Cortical Indexes of Saccade Planning Following Covert Orienting in 20‐Week‐Old Infants

This study examined scalp‐recorded, event‐related potential (ERP) indexes of saccade planning in 20‐week‐old infants. A spatial cuing procedure was used in which the infants were presented with a central fixation stimulus and a peripheral cue. A peripheral target followed the cue on the ipsilateral or contralateral side of the cue. The procedure resulted in covert orienting of attention in these participants, reflected in behavioral (e.g., response facilitation or inhibition of return depending on cue‐target stimulus‐onset asynchrony) and ERP (P1 facilitation to ipsilateral target) indexes of covert orienting of attention. A presaccadic ERP that occurred over the frontal cortex about 50 msec before the saccade onset was largest when the saccade was to a target in a cued location. A presaccadic ERP potential that occurred about 300 msec before the saccade onset was largest for the saccades toward the cued location whether the target was present or not. These results suggest that saccade planning occurs in infants at this age and that infant saccade planning is controlled by cortical systems.     

To Cue or Not to Cue: Toddlers’ Use of Beacons and Associative Cues in Object‐displacement Tasks

Two experiments examined 24‐ and 30‐month‐olds' use of different forms of landmark information in an object‐displacement task involving a car rolling down a ramp whose trajectory was occluded by a screen containing doors. A pompom attached to the car, visible through a transparent window running across the screen, served as a cue for the car's location and functioned either as a beacon cue, directly guiding search to a given location, or an associative cue, indirectly marking target location. Interestingly, one way in which the cue information was modified from a beacon to an associative cue was in terms of the structure of the search apparatus, and not necessarily the cue information itself. Consistent with previous literature, 24‐month‐olds' search was significantly influenced by the shift from beacon to associative cue information, whereas 30‐month‐olds, although affected by the shift from one to the other, were less affected by this variation. These findings suggest that the cue drives attention to specific locations in space, with search behavior being more accurate when the cue directly marks the hiding location (i.e., beacon) than when the cue indirectly marks it (i.e., associative cue).     

It Is Not Just About Location: Infants Perseverate to Container Shape During Object Search

In searching for a toy hidden at a new location, infants will err by searching at the previously correct location. This study investigated the possibility that 8.5‐month‐old infants would perseverate on the basis of other visual features by which covers could be individuated. Infants saw a toy hidden under 1 of 2 distinctly shaped covers. Following successful retrievals from the Shape A cover, infants saw the toy hidden under the Shape B cover. On this B trial, the covers were at locations that had not been baited on the preceding trials, precluding location perseveration. The infants erred by choosing the unbaited Shape A cover more often than control infants presented with 1 type of cover throughout. The findings suggest that infants perseverate to cover shape and are form biases biased toward cover shape even when location information is sufficient to support retrieval.     

Anticipatory Eye Movements Reveal Infants' Auditory and Visual Categories

We introduce a new paradigm for the assessment of auditory and visual categories in 6‐month‐old infants using a 2‐alternative anticipatory eye‐movement response. Infants were trained by 2 different methods to anticipate the location of a visual reinforcer at 1 of 2 spatial locations (right or left) based on the identity of 2 cuing stimuli. After a training phase, infants were presented with a series of generalization trials in which novel (untrained) stimuli served as the cue to the anticipatory eye movement. Four experiments illustrated that infants can learn the 2‐choice discriminative response during training. Infants also showed anticipatory eye movements to novel stimuli, indicating sensitivity to variations along a variety of stimulus dimensions (e.g., color, shape, orientation, spatial frequency, pitch, and duration). In addition, the paradigm can be used to assess categorization in individual infants, thereby revealing the stimulus dimensions to which infants naturally attend.     

Six‐Month‐Old Infants Predict Agents’ Goal‐Directed Actions on Occluded Objects

Infants can infer agents’ goals after observing agents’ goal‐directed actions on objects and can subsequently make predictions about how agents will act on objects in the future. We investigated the representations supporting these predictions. We familiarized 6‐month‐old infants to an agent who preferentially reached for one of two featurally distinct objects following a cue. At test, the objects were sequentially occluded from the infant in the agent's presence. We asked whether infants could generate action predictions without visual access to the relevant objects by measuring whether infants shifted their gaze to the location of the agent's hidden goal object following the cue. We also examined what infants represented about the hidden objects by removing one of the occluders to reveal either the original hidden object or the unexpected other object and measuring infants’ looking time. We found that, even without visual access to the objects, infants made predictive gazes to the location of the agent's occluded goal object, but failed to represent the features of either hidden object. These results suggest that infants make goal‐based action predictions when the relevant objects in the scene are occluded, but doing so may come at the expense of maintaining representations of the objects.     

18‐Month‐Olds Predict Specific Action Mistakes Through Attribution of False Belief,Not Ignorance,and Intervene Accordingly

This study employed a new “anticipatory intervening” paradigm to tease apart false belief and ignorance‐based interpretations of 18‐month‐olds’ helpful informing. We investigated in three experiments whether 18‐month‐old infants inform an adult selectively about one of the two locations depending on the adult’s belief about which of the two locations held her toy. In experiments 1 and 2, the adult falsely believed that one of the locations held her toy. In experiment 3, the adult was ignorant about which of the two locations held her toy. In all cases, however, the toy had been removed from the locations and the locations contained instead materials which the adult wanted to avoid. In experiments 1 and 2, infants spontaneously and selectively informed the adult about the aversive material in the location the adult falsely believed to hold her toy. In contrast, in experiment 3, infants informed the ignorant adult about both locations equally. Results reveal that infants expected the adult to commit a specific action mistake when she held a false belief, but not when she was ignorant. Further, infants were motivated to intervene proactively. Findings reveal a predictive action‐based usage of “theory‐of‐mind” skills at 18 months of age.     

Development of Visual Selection in 3‐ to 9‐Month‐Olds: Evidence From Saccades to Previously Ignored Locations

We examined changes in the efficiency of visual selection over the first postnatal year with an adapted version of a spatial negative priming paradigm. In this task, when a previously ignored location becomes the target to be selected, responses to it are impaired, providing a measure of visual selection. Oculomotor latencies to target selection were the dependent measure. Each trial consisted of a prime and a probe presentation, separated by a 67‐, 200‐, or 550‐msec interstimulus interval (ISI), to test the efficiency of selection as a function of processing time. In the prime, the target was accompanied by a distractor item. In the probe, the target appeared either in the location formerly occupied by the distractor (repeated distractor trials) or in one of the other two locations (control trials). We tested 41 infants in each of 3 age groups (3, 6, and 9 months) on the three different ISIs. Nine‐month‐old infants' saccade latencies were slowed on repeated distractors relative to control trials, given sufficiently long ISIs. Saccade latencies in the youngest two age groups showed only facilitation on repeated distractor trials at short ISIs. These results suggest that visual selection efficiency is a function of the interaction of the processing limitations of a system with environmental conditions, in this case the time allotted for the selection process.     

Infants use contextual memory to attend and learn in naturalistic scenes

Infants encounter new objects and learn about object features in relation to a rich and detailed visuospatial context. Using a contextual cueing task, recent work showed that 6- and 10-month-old infants search more efficiently for target objects in repeated rather than novel visuospatial contexts (i.e., arrays of shapes on a blank background). Here, we investigate whether infants' sensitivity to visuospatial context scales up to more complex and potentially more distracting, naturalistic scenes. In an eye-tracking task, 8-month-olds searched for a novel target object in colorful photographs of everyday environments (e.g., bedrooms and kitchens). Repeated (“Old”) contexts co-varied with target locations, such that the target object appeared in exactly the same location on the same scene, while varying (“New”) contexts contained target objects placed in different counterbalanced locations across a variety of scenes. Infants exhibited faster search times, more anticipation of target animation, and longer looking at targets that appeared in Old relative to New contexts. In a subsequent memory test, infants showed better recognition of label-object pairings for target objects that had appeared in Old, rather than New, contexts. These results indicate that infants can use visuospatial contextual information in complex naturalistic scenes to facilitate memory-guided attention and learning of object-paired labels.     

Object Locations,Identity and Absent Reference Understanding at 12 Months

Spatial and contextual information plays an organizing role in many cognitive processes including object individuation and memory retrieval. Recently, attention has been drawn to the fact that changes in an object's location negatively affect infants' learning in different domains. One example is that prestudy exposure to a target object in a nontest location disrupts infants' ability to locate that object when it is hidden in a test room. In the current study, we investigate the possibility that infants' difficulty finding the object is the result of confusion about the identity of the target object. In the current research, infants were familiarized with an object in one room and tested in the other. Infants who were shown a characteristic identifying feature on the object in both locations and who were thus able to track the object identity could later locate the absent referent. In contrast, when infants' attention was drawn to different features on the object in the two locations or to the object itself via pointing, infants were unable to find the object.     

Effects of Gambling-Related Cues on the Activation of Implicit and Explicit Gambling Outcome Expectancies in Regular Gamblers

The current research examined whether the presentation of gambling-related cues facilitates the activation of gambling outcome expectancies using both reaction time (RT) and self-report modes of assessment. Gambling outcome expectancies were assessed by having regular casino or online gamblers (N = 58) complete an outcome expectancy RT task, as well as a self-report measure of gambling outcome expectancies, both before and after exposure to one of two randomly assigned cue conditions (i.e., casino or control video). Consistent with hypotheses, participants exposed to gambling-related cues (i.e., casino cue video condition) responded faster to positive outcome expectancy words preceded by gambling prime relative to non-gambling prime pictures on the post-cue RT task. Similarly, participants in the casino cue video condition self-reported significantly stronger positive gambling outcome expectancies than those in the control cue video condition following cue exposure. Activation of negative gambling outcome expectancies was not observed on either the RT task or self-report measure. The results indicate that exposure to gambling cues activates both implicit and explicit positive gambling outcome expectancies among regular gamblers.     

Why do Infants Look at and Use Positive Information from Some Informants Rather Than Others in Ambiguous Situations?

Three laboratory experiments on social referencing examined whether infants’ tendencies to look at and use positive information from the experimenter could be interpreted from a perspective of novelty or expertise. In Study 1, novelty was manipulated. Forty‐eight 12‐month‐old infants participated. In a between‐subject design, a more novel or a less novel experimenter presented an ambiguous object and provided positive information. The infants looked more at and regulated their behavior more in accordance with information coming from the less novel experimenter. In Study 2, expertise was manipulated. Forty‐eight 12‐month‐old infants were exposed to one experimenter who showed expertise about the laboratory situation and one experimenter who did not show such competence. The infants looked more at and regulated their behavior more in accordance with information coming from the expert. In Study 3, 40 12‐month‐old infants participated. The infants were exposed to a toy‐expert who was either novel or familiar. The infants, in both groups, looked as much at the toy‐experts and used the information regardless of whether the novel or familiar toy‐expert had provided information. The findings suggest that novelty does not increase looking in ambiguous situations. Instead, the results support the expertise perspective of infant looking preferences.     

Pointing to Nothing? Empty Places Prime Infants' Attention to Absent Objects

People routinely point to empty space when referring to absent entities. These points to “nothing” are meaningful because they direct attention to places that stand in for specific entities. Typically, the meaning of places in terms of absent referents is established through preceding discourse and accompanying language. However, it is unknown whether nonlinguistic actions can establish locations as meaningful places, and whether infants have the capacity to represent a place as standing in for an object. In a novel eye‐tracking paradigm, 18‐month‐olds watched objects being placed in specific locations. Then, the objects disappeared and a point directed infants' attention to an emptied place. The point to the empty place primed infants in a subsequent scene (in which the objects appeared at novel locations) to look more to the object belonging to the indicated place than to a distracter referent. The place–object expectations were strong enough to interfere when reversing the place–object associations. Findings show that infants comprehend nonlinguistic reference to absent entities, which reveals an ontogenetic early, nonverbal understanding of places as representations of absent objects.     

How Manual Object Exploration is Associated with 7‐ to 8‐Month‐Old Infants’ Visual Prediction Abilities in Spatial Object Processing

The present experiment examined whether infants’ visual prediction performance of the appearance of objects moving in space is related to their manual object exploration ability. Fifty‐five 7‐ to 8‐month‐old infants were tested. A visual object prediction paradigm was developed during which a three‐dimensional object was presented in a live eye‐tracking setting. During familiarization, the object rotated back and forth along the vertical axis. While the object was moving, two target parts of it were briefly occluded from view and uncovered again as the object changed its direction of motion. In the test phase, the entire object was rotated around 90° and now rotated along the horizontal axis. We recorded infants’ eye movements directed at the target locations and analyzed the prediction rates. All of the infants also participated in a manual object exploration task, in which they freely explored five toy blocks. Infants with a higher level of object exploration skill had higher prediction rates during test trials as compared to infants with less proficient object exploratory actions. The results support the interpretation that advanced manual object exploration experience is associated with infants’ advanced visual prediction ability of the appearance of objects moving in space.     

Infant Perception of Surface Texture and Relative Height as Distance Information: A Preferential‐Reaching Study

Two preferential‐reaching experiments explored 5‐ and 7‐month‐olds’ sensitivity to pictorial depth cues. In the first experiment, infants viewed a display in which texture gradients, linear perspective of the surface contours, and relative height in the visual field provided information that two objects were at different distances. Five‐ and 7‐month‐old infants reached preferentially for the apparently nearer object under monocular but not binocular viewing conditions, indicating that infants in both age groups respond to pictorial depth cues. In the second experiment, texture gradients and linear perspective of the surface contours were eliminated from the experimental display, making relative height the sole pictorial depth cue. Seven‐month‐olds again reached more often for the apparently nearer object under monocular, but not binocular viewing conditions. By contrast, the 5‐month‐olds’ reaching behavior did not differ between viewing conditions. These results indicate that 7‐month‐olds respond to the depth cue of relative height but provide no evidence of responsiveness to relative height in 5‐month‐olds. Both age groups responded more consistently to pictorial depth in Experiment 1 than in Experiment 2.     

Infants' Sensitivity to the Depth Cue of Height‐in‐the‐Picture‐Plane

Five‐ and 7‐month‐old infants' sensitivity to the pictorial depth cue of height‐in‐the‐picture‐plane was assessed. Infants were presented with 2 objects, 1 higher than the other, and their reaching was recorded under monocular and binocular viewing conditions. The results showed that both age groups reached significantly more to the lower, apparently closer object under monocular view and that they reached equally to the 2 objects under binocular view. The results suggest that both 5‐ and 7‐month‐old infants are sensitive to the depth information provided by height‐in‐the‐picture‐plane. Demonstration of pictorial depth sensitivity at 5 months has implications for the mechanism underlying the onset of sensitivity to this type of depth information.     

Rhythmic Grouping Biases Constrain Infant Statistical Learning

Linguistic stress and sequential statistical cues to word boundaries interact during speech segmentation in infancy. However, little is known about how the different acoustic components of stress constrain statistical learning. The current studies were designed to investigate whether intensity and duration each function independently as cues to initial prominence (trochaic‐based hypothesis) or whether, as predicted by the Iambic‐Trochaic Law (ITL), intensity and duration have characteristic and separable effects on rhythmic grouping (ITL‐based hypothesis) in a statistical learning task. Infants were familiarized with an artificial language (Experiments 1 and 3) or a tone stream (Experiment 2) in which there was an alternation in either intensity or duration. In addition to potential acoustic cues, the familiarization sequences also contained statistical cues to word boundaries. In speech (Experiment 1) and nonspeech (Experiment 2) conditions, 9‐month‐old infants demonstrated discrimination patterns consistent with an ITL‐based hypothesis: intensity signaled initial prominence and duration signaled final prominence. The results of Experiment 3, in which 6.5‐month‐old infants were familiarized with the speech streams from Experiment 1, suggest that there is a developmental change in infants’ willingness to treat increased duration as a cue to word offsets in fluent speech. Infants’ perceptual systems interact with linguistic experience to constrain how infants learn from their auditory environment.     

Infants Show Ratio‐dependent Number Discrimination Regardless of Set Size

Evidence for approximate number system (ANS) representations in infancy is robust but has typically only been found when infants are presented with arrays of four or more elements. In addition, several studies have found that infants fail to discriminate between small numbers when continuous variables such as surface area and contour length are controlled. These findings suggest that under some circumstances, infants fail to recruit either the ANS or object file representations for small sets. Here, we used a numerical change detection paradigm to assess 6‐month‐old infants' ability to represent small values. In Experiment 1, infants were tested with 1 versus 3, 1 versus 2, and 2 versus 3 dots. Infants successfully discriminated 1 versus 3 and 1 versus 2, but failed with 2 versus 3. In Experiment 2, we tested whether infants could compare small and large values with a 2 versus 4 condition. Across both experiments, infants' performance exhibited ratio dependence, the hallmark of the ANS. Our results indicate that infants can attend to the purely numerical attributes of small sets and that the numerical change detection paradigm accesses ANS representations in infancy regardless of set size.     

Young Infants' Perception of Object Unity in Rotation Displays

Much research has been devoted to questions regarding how infants begin to perceive the unity of partly occluded objects, and it is clear that object motion plays a central role. Little is known, however, about how infants' motion processing skills are used in such tasks. One important kinetic cue for object shape is structure from motion, but its role in unity perception remains unknown. To address this issue, we presented 2‐ and 4‐month‐old infants with displays in which object unity was specified by vertical rotation. After habituation to this display, infants viewed broken and complete versions of the object to test their preference for the broken object, an indication of perception of unity in the occlusion display. Positive evidence for the perception of unity was provided by both age groups. Concomitant edge translation available in 1 condition did not appear to contribute above and beyond simple rotation. These results suggest that structure from motion, and perhaps contour deformation and shading cues, can contribute important information for veridical object percepts in very young infants.     

Maternal intrusiveness predicts infants’ event‐related potential responses to angry and happy prosody independent of infant frontal asymmetry

Infants’ social‐cognitive skills first develop within the parent–infant relationship, but large differences between parents exist in the way they approach and interact with their infant. These may have important consequences for infants’ social‐cognitive development. The current study investigated effects of maternal sensitive and intrusive behavior on 6‐ to 7‐month‐old infants’ ERP responses to a socio‐emotional cue that infants are often confronted with from an early age: emotional prosody in infant‐directed speech. Infants may differ in their sensitivity to environmental (including parenting) influences on development, and the current study also explored whether infants’ resting frontal asymmetry conveys differential susceptibility to effects of maternal sensitivity and intrusiveness. Results revealed that maternal intrusiveness was related to the difference in infants’ ERP responses to happy and angry utterances. Specifically, P2 amplitudes in response to angry sounds were less positive than those in response to happy sounds for infants with less intrusive mothers. Whether this difference reflects an enhanced sensitivity to emotional prosody or a (processing) preference remains to be investigated. No evidence for differential susceptibility was found, as infant frontal asymmetry did not moderate effects of sensitivity or intrusiveness.     

Spatiotemporal Regularity and Interevent Contingencies as Information for Infants' Visual Expectations

This study examined infants' use of picture‐location contingencies and spatiotemporal regularity in forming visual expectations. Ninety‐six 3‐month‐olds watched an event sequence in which pictures appeared at 3 locations, either in regular left‐center‐right alternation or in a random center‐side pattern. For half of the infants, the content of the central picture was predictive of the location of the upcoming peripheral event. Analyses of anticipations and interpicture fixation shifts revealed that both spatiotemporal regularity and consistent interevent contingencies fostered increased anticipation of peripheral pictures. The type of spatiotemporal sequence that infants observed also differentially biased their responses to test trials that followed the picture sequence: Infants who experienced regular alternation sequences continued the side‐to‐side pattern during the 2‐choice test trials, whereas infants who experienced irregular sequences looked back to the location of the previous picture. Stable interevent contingencies, in contrast, did not bias infants' responses toward the contingent side during the choice test trials.