Verbal cues facilitate memory retrieval during infancy

In three experiments, 18-month-olds were tested in a deferred imitation paradigm. Some infants received verbal information during the demonstration and at the time of the test (full narration), and some did not (empty narration). When tested after a 4-week delay, infants given full narration exhibited superior retention relative to infants given empty narration (Experiment 1). This retention advantage appears to be due to the effects of verbal cues at the time of memory retrieval. There was no effect of verbal cues that were presented only at the time of original encoding (Experiment 2A). Furthermore, infants who received verbal cues only at the time of retrieval exhibited superior retention relative to infants who received verbal cues only at the time of original encoding (Experiment 2B). These findings demonstrate that verbal cues can enhance memory retrieval by participants who are not yet fluent speakers themselves.     

Televised social interaction and object learning in 14- and 18-month-old infants

We examined object learning in infants who viewed a televised adult speaking about a novel toy in videos that varied in the social cues provided. Novelty preference in following test trials differed as a function of televised social cues in 18-month-old, but not 14-month-old infants.     

Adult language use and infant comprehension of English: Associations with encoding and generalization across cues at 20 months

Adult-provided language shapes event memory in children who are preverbal and in those who are able to discuss the past using language. The research conducted to date, however, has not yet established whether infant language comprehension abilities moderate the extent to which preverbal infants benefit from adult-provided supportive language. The present study was conducted to address this question by examining immediate imitation and 1-week delayed generalization across cues in 20-month-old infants as a function of (a) variability in adult-provided linguistic support at encoding and test, (b) infant language comprehension abilities, and (c) their interaction. The provision of supportive adult language at encoding and test was associated with delayed generalization across cues although supportive adult language at encoding did not influence performance at immediate imitation. Infant language comprehension abilities were associated with performance at immediate imitation and delayed generalization across cues. In addition, infant language comprehension abilities moderated the extent to which infants benefited from adult-provided supportive language at encoding and test. The findings contribute to the literature by demonstrating that adult language use and infant language comprehension are independently and differentially associated with immediate imitation and 1-week delayed generalization across cues but also serve to jointly structure event memory in the second year of life.     

Infants’ responsiveness to pictorial depth cues in preferential-reaching studies: A meta-analysis

The findings of numerous preferential-reaching studies suggest that infants first respond to pictorial depth cues between 5 and 7 months of age. However, three recent preferential-reaching studies have found evidence of responsiveness to pictorial depth cues in 5-month-olds. We investigated these apparently contradictory results by conducting meta-analyses of the data from 5-month-olds who participated in preferential-reaching studies. The data from 16 samples, comprising 475 infants 5–5.5 months of age, were integrated. The results showed that the infants responded more consistently to depth relationships specified by pictorial cues under monocular than under binocular viewing conditions (p < .001), indicating that 5-month-old infants respond to pictorial depth cues. This effect remained significant (p < .001) when the individual experiments that had found significant results were omitted from the analysis. Although the majority of experiments were unable to find evidence of pictorial depth perception individually, this ability was clearly revealed when their results were combined.     

Response versus place learning by human infants

Two cross-setional studies examined how infants learn the location of visual events. In Experiment 1, infants of 4, 8, and 12 mo of age learned to turn one way to view a novel pattern. In a subsequent transfer task, they were rotated to face the opposite side of the room. The 4-mo-old infants tended to err by repeating their previously learned response, but within 16-20 trials their performance was comparable to the higher levels maintained by the older infants. These results suggest that young infants learn the location of the pattern primarily in terms of response cues, whereas older infants employ both response cues and place cues. Experiment 2 was designed to independently assess the use of response cues and place cues by infants of 4, 8, 12, and 16 mo of age. All infants were able to rapidly learn and remember the location of the novel pattern when they were given response cues. There was a gradual emergence of place-cue use associated with age. It is suggested that the decrease in infant egocentricity in such spatial localization tasks may in fact reflect an age-related increase in the variety of reliable cues responded to by infants.     

When cues collide: use of stress and statistical cues to word boundaries by 7- to 9-month-old infants

Prior research suggests that stress cues are particularly important for English-hearing infants' detection of word boundaries. It is unclear, though, how infants learn to attend to stress as a cue to word segmentation. This series of experiments was designed to explore infants' attention to conflicting cues at different ages. Experiment 1 replicated previous findings: When stress and statistical cues indicated different word boundaries, 9-month-old infants used syllable stress as a cue to segmentation while ignoring statistical cues. However, in Experiment 2, 7-month-old infants attended more to statistical cues than to stress cues. These results raise the possibility that infants use their statistical learning abilities to locate words in speech and use those words to discover the regular pattern of stress cues in English. Infants at different ages may deploy different segmentation strategies as a function of their current linguistic experience.     

Infants infer intentions from prosody

Two studies were conducted to examine infants’ ability to discern intentions from lexical and prosodic cues. Two groups of 14-18-month-olds participated in these studies. In both studies, infants watched an adult perform a sequence of two-step actions on novel toys that produced an end-result. In the first study actions were marked intentionally with both lexical and prosodic cues. In the second study, the lexical markers of intention were presented in Greek, thus providing infants with prosodic but not lexical cues. In both studies, infants reproduced more intentional than accidental actions, suggesting that infants can infer intentions from prosodic cues.     

Prenatal intervention and support for low-income fathers

The focus of this study was to determine the effectiveness of prenatal intervention with low socioeconomic, first-time fathers whose partners were experiencing a high- or low-risk pregnancy. Of the 67 men, who were recruited by their partners, half were randomly assigned to participate in an intervention program designed to acquaint fathers-to-be with information, insights, and clinically appropriate techniques in responsive care for infants. Intervention group fathers received two intensive 1¹/₂-hour sessions emphasizing the nature and capabilities of the prebornhewborn and sensitive responsiveness to preborn/newborn cues and to partner cues. Postnatally, fathers were videotaped with their infants during two feeding interactions. At Time 1, intervention fathers were rated from videotapes as significantly more sensitive during feeding interactions with their newborn infants. At Time 2, 1 month later, differences between father groups approached significance.     

Fifteen-Month-Old Infants Match Vocal Cues to Intentional Actions

Fifteen-month-old infants detected a violation when an actor performed an action that did not match her preceding vocal cue: The infants looked reliably longer when the actor expressed a humorous vocal cue followed by a sweet action or expressed a sweet vocal cue followed by a humorous action, than when the vocal cue was followed by a matching action. The infants failed to detect the mismatch when one person expressed the vocal cue and another performed the action. The results suggest that by 15 months of age, infants are capable of distinguishing between two types of vocal cues and actions along the positive emotional spectrum: humor and sweetness. Furthermore, they match humorous vocal cues to humorous actions and sweet vocal cues to sweet actions only when the cues and actions are made by the same person.     

Changing the tune: the structure of the input affects infants' use of absolute and relative pitch

Sequences of notes contain several different types of pitch cues, including both absolute and relative pitch information. What factors determine which of these cues are used when learning about tone sequences? Previous research suggests that infants tend to preferentially process absolute pitch patterns in continuous tone sequences, while other types of input elicit relative pitch use by infants. In order to ask whether the structure of the input influences infants’ choice of pitch cues, we presented learners with continuous tone streams in which absolute pitch cues were rendered uninformative by transposing the tone sequences. Under these circumstances, both infants and adults successfully tracked relative pitches in a statistical learning task. Implications for the role played by the structure of the input in the learning process are considered.     

Comment on Hofsten and Spelke, object perception and object-directed reaching in infancy

Hofsten and Spelke (1985) reported a series of studies that quite clearly demonstrated infant sensitivity to depth and relative motion cues. They suggest a salience hierarchy for those cues in which relative motion takes precedence over depth when both cues are present. Based on reports that infants reach for and grasp boundaries in the visual display, the authors make the further claim that these data argue for object perception infants by the time they are 5 months old. The present article argues against this claim on two grounds: First, the authors do not report that infants specifically reached and grasped at boundaries in the display. Second, although patterns of reach are clearly affected by changes in boundary cues, there is no evidence that the boundaries the infants perceive are necessarily object boundaries.     

Discrimination of possible and impossible objects in infancy

Adults can use pictorial depth cues to infer three-dimensional structure in two-dimensional depictions of objects. The age at which infants respond to the same kinds of visual information has not been determined, and theories about the underlying developmental mechanisms remain controversial. In this study, we used a visual habituation/novelty-preference procedure to assess the ability of 4-month-old infants to discriminate between two-dimensional depictions of structurally possible and impossible objects. Results indicate that young infants are sensitive to junction structures and interposition cues associated with pictorial depth and can detect inconsistent relationships among these cues that render an object impossible. Our results provide important insights into the development of mechanisms for processing pictorial depth cues that allow adults to extract three-dimensional structure from pictures of objects.     

Influence of infant and child facial cues of low body weight on adults' ratings of adoption preference,cuteness, and health

Infant and child facial cues have been shown to influence decisions and perceptions associated with parental care in adults. Low body weight reflects health problems in infants and children; therefore, facial cues associated with low body weight may influence adult cognitive processes associated with parental care and investment. Facial images of infants and children were digitally manipulated to simulate cues of low body weight and presented to adults using a hypothetical adoption paradigm. Participants' ratings of adoption preference, cuteness, and health were significantly lower for the digitally manipulated low body weight facial images than their unaltered counterparts. These findings support the hypothesis that facial cues of poor health negatively influence adults' responses to infants and children.     

Word segmentation with universal prosodic cues

When listening to speech from one’s native language, words seem to be well separated from one another, like beads on a string. When listening to a foreign language, in contrast, words seem almost impossible to extract, as if there was only one bead on the same string. This contrast reveals that there are language-specific cues to segmentation. The puzzle, however, is that infants must be endowed with a language-independent mechanism for segmentation, as they ultimately solve the segmentation problem for any native language. Here, we approach the acquisition problem by asking whether there are language-independent cues to segmentation that might be available to even adult learners who have already acquired a native language. We show that adult learners recognize words in connected speech when only prosodic cues to word-boundaries are given from languages unfamiliar to the participants. In both artificial and natural speech, adult English speakers, with no prior exposure to the test languages, readily recognized words in natural languages with critically different prosodic patterns, including French, Turkish and Hungarian. We suggest that, even though languages differ in their sound structures, they carry universal prosodic characteristics. Further, these language-invariant prosodic cues provide a universally accessible mechanism for finding words in connected speech. These cues may enable infants to start acquiring words in any language even before they are fine-tuned to the sound structure of their native language.     

Infants’ reasoning about ambiguous motion events: The role of spatiotemporal and dispositional status information

Two experiments investigate whether 7-month-olds reason about the origin of motion events by considering two sources of causally relevant information: spatiotemporal cues and dispositional status information derived from the identification of an object as either animate (with the enduring causal property of self-initiated motion) or inanimate (requiring an external cause of motion). Infants were shown a ball, a human hand, and an animal engaged in a motion event. While dispositional status information remained constant, spatiotemporal relations varied across conditions. Based on looking time data, we conclude that infants attend flexibly to both types of information. Without spatiotemporal cues, infants rely on dispositional status information. When two objects provide dispositional cues to motion origin, but only one also provides corresponding spatiotemporal information, infants attribute the motion to the object providing both types of information. Given an ambiguous motion event with two dispositional motion originators but no additional spatiotemporal cues, infants may prefer either of the two.     

Five-Month-Old Infants Have Different Expectations for Solids and Liquids

ABSTRACT— Many studies have established that 2-month-old infants have knowledge of solid objects' basic physical properties. Evidence about infants' understanding of nonsolid substances, however, is relatively sparse and equivocal. We present two experiments demonstrating that 5-month-old infants have distinct expectations for how solids and liquids behave. Experiment 1 showed that infants use the motion cues from the surface of a contained liquid or solid to predict whether it will pour or tumble from a cup if the cup is upended. Experiment 2 extended these findings to show that motion cues lead to distinct expectations about whether a new object will pass through or remain on top of a substance. Together, these experiments demonstrate that 5-month-old infants are able to use movement cues and solidity to discriminate a liquid from an object of similar appearance, providing the earliest evidence that infants can reason about nonsolid substances.     

Exploring early developmental changes in face scanning patterns during the perception of audiovisual mismatch of speech cues

Young infants are capable of integrating auditory and visual information and their speech perception can be influenced by visual cues, while 5-month-olds detect mismatch between mouth articulations and speech sounds. From 6 months of age, infants gradually shift their attention away from eyes and towards the mouth in articulating faces, potentially to benefit from intersensory redundancy of audiovisual (AV) cues. Using eye tracking, we investigated whether 6- to 9-month-olds showed a similar age-related increase of looking to the mouth, while observing congruent and/or redundant versus mismatched and non-redundant speech cues. Participants distinguished between congruent and incongruent AV cues as reflected by the amount of looking to the mouth. They showed an age-related increase in attention to the mouth, but only for non-redundant, mismatched AV speech cues. Our results highlight the role of intersensory redundancy and audiovisual mismatch mechanisms in facilitating the development of speech processing in infants under 12 months of age.     

Infants' sensitivity to pictorial depth cues: a review and meta-analysis of looking studies

This paper reviews habituation-dishabituation and preferential-looking studies on the emergence of sensitivity to pictorial depth cues in infancy. This research can be subdivided into two groups. While one group of studies has established responsiveness to pictorial depth cues at 3-5 months of age, the other has found that the ability to extract pictorial 3D information emerges at about 6 months. In the former, young infants were tested for their ability to distinguish between displays that differ in spatial information provided by pictorial depth cues. The results of these studies might demonstrate that 3-5-month-old infants perceive spatial layout from pictorial cues. It is possible, however, that the infants in these studies responded primarily to low-level, two-dimensional stimulus differences. In contrast, the second group of studies controlled for the potential influence of lower-level stimulus features on the infants' experimental performance and more unambiguously demonstrated sensitivity to pictorial depth information in infants 6 months of age and older. In sum, the divergent findings of studies in this area may be resolved by assuming substantial developmental progress in infant sensitivity to pictorial depth cues during the first months of life.     

Selectivity in paternal and infanticidal responses by male mice: effects of relatedness, location, and previous sexual partners.

Male mice tend to be infanticidal to unrelated infants but parental to their own offspring. The present study examines three hypotheses that might explain this apparent discrimination. There was no evidence of selective infanticide toward infants encountered for the first time on the basis of kinship, location, or cues associated with previous sexual partners. However, males tended to direct more paternal responses toward their own unfamiliar infants than toward unrelated infants, infants encountered in the male's home cage than those in the cage of another male, and when cues associated with a previous sexual partner were present. Data suggested that the responses of females to male intruders might influence the responses of those males. It was concluded that the infanticidal responses of male mice are mediated by a particular state of the male but that males in a noninfanticidal state may vary their paternal responsiveness on the basis of direct and indirect cues concerning relatedness.     

Eighteen-month-olds integrate verbal cues into their action processing: Evidence from ERPs and mu power

Behavioral research has shown that infants use both behavioral cues and verbal cues when processing the goals of others’ actions. For instance, 18-month-olds selectively imitate an observed goal-directed action depending on its (in)congruence with a model’s previous verbal announcement of a desired action goal. This EEG-study analyzed the electrophysiological underpinnings of these behavioral findings on the two functional levels of conceptual action processing and motor activation. Mid-latency mean negative ERP amplitude and mu-frequency band power were analyzed while 18-month-olds (N = 38) watched videos of an adult who performed one out of two potential actions on a novel object. In a within-subjects design, the action demonstration was preceded by either a congruent or an incongruent verbally announced action goal (e.g., “up” or “down” and upward movement). Overall, ERP negativity did not differ between conditions, but a closer inspection revealed that in two subgroups, about half of the infants showed a broadly distributed increased mid-latency ERP negativity (indicating enhanced conceptual action processing) for either the congruent or the incongruent stimuli, respectively. As expected, mu power at sensorimotor sites was reduced (indicating enhanced motor activation) for congruent relative to incongruent stimuli in the entire sample. Both EEG correlates were related to infants’ language skills. Hence, 18-month-olds integrate action-goal-related verbal cues into their processing of others’ actions, at the functional levels of both conceptual processing and motor activation. Further, cue integration when inferring others’ action goals is related to infants’ language proficiency.