Improving the generalizability of infant psychological research: The ManyBabies model.

Yarkoni's analysis clearly articulates a number of concerns limiting the generalizability and explanatory power of psychological findings, many of which are compounded in infancy research. ManyBabies addresses these concerns via a radically collaborative, large-scale and open approach to research that is grounded in theory-building, committed to diversification, and focused on understanding sources of variation.

Coding of featural information in visual working memory in 2.5-year-old toddlers.

The number of objects that infants can remember in visual working memory (VWM) increases rapidly during the first few years of life (Kaldy & Leslie, 2005; Ross-Sheehy, Oakes, & Luck, 2003). However, less is understood about the representational format of VWM: whether storage is determined by fixed-precision memory slots, or the allocation of a limited continuous resource. In the current study, we adapted the Delayed Match Retrieval eye-tracking paradigm (Kaldy, Guillory, & Blaser, 2016), to test 2.5-year-old toddlers' ability to remember three object-location bindings when the to-be-remembered objects were all unique (Experiment 1) versus when they shared features such as color or shape (Experiment 2). 2.5-year-olds succeeded in Experiment 1, but only performed marginally better than chance in Experiment 2. Interestingly, when incorrect, participants in Experiment 2 were no more likely to select a decoy item that shared a feature with the target item. It seems that the increased similarity of to-be-remembered objects did not impair memory for the objects directly, but instead increased the likelihood of catastrophic forgetting.

Two-year-olds succeed at MIT: Multiple identity tracking in 20- and 25-month-old infants.

Infants' ability to remember objects and their locations emerges during the first year of life. However, not much is known about infants' ability to track objects' identities in a dynamic environment. Here, we tailored the delayed match retrieval eye-tracking paradigm to study infants' ability to track two object identities during occlusion-an infant version of multiple identity tracking (MIT). Delayed match retrieval uses virtual "cards" as stimuli that are first shown face up, exposing to-be-remembered information, and then turned face down, occluding it. Here, cards were subject to movement during the face-down occlusion period. We used complex non-nameable objects as card faces to discourage verbal rehearsal. In three experiments (N = 110), we compared infants' ability to track object identities when two previously exposed cards were static (Experiment 1), were moved into new positions along the same trajectory (Experiment 2), or were moved along different trajectories (Experiment 3) while face down. We found that 20-month-olds could remember two object identities when static; however, it was not until 25 months of age that infants could track when movement was introduced. Our results show that the ability to track multiple identities in visual working memory is present by 25 months.

Visual temporal integration windows are adult-like in 5- to 7-year-old children.

The visual system must organize dynamic input into useful percepts across time, balancing between stability and sensitivity to change. The temporal integration window (TIW) has been hypothesized to underlie this balance: If two or more stimuli fall within the same TIW, they are integrated into a single percept; those that fall in different windows are segmented (Arnett & Di Lollo, 1979; Wutz, Muschter, van Koningsbruggen, Weisz, & Melcher, 2016). Visual TIWs have been studied in adults, showing average windows of 65 ms (Wutz et al., 2016); however, it is unclear how windows develop through early childhood. Here we measured TIWs in 5- to 7-year-old children and adults, using a variant of the missing dot task (Di Lollo, 1980; Wutz et al. 2016), in which integration and segmentation thresholds were measured within the same participant, using the same stimuli. Participants saw a sequence of two displays separated by an interstimulus interval (ISI) that determined the visibility of a visual search target. Longer ISIs increased the likelihood of detecting a segmentation target (but decreased detection for the integration target) although shorter ISIs increased the likelihood of detecting the integration target (but decreased detection of the segmentation target). We could then estimate the TIW by measuring the point at which these two functions intersect. Children's TIWs (M = 68 ms) were comparable to adults' (M = 73 ms) with no appreciable age trend within our sample, indicating that TIWs reach adult levels by approximately 5 years of age.

Quantifying attentional effects on the fidelity and biases of visual working memory in young children.

Attentional control enables us to direct our limited resources to accomplish goals. The ability to flexibly allocate resources helps to prioritize information and inhibit irrelevant/distracting information. We examined developmental changes in visual working memory (VWM) fidelity in 4- to 7-year-old children and the effects that a distracting non-target object can exert in biasing their memory representations. First, we showed that VWM fidelity improves from early childhood to adulthood. Second, we found evidence of working memory load on recall variability in children and adults. Next, using cues to manipulate attention, we found that older children are able to construct a more durable memory representation for an object presented following a non-target using a pre-cue (that biases encoding before presentation) compared with a retro-cue (that signals which item to recall after presentation). In addition, younger children had greater difficulties maintaining an item in memory when an intervening item was presented. Lastly, we found that memory representations are biased toward a non-target when it is presented following the target and away from a non-target when it precedes the target. These bias effects were more pronounced in children compared with adults. Together, these results demonstrate changes in attention over development that influence VWM memory fidelity.

Preschoolers have better long-term memory for rhyming text than adults.

The dominant view of children's memory is that it is slow to develop and is inferior to adults'. Here we pitted 4-year-old children against adults in a test of verbatim recall of verbal material. Parents read a novel rhyming verse (and an integrated word list) as their child's bedtime story on ten consecutive days. A group of young adults listened to the verse, matching the exposure of children. All participants subsequently performed a free-recall of the verse, verbatim. (Parents and young adults knew they would be tested; children did not.) Four-year-olds significantly outperformed both their parents and the young adults. There were no significant differences in the ability to recall the gist of the verse, nor the integrated word list, allaying concerns about differences in engagement or motivation. Verbatim recall of verse is a skill amenable to practice, and children, we argue, by virtue of the prominence of verse in their culture and their reliance on oral transmission, have honed this skill to exceed adults'.

Delayed Match Retrieval: a novel anticipation-based visual working memory paradigm.

We tested 8- and 10-month-old infants' visual working memory (VWM) for object-location bindings - what is where - with a novel paradigm, Delayed Match Retrieval, that measured infants' anticipatory gaze responses (using a Tobii T120 eye tracker). In an inversion of Delayed-Match-to-Sample tasks and with inspiration from the game Memory, in test trials, three face-down virtual 'cards' were presented. Two flipped over sequentially (revealing, e.g. a swirl pattern and then a star), and then flipped back face-down. Next, the third card was flipped to reveal a match (e.g. a star) to one of the previously seen, now face-down cards. If infants looked to the location where the (now face-down) matching card had been shown, this was coded as a correct response. To encourage anticipatory looks, infants subsequently received a reward (a brief, engaging animation) presented at that location. Ten-month-old infants performed significantly above chance, showing that their VWM could hold object-location information for the two cards. Overall, 8-month-olds' performance was at chance, but they showed a robust learning trend. These results corroborate previous findings (Kaldy & Leslie, 2005; Oakes, Ross-Sheehy & Luck, 2006) and point to rapid development of VWM for object-location bindings. However, compared to previous paradigms that measure passive gaze responses to novelty, this paradigm presents a more challenging, ecologically relevant test of VWM, as it measures the ability to make online predictions and actively localize objects based on VWM. In addition, this paradigm can be readily scaled up to test toddlers or older children without significant modification.

Unimpaired attentional disengagement in toddlers with autism spectrum disorder.

A prominent hypothesis holds that 'sticky' attention early in life in children with autism spectrum disorder (ASD) limits their ability to explore and learn about the world. Under this hypothesis, the core clinical symptoms of ASD - restricted interests, repetitive behaviors and impaired social/communication abilities - could all result from impaired attentional disengagement during development. However, the existence of disengagement deficits in children with ASD is controversial, and a recent study found no deficit in 5- to 12-year-olds with ASD. Nonetheless, the possibility remains that disengagement is impaired earlier in development in children with ASD, altering their developmental trajectory even if the attentional deficit itself is remediated or compensated for by the time children with ASD reach school age. Here, we tested this possibility by characterizing attentional disengagement in a group of toddlers just diagnosed with ASD (age 21 to 37 months). We found strikingly similar performance between the ASD and age-matched typically developing (TD) toddlers, and no evidence of impaired attentional disengagement. These results show that even at a young age when the clinical symptoms of ASD are first emerging, disengagement abilities are intact. Sticky attention is not a fundamental characteristic of ASD, and probably does not play a causal role in its etiology.

Sixteen-month-olds can use language to update their expectations about the visual world.

The capacity to use language to form new representations and to revise existing knowledge is a crucial aspect of human cognition. Here we examined whether infants can use language to adjust their representation of a recently encoded scene. Using an eye-tracking paradigm, we asked whether 16-month-old infants (N=26; mean age=16;0 [months;days], range=14;15-17;15) can use language about an occluded event to inform their expectation about what the world will look like when the occluder is removed. We compared looking time to outcome scenes that matched the language input with looking time to those that did not. Infants looked significantly longer at the event outcome when the outcome did not match the language input, suggesting that they generated an expectation of the outcome based on that input alone. This effect was unrelated to infants' vocabulary size. Thus, using language to adjust expectations about the visual world is present at an early developmental stage even when language skills are rudimentary.

The resolution of proactive interference in a novel visual working memory task: A behavioral and pupillometric study.

Proactive interference (PI) occurs when previously learned information impairs memory for more recently learned information. Most PI studies have employed verbal stimuli, while the role of PI in visual working memory (VWM) has had relatively little attention. In the verbal domain, Johansson and colleagues (2018) found that pupil diameter - a real-time neurophysiological index of cognitive effort - reflects the accumulation and resolution of PI. Here we use a novel, naturalistic paradigm to test the behavioral and pupillary correlates of PI resolution for what-was-where item-location bindings in VWM. Importantly, in our paradigm, trials (PI vs. no-PI condition) are mixed in a block, and participants are naïve to the condition until they are tested. This design sidesteps concerns about differences in encoding strategies or generalized effort differences between conditions. Across three experiments (N = 122 total) we assessed PI's effect on VWM and whether PI resolution during memory retrieval is associated with greater cognitive effort (as indexed by the phasic, task-evoked pupil response). We found strong support for PI's detrimental effect on VWM (even with our spatially distributed stimuli), but no consistent link between interference resolution and effort during memory retrieval (this, even though the pupil was a reliable indicator that higher-performing individuals tried harder during memory encoding). We speculate that when explicit strategies are minimized, and PI resolution relies primarily on implicit processing, the effect may not be sufficient to trigger a robust pupillometric response.

Can't get it out of my head: Proactive interference in the visual working memory of 3- to 8-year-old children.

Proactive interference (PI) occurs when previously learned memories compete with currently relevant information. Despite extensive literature investigating the effect in adults, little work has been done in young children. In three preregistered studies (N = 38, 35, 172; convenience samples from the Northeastern United States), first, we showed that 3-year-old toddlers are highly sensitive to the effect of PI in visual working memory and second, that these effects can originate from the reactivation of previously encoded information. Third, we tested how the ability to cope with PI changes between 2.5 and 7.5 years of age. Besides providing an estimate for the size of the interference effect at the youngest age to date, our findings have an important methodological implication: paradigms that repeat items across trials potentially underestimate young children's working memory abilities. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Red to green or fast to slow? Infants' visual working memory for "just salient differences".

In this study, 6-month-old infants' visual working memory for a static feature (color) and a dynamic feature (rotational motion) was compared. Comparing infants' use of different features can only be done properly if experimental manipulations to those features are equally salient (Kaldy & Blaser, 2009; Kaldy, Blaser, & Leslie, 2006). The interdimensional salience mapping method was used to find two objects that each were one Just Salient Difference from a common baseline object (N = 16). These calibrated stimuli were then used in a subsequent two-alternative forced-choice preferential looking memory test (N = 28). Results showed that infants noted the color change, but not the equally salient change in rotation speed.

The pupil collaboration: A multi-lab, multi-method analysis of goal attribution in infants.

The rise of pupillometry in infant research over the last decade is associated with a variety of methods for data preprocessing and analysis. Although pupil diameter is increasingly recognized as an alternative measure of the popular cumulative looking time approach used in many studies (Jackson & Sirois, 2022), an open question is whether the many approaches used to analyse this variable converge. To this end, we proposed a crowdsourced approach to pupillometry analysis. A dataset from 30 9-month-old infants (15 girls; Mage = 282.9 days, SD = 8.10) was provided to 7 distinct teams for analysis. The data were obtained from infants watching video sequences showing a hand, initially resting between two toys, grabbing one of them (after Woodward, 1998). After habituation, infants were shown (in random order) a sequence of four test events that varied target position and target toy. Results show that looking times reflect primarily the familiar path of the hand, regardless of target toy. Gaze data similarly show this familiarity effect of path. The pupil dilation analyses show that features of pupil baseline measures (duration and temporal location) as well as data retention variation (trial and/or participant) due to different inclusion criteria from the various analysis methods are linked to divergences in findings. Two of the seven teams found no significant findings, whereas the remaining five teams differ in the pattern of findings for main and interaction effects. The discussion proposes guidelines for best practice in the analysis of pupillometry data.

Proactive interference and the development of working memory.

Working memory (WM), the ability to maintain information in service to a task, is characterized by its limited capacity. Several influential models attribute this limitation in a large extent to proactive interference (PI), the phenomenon that previously encoded, now-irrelevant information competes with relevant information. Here, we look back at the adult PI literature, spanning over 60 years, as well as recent results linking the ability to cope with PI to WM capacity. In early development, WM capacity is even more limited, yet an accounting for the role of PI has been lacking. Our Focus Article aims to address this through an integrative account: since PI resolution is mediated by networks involving the frontal cortex (particularly, the left inferior frontal gyrus) and the posterior parietal cortex, and since children have protracted development and less recruitment of these areas, the increase in the ability to cope with PI is a major factor underlying the increase in WM capacity in early development. Given this, we suggest that future research should focus on mechanistic studies of PI resolution in children. Finally, we note a crucial methodological implication: typical WM paradigms repeat stimuli from trial-to-trial, facilitating, inadvertently, PI and reducing performance; we may be fundamentally underestimating children's WM capacity. This article is categorized under: Psychology > Memory Neuroscience > Cognition Neuroscience > Development.

The development of peak alpha frequency from infancy to adolescence and its role in visual temporal processing: A meta-analysis.

While it has been shown that alpha frequency increases over development (Stroganova et al., 1999), a precise trajectory has not yet been specified, making it challenging to constrain theories linking alpha rhythms to perceptual development. We conducted a comprehensive review of studies measuring resting-state occipital peak alpha frequency (PAF, the frequency exhibiting maximum power) from birth to 18 years of age. From 889 potentially relevant studies, we identified 40 reporting PAF (109 samples; 3882 subjects). A nonlinear regression revealed that PAF increases quickly in early childhood (from 6.1 Hz at 6 months to 8.4 Hz at 5 years) and levels off in adolescence (9.7 Hz at 13 years), with an asymptote at 10.1 Hz. We found no effect of resting state procedure (eyes-open versus eyes-closed) or biological sex. PAF has been implicated as a clock on visual temporal processing, with faster frequencies associated with higher visual temporal resolution. Psychophysical studies have shown that temporal resolution reaches adult levels by 5 years of age (Freschl et al., 2019, 2020). The fact that PAF reaches the adult range of 8-12 Hz by that age strengthens the link between PAF and temporal resolution.

Toddlers with Autism Spectrum Disorder are more successful at visual search than typically developing toddlers.

Plaisted, O'Riordan and colleagues (Plaisted, O'Riordan & Baron-Cohen, 1998; O'Riordan, 2004) showed that school-age children and adults with Autism Spectrum Disorder (ASD) are faster at finding targets in certain types of visual search tasks than typical controls. Currently though, there is very little known about the visual search skills of very young children (1-3-year-olds) - either typically developing or with ASD. We used an eye-tracker to measure looking behavior, providing fine-grained measures of visual search in 2.5-year-old toddlers with and without ASD (this representing the age by which many children may first receive a diagnosis of ASD). Importantly, our paradigm required no verbal instructions or feedback, making the task appropriate for toddlers who are pre- or nonverbal. We found that toddlers with ASD were more successful at finding the target than typically developing, age-matched controls. Further, our paradigm allowed us to estimate the number of items scrutinized per trial, revealing that for large set size conjunctive search, toddlers with ASD scrutinized as many as twice the number of items as typically developing toddlers, in the same amount of time.

The role of redundant verbal labels in 8- and 10-month-olds' working memory.

Verbal labels have been shown to help preverbal infants' performance on various cognitive tasks, such as categorization. Redundant labels also aid adults' visual working memory (WM), but it is not known if this linguistic benefit extends to preverbal infants' WM. In two eye-tracking studies, we tested whether 8- and 10-month-old infants' WM performance would improve with the presence of redundant labels in a Delayed Match Retrieval (DMR) paradigm that tested infants' WM for object-location bindings. Findings demonstrated that infants at both ages were unable to remember two object-location bindings when co-presented with labels at encoding. Moreover, infants who encoded the object-location bindings with labels were not significantly better than those who did so in silence. These findings are discussed in the context of label advantages in cognition and auditory dominance.

Seeing a Page in a Flipbook: Shorter Visual Temporal Integration Windows in 2-Year-Old Toddlers with Autism Spectrum Disorder.

Individuals with autism spectrum disorder (ASD) experience differences in visual temporal processing, the part of vision responsible for parsing continuous input into discrete objects and events. Here we investigated temporal processing in 2-year-old toddlers diagnosed with ASD and age-matched typically developing (TD) toddlers. We used a visual search task where the visibility of the target was determined by the pace of a display sequence. On integration trials, each display viewed alone had no visible target, but if integrated over time, the target became visible. On segmentation trials, the target became visible only when displays were perceptually segmented. We measured the percent of trials when participants fixated the target as a function of the stimulus onset asynchrony (SOA) between displays. We computed the crossover point of the integration and segmentation performance functions for each group, an estimate of the temporal integration window (TIW), the period in which visual input is combined. We found that both groups of toddlers had significantly longer TIWs (125 ms) than adults (65 ms) from previous studies using the same paradigm, and that toddlers with ASD had significantly shorter TIWs (108 ms) than chronologically age-matched TD controls (142 ms). LAY SUMMARY: We investigated how young children, with and without autism, organize dynamic visual information across time, using a visual search paradigm. We found that toddlers with autism had higher temporal resolution than typically developing (TD) toddlers of the same age - that is, they are more likely to be able to detect rapid change across time, relative to TD toddlers. These differences in visual temporal processing can impact how one sees, interprets, and interacts with the world. Autism Res 2021, 14: 946-958. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

Putting effort into infant cognition.

Working memory allows for the manipulation of information in support of ongoing tasks, providing a workspace for cognitive processes such as learning, reasoning, and decision making. How well working memory works depends, in part, on effort. Someone who pays attention at the right time and place will have better memory, and performance. In adult cognitive research studies, participants' devotion of maximal task-focused effort is often taken for granted, but in infant studies researchers cannot make that assumption. Here we showcase how pupillometry can provide an easy-to-obtain physiological measure of cognitive effort, allowing us to better understand infants' emerging abilities. In our work, we used pupillometry to measure trial-by-trial fluctuations of effort, establishing that, just as in adults, it influences how well infants could encode information in visual working memory. We hope that by using physiological measures such as pupil dilation, there will be a renewed effort to investigate the interaction between infants' attentive states and cognition.

Persistence and Accumulation of Visual Memories for Objects in Scenes in 12-Month-Old Infants.

Visual memory for objects has been studied extensively in infants over the past 20 years, however, little is known about how they are formed when objects are embedded in naturalistic scenes. In adults, memory for objects in a scene show information accumulation over time as well as persistence despite interruptions (Melcher, 2001, 2006). In the present study, eye-tracking was used to investigate these two processes in 12-month-old infants (N = 19) measuring: (1) whether longer encoding time can improve memory performance (accumulation), and (2) whether multiple shorter exposures to a scene are equivalent to a single exposure of the same total duration (persistence). A control group of adults was also tested in a closely matched paradigm (N = 23). We found that increasing exposure time led to gains in memory performance in both groups. Infants were found to be successful in remembering objects with continuous exposures to a scene, but unlike adults, were not able to perform better than chance when interrupted. However, infants' scan patterns showed evidence of memory as they continued the exploration of the scene in a strategic way following the interruption. Our findings provide insight into how infants are able to build representations of their visual environment by accumulating information about objects embedded in scenes.