The development of infants' reaches for stationary and moving targets.

The organization of infants' reaching skill for stationary and moving targets was examined. While 58 term, healthy infants at 5.5, 8.5, and 11.5 months of age reached for and grasped a cloth-covered dowel, their reaches were videotaped for later slow-motion analysis. Analyses addressed infants' anticipatory adjustment of hand alignment, use of information from spinning and oscillating targets to update ongoing reaches, and ability to capture targets moving in depth. Infants at all ages made anticipatory adjustments of hand alignment, although the effectiveness of these adjustments improved with age. Regardless of age, infants also used dynamic information from spinning and oscillating targets to update ongoing reaches, but the way infants used this information was related to age. Developmental constancy characterized infants' reaches for approaching targets. By observing infants' reaches for stationary, spinning, and approaching targets, the study expands the range of conditions under which adaptive reaching skill has been examined and provides insight into the roles of anticipation and updating in the development of early manual skill.

Infants' acquisition of spatiotemporal expectations.

The microdevelopment of infants' visual expectations was examined by analysis of the eye movements that 80 three-month-old human infants made during interstimulus intervals (ISIs) of an alternating picture sequence. For comparison, identical eye movement data were gathered from 10 infants who watched an irregular sequence. Shifts during ISIs were exhibited by all infants and occurred on 48% of all trials. Initially, infants' ISI shifts repeated saccades that had successfully located the preceding picture; during the course of the alternating session, repetitive saccades declined while alternating and anticipatory saccades increased. For infants who saw the irregular sequence, the frequency of ISI shifts did not vary systematically over trials. Analysis of saccade latencies suggested that infants quickly learned to inhibit a prepotent tendency in order to execute task-appropriate saccades.

Infant expectations and reaction time as predictors of childhood speed of processing and IQ.

A longitudinal study investigated the relation between infant expectations and reaction time (RT) and childhood IQ and RT. Measures of visual anticipation and visual RT were taken at 3.5 months and 4 years of age. In addition, manual RT and verbal and performance IQ were measured at 4 years of age. Infant visual RT correlated reliably with childhood visual RT, and infant performance correlated significantly with childhood IQ. Childhood performance also correlated with concurrent childhood IQ. Children were slower to initiate eye movements when a manual choice button press was required than when it was not required. This load effect decreased as IQ increased. Visual RT and manual RT in childhood correlated only marginally. These are the first data to suggest stability in RT between early infancy and childhood or predictability from infant RT and anticipation in the first half-year of life to childhood IQ.

Phonological processing skills and deficits in adult dyslexics.

This article presents 4 experiments aimed at defining the primary underlying phonological processing deficit(s) in adult dyslexia. 5 phonological processes, all involving spoken language, were studied: phoneme perception, phoneme awareness, lexical retrieval of phonology, articulatory speed, and phonetic coding in verbal short-term memory. 2 differently ascertained adult dyslexic groups, familial dyslexics (n = 15) and clinic dyslexics (n = 15), were the subjects in each experiment. These dyslexic groups were chosen because deficits that persist until adulthood and that are found in differently ascertained dyslexic groups are more likely to be primary. Each dyslexic group was compared to 2 control groups, chronological age (CA) controls who were similar in age and sex, and younger reading age (RA) controls who were similar in reading age and sex. The main finding was a clear deficit in phoneme awareness in both dyslexic groups, with each dyslexic group performing significantly worse than both CA and RA controls. Moreover, performance on the 2 phoneme awareness tasks together uniquely accounted for substantial variance in nonword reading. The clinic but not the familial dyslexics appeared to have an additional deficit in verbal short-term memory. No clear deficits were found in either dyslexic group in phoneme perception, lexical retrieval, or articulatory speed.

Expectation and anticipation of dynamic visual events by 3.5-month-old babies.

We report an investigation of the development of visual expectancies in 3.5-month-old infants. One of the infant's eyes was videorecorded as the infant watched a series of slides that were presented noncontingent on behavior. Babies were presented an alternating and an irregular series of 30 slides with a 700-msec onset duration separated by an interstimulus interval (ISI). The ISI for the alternating series was 1,100 msec, whereas the slides for the irregular series were separated by 900, 1,100, or 1,300 msec, randomly ordered. One-half of the babies saw the irregular series first, and one-half saw the regular series first. Babies in both groups provided evidence that they developed expectations for the visual events in the alternating series. Their reaction times (RTs) declined significantly from 3-5 "baseline" presentations, and their RTs were reliably faster during the alternating than the irregular series. Additionally, babies in the alternating-late group had significantly more stimulus anticipations during the alternating than during the irregular series. These findings indicate that 3.5-month-olds can detect regularity in a spatiotemporal series, will develop expectancies for events in the series, and will act on the basis of those expectancies even when those actions have no effect on the stimulus events. We believe that infants are motivated to develop expectations for noncontrollable spatiotemporal events, because these expectations permit them to bring their visual behavior under partial internal control.

Left-handedness and immune disorders in familial dyslexics.

We examined the frequency of left-handedness, various immune disorders, and comparison disorders in 87 dyslexics and 86 nondyslexics from 14 extended dyslexic families. These families were participants in our genetic linkage studies of dyslexia, which found linkage to chromosome 15 in some families but not others. In the present study, we found a significant elevation of both autoimmune and allergic disorders in the dyslexics only, but no elevation in mixed- or left-handedness in either group. Moreover, the frequency of immune disorders was not higher in the mixed- or left-handed subjects. There was also no elevation in the comparison disorders, which argues against an overreporting bias. The elevation of immune disorders did not vary with linkage status, arguing against a common cause for dyslexia and immune disorders. These findings are discussed in light of Geschwind's hypothesis of a testosterone-mediated association within families between left-handedness, immune disorders, and dyslexia.

Memory development and neurophysiology: accomplishments and limitations.

The review of Teyler and Fountain offers developmental psychologists an update on the status of neurophysiological theorizing and findings related to memory and learning. Recent findings of LTP and of localization of different types of memory in different brain areas have potential for enriching our understanding of memory development. However, we note several limitations in Teyler and Fountain's presentation in that they do not: distinguish between learning and memory, nor between storage and retrieval; address the role of knowledge-based or top-down influences in memory and learning; employ concepts that can accommodate such developmental phenomena as stages in the hierarchical reorganization of memory. We conclude that even when the age-old search for the "engram" is accomplished, these issues will remain, and that different levels of neural modeling will be required to accommodate them. It is important for developmental psychologists and neuroscientists to maintain communication for the purpose of mutual refinement of models as their knowledge bases continue to grow.

Automatic processing of word meaning: intralingual and interlingual interference.

Automatic processing of word meaning was studied in bilingual children and children in various stages of second-language acquisition in 2 experiments. A picture-word interference task was used. The children named outlined pictures as rapidly as possible while attempting to ignore distractor words printed inside the pictures' borders. For children proficient in the 2 languages (Experiment 1), the printed distractors interfered with naming on both intralingual trials, for which the distractor and naming language were the same, and on interlingual trials, for which they were different. The pattern of interference across 6 levels of name-distractor relation was similar for the intralingual and interlingual conditions and indicated that at least part of the interference occurred at a semantic level. For children who were in various phases of learning a second language (Experiment 2), second-language words were automatically processed to the level of meaning early in the course of second-language reading instruction. As was found for the more proficient groups, both the pattern and the amount of interlingual interference matched that for intralingual interference. The results question whether an "input switch" operates for bilingual word processing.

Infant visual responses to pattern: which metric predicts best?

Visual fixations were recorded in newborn, 4-, and 8-week old human infants as they scanned displays that varied along several dimensions. These displays were designed to evaluate four metrics that have been theorized to control infant visual preference: Contour length, size, number, and a new metric, CVAL, based on Contour Variability, Amount, and Location. This latter metric reflects characteristics of the visual system that other metrics ignore. Both contour length and CVAL separately accounted for approximately 95% of looking-duration variance, a much larger portion than the other metrics considered; however, CVAL accounted for more looking variance than contour length when the number of lines and contour length were deconfounded, and uniquely accommodated a large orientation effect. Finally, several predictions were confirmed about characteristics of visual scanning. Retinal structure and natural scanning dispositions should be considered in accounts of infants' reactions to visual stimuli.

Eye-movement control in newborns in darkness and in unstructured light.

Infrared television recordings were made of newborn visual activity in darkness and in the presence of uniform light fields under monocular and binocular viewing conditions. Out-of-control eye movements were substantially more frequent in light than in dark for both groups. Thus, earlier findings of more out-of-control activity in light than in darkness are not attributable to monocular viewing or to the presence of distracting contours produced by an eye patch. A distinction between exogenous and endogenous control of eye movements in newborns in supported.

Development of visual organization: the perception of subjective contours.

This study examines the development of infants' sensitivity to the organization of a subjective-contour stimulus array. 5- and 7-month-olds were sequentially shown 3 stimulus arrays of elements, only 1 of which was capable of producing subjective contours. Only the orientational relations among elements was varied. An infant habituation control procedure was used to test infants' abilities to discriminate these arrays. The results indicated that (1) only 7-month-olds showed consistent differential responsiveness to changes from an illusory array to a nonillusory array or vice versa, (2) 5-month-olds showed a weaker tendency to respond similarly and only when they had prolonged experience with the illusory array, and (3) neither age group showed much response recovery to a change from one nonillusory array to another. These findings are interpreted as indicating that infants can perceive subjective contours. However, the age of this accomplishment probably varies with both the characteristics of the array and the abilities of the observer.

A developmental study of automatic word processing in a picture classification task.

Second-grade children, third-grade children, and adults judged whether pictures were members of a positive or negative memory set while trying to ignore irrelevant words printed inside the pictures. There were 3 types of picture-word relation. In 1 condition, the words corresponded to the pictures. In a second condition, the pictures and words were incongruent, but the words corresponded to the correct response (e.g., with dog and horse the positive set pictures, a picture of a dog containing the word "horse"). In the third condition, the pictures and words were incongruent and corresponded to conflicting responses. For all 3 subject groups, the type of picture-word relation reliably affected response latencies, indicating that subjects automatically processed the irrelevant printed words.

Infant visual scanning of two- and three-dimensional forms.

2- and 3-dimensional forms affected 4- and 8-week-old infant visual behavior differently, 4-week-old infants fixated a recessed 3-dimensional form more than a 2-dimensional form but did not scan it differently. 8-week-old infants did not look more at 1 stimulus than another but scanned a raised 3-dimensional form differently than a 2-dimensional equivalent. For all stimuli and both age groups, there was a relation between attractiveness of stimuli and how they were scanned; babies who were most attracted to stimuli inspected them with the smallest eye movements.

Eye contact and face scanning in early infancy.

Visual fixations of 3- to 5-week-old, 7-week-old, and 9- to 11-week-old infants were recorded as they scanned an adult's face which was stationary, moving, or talking. A dramatic increase in face fixations occurred between 5 and 7 weeks for all conditions. Talking produced an intensification of scanning in the eye area in the two older groups.

The relation between nonnutritive sucking and visual information processing in the human newborn.

This paper considers the relation between visual information processing and the burst-pause pattern of nonnutritive sucking in the human infant. Sucking and visual scanning activity were investigated in 2 independent studies. The results did not support the view that sucking is affected by ongoing processing activity. It is argued that previously reported effects of processing on sucking reflect a phasic component of the orientation reaction (OR) to stimuli, not a sustained processing of those stimuli. Additionally, no existing evidence supports the idea that the components of the natural burst-pause pattern of sucking differentially affect information processing in the human newborn.