Twelve‐month‐olds’ comprehension and production of pointing

This study explored whether infants aged 12 months already recognize the communicative function of pointing gestures. Infants participated in a task requiring them to comprehend an adult's informative pointing gesture to the location of a hidden toy. They mostly succeeded in this task, which required them to infer that the adult was attempting to direct their attention to a location for a reason – because she wanted them to know that a toy was hidden there. Many of the infants also reversed roles and produced appropriate pointing gestures for the adult in this same game, and indeed there was a correlation such that comprehenders were for the most part producers. These findings indicate that by 12 months of age infants are beginning to show a bidirectional understanding of communicative pointing.     

Actions speak louder than words: Differences in memory flexibility between monolingual and bilingual 18‐month‐olds

Bilingual infants from 6‐ to 24‐months of age are more likely to generalize, flexibly reproducing actions on novel objects significantly more often than age‐matched monolingual infants are. In the current study, we examine whether the addition of novel verbal labels enhances memory generalization in a perceptually complex imitation task. We hypothesized that labels would provide an additional retrieval cue and aid memory generalization for bilingual infants. Specifically, we hypothesized that bilinguals might be more likely than monolinguals to map multiple perceptual features onto a novel label and therefore show enhanced generalization. Eighty‐seven 18‐month‐old monolingual and bilingual infants were randomly assigned to one of two experimental conditions or a baseline control condition. In the experimental conditions, either no label or a novel label was added during demonstration and again at the beginning of the test session. After a 24‐hr delay, infants were tested with the same stimulus set to test cued recall and with a perceptually different but functionally equivalent stimulus set to test memory generalization. Bilinguals performed significantly above baseline on both cued recall and memory generalization in both experimental conditions, whereas monolinguals performed significantly above baseline only on cued recall in both experimental conditions. These findings show a difference between monolinguals and bilinguals in memory generalization and suggest that generalization differences between groups may arise from visual perceptual processing rather than linguistic processing. A video abstract of this article can be viewed at https://youtu.be/yXB4pM3fF2k     

Two‐year‐olds’ understanding of self‐symbols

This study investigated 48 2.5‐year‐olds’ ability to map from their own body to a two‐dimensional self‐representation and also examined relations between parents’ talk about body representations and their children's understanding of self‐symbols. Children participated in two dual‐representation tasks in which they were asked to match body parts between a symbol and its referent. In one task, they used a self‐symbol and in the other they used a symbol for a doll. Participants were also read a book about body parts by a parent. As a group, children found the self‐symbol task more difficult than the doll‐task; however, those whose parents explicitly pointed out the relation between their children's bodies and the symbols in the book performed better on the self‐symbol task. The findings demonstrate that 2‐year‐old children have difficulty comprehending a self‐symbol, even when it is two‐dimensional and approximately the same size as them, and suggest that parents’ talk about self‐symbols may facilitate their understanding.     

Developmental changes in infants’ visual short-term memory for location

To examine the development of visual short-term memory (VSTM) for location, we presented 6- to 12-month-old infants (N = 199) with two side-by-side stimulus streams. In each stream, arrays of colored circles continually appeared, disappeared, and reappeared. In the changing stream, the location of one or more items changed in each cycle; in the non-changing streams the locations did not change. Eight- and 12.5-month-old infants showed evidence of memory for multiple locations, whereas 6.5-month-old infants showed evidence of memory only for a single location, and only when that location was easily identified by salient landmarks. In the absence of such landmarks, 6.5-month-old infants showed evidence of memory for the overall configuration or shape. This developmental trajectory for spatial VSTM is similar to that previously observed for color VSTM. These results additionally show that infants’ ability to detect changes in location is dependent on their developing sensitivity to spatial reference frames.     

Categorization and understanding of facial expressions in 4‐month‐old infants

This study examined whether 4‐month‐olds (N = 40) could perceptually categorize happy and angry faces, and show appropriate behavior in response to these faces. During the habituation phase, infants were shown the same type of facial expressions (happy or angry) posed by three models, and their behavior in response to those faces was observed. During the test phase immediately after the habituation phase, infants saw a novel emotional expression and a familiar expression posed by a new model, and their looking times were measured. The results indicated that, although 4‐month‐olds could perceptually categorize happy and angry faces accurately, they responded positively to both expression types. These findings suggest that, although infants can perceptually categorize facial expressions at 4 months of age, they require further time to learn the affective meanings of the facial expressions.     

The movement of internal facial features elicits 7 to 8‐month‐old infants' preference for face patterns

A preference for static face patterns is observed in newborns and disappears around 3 months after birth. A previous study has demonstrated that 5‐month‐old infants prefer schematic faces only when the internal features are moving, suggesting that face‐specific movement enhances infants' preference. The present study investigates the facilitative effect of the movement of internal facial features on infants' preference. To examine infants' preference, we used animated face patterns consisting of a head‐shaped contour and three disk blobs. The inner blobs expanded and contracted to represent the opening and closing of the eyes and mouth, and were constrained to open and close only in a biologically possible vertical direction resembling the facial muscle structure. We compared infants' preferential looking time for this vertically moving (VM) face pattern with their looking time for a horizontally moving (HM) face pattern in which blobs transformed at the same speed in a biologically impossible, horizontal direction. In Experiment 1, 7 to 8‐month‐olds preferred the VM to the HM, but 5 to 6‐month‐olds did not. However, the preference was diminished in both cases when the moving face patterns were presented without contour (Experiment 2). Our results suggest that internal facial features with vertical movements promote face preference in 7 to 8‐month‐olds. Copyright © 2011 John Wiley & Sons, Ltd.     

Executive functioning by 18‐24‐month‐old children: effects of inhibition,working memory demands and narrative in a novel detour‐reaching task

Infants can inhibit a prepotent but wrong action towards a goal in order to perform a causal means‐action. It is not clear, however, whether infants can perform an arbitrary means‐action while inhibiting a prepotent response. In four experiments, we explore this executive functioning in 18–24‐month‐old children. The working memory and inhibition demands in a novel means‐end problem were systematically varied in terms of the type and combination of means‐action(s) (causal or arbitrary) contained within the task, the number of means‐actions (1 or 2), the goal visual availability and whether the task was accompanied by a narrative. Experiments 1 and 2 showed that children performed tasks that contained causal as opposed to arbitrary information more accurately; accuracy was also higher in tasks containing only one step. Experiment 2 also demonstrated that performance in the arbitrary task improved significantly when all sources of prepotency were removed. In Experiment 3, task performance improved when the two means‐actions were intelligibly linked to the task goal. Experiment 4 demonstrated that the use of a narrative that provided a meaningful (non‐causal) link between the two means‐actions also improved children's performance by assisting their working memory in the generation of a rationale. Findings provide an initial account of executive functioning in the months that bring the end of infancy. Copyright © 2006 John Wiley & Sons, Ltd.     

Disentangling boundary extension and normalization of view memory for scenes

Boundary extension (BE) is a memory error for close-up views of scenes in which participants tend to remember a picture of a scene as depicting a more wide-angle view than what was actually displayed. However, some experiments have yielded data that indicate a normalized memory of the views depicted in a set of scenes, suggesting that memory for the previously studied scenes has become drawn toward the average view in the image set. In previous studies, normalization is only found when the retention interval is very long or when the stimuli no longer appear to represent a spatial expanse. In Experiment 1, we examine whether normalization can influence results for scenes depicting a partial view of space and when the memory test occurs immediately following the study block by manipulating the degree of difference between studied close-up and wide-angle scenes. In Experiment 2, normalization is induced in a set of scenes by creating conditions expected to lead to memory interference, suggesting that this may be the cause of view normalization. Based on the multi-source model of BE, these scenes should be extended during perception (Intraub, H. (2010). Rethinking scene perception: A multisource model. Psychology of Learning and Motivation, 52, 231–265). In Experiment 3, we show that BE is indeed observable if the same scenes are tested differently, supporting the notion that BE is primarily a perceptual phenomenon while normalization is a memory effect.     

Perception of correlated attributes involving African–American and white females' faces by 10‐month‐old infants

Thirty‐two 10‐month‐olds were habituated to stimuli containing an African–American female face or a white female face paired with a specific object. Test stimuli maintained or violated habituation stimuli pairings (i.e. categories). Results add to an emerging literature showing that 10‐month‐olds perceive categories of social information based on detection of correlated attributes. Copyright © 2003 John Wiley & Sons, Ltd.     

Sparse distributed memory for ‘conscious’ software agents

In this work we are reporting a case study on the use of SDM as the associative memory for a software agent, CMattie, whose architecture is modeled on human cognition. Sparse distributed memory (SDM) is a content-addressable memory technique that relies on close memory items tending to be clustered together. In this work, we used an enhanced version of SDM augmented with the use of genetic algorithms as an associative memory in our ‘conscious’ software agent, CMattie, who is responsible for emailing seminar announcements in an academic department. Interacting with seminar organizers via email in natural language, CMattie can replace the secretary who normally handles such announcements. SDM is a key ingredient in a complex agent architecture that implements global workspace theory, a psychological theory of consciousness and cognition. In this architecture, SDM, as the primary memory for the agent, provides associations with incoming percepts. These include disambiguation of the percept by removing noise, correcting misspellings, and adding missing pieces of information. It also retrieves behaviors and emotions associated with the percept. These associations are based on previous similar percepts, and their consequences, that have been recorded earlier. SDM also possesses several key psychological features. Some enhancements to SDM including multiple writes of important items, use of error detection and correction, and the use of hashing to map the original information into fixed size keys were used. Test results indicate that SDM can be used successfully as an associative memory in such complex agent architectures. The results show that SDM is capable of recovering a percept based on a part of that percept, and finding defaults for empty perception registers. The evaluation of suggested actions and emotional states is satisfactory. We think that this work opens the door to more scientific and empirical uses for SDM.     

Incidental memory for parts of scenes from eye movements

Incidental memory for parts of scenes was examined in two search experiments and one memory control experiment. Eye movements were recorded during the search experiments and used to select gaze-contingent sections from search scenes for a surprise memory recognition task. Results from the recognition task showed incidental memory was better for sections viewed longer and with multiple fixations. Sections not fixated during search were still recognized above chance as well. Differences in sections did not affect memory performance in a control experiment when viewing time was held constant. These results show that memory for parts of scenes can occur incidentally during search and encoding of tested sections is better with longer viewing time and with multiple fixations.     

Development of category formation for faces differing by age in 9‐ to 12‐month‐olds: An effect of experience with infant faces

We examined category formation for faces differing in age in 9‐ and 12‐month‐olds, and the influence of exposure to infant faces on such ability. Infants were familiarized with adult or infant faces, and then tested with a novel exemplar from the familiarized category paired with a novel exemplar from a novel category (Experiment 1). Both age groups formed discrete categories of adult and infant faces, but exposure to infant faces in everyday life did not modulate performance. The same task was conducted with child versus infant faces (Experiment 2). Whereas 9‐month‐olds preferred infant faces after familiarization with child faces, but not child faces after familiarization with infant faces, 12‐month‐olds formed discrete categories of child and infant faces. Moreover, more exposure to infant faces correlated with higher novel category preference scores when infants were familiarized with infant faces in 12‐month‐olds, but not 9‐month‐olds. The 9‐month‐old asymmetry did not reflect spontaneous preference for infant over child faces (Experiment 3). These findings indicate that 9‐ and 12‐month‐olds can form age‐based categories of faces. The ability of 12‐month‐olds to form separate child and infant categories suggests that they have a more exclusive representation of face age, one that may be influenced by prior experience with infant faces.     

The role of attention in the contextual enhancement of visual memory for natural scenes

The role of attention in memory for objects in natural scenes was investigated using a visual memory. In Experiment 1, participants were asked to memorize six cued (to be attended) objects in a natural scene, and were subsequently tested on one of the cued objects. Four types of test scene images were created by jumbling different sections in scene's background: Attended sections changed, unattended sections changed, both sections changed, and both unchanged. In Experiment 2, the procedure was the same as that of the jumble condition except that scenes to be memorized were also jumbled. Results showed that jumbling of attended sections reduced memory performance, whereas jumbling unattended sections did not, irrespective of the regularity of scene to be memorized. This finding suggests that attention plays an important role in mental construction of a natural scene representation, and leads to enhanced visual memory.     

The co‐construction of joint action between mothers and 2–4‐month‐old infants: the mother's role

The purpose of this longitudinal study was to describe object‐centred interactions between mothers and their 2–4‐month‐old infants, before and during the emergence of reaching and grasping movements. We hypothesized that when reaching movements emerge at around 3 months, mothers alternate between attention stimulation and reaching stimulation, before joint actions between mother and infant develop around objects. Twelve dyads were recorded when infants were 2 months, 3 months and 4 months. The interactive sessions lasted 5 min. Three age‐appropriate toys the infant could handle were available to the mother. A principal component analysis (PCA) was performed on verbal and non‐verbal maternal behaviours, motor infant behaviours and co‐occurrences of those behaviours. The developmental course of prehension in infants when playing with their mother follows similar pathways, as was described when they are observed alone. Mothers appeared to early scaffold prehension skills by verbal and non‐verbal means. Moreover, maternal behaviours change according to the infant's behaviour, and conversely, infant's behaviours influence maternal behaviours: mother plays first an active part in joint action, while later on, the infant achieves joint action when motor skills develop. Copyright © 2000 John Wiley & Sons, Ltd.     

Influence of a psychological perspective on scene viewing and memory for scenes

In the study, 33 participants viewed photographs from either a potential homebuyer's or a burglar's perspective, or in preparation for a memory test, while their eye movements were recorded. A free recall and a picture recognition task were performed after viewing. The results showed that perspective had rapid effects, in that the second fixation after the scene onset was more likely to land on perspective-relevant than on perspective-irrelevant areas within the scene. Perspective-relevant areas also attracted longer total fixation time, more visits, and longer first-pass dwell times than did perspective-irrelevant areas. As for the effects of visual saliency, the first fixation was more likely to land on a salient than on a nonsalient area; salient areas also attracted more visits and longer total fixation time than did nonsalient areas. Recall and recognition performance reflected the eye fixation results: Both were overall higher for perspective-relevant than for perspective-irrelevant scene objects. The relatively low error rates in the recognition task suggest that participants had gained an accurate memory for scene objects. The findings suggest that the role of bottom-up versus top-down factors varies as a function of viewing task and the time-course of scene processing.     

Longitudinal study of declarative and procedural memory in primary school‐aged children

This study examined the development of declarative and procedural memory longitudinally in primary school‐aged children. At present, although there is a general consensus that age‐related improvements during this period can be found for declarative memory, there are conflicting data on the developmental trajectory of the procedural memory system. At Time 1 children aged around 5½ years were presented with measures of declarative and procedural memory. The tasks were then administered 12 months later. Performance on the declarative memory task was found to improve at a faster rate in comparison to the procedural memory task. The findings of the study support the view that multiple memory systems reach functional maturity at different points in development.     

Follow-up of a cross-national comparison on flashbulb and event memory for the September 11th attacks

Flashbulb memories are defined as vivid and long-lasting memories for the reception context of an important public event (Brown & Kulik, 1977). They are supposed to be triggered by both emotional reactions to the original event and rehearsal processes (Brown & Kulik, 1977; Finkenauer, Luminet, Gisle, El-Ahmadi, van der Linden, & Philippot, 1998; Neisser & Harsch, 1992). A test-retest design (21 vs 524 days after the event on average) was employed to assess flashbulb memory and event memory for the September 11th attacks and the impact of their emotional and rehearsal predictors in a sample of 985 respondents coming from six countries (i.e., Belgium, Italy, the Netherlands, Romania, Japan, and the USA). Results showed that national membership had a significant impact on event memory, and the emotional and rehearsal variables, but flashbulb memories for the September 11th attacks were found to be high and consistent across different countries. The implications of these findings for the debate about the nature and maintenance of flashbulb memories are discussed.     

Infant gaze following depends on communicative signals: An eye‐tracking study of 5‐ to 7‐month‐olds in Vanuatu

Gaze is considered a crucial component of early communication between an infant and her caregiver. When communicatively addressed, infants respond aptly to others’ gaze by following its direction. However, experience with face‐to‐face contact varies across cultures, begging the question whether infants’ competencies in receiving others’ communicative gaze signals are universal or culturally specific . We used eye‐tracking to assess gaze‐following responses of 5‐ to 7‐month olds in Vanuatu, where face‐to‐face parent–infant interactions are less prevalent than in Western populations. We found that—just like Western 6‐month‐olds studied previously—5‐ to ‐7‐month‐olds living in Vanuatu followed gaze only, when communicatively addressed. That is, if presented gaze shifts were preceded by infant‐directed speech, but not if they were preceded by adult‐directed speech. These results are consistent with the notion that early infant gaze following is tied to infants’ early emerging communicative competencies and rooted in universal mechanisms rather than being dependent on cultural specificities of early socialization.