Crossmodal learning in newborn infants: Inferences about properties of auditory-visual events

The majority of research on infant crossmodal perception has addressed the question of whether infants 4 months and older demonstrate the ability. By contrast, the focus in the present study was on newborns and the primary goal was twofold: to determine if newborns can learn arbitrary sight-sound pairings and to evaluate possible inferences that neonates make when repeatedly presented arbitrary sight-sound pairings. Alert neonates were familiarized with toy-sound pairs using an infant-controlled habituation procedure. They were then given a violation-of-expectancy test to determine if they had learned these sight-sound pairings and drawn any inferences about certain properties of these bimodal events. Results supported the conclusion that infants just a few hours old can learn sight-sound pairings. Furthermore, the findings suggested that newborns expected sight-sound pairs to remain colocated even when they move to a new location, they recognized that the sound was an attribute of a specific object, and they recognized that a specific spatial location was not an attribute of the sight-sound pair. Thus, infants made important and correct inferences based on limited experiences with specific auditory-visual events, and they did so just after birth. Implications of these findings for theories of crossmodal perceptual development are discussed.     

Developmental changes in associations between auditory-visual events

The goal of the present study was twofold: to examine the influence of two amodal properties, co-location and temporal synchrony, on infants' associating a sight with a sound, and to determine if the relative influence of these properties on crossmodal learning changes with age. During familiarization 2-, 4-, 6- and 8-month-olds were presented two toys and a sound, with sights and sounds varying with respect to co-location and temporal synchrony. Following each familiarization phase infants were given a paired preference test to assess their learning of sight-sound associations. Measures of preferential looking revealed age-related changes in the influence of co-location and temporal synchrony on infants' learning sight-sound associations. At all ages, infants could use temporal synchrony and co-location as a basis for associating an auditory with a visual event and, in the absence of temporal synchrony, co-location was sufficient to support crossmodal learning. However, when these cues conflicted there were developmental changes in the influence of these cues on infants' learning auditory-visual associations. At 2 and 4 months infants associated the sounds with the toy that moved in synchrony with the sound's rhythm despite extreme violation of co-location of this sight and sound. In contrast, 6- and 8-month-olds did not associate a specific toy with the sound when co-location and synchrony information conflicted. The findings highlight the unique and interactive effects of distinct amodal properties on infants' learning arbitrary crossmodal relations. Possible explanations for the age shift in performance are discussed.     

Does category-training facilitate 11-month-olds’ acquisition of unfamiliar category-property associations?

The ability to form category-property links allows infants to extend a property from one category member to another. In two experiments, we examined whether orienting infants to the demands of the task, through categorization training, would facilitate 11-month-old infants’ category-property extensions when familiarized with a single exemplar of an unfamiliar animal category. In Experiment 1, 11-month-olds (N = 35) were trained with two familiar animal-sound pairings (i.e., dog-bark, cat-meow), familiarized with two unfamiliar animal-sound pairings and then tested on their learning and generalization of the unfamiliar animal-sound associations. Across two conditions, Experiment 2 familiarized 11-month-olds (N = 69) to one familiar (i.e., dog-bark) and one novel animal-sound pairing. Conditions differed in their presentation of familiarization trials (i.e., random or blocked). Infants were then tested on their learning and extension of the animal-sound associations. In both experiments, infants did not demonstrate learning of the original animal sound pairing, nor generalization of the sound property to new members of the animal categories. These results indicate that the two category training paradigms implemented in the current studies did not facilitate 11-month-olds’ ability to learn or generalize an unfamiliar animal-sound association, when familiarized with a single exemplar.     

Cortisol reactivity, maternal sensitivity, and learning in 3-month-old infants

This study investigated the effects of adrenocortical functioning on infant learning during an emotionally challenging event (brief separation from mother). We also explored possible relationships between maternal sensitivity and both infant and maternal cortisol reactivity during the learning/maternal separation episode. Sixty-three 3-month-olds and their mothers were videotaped for a 10 min normal interaction period, and mother-infant behavioral synchrony was measured using Isabella and Belsky's [Isabella, R. A., & Belsky, J. (1991). Interactional synchrony and the origins of infant-mother attachment: A replication study. Child Development, 62, 373-384] coding scheme. The percentage of synchronous behaviors served as a measure of maternal sensitivity. Learning and short-term memory involved relating the infant's mother's voice with a moving colored block in a preferential looking paradigm. Infants whose cortisol increased during the session showed no learning or memory, infants whose cortisol declined appeared to learn and remember the association, while infants whose cortisol did not change evidenced learning, but not memory for the voice/object correspondence. Sensitivity and cortisol reactivity were correlated for mothers, but not for infants. Infant and maternal cortisol values for the first sampling period were highly correlated, but their cortisol reactivity values were uncorrelated, supporting the notion that infants and mothers have coordinated adrenocortical functioning systems when physically together, but become uncoordinated during a separation/learning event.     

Infants' intermodal perception of two levels of temporal structure in natural events

Infants' intermodal perception of two levels of temporal structure uniting the visual and acoustic stimulation from natural, complex events was investigated in four experiments. Films depicting a single object (single, large marble) and a compound object (group of smaller marbles) colliding against a surface in an erratic pattern were presented to infants between 3 and months of age using an intermodal preference and search method. These stimulus events portrayed two levels of invariant temporal structure: (a) temporal synchrony united the sights and sounds of object impact, and (b) temporal microstructure, the internal temporal structure of each impact sound and motion, specified the composition of the object (single vs. compound). Experiment 1 demonstrated that by 6 months infants detected a relation between the audible and visible stimulation from these events when both levels of invariant temporal structure guided their intermodal exploration. Experiment 2 revealed that by 6 months infants detected the bimodal temporal microstructure specifying object composition. They looked predominantly to the film whose natural soundtrack was played even though the motions of objects in both films were synchronized with the soundtrack. Experiment 3 assessed infants' sensitivity to temporal synchrony relations. Two films depicting objects of the same composition were presented while the motions of only one of them was synchronized with the appropriate soundtrack. Both 6-month-olds showed evidence of detecting temporal synchrony relations under some conditions. Experiment 4 examined how temporal synchrony and temporal microstructure interact in directing intermodal exploration. The natural soundtrack to one of the objects was played out-of-synchrony with the motions of both. In contrast with the results of Experiment 2, infants at 6 months showed no evidence of detecting a relationship between the film and its appropriate soundtrack. This suggests that the temporal asynchrony disrupted their detection of the temporal microstructure specifying object composition. Results of these studies support on invariant-detection view of the development of intermodal perception.     

Learning of syllable-object relations by preverbal infants: The role of temporal synchrony and syllable distinctiveness

The role of temporal synchrony and syllable distinctiveness in preverbal infants’ learning of word-object relations was investigated. In Experiment 1, 7- and 8-month-olds (N = 64) were habituated under conditions where two similar-sounding syllables, /tah/ and /gah/, were spoken simultaneously with the motions of one of two sets of objects (synchronous) or out of phase with the motions (asynchronous). On test trials, 8-month-olds, but not 7-month-olds, showed learning of the relations in the synchronous condition but not in the asynchronous condition. Furthermore, in Experiment 2, following habituation to one of the synchronous syllable-object pairs, 7-month-olds (n = 8) discriminated the syllables and the objects. In Experiment 3, following habituation to two distinct syllables, /tah/-/gih/ or /gah/-/tih/, paired with identical objects, 7-month-olds (n = 40) showed learning of the relations, again only in the synchronous condition. Thus, synchrony, which mothers naturally provide between words and object motions, facilitated the mapping onto objects of similar-sounding syllables at 8 months of age and distinct syllables at 7 months of age. These findings suggest an interaction between infants’ synchrony and syllable distinctiveness perception during early word mapping development.     

When the event is more than the sum of its parts: 9-month-olds' long-term ordered recall

Research suggests that 9-month-old infants are able to recall single object-specific actions over delays of 24 hours. In the present research we investigated whether 9-month-olds are able to recall over more extended delays, and to recall the temporal order of events, as well as the individual actions in them. In addition, we investigated whether recall can be enhanced by pre- and/or re-exposure to target events. Using elicited imitation of novel, multi-step event sequences, we demonstrated that, as a group, 9-month-olds are able to recall target actions after delays of five weeks. However, after this long delay, only 45% of the infants recalled the temporal order of the events. Re-exposure to events during the delay interval proved necessary for boys, but not for girls; pre-exposure to events did not affect later recall. The implications of individual differences in infants' recall ability for the understanding of the development of the neural correlates of declarative memory are discussed.     

Intersensory redundancy facilitates prenatal perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) selectively recruits attention and facilitates perceptual learning in human infants. This comparative study examined whether intersensory redundancy also facilitates perceptual learning prenatally. The authors assessed quail (Colinus virginianus) embryos' ability to learn a maternal call when it was (a) unimodal, (b) concurrent but asynchronous with patterned light, or (c) redundant and synchronous with patterned light. Chicks' preference for the familiar over a novel maternal call was assessed 24 hr following hatching. Chicks receiving redundant, synchronous stimulation as embryos learned the call 4 times faster than those who received unimodal exposure. Chicks who received asynchronous bimodal stimulation showed no evidence of learning. These results provide the first evidence that embryos are sensitive to redundant, bimodal information and that it can facilitate learning during the prenatal period.     

The effects of exposure to dynamic expressions of affect on 5-month-olds’ memory

The purpose of this study was to examine the behavioral effects of adults’ communicated affect on 5-month-olds’ visual recognition memory. Five-month-olds were exposed to a dynamic and bimodal happy, angry, or neutral affective (face–voice) expression while familiarized to a novel geometric image. After familiarization to the geometric image and exposure to the affective expression, 5-month-olds received either a 5-min or 1-day retention interval. Following the 5-min retention interval, infants exposed to the happy affective expressions showed a reliable preference for a novel geometric image compared to the recently familiarized image. Infants exposed to the neutral or angry affective expression failed to show a reliable preference following a 5-min delay. Following the 1-day retention interval, however, infants exposed to the neutral expression showed a reliable preference for the novel geometric image. These results are the first to demonstrate that 5-month-olds’ visual recognition memory is affected by the presentation of affective information at the time of encoding.     

Development of perception of the unity of musical events

Infants' and young children's perception of the unity of musical events was investigated in three studies. In the first two, children watched video displays of two musicians playing different musical instruments side by side in synchrony, and heard a soundtrack in synchrony with both instruments but specific to one. The children judged which instrument was producing the music they heard. Three- to 4-year-olds differentiated instruments from different families but not instruments from the same family. Five- to 7-year-olds additionally differentiated instrument pairs differing in size and pitch range (e.g., violin, cello). In the third study, infants were presented some of the same musical events in order to assess whether specific experience with the instruments is necessary for perceiving the unity of musical events. Looking times revealed that 7- to 9-month-olds detected the correspondence of the sight and sound of some musical instruments. Specific experience with a variety of instruments is evidently not necessary for detecting correspondences of audible and visible properties and for differentiating instruments from different families.     

Increasing specificity in perceptual development: infants' detection of nested levels of multimodal stimulation

This research assessed the development of infants' sensitivity to two nested amodal temporal relations in audible and visible events. Their detection of global temporal synchrony between visible and audible impacts and internal temporal structure nested within each impact specifying object composition (single versus compound objects) was assessed. Infants of 4, 7, and 11 weeks of age were habituated to a single and a compound object striking a surface and then received test trials depicting a change in synchrony or object composition. Results indicated an interaction between age and condition where sensitivity to synchrony was present by 4 weeks and remained stable across age, whereas sensitivity to composition emerged later, by 7 weeks, and increased dramatically with age. These findings converge with other recent findings to illustrate a pattern of increasing specificity in the development of perception, where infants first detect global and later detect embedded relations. The early sensitivity to global relations may provide an organizational framework for development by focusing infant attention on unitary events, guiding and constraining further exploration, and buffering infants from learning incongruent relations.     

Reexposure breeds recall: effects of experience on 9-month-olds' ordered recall

On the basis of three experiences, 9-month-olds recall specific events after one month. We tested whether multiple experiences are necessary, or merely facilitative, of 9-month-olds' long-term recall. In two experiments, using deferred imitation, infants were exposed to multi-step sequences either one time, two times, or three times prior to a one-month delay. In Experiment 1, regardless of the number of experiences, infants did not demonstrate recall. In Experiment 2, infants were tested on and reexposed to the events after one week; recall was tested again one month later. Performance after 1 week in Experiment 2 was greater than performance after one month in Experiment 1. Moreover, presumably as a function of reexposure after one week, infants recalled the individual actions of the events one month later. Infants in the three-experience condition also evidenced ordered recall after one month. Implications for the developmental status of the neural substrate supporting long-term recall are discussed.     

Study for now,but judge for later: Delayed judgments of learning promote long‐term retention

Larsson Sundqvist, M., Todorov, I., Kubik, V. & Jönsson, F.U. (2012) Study for now, but judge for later: Delayed judgments of learning promote long‐term retention. Scandinavian Journal of Psychology 53, 450–454. Delayed judgments of learning (JOL) are assumed to be based on covert retrieval attempts. A common finding is that testing memory during learning improves later retention (i.e., the testing effect), and even more so than an equivalent amount of study, but only after a longer retention interval. To test the assertion that also delayed JOLs improve memory, the participants either studied Swahili‐Swedish word pairs four times, or they both studied (two times) and performed delayed JOLs (two times) alternately. Final cued recall test were given after either five minutes or one week. Results showed a reliable learning‐group by retention‐interval interaction, with less forgetting in the group that alternated between studying and making JOLs. The results are discussed in relation to the self‐fulfilling prophecy account of Spellman and Bjork (1992) , and in terms of study advice, the results further underscore the importance of delaying JOLs when studying and evaluating one’s ongoing learning.     

The development of infant learning about specific face-voice relations

This study examined the development of infants' ability to perceive, learn, and remember the unique face-voice relations of unfamiliar adults. Infants of 2, 4, and 6 months were habituated to the faces and voices of 2 same-gender adults speaking and then received test trials where the faces and voices were synchronized yet mismatched. Results indicated that 4- and 6-month-olds, but not 2-month-olds, detected the change in face-voice pairings. Two-month-olds did, however, discriminate among the faces and voices in a control study. Results of a subsequent intermodal matching procedure indicated that only the 6-month-olds showed matching and memory for the face-voice relations. These findings suggest that infants' ability to detect the arbitrary relations between specific faces and voices of unfamiliar adults emerges between 2 and 4 months of age, whereas matching and memory for these relations emerges somewhat later, perhaps between 4 and 6 months of age.     

Transfer of associative grouping to novel perceptual contexts in infancy

Learning can be highly adaptive if associations learned in one context are generalized to novel contexts. We examined the development of such generalization in infancy in the context of grouping. In Experiment 1, 3- to 4-month-olds and 6- to 7-month-olds were habituated to shapes grouped via the organizational principle of common region and were tested with familiar and novel pairs as determined by the principle of proximity. Older infants generalized from common region to proximity, but younger infants did not. Younger infants failed to generalize when the task was easier (Experiment 2), and their failure was not due to inability to group via proximity (Experiment 3). However, in Experiment 4, even younger infants generalized grouping on the basis of connectedness to proximity. Thus, the ability to transfer learned associations of shapes to novel contexts is evident early in life, although it continues to undergo quantitative change during infancy. Moreover, the operation of this generalization mechanism may be induced by means of bootstrapping onto functional organizational principles, which is consistent with a developmental framework in which core processes scaffold learning.     

Word learning in deaf children with cochlear implants: effects of early auditory experience

Word-learning skills were tested in normal-hearing 12- to 40-month-olds and in deaf 22- to 40-month-olds 12 to 18 months after cochlear implantation. Using the Intermodal Preferential Looking Paradigm (IPLP), children were tested for their ability to learn two novel-word/novel-object pairings. Normal-hearing children demonstrated learning on this task at approximately 18 months of age and older. For deaf children, performance on this task was significantly correlated with early auditory experience: Children whose cochlear implants were switched on by 14 months of age or who had relatively more hearing before implantation demonstrated learning in this task, but later implanted profoundly deaf children did not. Performance on this task also correlated with later measures of vocabulary size. Taken together, these findings suggest that early auditory experience facilitates word learning and that the IPLP may be useful for identifying children who may be at high risk for poor vocabulary development.     

Ontogeny of early event memory: II. Encoding and retrieval by 2- and 3-month-olds

The ability of 2-month-old infants to discriminate changes in a 5-object crib mobile following a retention interval of 24 hr was assessed using the mobile conjugate reinforcement paradigm. Infants were trained in 3 daily 15-min sessions to produce mobile movement by footkicking. Twenty-four hr later, independent groups received generalization tests with mobiles containing 1–5 novel objects substituted into their original training mobile. A control group was tested with the original training mobile. These findings were compared with findings of 2 previous studies involving identical procedures with 3-month-olds, reanalyzed for measures of individual performance over successive test minutes. Although, in absolute terms, 2-month-olds had a flat generalization gradient relative to 3-month-olds, when each infant's kick rate during the generalization test was expressed relative to that infant's kick rate before, and at the end of, training, it was found that the generalization gradients of 2- and 3-month-olds were indistinguishable. The relative response measures indicated a surprising degree of specificity by both age groups: Test mobiles containing more than 1 novel object did not cue retrieval, but test mobiles containing no more than 1 new object yielded perfect retention and complete generalization. These data indicate that infants as young as 2 months are capable of encoding and maintaining a representation of the specific details of their training context for at least 24 hr and, after that delay, can perform fine discriminations based on the discrepancy between their test context and that representation.     

No two cues are alike: Depth of learning during infancy is dependent on what orients attention

Human infants develop a variety of attentional mechanisms that allow them to extract relevant information from a cluttered multimodal world. We know that both social and nonsocial cues shift infants’ attention, but not how these cues differentially affect learning of multimodal events. Experiment 1 used social cues to direct 8- and 4-month-olds’ attention to two audiovisual events (i.e., animations of a cat or dog accompanied by particular sounds) while identical distractor events played in another location. Experiment 2 directed 8-month-olds’ attention with colorful flashes to the same events. Experiment 3 measured baseline learning without attention cues both with the familiarization and test trials (no cue condition) and with only the test trials (test control condition). The 8-month-olds exposed to social cues showed specific learning of audiovisual events. The 4-month-olds displayed only general spatial learning from social cues, suggesting that specific learning of audiovisual events from social cues may be a function of experience. Infants cued with the colorful flashes looked indiscriminately to both cued locations during test (similar to the 4-month-olds learning from social cues) despite attending for equal duration to the training trials as the 8-month-olds with the social cues. Results from Experiment 3 indicated that the learning effects in Experiments 1 and 2 resulted from exposure to the different cues and multimodal events. We discuss these findings in terms of the perceptual differences and relevance of the cues.     

Rapid word learning in 13- and 17-month-olds in a naturalistic two-word procedure: looking versus reaching measures

This study investigated infants’ rapid learning of two novel words using a preferential looking measure compared with a preferential reaching measure. In Experiment 1, 21 13-month-olds and 20 17-month-olds were given 12 novel label exposures (6 per trial) for each of two novel objects. Next, in the label comprehension tests, infants were shown both objects and were asked, “Where’s the [label]?” (looking preference) and then told, “Put the [label] in the basket” (reaching preference). Only the 13-month-olds showed rapid word learning on the looking measure; neither age group showed rapid word learning on the reaching measure. In Experiment 2, the procedure was repeated 24 h later with 10 participants per age group from Experiment 1. After a further 12 labels per object, both age groups now showed robust evidence of rapid word learning, but again only on the looking measure. This is the earliest looking-based evidence of rapid word learning in infants in a well-controlled (i.e., two-word) procedure; our failure to replicate previous reports of rapid word learning in 13-month-olds with a preferential reaching measure may be due to our use of more rigorous controls for object preferences. The superior performance of the younger infants on the looking measure in Experiment 1 was not straightforwardly predicted by existing theoretical accounts of word learning.     

Spacing Simultaneously Promotes Multiple Forms of Learning in Children's Science Curriculum

The spacing effect refers to the robust finding that long‐term memory is promoted when learning events are distributed in time rather than massed in immediate succession. The current study extended research on the spacing effect by examining whether spaced learning schedules can simultaneously promote multiple forms of learning, such as memory and generalization, in the context of an educational intervention. Thirty‐six early elementary school‐aged children were presented with science lessons on one of three schedules: massed, clumped, and spaced. At a 1‐week delayed test, children in the spaced condition demonstrated improvements in both memory and generalization, significantly outperforming children in the other conditions. However, there was no observed relationship between children's memory performance and generalization performance. The current study highlights directions for future research and contributes to a growing body of work demonstrating the benefits of spaced learning for educational curriculum. Copyright © 2014 John Wiley & Sons, Ltd.