The perception of static subjective contours in infancy

Only a few empirical investigations have focused on infants' ability to perceive static subjective contours. Furthermore, these experiments have provided contradictory findings regarding the age at which this capability emerges. The present study examined the development of infants' sensitivity to an elliptical version of the subjective circle described by Ehrenstein. A habituation-dishabituation procedure was used to test the ability of 4-, 5-, and 7-month-old infants (N = 128) to differentiate between a subjective ellipse and a nonsubjective pattern that was constructed by displacing the inducing elements of the illusory figure. Results indicated that even the 4-month-olds were capable of discriminating between the subjective ellipse and the nonillusory display. A control experiment secured that this behavior was not generated by certain local differences between the test patterns. Furthermore, the results suggest that the perceived strength of the subjective contour was size dependent. This observation is discussed within the context of more recent neurophysiological models.     

Effects of motion and figural goodness on haptic object perception in infancy

4-month-old infants held 2 rings, 1 in each hand, out of view. The rings moved rigidly together and were either the same (Experiment 1) or different (Experiment 2) in substance, weight, texture, and shape. After haptic habituation to a ring display, patterns of preferential looking to visibly connected vs. separated rings provided evidence that the infants perceived the rings in both experiments as parts of one connected object. This perception was no weaker when the rings differed in shape and substance, even though infants were shown (Experiment 3) to detect that difference. In the haptic mode, as in the visual mode, infants appear to perceive object unity by analyzing motion but not by analyzing figural goodness. The findings suggest that an amodal mechanism underlies object perception.     

Linguistic experience and phonemic perception in infancy: a crosslinguistic study.

English- and Spanish-learning infants were tested for perception of 2 synthetic speech contrasts differing in voice onset time. The 2 pairs were chosen so that they were native to either Spanish or English. Using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm, 6--8-month-old infants were taught to respond to a change in auditory stimuli with a headturn. Correct headturns were reinforced by the activation of a lighted animated toy. While Spanish-learning infants provided evidence of discriminating both English and Spanish contrasts, English-learning infants only provided evidence of discriminating their native contrast. The results are discussed in terms of the role of linguistic experience in the development of speech perception skills in infancy.     

一种符合视觉感知的视频运动模糊帧检测方法

为了更准确地检测视频中的场景运动模糊帧,首先利用稀疏表示的图像模糊特征,结合恰可察觉模糊概念,定义1种敏感的图像模糊度度量,用于检测视频序列中的非清晰帧;然后通过计算相邻帧之间的单应矩阵,估计相机的运动速度,并根据运动速度从非清晰帧中选择出观看过程中产生模糊感受的场景运动模糊帧。实验结果表明,所提出的算法可以有效地检测出视频场景运动模糊帧,相比于传统图像模糊检测算法,检测结果更符合人眼观看视频的主观感受。     

Exploring the presence of imitation during early infancy

2 investigations of early imitative ability were conducted with cross-sectional samples of infants between 4 and 21 weeks. Study 1 involved 2 rounds of modeling 5 gestures to infants. In Study 2, the number of modeled gestures was reduced to 3, but each one was modeled many more times--for the duration of the infant's attention over a 3-min period. When frequencies of reproduction of a modeled act were compared against baseline frequencies and against average frequencies of the act during periods when other actions were modeled, several main results were obtained. First, the most general finding was that imitative-like matching of modeled gestures was the exception, not the rule, at all ages. Second, even where significantly greater frequencies of a gesture occurred during modeling than during control periods, it was always a partial and incomplete version of the modeled act that was reproduced, not a well-formed copy of the adult's gesture. Finally, where results were consistent with an interpretation of imitation, as with responses to tongue protrusion modeling, the effect was restricted to the youngest ages: 4-6 weeks. Given the restricted evidence for imitation, and the fact that neither linear nor curvilinear growth trends were apparent, the most appropriate explanation for the reproduction of tongue protrusions at the youngest age is to be sought in terms of a reflexive or fixed action pattern type of response.     

Infant perception of the invariant shape of objects varying in slant.

In a previous study employing habituation-recovery techniques, partial confirmation for shape constancy in 12-week-old infants was found. The infants may have been responding to changes in slant or slant-related cues, leaving unresolved the question of whether shape perception should be considered proximal (retinal) or distal (objective). In the present experiment 12-week-old infants were desensitized to changes in slant prior to test. Following habituation to a shape exposed at varying slants, magnitude of recovery was overwhelmingly greater for a different shape than for the same shape, indicating that the constant real shape of the habituated figure had been perceived across rotational transformations.     

Action imitation: the early phase of infancy.

The early phase of imitation was studied in children between 6 and 18 months by means of the presentations of 22 actions. Comparison groups were used to assess spontaneous production of actions modeled for the treatment samples. Aanalyses yielded 4 clusters of actions, with 1 cluster showing age and treatment versus comparison group effects and others failing to show both these effects. An important factor affecting imitation was the presence of objects. Actions with objects were imitated more than actions without objects. Measures of attention were found to correlate with imitation level, wheras latency was inversely related to imitation. The presence of sound as a variable that potentially influences imitation was studied, but results were inconclusive. Moreover, imitation and object concept performance were unrelated when the factor of age was controlled.     

Young children's knowledge about visual perception: projective size and shape

Although recent research indicates that an increased sensitivity to visual appearances develops around 4 or 5 years of age, evidence from perceptual studies suggests that certain types of appearances, that is, projective size and shape, are not noticed or understood until at least 7. 4 experiments investigated preschool children's knowledge of the projective size--distance and projective shape--orientation relationships. In Experiment 1, 3- and 4-year-olds were asked whether an object should be moved farther or nearer in order to increase or decrease its apparent size. 4-year-olds performed significantly better than chance, but 3-year-olds did not. Experiment 2 showed that 3-year-olds are able to perceive projective size changes, indicating that although they do not fully understand the projective size-distance relationship, the necessary perceptual information is potentially available to them. In Experiment 3, 3- and 4-year-olds were asked to indicate how a circular object should be rotated to make it appear either circular or elliptical. Again, 4-year-olds performed significantly better than chance, but 3-year-olds did not. Again also, the results of Experiment 4 indicate that although 3-year-olds are not aware of the projective shape-orientation relationship, they are capable of attending to changes in projective shape. Thus, the constraints on children's knowledge of the projective size-distance and projective shape-orientation relationships seem to be at least partly cognitive rather than wholly perceptual. These results are interpreted as further evidence for the acquisition of level 2 percept knowledge during early childhood.     

Limits of dynamic object perception in pigeons: Dynamic stimulus presentation does not enhance perception and discrimination of complex shape

A go/no-go procedure was used to train pigeons to discriminate pictures of human faces differing only in shape, with either static images or movies of human faces dynamically rotating in depth. On the basis of experimental findings in humans and some earlier studies on three-dimensional object perception in pigeons, we expected dynamic stimulus presentation to support the pigeon’s perception of the complex morphology of a human face. However, the performance of the subjects presented with movies was either worse than (AVI format movies) or did not differ from (uncompressed dynamic presentation) that of the subjects trained with a single or with multiple static images of the faces. Furthermore, generalization tests to other presentation conditions and to novel static views revealed no promoting effect of dynamic training. Except for the subjects trained on multiple static views, performance dropped to chance level with views outside the training range. These results are in contrast to some prior reports from the literature, since they suggest that pigeons, unlike humans, have difficulty using the additional structural information provided by the dynamic presentation and integrating the multiple views into a three-dimensional object.     

Assessing adverse experiences from infancy through early childhood in home visiting programs

The general aim of early intervention and home visiting programs is to support families to minimize Adverse Childhood Experiences (ACEs). However, assessing children's exposure to these risks is complicated because parents serve as the conduit for both measurement and intervention. The primary aims of the study were to develop an assessment of children's exposure to ACEs and to examine concurrently measured parental child abuse and neglect potential and child social–emotional functioning. Home visiting programs in a southern state implemented the Family Map Inventories (FMI) as comprehensive family assessment and child screenings (N = 1,282) within one month of enrollment. Children (M = 33 months of age, SD = 20) were exposed at rates of 27% to one, 18% to two, 11% to three, and 12% to four or more FMI-ACEs. FMI-ACEs were associated with increased parental beliefs and behaviors associated with child abuse and neglect. FMI-ACEs also significantly predicted the likelihood of the child having at-risk social–emotional development; children with 4 or more FMI-ACEs were over 6 times more likely than those with none to have at-risk scores. The findings add to our understanding of the negative impact of trauma on children and families. Assessing these risks as they occur in a family-friendly manner provides a platform for early intervention programs to work with families to increase family strengths and reduce the impacts of adverse experiences for their children.     

Attachment security in infancy and early adulthood: a twenty-year longitudinal study

Sixty White middle-class infants were seen in the Ainsworth Strange Situation at 12 months of age; 50 of these participants (21 males, 29 females) were recontacted 20 years later and interviewed by using the Berkeley Adult Attachment Interview (AAI). The interviewers were blind to the participants' Strange Situation classifications. Overall, 72% of the infants received the same secure versus insecure attachment classification in early adulthood, K = .44, p < .001. As predicted by attachment theory, negative life events-defined as (1) loss of a parent, (2) parental divorce, (3) life-threatening illness of parent or child (e.g., diabetes, cancer, heart attack), (4) parental psychiatric disorder, and (5) physical or sexual abuse by a family member-were an important factor in change. Forty-four percent (8 of 18) of the infants whose mothers reported negative life events changed attachment classifications from infancy to early adulthood. Only 22% (7 of 32) of the infants whose mothers reported no such events changed classification, p < .05. These results support Bowlby's hypothesis that individual differences in attachment security can be stable across significant portions of the lifespan and yet remain open to revision in light of experience. The task now is to use a variety of research designs, measurement strategies, and study intervals to clarify the mechanisms underlying stability and change.     

Speech perception in infancy predicts language development in the second year of life: a longitudinal study

Infants' early phonetic perception is hypothesized to play an important role in language development. Previous studies have not assessed this potential link in the first 2 years of life. In this study, speech discrimination was measured in 6-month-old infants using a conditioned head-turn task. At 13, 16, and 24 months of age, language development was assessed in these same children using the MacArthur Communicative Development Inventory. Results demonstrated significant correlations between speech perception at 6 months of age and later language (word understanding, word production, phrase understanding). The finding that speech perception performance at 6 months predicts language at 2 years supports the idea that phonetic perception may play an important role in language acquisition.     

Enhanced handling and positioning in early infancy advances development throughout the first year

Behaviors emerge, in part, from the interplay of infant abilities and caregiver–infant interactions. Cross‐cultural and developmental studies suggest caregiver handling and positioning influence infant development. In this prospective, longitudinal study, the effects of 3 weeks of enhanced handling and positioning experiences provided to 14 infants versus control experiences provided to 14 infants at 2 months of age were assessed with follow‐up through 15 months of age. Behaviors in prone were immediately advanced. Short‐term advancements occurred in multiple behaviors, including prone, head control, reaching, and sitting behaviors. Longer term advancements, up to 12 months after the experience period, occurred in object transfer, crawling and walking behaviors. This suggests broad and long‐lasting changes can arise via brief periods of change in caregiver–infant interactions.     

Parameters of remembering and forgetting in the transition from infancy to early childhood

The ability to recall is something that most intact adults take for granted. For much of the last century, this feature of mental life was not considered to extend to very young children. There now is evidence that 1- to 2-year-olds are able to recall specific events after delays of several months. Over the short term, 1- to 2-year-olds' recall is affected by the same factors that affect older children's recall; it is not clear whether similar effects are apparent over the long term. Moreover, although age-related increases in long-term recall are assumed, there have been few empirical tests of the question. We examined recall by 14- to 32-month-olds for events experienced at 13 to 20 months. Using elicited imitation of novel multistep event sequences we examined effects of (a) delay length, (b) age at the time of experience, (c) temporal structure of events, (d) mode of experience of events, and (e) availability of verbal reminders, on long-term recall. Participants were 360 children enrolled at 13 (n = 90), 16 (n = 180), and 20 (n = 90) months. All of the 13-month-olds and half of the 16-month-olds were tested on 3-step event sequences; all of the 20-month-olds and half of the 16-month-olds were tested on 4-step event sequences. Within each age and step-length group, equal numbers of children were tested after intervals of 1, 3, 6, 9, and 12 months (n = 18 per cell). Children were tested on a variety of sequence types. For half of the events, imitation was permitted prior to the delay; for the other half, children were not permitted imitation. At delayed testing, children experienced a recall period during which they were cued by the event-related props alone, followed by a period in which recall was cued both by the event-related props and by verbal labels for the event sequences. Within step-length groups, the length of time for which older and younger children showed evidence of memory did not differ. Nevertheless, when the children were prompted by the event-related props alone, there were age-related differences in the robustness of children's memories (as indexed by higher levels of recall for older children relative to younger children). When the children were prompted by the props and by verbal labels for the event sequences, at the longer retention intervals, there were age-related differences in the robustness of children's memories and in the reliability with which recall was evidenced (as indexed by the larger numbers of older children evincing recall). Age-related effects were particularly apparent on children's ordered recall. Across the entire age range, the children were similarly affected by the variables of sequence type, opportunity for imitation, and verbal reminding.     

The perception of stimulus shape: the influence of velocity of stimulus movement

46 3-month-old infants were presented with geometric stimuli moving laterally at two different velocities (34.8 degrees/sec; 103.3 degrees/sec). The results were interpreted as evidence that 3-month-old infants could discriminate between geometric forms moving at velocities that, according to previous findings, might interfere with shape discrimination. The findings are discussed in relation to the possible interactive effect of type and velocity of movement on geometric form discrimination.