedule by viewing five demonstrations prior to practice, then five more once practice had begun (one every three attempts) so that modeling was completed by mid-acquisition. Ratings of form and accuracy were assessed in an acquisition phase, an immediate retention test, and a 48-h retention test. Group main effects for form scores were detected in acquisition, immediate, and 48-h retention, with the combination group obtaining the highest form scores, followed by the all-pre-practice group, and finally the interspersed group. These findings suggest that several modeling exposures before practice and several more exposures in the early stages of practice were optimal for acquisition and retention of form.     

What are theories for? Concept use throughout the continuum of dinosaur expertise

Although it is now well established that object concepts are situated within broader systems of theoretical knowledge, it is less clear how theories influence the use of object concepts at various points throughout the continuum of expertise. Two studies were conducted to investigate the impact of specific theories (concerning dinosaurs) and overarching framework theories (of biology) on children's and adults' performance on categorization tasks involving familiar and less familiar concepts. Although expertise increased the quantity of deep feature knowledge possessed by children and increased their understanding of biologically adaptive relations among features, few aspects of children's performance generalized beyond highly familiar dinosaurs. Children's specific theories related to dinosaurs were empirically constrained and relatively dissociated from other types of biological knowledge. The interaction of specific concept knowledge with broader framework theories of biology throughout the continuum of expertise is considered.     

Parenting Competency Across Pregnancy and Postpartum Among Urban Minority Women

Taking a life-course perspective, we explored the sense of parenting efficacy during the pregnancy-postpartum transition among a group under-represented in much of adult developmental research, minority women. Our intent was to describe the women's report of parenting competency in a major life transition occurring within the context of an impoverished urban environment. We also explored associations with depression, social support, and life events. One hundred and eighty-two African-American and Hispanic mothers at community health centers in low-income urban areas completed measures early in the third trimester and again at 3 months postpartum. Across time, the levels of reported parental efficacy and satisfaction increased while depressive symptoms decreased. Negative life events and levels of depressive symptomatology differentially influenced women's experience of parenting satisfaction and efficacy feelings before and after their babies were born.     

Children's face recognition memory: more evidence for the cross-race effect

It is well established that own-race faces are recognized more accurately than cross-race faces. However, there are mixed results regarding the developmental consistency of the cross-race effect White and Black kindergarten children, 3rd graders, and young adults viewed a Black and a White target individual. One day later, recognition memory for each target was tested with a 6-person lineup. The interaction of race of participant by race of target face on Ag scores was significant, demonstrating an overall cross-race effect. The 2nd-order interaction with age did not approach significance; for each age group, own-race identification was more accurate than cross-race identification. The age consistency of the cross-race effect in light of the significant main effect of age suggests quantitative but not qualitative differences in face memory processing at various ages. For children, as well as adults, own-race faces are recognized more accurately than cross-race faces.