Long-looking Infants Research Articles

Modeling Infant i's Look on Trial t: Race-Face Preference Depends on i's Looking Style.

When employing between-infant designs young infants' looking style is related to their development: Short looking (SL) infants are cognitively accelerated over their long looking (LL) peers. In fact, looking style is a within-infant variable, and depends on infant i's look distribution over trials. For the paired array setting, a model is provided which specifies the probability, πi ∈ [0, 1], that i is SL. The model is employed in a face preference study; 74 Caucasian infants were longitudinally assessed at 3, 6, and 9 months. Each i viewed same race (Caucasian) vs. other race (African) faces. Infants become SL with development, but there are huge individual differences in rate of change over age. Three month LL infants, , preferred other race faces. SL infants, , preferring same race faces at 3, and other race faces at 6 and 9 months. Looking style changes precede and may control changes in face preference. Ignoring looking style can be misleading: Without considering looking style, 3 month infants show no face preference.

The effects of stimulus symmetry on hierarchical processing in infancy.

The current study investigated the effects of stimulus symmetry on the processing of global and local stimulus properties by 6-month-old short- and long-looking infants through the use of event-related potentials (ERPs). Previous research has shown that individual differences in infant visual attention are related to hierarchical stimulus processing, such that short lookers show a global processing bias, while long lookers demonstrate a local processing bias (Guy, Reynolds, & Zhang, 2013). Additional research has shown that in comparison with asymmetry, symmetry is associated with more efficient stimulus processing and more accurate memory for stimulus configuration (Attneave, 1955; Perkins, 1932). In the current study, we utilized symmetric and asymmetric hierarchical stimuli and predicted that the presence of asymmetry would direct infant attention to the local features of stimuli, leading short lookers to regress to a local processing strategy. Results of the ERP analysis showed that infants familiarized with a symmetric stimulus showed evidence of global processing, while infants familiarized with an asymmetric stimulus did not demonstrate evidence of processing at the global or local level. These findings indicate that short- and long-looking infants, who might otherwise fail to process global stimulus properties due to limited visual scanning, may succeed at global processing when exposed to symmetric stimuli. Furthermore, stimulus symmetry may recruit selective attention toward global properties of visual stimuli, facilitating higher-level cognitive processing in infancy.

Visual Attention to Global and Local Stimulus Properties in 6‐Month‐Old Infants: Individual Differences and Event‐Related Potentials

Event-related potentials (ERPs) were utilized in an investigation of 21 six-month-olds' attention to and processing of global and local properties of hierarchical patterns. Overall, infants demonstrated an advantage for processing the overall configuration (i.e., global properties) of local features of hierarchical patterns; however, processing advantages were found to vary based on individual differences in look duration. Short-looking infants showed differences in the negative central ERP component and the late slow wave (LSW) indicating greater attention to and discrimination of changes in global properties. Analysis of the LSW revealed that long-looking infants discriminated changes in local features, but did not discriminate changes in global properties of visual stimuli. These findings indicate that short- and long-looking infants utilize different approaches when processing hierarchical patterns.

Neural Correlates of Individual Differences in Infant Visual Attention and Recognition Memory.

Past studies have identified individual differences in infant visual attention based upon peak look duration during initial exposure to a stimulus. Colombo and colleagues (e.g., Colombo & Mitchell, 1990) found that infants that demonstrate brief visual fixations (i.e., short lookers) during familiarization are more likely to demonstrate evidence of recognition memory during subsequent stimulus exposure than infants that demonstrate long visual fixations (i.e., long lookers). The current study utilized event-related potentials to examine possible neural mechanisms associated with individual differences in visual attention and recognition memory for 6- and 7.5-month-old infants. Short- and long-looking infants viewed images of familiar and novel objects during ERP testing. There was a stimulus type by looker type interaction at temporal and frontal electrodes on the late slow wave (LSW). Short lookers demonstrated a LSW that was significantly greater in amplitude in response to novel stimulus presentations. No significant differences in LSW amplitude were found based on stimulus type for long lookers. These results indicate deeper processing and recognition memory of the familiar stimulus for short lookers.

Autonomic correlates of individual differences in sensitization and look duration during infancy

Patterns of infant visual attention have been attributed to both the processes of habituation and arousal. Previous research has linked individual differences in arousal (sensitization) with measures from habituation that have been associated with the efficiency of stimulus encoding (look duration). The aim of current study was to validate individual differences in these realms with a convergent measure of attention based on heart rate (HR) that might presumably reflect autonomic function and arousal. In contrast with previous work, neither habituation nor look durations differed significantly as a function of the presence of sensitization. HR variables did not differentiate infants who showed sensitization from those who did not. HR analyses on individual differences in look duration, however, yielded two significant findings: short-looking infants maintained higher levels of HR variability than long-looking infants across the session, and long-looking infants had greater HR accelerations to stimulus onsets than did short-looking infants.

Individual and developmental differences in disengagement of fixation in early infancy.

The current study investigated whether individual and developmental differences in look duration are correlated with the latency for infants to disengage fixation from a visual stimulus. Ninety-four infants (52 3-month-olds, 42 4-month-olds) were tested in a procedure that measured ocular reaction time to shift fixation from a central target to a peripheral target under conditions in which the central-target either remained present ("competition" condition) or was removed from the display ("noncompetition" condition). Look duration was correlated with disengagement latency; longer-looking infants were slower than shorter-looking infants to shift fixation to the peripheral target on competition trials, but not noncompetition trials. Results were similar for 3- and 4-month-olds, although 3-month-olds showed slower latencies on all trials. Furthermore, long-looking infants were not consistently slower, but rather showed greater variability in their response latencies under conditions that required disengagement of fixation. The results support the position that developmental and individual differences in look duration are linked to the development of the neural attentional systems that control the ability to disengage, or inhibit, visual fixation.

Long- and Short-Looking Infants' Recognition of Symmetrical and Asymmetrical Forms

Adults process symmetrical visual forms more rapidly than asymmetrical visual forms, presumably because symmetrical forms are amenable to a global visual encoding strategy. Individual differences in look duration during infancy have been hypothesized to covary with different modes of visual intake and encoding, with longer look durations reflecting encoding based on prolonged inspection of local visual properties, and briefer look durations reflecting encoding based on more of a global, or global-to-local processing sequence. This hypothesis predicts that short-looking infants would process symmetrical stimuli faster than asymmetrical stimuli, but that long-looking infants would not. Three experiments are described here in which this prediction is tested. Results were in general accord with the prediction, and provide further support for the hypothesis that individual differences in look duration may reflect different modes of visual encoding or inspection.

Why does infant attention predict adolescent intelligence?

Ninety-three 18-year-olds were tested with measures thought to tap information processing, sustained attention, executive function, and intelligence. The visual fixation patterns and home rearing conditions of these adolescents, born preterm, had been observed in early infancy. Infant fixation durations were negatively associated with information processing, executive function, and intelligence scores but did not predict ability to sustain attention. Continuity between infant attention and adolescent intelligence was moderated by qualities of the home environment so that “short-looking infants” whose caregivers vocalized a great deal had mean intelligence quotients that were 20 points higher than “long-looking infants” with less vocal caregivers. The results suggest that at least some of the continuity between infant attention and adolescent intelligence stems from infant capacities to process information efficiently and to inhibit prepotent responses and that this continuity is affected by caregiver responsiveness.

Long-looking infants are slower to disengage fixation

Long-looking infants are slower to disengage fixation

Individual Differences in Infant Visual Attention: Recognition of Degraded Visual Forms by Four-Month-Olds

In 5 experiments, 4-month-old infants were tested for their ability to recognize degraded visual targets as a function of individual differences in fixation duration. Targets were degraded by removing 10% of the total contour either from vertices (vertex-absent) or from midsegments (vertex-present). Both qualitative and quantitative differences were found in long and short lookers' ability to recognize the degraded forms. Short-looking infants were able to recognize degraded forms in both vertex-absent and vertex-present conditions, but the vertex-absent discrimination was more difficult. Long-looking infants required longer familiarization times before showing evidence of recognition in the vertex-present condition, and were unable to recognize targets in which contour was removed at vertices. The findings are discussed within the framework of the persistence of early visual processing strategies, and reliance of long-looking infants on particular local elements in visual analysis.

Individual differences in infant fixation duration: Dominance of global versus local stimulus properties

In three experiments, the dominance of global versus local visual properties was investigated in 4-month-old infants as a function of individual differences in fixation duration (i.e., “long-” versus “short-looking” infants). Dominance was assessed through paired-comparison discrimination tasks in which global and local visual properties were placed in competition with one another for infants' attention. Familiarization time was varied parametrically across experiments. Short-looking infants showed responses consistent with a global-to-local sequence of processing: dominance for the global attribute was supplanted by dominance for the local attribute as familiarization was extended. Long-looking infants, however, did not show dominance for either visual property until after considerable familiarization. When dominance was observed for this group, it was for the local visual attribute. These findings are in accord with previous observations that long-looking infants process visual information more slowly than short-looking infants, but further suggest that there may be qualitative differences in the manner in which the two groups of infants attend to the properties of visual stimuli. Links between this finding and the long-term predictive validity of fixation duration are discussed.

Individual Differences in Infant Visual Attention: Four-Month-Olds' Discrimination and Generalization of Global and Local Stimulus Properties

Cognitive performance and development is negatively correlated with fixation duration patterns during infancy, and evidence suggests that long-looking infants may process visual information more slowly than short-looking infants. 3 experiments described here tested the possibility that these differences may be due to differential sensitivity to global and local visual information. Infants were administered discrimination and generalization tasks involving global and local information at varying levels of familiarization time. Results indicated that 4-month-olds process visual information in a global-to-local sequence. Both long- and short-looking infants were sensitive to both types of information, although long lookers required additional familiarization time to match the performance of short lookers. Finally, apparent "generalization" of global information at brief familiarization levels was traced to insensitivity to local stimulus properties. The results do not support the hypothesis that long- and short-looking infants are differentially sensitive to global versus local visual information at 4 months of age.

Individual Differences in Infant Visual Attention: Are Short Lookers Faster Processors or Feature Processors?

Individual differences in the duration of infants' visual fixations are reliable and stable and have been linked to differential cognitive performance; short-looking infants typically perform better than long-looking infants. 4 experiments tested the possibility of whether short lookers' superiority on perceptual-cognitive tasks is attributable to attention to the featural details of visual stimuli, or simply to differences in the speed or efficiency of visual processing. To do this, the performance of long- and short-looking 4-month-olds was examined on separate discrimination tasks that could be solved only by processing either featural or global information. The global task was easier than the featural task, but as the amount of time allotted for infants to solve either type of task was decreased, short lookers' performance was superior to that of long lookers. These results thus lend support to a speed or efficiency of stimulus processing interpretation of infant fixation duration.