Susan A. Rose

Differential Rates of Visual Information Processing in Full-Term and Preterm Infants.

This study investigated the effect of increasing familiarization time on the visual recognition memory of 6- and 12-month-old full-term and preterm infants. Infants were given trials in which they viewed a shape for either 10-, 15-, 20-, or 30-sec familiarization and were then tested for visual recognition memory using the paired comparison technique. While the older infants showed evidence of recognition memory after less familiarization time than the younger ones, at both ages preterms required considerably longer familiarization than full-terms. The pattern of performance replicates our earlier finding of developmental lags in the visual information processing of 6-month-old preterms and extends these findings to 12-month-olds. These results suggest that there are persistent differences between preterm and full-term infants throughout at least the first year of life in this very fundamental aspect of cognition.

Attention and Recognition Memory in the 1st Year of Life: A Longitudinal Study of Preterm and Full-Term Infants.

Several aspects of visual attention and their implications for recognition memory were examined in a longitudinal sample of full-term and preterm (birth weight < 1,750 g) infants seen at 5, 7, and 12 months of age. At all 3 ages, full-terms had shorter look durations, faster shift rates, less off-task behavior, and higher novelty scores than preterms. Both groups followed similar developmental trajectories, with older infants having shorter looks and more shifts. Infants were consistent in attentional style across problems of the same type, across problems that used different types of stimuli (faces and patterns), and across the familiarization and test phases of this paired-comparison design; there was also modest cross-age stability. Shorter looks and higher shift rates during familiarization were related to better recognition memory, with shift rate adding to prediction independently of either peak or mean look. These findings underscore the importance of attention to infant information processing.

Processing Speed in the 1st Year of Life: A Longitudinal Study of Preterm and Full-Term Infants

Processing speed was assessed at 5, 7, and 12 months in full-term and preterm infants (birth-weight < 1,750 g). Speed was gauged directly in a new task by presenting infants with a series of paired faces, one that remained the same across trials and one that changed; trials continued until infants showed a consistent novelty preference. At all ages, preterms required about 20% more trials and 30% more time than full-terms to reach criterion. Among preterms, slower processing was associated with greater medical risk (e.g., respiratory distress syndrome). Developmental trajectories for speed (and attention) were similar for both groups. Thus, the deficits in processing speed previously found for preterms in childhood are already present in the 1st year of life.

Modeling a cascade of effects: the role of speed and executive functioning in preterm/full-term differences in academic achievement.

This study identified deficits in executive functioning in pre-adolescent preterms and modeled their role, along with processing speed, in explaining preterm/full-term differences in reading and mathematics. Preterms (< 1750 g) showed deficits at 11 years on a battery of tasks tapping the three basic executive functions identified by Miyake - updating/working memory, inhibition, and shifting. Confirmatory factor analysis showed that these executive functions, though correlated, were distinct from one another and from processing speed, which later proved to account for much of the intercorrelation among executive functions. In the best-fitting structural equation model, the negative effects of prematurity on achievement were completely mediated by the three executive functions and speed in a cascade of effects: prematurity → slower processing speed → poorer executive functioning (working memory) → lower achievement in math and reading.

Cross-modal Transfer in Human Infants.

GOTTFRIED, ALLEN W.; ROSE, SUSAN A.; and BRIDGER, WAGNER H. Cross-modal Transfer in Human Infants. CHILD DEVELOPMENT, 1977, 48, 118-123. This study investigated cross-modal transfer in infants by their proclivity to respond differentially to novel and familiar stimuli after familiarization in a different sensory modality. Across a variety of stimulus shapes, 1-year-old infants significantly and reliably looked more at and reached more for the novel than the familiar stimulus subsequent to information input from tactual stimulation. Furthermore, for the first time, it is demonstrated that not only do infants gain information about the shape of objects from their oral experience with them but this information can be made available to the visual modality.

A Cognitive Approach to the Development of Early Language

A controversial issue in the field of language development is whether language emergence and growth is dependent solely on processes specifically tied to language or could also depend on basic cognitive processes that affect all aspects of cognitive competence (domain-general processes). The present article examines this issue using a large battery of infant information-processing measures of memory, representational competence, processing speed, and attention, many of which have been shown to predict general cognition in a cohort of full-terms and preterms. Results showed that various aspects of infant memory and representational competence (a) related to language at both 12 and 36 months, (b) predicted similarly for the two groups, and (c) predicted 36-month language, independently of birth status, 12-month language, and the 12-month Bayley Mental Development Index. Additionally, the results established predictive validity for the MacArthur 12-month language measure. These findings support a domain-general view of language.

Visual Short-Term Memory in the First Year of Life: Capacity and Recency Effects.

A span task was developed to assess the amount of information infants could hold in short-term memory. In this task, infants were presented with up to 4 items in succession and then tested for recognition by successively pairing each item with a novel one. A large sample of full-terms and low-birth-weight preterms (< 1,750 g) was tested longitudinally, at 5, 7, and 12 months of age. Results were similar for both groups: (a) Longer spans were more difficult, especially at the 2 younger ages; (b) memory capacity increased over the 1st year of life--whereas less than 25% of the sample could hold as many as 3-4 items in mind at once at the younger ages, nearly half could do so by 12 months of age; (c) there was a marked recency effect (greater memory for the final item) for spans of 3 and 4 at all ages; and (d) there were modest cross-age correlations, indicating that individual differences in memory capacity showed some stability from age to age.

Information Processing at 1 Year: Relation to Birth Status and Developmental Outcome during the First 5 Years.

As part of a longitudinal study of high-risk preterm infants (birthweight less than 1500 g) and a low socioeconomic status (SES) comparison group of full-term infants, measures of information processing were obtained at 1 year : visual and tactual recognition memory, cross-modal transfer, and object permanence. Of these, cross-modal transfer was the most strongly related to later intelligence, correlating with outcome at 1.5, 2, 3, 4, and 5 years for preterms and from 3-5 years for full-terms (rs=44 to 54) ; relations with outcome were independent of SES, maternal education, medical risk, and early Bayley scores. When this 1-year measure of cross-modal transfer was combined with 7-month visual recognition memory, 35%-51% of the variance in 3-,4-, and 5-year IQ was explained

Modifying the distribution of attention in infants

In three experiments, the distribution and malleability of infant visual attention were studied in 5-month-olds (N = 72) while they inspected large geometric designs. In Experiment 1, we established that infants maintained their distribution of attention from a pretest to a familiarization phase. We also replicated and extended our previous findings that infants who examined targets with briefer, more numerous looks and shifts-short lookers-had novelty scores above chance, whereas long lookers demonstrated chance responding. In Experiment 2, different portions of the display were successively illuminated with red light. This manipulation induced long lookers to scan like short lookers during familiarization; they then showed novelty scores well above chance. A third experiment ruled out the simple presence of a red light as the source of this effect. In sum, then, these results suggest that the distribution of attention is malleable, and that a broader distribution of attention, as reflected in briefer and more numerous looks and shifts, can improve processing.

A longitudinal study of visual expectation and reaction time in the first year of life.

Developmental change and stability of visual expectation and reaction times (RT) were examined at 5, 7, and 12 months in a longitudinal sample of term and preterm infants (birthweight <1,750 g). Using the traditional 200-ms cut-point to separate anticipatory from reactive saccades, RTs (and their standard deviations) declined markedly over age, whereas anticipations increased. Those infants who had faster RTs were more likely to anticipate upcoming events and were more attentive (fewer trials off-task and less response variability). Crossage stability was modest for most measures from 5 to 7 and 7 to 12 months, but rarely significant from 5 to 12 months. When the cut-point was lowered to 150 ms (to accommodate recent concerns that the higher cut-point may misclassify some true RTs as anticipations), the age-related increase in anticipations disappeared. Thus, although the results indicate marked increases in processing speed with age, evidence for increasing anticipations is equivocal. Findings were similar for preterm and term infants.