Young Infants' Performance in the Object-Variation Version of the Above-Below Categorization Task: A Result of Perceptual Distraction or Conceptual Limitation?

Linguistic and developmental influences on superordinate facial configuration categorization in infancy

Humans perceive emotions in terms of categories, such as "happiness," "sadness," and "anger." To learn these complex conceptual emotion categories, humans must first be able to perceive regularities in expressive behaviors (e.g., facial configurations) across individuals. Recent research suggests that infants spontaneously form "basic-level" categories of facial configurations (e.g., happy vs. fear), but not "superordinate" categories of facial configurations (e.g., positive vs. negative). The current studies further explore how infant age and language impact superordinate categorization of facial configurations associated with different negative emotions. Across all experiments, infants were habituated to one person displaying facial configurations associated with anger and disgust. While 10-month-olds formed a category of person identity (Experiment 1), 14-month-olds formed a category that included negative facial configurations displayed by the same person (Experiment 2). However, neither age formed the hypothesized superordinate category of negative valence. When a verbal label ("toma") was added to each of the habituation events (Experiment 3), 10-month-olds formed a category similar to 14-month-olds in Experiment 2. These findings intersect a larger conversation about the nature and development of children's emotion categories and highlight the importance of considering developmental processes, such as language learning and attentional/memory development, in the design and interpretation of infant categorization studies.

The benefit of simultaneously encountered exemplars and of exemplar variability to verb learning

Young children are conservative when extending novel verbs to novel exemplars. We investigated whether multiple, simultaneously presented exemplars would aid young children's verb learning, as well as the importance of exemplar variability. Three-year-olds were taught novel verbs, while viewing either one action-scene featuring a novel action performed on a novel object, or two action-scenes side-by-side in which the action performed was the same but the object varied, or two action-scenes side-by-side in which no aspect of the scenes varied. They were asked to extend the novel verbs to one of two scenes: one that maintained the action and one that maintained the object. Findings indicated that children were only able to extend verbs correctly after viewing two action-scenes in which the content varied. These findings suggest that simultaneously presented exemplars of a verb can support verb learning in younger children, but only when the content of the exemplars varies.

Above and Beyond Objects: The Development of Infants' Spatial Concepts

Early in development infants form categorical representations of small-scale spatial relations, such as left vs right and above vs below. This spatial skill allows infants to experience coherence in the layout of the objects in their environment and to note the equivalence of a spatial relation across changes in objects. Comparisons across studies of infant spatial categorization offer insight into the processes that contribute to the development of this skill. Rather than viewing contrasting results across studies as contradictory, identifying how infant spatial categorization tasks recruit distinct processes can not only reconcile findings but also yield insight into the starting points, development, and emerging nature of infants' representations of spatial relations. Also, situating infants' spatial categorization in the context of advances in nonspatial domains may reveal synergistic relations among these domains, particularly in relation to advances in infants' manipulative play with objects and their acquisition of spatial language. A central argument is that broadening the study of infants' spatial categorization may yield further insights into the nature of early spatial concepts and the processes that promote their development.

Prelinguistic foundations of verb learning: Infants discriminate and categorize dynamic human actions

Action categorization is necessary for human cognition and is foundational to learning verbs, which label categories of actions and events. In two studies using a nonlinguistic preferential looking paradigm, 10- to 12-month-old English-learning infants were tested on their ability to discriminate and categorize a dynamic human manner of motion (i.e., way in which a figure moves; e.g., marching). Study 1 results reveal that infants can discriminate a change in path and actor across instances of the same manner of motion. Study 2 results suggest that infants categorize the manner of motion for dynamic human events even under conditions in which other components of the event change, including the actor's path and the actor. Together, these two studies extend prior research on infant action categorization of animated motion events by providing evidence that infants can categorize dynamic human actions, a skill foundational to the learning of motion verbs.

Learning to navigate in a three-dimensional world: from bees to primates

We discuss the idea that environmental factors influence the neural mechanisms that evolved to enable navigation, and propose that a capacity to learn different spatial relationship rules through experience may contribute to bicoded processing. Recent experiments show that free-flying bees can learn abstract spatial relationships, and we propose that this could be combined with optic flow processing to enable three-dimensional navigation.

Developmental changes in infant spatial categorization: when more is best and when less is enough

Two experiments examined infants' ability to form a spatial category when habituated to few (only 2) or many (6) exemplars of a spatial relation. Sixty-four infants of 10 months and 64 infants of 14 months were habituated to dynamic events in which a toy was placed in a consistent spatial relation (in or on) to a referent object. At 10 months, infants formed a spatial category (looking longer at an unfamiliar than familiarized spatial relation) only when habituated to 6 exemplars. At 14 months, infants formed the spatial category regardless of the number of habituation exemplars. The results highlight developmental changes in infant spatial categorization and show that increasing exemplar number facilitates this ability in infants of 10 months.

Does changing the reference frame affect infant categorization of the spatial relation BETWEEN?

Past research has shown that variation in the target objects depicting a given spatial relation disrupts the formation of a category representation for that relation. In the current research, we asked whether changing the orientation of the referent frame depicting the spatial relation would also disrupt the formation of a category representation for that relation. Experiments 1 to 3 provided evidence that 6- and 7-month-olds formed a category representation for BETWEEN when a diamond shape was depicted in different locations between two vertical or horizontal reference bars during familiarization and in a novel location between the same orientation of bars during test. By contrast, in Experiment 4, same-age infants did not form a category representation for BETWEEN when the diamond shape was depicted between two vertical (or horizontal) bars during familiarization and between two horizontal (or vertical) bars during test. Moreover, in Experiment 5, 9- and 10-month-olds did form a category representation for BETWEEN when the orientation of the referent bars depicting the relation changed from familiarization to test. The findings suggest that the formation of category representations for spatial relations by infants is affected by changes to either target (figure) or referent (ground).

The Representation of Geometric Cues in Infancy

There is evidence that, from an early age, humans are sensitive to spatial information such as simple landmarks and the size of objects. This study concerns the ability to represent a particular kind of spatial information, namely, the geometry of an enclosed layout-an ability present in older children, adults, and nonhuman animals (e.g., Cheng, 1986; Hermer & Spelke, 1996). Using a looking-time procedure, 4.5- to 6.5-month-olds were tested on whether they could distinguish among the corners of an isosceles triangle. On each trial, the target corner was marked by a red dot. The stimulus (triangle with dot) appeared from different orientations across trials, ensuring that only cues related to the triangle itself could be used to differentiate the corners. When orientations were highly variable, infants discriminated the unique corner (i.e., the corner with the smaller angle and two equal-length sides) from a nonunique corner; they could not discriminate between the two nonunique corners. With less variable orientations, however, infants did discriminate between the nonunique corners of the isosceles triangle. Implications for how infants represent geometric cues are discussed.

Can language do the driving? The effect of linguistic input on infants' categorization of support spatial relations

Two experiments explored the effect of linguistic input on 18-month-olds' ability to form an abstract categorical representation of support. Infants were habituated to 4 support events (i.e., one object placed on another) and were tested with a novel support and a novel containment event. Infants formed an abstract category of support (i.e., looked significantly longer at the novel than familiar relation) when hearing the word "on" during habituation but not when viewing the events in silence (Experiment 1) or when hearing general phrases or a novel word (Experiment 2). Results indicate that a familiar word can facilitate infants' formation of an abstract spatial category, leading them to form a category that they do not form in the absence of the word.

When less is more: how infants learn to form an abstract categorical representation of support

Two experiments explored how infants learn to form an abstract categorical representation of support (i.e., on) when habituated to few (i.e., 2) or many (i.e., 6) examples of the relation. When habituated to 2 pairs of objects in a support relation, 14-month-olds, but not 10-month-olds, formed the abstract spatial category (i.e., generalized the relation to novel objects). When habituated to 6 object pairs in a support relation, infants did not attend to the relation. The results indicate that infants learn to form an abstract spatial category of support between 10 and 14 months and that having fewer object pairs depicting this relation facilitates their acquisition of the abstract categorical representation.

Spatial representation by young infants: Categorization of spatial relations or sensitivity to a crossing primitive?

The spatial representation abilities of 3- to 4-month-old infants were examined in four experiments. Experiments 1 and 2 showed that infants familiarized with a diamond appearing in distinct locations to the left or right of a vertical bar subsequently preferred a stimulus depicting the diamond on the opposite side of the bar over a stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 3 was a replication of Experiment 1, except that the bar was oriented at 45 degrees. In this instance, infants divided their attention between the stimulus depicting the diamond on the opposite side of the bar and the stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 4 demonstrated that the results of Experiment 3 were not a consequence of a failure to process the diagonal bar. When considered with previous reports that infants can represent the categories of above and below (Quinn, 1994), the present results suggest that (1) infants can also represent the categories of left and right, and (2) performance cannot be interpreted as a response to an arbitrary crossing of one object relative to another. Although recent discussions of the relation between language and cognition have pointed to the ways in which spatial language influences spatial cognition (Bowerman & Levinson, 2001), the present findings are consistent with an influence in the opposite direction: Spatial cognition may in some instances shape spatial language.

Six-month-old infants' categorization of containment spatial relations

Six-month-old infants' ability to form an abstract category of containment was examined using a standard infant categorization task. Infants were habituated to 4 pairs of objects in a containment relation. Following habituation, infants were tested with a novel example of the familiar containment relation and an example of an unfamiliar relation. Results indicate that infants look reliably longer at the unfamiliar versus familiar relation, indicating that they can form a categorical representation of containment. A second experiment demonstrated that infants do not rely on object occlusion to discriminate containment from a support or a behind spatial relation. Together, the results indicate that by 6 months, infants can recognize a containment relation from different angles and across different pairs of objects.

Development of an abstract category representation for the spatial relation between in 6- to 10-month-old infants

Nine experiments examined the formation of an abstract category representation for the spatial relation between by 6- to 10-month-old infants. The experiments determined that 9- to 10-month-olds, but not 6- to 7-month-olds, could form an abstract category representation for between when performing in an object-variation version of the between categorization task. The results also demonstrated that 6- to 7-month-olds could form category representations for between in the object-variation version of the between categorization task but that such representations were specific to the particular objects presented. The evidence confirms that representations for different spatial relations emerge at different points during development, and suggests that each representation undergoes its own period of development from concrete to abstract.