Developmental differences in the role of detail in picture recognition memory

Two experiments assess the effect of the amount of physical detail in pictures on picture recognition memory. Children and adults were presented simple and complex line drawings. A “same-different” recognition test followed in which the distractor items were original pictures from the presentation phase with the amount of physical detail altered. For second- and fourth-grade subjects, recognition sensitivity, measured in terms of d′, was similar for pictures in the simple and complex presentation conditions. For adults, however, recognition sensitivity was greater for pictures in the simple than complex presentation condition. This finding with adults was replicated in Experiment 2. Interpretations of this age difference in picture memory processing are discussed, as well as the constraints imposed by various dependent measures used in picture memory studies.     

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.     

Comprehension and production of body part labels in 2‐ to 3‐year‐old children

This study examined which body part labels children could (i) produce when the experimenter touched different locations on her own body, asking each time ‘What's this?’ and (ii) comprehend by touching the correct locations on their own bodies in response to the experimenter asking ‘Where's the [body‐part label]?’. Seventeen children aged between 26 and 41 months, tested in a repeated measures procedure, were presented with 50 different body part stimuli in 200 test trials per child. Overall, the children produced fewer body part labels than they could comprehend. The accuracy of children's responses depended on (i) the location or extent of each body part (facial and broad body features were better known; joints and features in or attached to broad body parts the least well known); (ii) the amount of sensory (but not motor) representation each body part has in the human cortex; and (iii) whether a body part was commonly named by caregivers. These results present a precise mapping of the body parts that young children are able to name and locate on their own bodies in response to body part names; they suggest several possible determinants of lexical‐semantic body knowledge and add to the understanding of how it develops in childhood.     

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.