Get the picture? The effects of iconicity on toddlers' reenactment from picture books.

What do toddlers learn from everyday picture-book reading interactions? To date, there has been scant research exploring this question. In this study, the authors adapted a standard imitation procedure to examine 18- to 30-month-olds' ability to learn how to reenact a novel action sequence from a picture book. The results provide evidence that toddlers can imitate specific target actions on novel real-world objects on the basis of a picture-book interaction. Children's imitative performance after the reading interaction varied both as a function of age and the level of iconicity of the pictures in the book. These findings are discussed in terms of children's emerging symbolic capacity and the flexibility of the cognitive representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When even arbitrary order becomes important: developments in reliable temporal sequencing of arbitrarily ordered events

By late in the first year of life, children show temporally ordered recall of event sequences, the orders of which are constrained by enabling relations; they do not reliably recall arbitrarily ordered events. Using elicited imitation, in two experiments, we examined age- and experience-related changes in young children's recall of events, the orders of which are arbitrary. The changes were found to have implications for the efficacy of verbal reminding and to be related to developments in language. Specifically, on the basis of a single experience, 16-month-olds did not accurately recall arbitrarily ordered event sequences either immediately or after a two-week delay (Experiment 1); 22-month-olds recalled the events immediately, but not after the delay; by 28 months, children recalled the events even after the delay (Experiment 2A). This development was accompanied by changes in the ability to benefit from verbal reminders: 28-month-olds' recall was facilitated by provision of verbal reminders, whereas that of the younger children was not. Moreover, age-related changes in accurate reproduction of lengthy arbitrarily ordered event sequences were found to be related to developments in language (Experiment 2B). Critically, the limitations on 1-year-olds' performance that are overcome with age are not absolute: After three experiences, 16-month-olds accurately recalled the events after a two-week delay; their recall was facilitated by verbal reminders (Experiment 1). The implications of these findings are discussed.     

Memory retrieval by 18–30-month-olds: Age-related changes in representational flexibility.

Deferred imitation was used to trace changes in memory retrieval by 18–30-month-olds. In all experiments, an adult demonstrated 2 sets of actions using 2 different sets of stimuli. In Experiments 1A and 1B, independent groups of infants were tested immediately or after a 24-hr delay. Each infant was tested with 1 set of stimuli from the original demonstration and 1 set of stimuli that was different. Recall of the target actions when tested with different stimuli increased as a function of age, particularly after a delay. In Experiment 2, infants were provided with a unique verbal label for the stimuli during the demonstration and the test. The verbal label facilitated performance by 24-month-olds tested with different stimuli but had no effect on performance by 18-month-olds. One hallmark of memory development appears to be an age-related increase in the range of effective retrieval cues for a particular memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How imitation begets imitation and toddlers' generation of games.

24-month-old toddlers were observed interacting with a programmed adult partner to assess how being imitated leads to imitative acts by toddlers and the generation of social games. For 8 toddlers, the partner imitated the toddler's actions on objects; for 8 others, she performed a different, parallel action on the same play material. The former reaction approximates conditions after repeated imitation of one another emerges in peer interaction around 24 months of age—the latter, conditions of the immediately prior developmental period. When imitated, toddlers were more likely to (a) continue to act on the object, (b) repeat their same action on that object given that they continued, (c) generate games, especially imitation games, and (d) look at the partner's face. These social influence processes are thought to operate in naturally occurring peer interactions and to contribute to the new forms of behavioral organization seen around 24 months of age. The study illustrates a dynamic systems approach to behavioral organization and development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning the rules: Observation and imitation of a sorting strategy by 36-month-old children.

Two experiments were used to investigate the scope of imitation by testing whether 36-month-olds can learn to produce a categorization strategy through observation. After witnessing an adult sort a set of objects by a visible property (their color; Experiment 1) or a nonvisible property (the particular sounds produced when the objects were shaken; Experiment 2), children showed significantly more sorting by those dimensions relative to children in control groups, including a control in which children saw the sorted endstate but not the intentional sorting demonstration. The results show that 36-month-olds can do more than imitate the literal behaviors they see; they also abstract and imitate rules that they see another person use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prior experiences and perceived efficacy influence 3-year-olds' imitation.

Children are selective and flexible imitators. They combine their own prior experiences and the perceived causal efficacy of the model to determine whether and what to imitate. In Experiment 1, children were randomly assigned to have either a difficult or an easy experience achieving a goal. They then saw an adult use novel means to achieve the goal. Children with a difficult prior experience were more likely to imitate the adult's precise means. Experiment 2 showed further selectivity--children preferentially imitated causally efficacious versus nonefficacious acts. In Experiment 3, even after an easy prior experience led children to think their own means would be effective, they still encoded the novel means performed by the model. When a subsequent manipulation rendered the children's means ineffective, children recalled and imitated the model's means. The research shows that children integrate information from their own prior interventions and their observations of others to guide their imitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When does and ostrich become a bird? The role of typicality in early word comprehension.

Which objects and animals are children willing to accept as referents for words they know? To answer this question, the authors assessed early word comprehension using the preferential looking task. Children were shown 2 stimuli side by side (a target and a distractor) and heard the target stimulus named. The target stimulus was either a typical or an atypical exemplar of the named category. It was predicted that children first connect typical examples with the target name and broaden the extension of the name as they get older to include less typical examples. Experiment 1 shows that when targets are named, 12-month-olds display an increase in target looking for typical but not atypical targets whereas 24-month-olds display an increase for both. Experiment 2 shows that 18-month-olds display a pattern similar to that of 24-month-olds. Implications for the early development of word comprehension are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Producing and processing self-propelled motion in infancy.

Three experiments investigated 5- through 8-month-olds' ability to encode self-propelled and caused motion and examined whether processing of motion onset changes when crawling begins. Infants were habituated (Experiments 1 and 2) or familiarized (Experiment 3) with simple causal and noncausal launching events. They then viewed the caused-to-move and self-propelled objects from the events both stationary and side-by-side, and their preferential looking to the objects was assessed. Results revealed that 5- and 6-month-olds displayed a different pattern of looking than did 8-month-olds. More notably, noncrawling 7-month-olds and 7-month-olds with crawling experience also demonstrated such a differential pattern. These data suggest that processing of motion onset changes in concert with the commencement of self-locomotion. Findings are discussed in reference to the mechanisms underlying infants' ability to recognize self-propelled motion and the scope of the relationship between action production and action perception in infancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Young children associate novel words with complex objects rather than salient parts.

How do children learn associations between novel words and complex perceptual displays? Using a visual preference procedure, the authors tested 12- and 19-month-olds to see whether the infants would associate a novel word with a complex 2-part object or with either of that object's parts, both of which were potentially objects in their own right and 1 of which was highly salient to infants. At both ages, children's visual fixation times during test were greater to the entire complex object than to the salient part (Experiment 1) or to the less salient part (Experiment 2)--when the original label was requested. Looking times to the objects were equal if a new label was requested or if neutral audio was used during training (Experiment 3). Thus, from 12 months of age, infants associate words with whole objects, even those that could potentially be construed as 2 separate objects and even if 1 of the parts is salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Viewing imitation as child responsiveness: A link between teaching and discipline domains of socialization.

The authors observed 106 children's imitation and responses to maternal control at 14 and 22 months. Imitation was observed in a teaching task in which mothers modeled 3 standard pretend-play sequences. Responses to control were observed in typical discipline contexts. Girls imitated more than boys. Responsive imitation measures were coherent and longitudinally stable and correlated significantly with responsiveness to maternal control. The authors propose that a young child's willingness to imitate his or her parent in a teaching context and to comply in a control context both reflect a responsive or receptive stance toward parental socialization. The consistency of children's responsiveness across contexts has implications for both sociomoral and cognitive development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related changes in imitating sequences of observed movements.

Three experiments investigated the size and sources of age-related changes in visual imitation. In Experiment 1, young and older adults viewed sequences of quasi-random movements and then reproduced from memory what they had seen. As expected, older adults made more errors in imitation than their younger counterparts. However, older adults seemed to supplement their memory by exploiting an abstracted representation (gist) of a sequence. Experiments 2 and 3 apportioned the observed age-related changes in imitation performance among several possible causes. Experiment 2 showed that changes in precision of visual perception and motor control together accounted for only a small fraction of age-related changes in imitation quality; Experiment 3 showed that the bulk of the age-related changes arose from the older participants’ reduced ability to accommodate for increases in memory load, likely caused by diminished ability to encode or retain detailed information about movement sequences. Guided by these results, strategies are proposed for enhancing older adults’ imitation learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of semantic context and memory in the acquisition of novel nouns

Three studies assessed the ability of 2-year-olds to use semantic context to infer the meanings of novel nouns and to retain those meanings a day later. In the first experiment, 24 2-year-olds heard novel nouns in sentences that contained semantically constraining verbs (e.g., "Mommy feeds the ferret"). They chose from a set of four novel object pictures to indicate the referent. Children learned a majority of the novel words. However, they occasionally failed to choose the correct object even when they understood the verb. Experiment 2 examined whether this was due to an inability to identify some of the pictures of novel objects. Experiment 3 tested 24 2-year-olds' memory for the newly learned nouns following a 24 hr delay and found significant retention. Results are discussed in terms of learning mechanisms that facilitate vocabulary acquisition in young children.     

Two-month-old infants' sensitivity to changes in arbitrary syllable–object pairings: The role of temporal synchrony.

To explore early lexical development, the authors examined infants' sensitivity to changes in spoken syllables and objects given different temporal relations between syllable–object pairings. In Experiment 1, they habituated 2-month-olds to 1 syllable, /tah/ or /gah/, paired with an object in synchronous (utterances coincident with object motions, N = 16) or asynchronous (utterances erratic relative to object motions, N = 16) conditions. In the asynchronous condition, the audio track preceded or succeeded the visual track by 1,200 ms. On test, infants in the synchronous condition alone detected the changes. Post hoc computational analyses confirmed lower time separation, interpreted as greater synchrony, between peaks and onsets–offsets of visual motion and audio energy in the synchronous relative to the asynchronous condition. Further examining lexical development, in Experiment 2 they habituated 2-month-olds (N = 16) to two synchronous syllable–object pairs and tested them on switch versus same pairings. Infants failed to detect the switch in the pairings. These results suggest that 2-month-olds use synchrony to detect changes in one novel syllable–object pairing at a time, providing a basis for further word mapping development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Linguistic and Conceptual Influences on Adjective Acquisition in 24- and 36-Month-Olds.

Two hundred forty English-speaking toddlers (24- and 36-month-olds) heard novel adjectives applied to familiar objects (Experiment 1) and novel objects (Experiment 2). Children were successful in mapping adjectives to target properties only when information provided by the noun, in conjunction with participants' knowledge of the objects, provided coherent category information: when basic-level nouns or superordinate-level nouns were used with familiar objects, when novel basic-level nouns were used with novel objects, and-for 36-month-olds-when the nouns were underspecified with respect to category (thing or one) but participants could nonetheless infer a category from pragmatic and conceptual knowledge. These results provide evidence concerning how nouns influence adjective learning, and they support the notion that toddlers consider pragmatic factors when learning new words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming of familiar and unfamiliar visual objects over delays in young and older adults.

Although priming of familiar stimuli is usually age invariant, little is known about how aging affects priming of preexperimentally unfamiliar stimuli. Therefore, this study investigated the effects of aging and encoding-to-test delays (0 min, 20 min, 90 min, and 1 week) on priming of unfamiliar objects in block-based priming paradigms. During the encoding phase, participants viewed pictures of novel objects (Experiments 1 and 2) or novel and familiar objects (Experiment 3) and judged their left–right orientation. In the test block, priming was measured using the possible–impossible object-decision test (Experiment 1), symmetric–asymmetric object-decision test (Experiment 2), and real–nonreal object-decision test (Experiment 3). In Experiments 1 and 2, young adults showed priming for unfamiliar objects at all delays, whereas older adults whose baseline task performance was similar to that of young adults did not show any priming. Experiment 3 found no effects of age or delay on priming of familiar objects; however, priming of unfamiliar objects was only observed in the young participants. This suggests that when older adults cannot rely on preexisting memory representations, age-related deficits in priming can emerge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of declarative memory in human infants: Age-related changes in deffered imitation.

In 2 experiments, deferred imitation procedures were used to trace age-related changes in declarative memory by human infants over the first 2 years of life. An adult modeled 3 actions with an object, and infants' ability to reproduce those actions was assessed 24 hr later. Some infants were tested with a new object or in a new context relative to the original demonstration. Changes in the context disrupted the performance of 6-month-olds but had no effect on the performance of 12- and 18-month-olds. Changes in the object disrupted the performance of 6- and 12-month-olds but had no effect on the performance of 18-month-olds. This age-related increase in representational flexibility may account for the decline of childhood amnesia during the 3rd year of life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interference effects by spatial proximity and age-related declines in spatial memory by Japanese monkeys (Macaca fuscata): Deficits in the combined use of multiple spatial cues.

Spatial information processing was assessed in 3 young (4-10 years old) and 4 aged (24-25 years old) Japanese monkeys (Macaca fuscata) on 3 delayed nonmatching-to-position (DNMP) tests with relatively short delays of 5 s. Each test had 3 conditions of different horizontal distances between sample and to-be-nonmatched positions. Experiment 1 demonstrated that the performance on the DNMP test in both age groups was impaired when 2 stimulus positions were located next to each other; however, it was fairly accurate when they were located farther apart, suggesting that interference is introduced by spatial proximity. Experiment 2 revealed age-related differences in the situation in which an additional spatial cue, depth information, was available by extending the stimulus array of the DNMP test to a 4 = 2 matrix. In this test, young monkeys performed accurately irrespective of position distance between stimuli, whereas the aged monkeys' performance remained the same as before. Experiment 3 confirmed that the recognition ability in aged monkeys was well preserved on DNMP tests with different objects. These patterns of results indicate that the ability to use information from multiple spatial cues is not accessible to the aged monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

One thing follows another: Effects of temporal structure on 1- to 2-year-olds' recall of events.

Investigated whether recall of events by children under 2 years of age is similar to that of older preschoolers and adults. Experiment 1 used elicited-imitation to test 16- and 20-month-olds' immediate and delayed recall (2-week delay) of familiar and novel events. Ordered recall at immediate and delayed test was superior for familiar events and for novel events with causal relations among the elements; ordered recall of novel events lacking causal relations was significantly lower. Experiment 2 tested children's sensitivity to differences in underlying structure of novel events. Nineteen-, 25-, and 31-month-olds organized recall around causal relations, in spite of experimental manipulations that interrupted causally connected pairs of elements. The experiments provide clear evidence that, like preschoolers and adults, children as young as 16 months include temporal order information in their representations of both familiar novel events and that the causal structure of novel events influences their recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

It's a sign of the kind: Gestures and words guide infants' inductive inferences.

The role of words and gestures in guiding infants' inductive inferences about nonobvious properties was examined. One hundred seventy-two 14-month-olds and 22-month-olds were presented with novel target objects followed by test objects that varied in similarity to the target. Objects were introduced with a novel word or a novel gesture or with no label. When target and test objects were highly similar in shape, both 14- and 22-month-olds inferred that these objects shared a nonobvious property, regardless of whether the objects were labeled with a word or a gesture or with no label. When objects were labeled with the same word, both 14- and 22-month-olds generalized the nonobvious properties to objects that shared minimal perceptual similarity. Finally, when objects were labeled with the same gesture, 14-month-olds, but not 22-month-olds, generalized the nonobvious properties to objects that shared minimal perceptual similarity. These results indicate that 14-month-olds possess a more generalized symbolic system as they will rely on both words and gestures to guide their inferences. By 22-months of age, infants treat words as a privileged referential form when making inductive inferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word learning in the context of referential and salience cues.

Adult referential behavior (gaze direction) and salience (target activation) were independently manipulated in a study of novel word learning. Children (seventy-five 18-month-olds and seventy-two 24-month-olds) were trained in different conditions with a novel word in the context of 2 remote-controlled toys. In response to the novel word at test, 24-month-olds tended to pick out the toy to which the adult referred in all conditions. They also tended to use the novel word appropriately. Comprehension by 18-month-olds was good when the salience of the toy did not conflict with the adult's referential intent, but it was disrupted when referential and salience cues conflicted and when referential cues were not available. Results imply that, at 24 months, children use the referential intent of the speaker to learn new words, but when first learning words, children may have a less secure grasp on the meaning of speakers' referential cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)