Short Lookers Research Articles

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.

Infant Attention and Early Childhood Executive Function

Individual differences in infant attention are theorized to reflect the speed of information processing and are related to later cognitive abilities (i.e., memory, language, and intelligence). This study provides the first systematic longitudinal analysis of infant attention and early childhood executive function (EF; e.g., working memory, inhibitory control, cognitive flexibility). A group of 5-month-olds (n = 201) were classified as short or long lookers. At 24, 36, and 48 months of age, children completed age-appropriate EF tasks. Infant short lookers (i.e., more efficient information processors) exhibited higher EF throughout early childhood as compared to infant long lookers, even after controlling for verbal ability (a potential indicator of intelligence). These findings are discussed in relation to the emergence of executive attention.

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.

Individual differences in 3.5-month-olds’ visual attention: what do they predict at 1 year?

Individual differences in infants’ attentional style at 3.5 months are only moderately stable across the first postnatal year. However, infants designated as short lookers based on a pattern examination pretest task at 3.5 months had better recognition memory at 1 year and were briefer in toy examination on post-habituation tests than were long lookers. When these infants were 8–12 months old, peak-look duration during habituation was a better predictor of concurrent task performance than was the original pattern examination task when given at the follow up. Short and long lookers did not differ on a deferred imitation task.

Habituation in high‐risk infants: reliability and patterns of responding

AbstractWe examined both the reliability of infant‐controlled habituation and patterns of responding in a group of high‐risk infants (mean age 16 mos). Good test–retest reliability was found for mean, total, and baseline looking time for one of the stimuli. Classification of infants' pattern of performance yielded two groups: linear (57%) and non‐linear (29%) responders; 14% of cases could not be classified because of cross‐session inconsistencies in performance. Linear responders had shorter total looking times, fewer trials to criterion, and showed more habituation than non‐linear responders, thus validating the linear/non‐linear distinction. Our findings indicate that the infant‐controlled habituation task can be used reliably with infants who are at high risk for developmental disorders. Indeed, we provide evidence that this task is not only reliable, but may also provide meaningful distinctions between infants within the high‐risk population. Discussion focuses on the role of attention in distinguishing between short (linear) and long (non‐linear) lookers. Copyright © 2003 John Wiley & Sons, Ltd.

Long-Term Retention in 3.5-Month-Olds: Familiarization Time and Individual Differences in Attentional Style

Using a paired-comparison procedure, we examined the effect of familiarization variables on 3.5-month-old infants' ( n = 120) retention of dynamic visual stimuli after 1-min, 1-day, and 1-month delays. The proportion of total looking time to the novel stimulus revealed novelty, null, and familiarity preferences after 1-min, 1-day, and 1-month delays, respectively, for infants who were permitted 30 s of familiarization time. Twenty seconds of familiarization time was insufficient to produce novelty preferences. These results support models of infant retention in which the direction of attentional preferences (novel, familiar, or null) depends on memory accessibility. To examine the impact of individual differences in familiarization or attentional style on memory, infants were identified as long or short lookers according to their peak-look duration on pretest and familiarization trial measures. Compared to long lookers, short lookers showed better retention over time indicating that much of the variability in the infant group data could be accounted for by these individual differences.

The Distribution of Visual Attention in Infants

In this study, the relationships between the length, number, and distribution of looks were investigated. To this end, 5-, 7-, and 9-month-old infants were familiarized for 24 or 36 s with two identical geometric forms and tested with a novel form paired with the familiar one. The distribution of individual looks to different portions of the display were monitored. At all ages, infants who had briefer looks (short lookers) demonstrated more broadly distributed looks than long lookers; they showed more looks, more shifts, and inspection of more stimulus areas. Also, the greater numbers of shifts exhibited by short lookers included more horizontal, vertical, and diagonal shifts than long lookers. During the test trials, short lookers, primarily in the 5- and 9-month sample, demonstrated greater novelty preference. Data from this study suggest that the distribution of attention is related to short and long looking as is found when visual attention is assessed at a micro level (e.g., Bronson, 1991).

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 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.

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

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

Categorical Habituation with Sex-typed Toy Stimuli in Older and Younger Preschoolers

FAULKENDER, PATRICIA J. Categorical Habituation with Sex-typed Toy Stimuli in Older and Younger Preschoolers. CmLD DEVELOPMENT, 1980, 51, 515-519. Looking times of 96 preschoolers were recorded as they were habituated on slides of sex-typed toys. After habituation, subjects were shown a test series of 24 slides containing the 6 habituated (familiar) slides, a set of 6 new slides from the same subcategory (similar), a set of 6 slides from the other subcategory of toys (opposite), and 6 from a new category of animal slides (novel). A generalized habituation gradient was present for subcategories and was steeper for younger children than for older children. There was a preference for same sex-typed toy stimuli, with stronger preference found in males than in females. Individual differences in habituation were examined by dividing subjects into slow habituators, rapid habituators, and short lookers. Results show differences between the three groups in response to the test slides, with rapid habituators exhibiting significant trends in support of the discrepancy hypothesis.