CUE: The continuous unified electronic diary method

In the present article, we introduce the continuous unified electronic (CUE) diary method, a longitudinal, event-based, electronic parent report method that allows real-time recording of infant and child behavior in natural contexts. Thirty-nine expectant mothers were trained to identify and record target behaviors into programmed handheld computers. From birth to 18 months, maternal reporters recorded the initial, second, and third occurrences of seven target motor behaviors: palmar grasp, rolls from side to back, reaching when sitting, pincer grip, crawling, walking, and climbing stairs. Compliance was assessed as two valid entries per behavior: 97 % of maternal reporters met compliance criteria. Reliability was assessed by comparing diary entries with researcher assessments for three of the motor behaviors: palmar grasp, pincer grip and walking. A total of 81 % of maternal reporters met reliability criteria. For those three target behaviors, age of emergence was compared across data from the CUE diary method and researcher assessments. The CUE diary method was found to detect behaviors earlier and with greater sensitivity to individual differences. The CUE diary method is shown to be a reliable methodological tool for studying processes of change in human development

Selective and faithful imitation at 12 and 15 months

Research on imitation in infancy has primarily focused on what and when infants imitate. More recently, however, the question why infants imitate has received renewed attention, partly motivated by the finding that infants sometimes selectively imitate the actions of others and sometimes faithfully imitate, or overimitate, the actions of others. The present study evaluates the hypothesis that this varying imitative behavior is related to infants' social traits. To do so, we assessed faithful and selective imitation longitudinally at 12 and 15 months, and extraversion at 15 months. At both ages, selective imitation was dependent on the causal structure of the act. From 12 to 15 months, selective imitation decreased while faithful imitation increased. Furthermore, infants high in extraversion were more faithful imitators than infants low in extraversion. These results demonstrate that the onset of faithful imitation is earlier than previously thought, but later than the onset of selective imitation. The observed relation between extraversion and faithful imitation supports the hypothesis that faithful imitation is driven by the social motivations of the infant. We call this relation the King Louie Effect: like the orangutan King Louie in The Jungle Book, infants imitate faithfully due to a growing interest in the interpersonal nature of interactions

Infant contributions to joint attention predict vocabulary development

Joint attention has long been accepted as constituting a privileged circumstance in which word learning prospers. Consequently research has investigated the role that maternal responsiveness to infant attention plays in predicting language outcomes. However there has been a recent expansion in research implicating similar predictive effects from individual differences in infant behaviours. Emerging from the foundations of such work comes an interesting question: do the relative contributions of the mother and infant to joint attention episodes impact upon language learning? In an attempt to address this, two joint attention behaviours were assessed as predictors of vocabulary attainment (as measured by OCDI Production Scores). These predictors were: mothers encouraging attention to an object given their infant was already attending to an object (maternal follow-in); and infants looking to an object given their mothers encouragement of attention to an object (infant follow-in). In a sample of 14-month old children (N=36) we compared the predictive power of these maternal and infant follow-in variables on concurrent and later language performance. Results using Growth Curve Analysis provided evidence that while both maternal follow-in and infant follow-in variables contributed to production scores, infant follow-in was a stronger predictor. Consequently it does appear to matter whose final contribution establishes joint attention episodes. Infants who more often follow-in into their mothers’ encouragement of attention have larger, and faster growing vocabularies between 14 and 18-months of age

Functional vision and cognition in infants with congenital disorders of the peripheral visual system

Aim To investigate how vision relates to early development by studying vision and cognition in a national cohort of 1‐year‐old infants with congenital disorders of the peripheral visual system and visual impairment. Method This was a cross‐sectional observational investigation of a nationally recruited cohort of infants with ‘simple’ and ‘complex’ congenital disorders of the peripheral visual system. Entry age was 8 to 16 months. Vision level (Near Detection Scale) and non‐verbal cognition (sensorimotor understanding, Reynell Zinkin Scales) were assessed. Parents completed demographic questionnaires. Results Of 90 infants (49 males, 41 females; mean 13mo, standard deviation [SD] 2.5mo; range 7–17mo); 25 (28%) had profound visual impairment (light perception at best) and 65 (72%) had severe visual impairment (basic ‘form’ vision). The Near Detection Scale correlated significantly with sensorimotor understanding developmental quotients in the ‘total’, ‘simple’, and ‘complex’ groups (all p<0.001). Age and vision accounted for 48% of sensorimotor understanding variance. Infants with profound visual impairment, especially in the ‘complex’ group with congenital disorders of the peripheral visual system with known brain involvement, showed the greatest cognitive delay. Interpretation Lack of vision is associated with delayed early‐object manipulative abilities and concepts; ‘form’ vision appeared to support early developmental advance. This paper provides baseline characteristics for cross‐sectional and longitudinal follow‐up investigations in progress. A methodological strength of the study was the representativeness of the cohort according to national epidemiological and population census data

Phrase-final words in Greek storytelling speech: a study on the effect of a culturally-specific prosodic feature on short-term memory

Prosodic patterns of speech appear to make a critical contribution to memoryrelated processing. We considered the case of a previously unexplored prosodic feature of Greek storytelling and its effect on free recall in thirty typically developing children between the ages of 10 and 12 years, using short ecologically valid auditory stimuli. The combination of a falling pitch contour and, more notably, extensive final-syllable vowel lengthening, which gives rise to the prosodic feature in question, led to statistically significantly higher performance in comparison to neutral phrase-final prosody. Number of syllables in target words did not reveal substantial difference in performance. The current study presents a previously undocumented culturally-specific prosodic pattern and its effect on short-term memory

Infants show stability of goal-directed imitation

Previous studies have reported that infants selectively reproduce observed actions and have argued that this selectivity reflects understanding of intentions and goals, or goal-directed imitation. We reasoned that if selective imitation of goal-directed actions reflects understanding of intentions, infants should demonstrate stability across perceptually and causally dissimilar imitation tasks. To this end, we employed a longitudinal within-participants design to compare the performance of 37 infants on two imitation tasks, with one administered at 13 months and one administered at 14 months. Infants who selectively imitated goal-directed actions in an object-cued task at 13 months also selectively imitated goal-directed actions in a vocal-cued task at 14 months. We conclude that goal-directed imitation reflects a general ability to interpret behavior in terms of mental states

Development of turn-taking during infancy: Does the infant contribute?

To develop into competent communicators infants need to learn to appropriately time their turns in social interaction. Few studies have assessed the actual timing of turn-taking in infant development and debate continues about whether infants actively contribute to the turn-taking. In order to assess whether changes in infants’ vocal turntaking abilities as they get older are really attributable to infants’ improving skills, we analyzed video recordings of 12 mother-infant dyads in free-play interactions longitudinally at 12 and 18 months. Findings indicate that in the first half of the second year of life infants become more skilled in taking turns in vocal exchanges, as evidenced by decreasing onset times of their turns as well as a decrease in the percentage of onsets produced in overlap with their mothers. These changes are not explained by the mothers providing more opportunities to their infants to take their turn. The mean number of utterances produced by the mother did not differ significantly at 12 and 18 months, mothers did not shorten their utterances, nor did they increase the pauses between their consecutive turns. We therefore conclude that infants play an active part in vocal turn-taking exchanges with their mothers and its developmental progress

Spontaneous imitation demonstrates infants' active contribution to development

Over the past decades experimental studies have considerably increased our knowledge of ‘when’ and ‘what’ infants are able to imitate. However, this knowledge is limited to elicited imitation. Not much is known about spontaneous imitation because one cannot ‘elicit’ spontaneous imitation in experimental studies: it must by definition be studied observationally. A few studies have observed the occurrence of spontaneous imitation in the home environment through mother-infant interaction observations (Pawlby, 1977; Masur, 1987; Masur & Rodemaker, 1999). However, their findings are based on limited hours of video observations (10-15 minutes per observation) and often did not distinguish between whether the imitative behaviour was encouraged by the mother or was truly spontaneous. As a consequence of the lack of information on spontaneous imitation, many theories of development of imitation (see for example Csibra & Gergely, 2006, 2009; or Jones, 2009) place much emphasis on the role of the environment on the infant’s development (unidirectional view). However others suggest a more active involvement of the child in its own developmental process (Flynn, Masur & Eichorst, 2004). The aim of the present longitudinal study was to assess the role of spontaneous and elicited imitation in the development of object imitation in the home during the first year of life, and to capture the developmental pattern from the earliest onset of object imitation. To do so, we used a Continuous Unified (CUE) Diary method. Method Thirty mothers made continuous observations of imitation from birth to 18 months and recorded them in an electronic diary. For the current study we analyzed all instances of imitation involving actions on objects at 4- to 6- months and at 10- to 12- months of age, distinguishing between spontaneous (Table 1) and elicited imitation (Table 2). Based on an unidirectional view of imitation, in which the child is merely a receiver of external inputs, no major role for spontaneous imitation is expected, instead one would expect a larger role for imitative instances which are elicited. In contrast, the hypothesis that children actively contribute to the development of imitation predicts an important role for spontaneous imitation in the development of object imitation during the first year of life. Results Object imitation occurred on average once per infant during the 4- to 6- month period. Object imitation significantly increased by the time infants were 10- to 12- months, with the largest increase observed in spontaneous imitation. Spontaneous imitation from 4- to 6- months significantly predicted the increase in spontaneous imitation from 10- to 12- months. This was not true for elicited imitation. Thus although object imitation is rare during the 4- to 6- month period, it is meaningful. In particular spontaneous object imitation plays an important role in the development of imitation. Summary Infants’ initiative in spontaneously imitating actions on objects early on in the first year predicts the development of object imitation toward the end of the first year. This provides support for the hypothesis that children actively contribute to the developmental process