The autistic-developed monotropism account suggests that atypical, domain-general attentional hyper-focus on interests is a central aspect of autism, but domain-general attention differences in autism can manifest differently. Prior research suggests autistic children are often slow to disengage attention from stimuli-a pattern often called \"sticky attention\"-and that they can show reduced novelty preference. These attentional patterns could influence sensory experiences and learning. We used eye-tracking to investigate novelty preference and \"sticky attention\" in young autistic children; we also examined whether attentional patterns were related to cognitive abilities and caregiver-reported sensory responsiveness. A total of 46 autistic and 28 nonautistic participants, aged between 2 and 4 years, provided usable data. We found no evidence that autistic children exhibited greater \"sticky attention\" than nonautistics, but \"sticky attention\" in autism was associated with more caregiver-reported sensory hyper-responsiveness, seeking/interests, and enhanced perception. Autistic children also nonsignificantly trended toward exhibiting reduced novelty preference. Unexpectedly, the time-course of this trending novelty preference difference implied it was not driven by reduced orienting to novelty, but increased returning to already-familiarized stimuli: what we call \"springy attention.\" Exploratory analyses of data from the attentional disengagement task suggest autistic participants may have exhibited greater \"springy attention,\" though further research with paradigms optimized for measuring this construct should confirm this. Importantly, \"springy attention\" was robustly related to reduced cognitive abilities and greater caregiver-reported hypo-responsiveness. Thus, this study illuminates two distinct domain-general attentional patterns, each with distinct correlates in young autistic children, which could have important implications for understanding autistic children\'s learning, development, and experiences.

OBJECTIVE: Epilepsy patients often report memory deficits despite normal objective testing, suggesting that available measures are insensitive or that non-mnemonic factors are involved. The Visual Paired Comparison Task (VPCT) assesses novelty preference, the tendency to fixate on novel images rather than previously viewed items, requiring recognition memory for the \"old\" images. As novelty preference is a sensitive measure of hippocampal-dependent memory function, we predicted impaired VPCT performance in epilepsy patients compared to healthy controls.
METHODS: We assessed 26 healthy adult controls and 31 epilepsy patients (16 focal-onset, 13 generalized-onset, 2 unknown-onset) with the VPCT using delays of 2 or 30 s between encoding and recognition. Fifteen healthy controls and 17 epilepsy patients (10 focal-onset, 5 generalized-onset, 2 unknown-onset) completed the task at 2-, 5-, and 30-minute delays. Subjects also performed standard memory measures, including the Medical College of Georgia (MCG) Paragraph Test, California Verbal Learning Test-Second Edition (CVLT-II), and Brief Visual Memory Test-Revised (BVMT-R).
RESULTS: The epilepsy group was high functioning, with greater estimated IQ (p = 0.041), greater years of education (p = 0.034), and higher BVMT-R scores (p = 0.024) compared to controls. Both the control group and epilepsy cohort, as well as focal- and generalized-onset subgroups, had intact novelty preference at the 2- and 30-second delays (p-values ≤ 0.001) and declined at 30 min (p-values > 0.05). Only the epilepsy patients had early declines at 2- and 5-minute delays (controls with intact novelty preference at p = 0.003 and p ≤ 0.001, respectively; epilepsy groups\' p-values > 0.05).
CONCLUSIONS: Memory for the \"old\" items decayed more rapidly in overall, focal-onset, and generalized-onset epilepsy groups. The VPCT detected deficits while standard memory measures were largely intact, suggesting that the VPCT may be a more sensitive measure of temporal lobe memory function than standard neuropsychological batteries.

Both words and gestures have been shown to influence object categorization, often even overriding perceptual similarities to cue category membership. However, gestures are often meaningful to infants while words are arbitrarily related to an object they refer to, more similar to arbitrary actions that can be performed on objects. In this study, we examine how words and arbitrary actions shape category formation. Across three conditions (word cue, action cue, word-action cue), we presented infants (N = 90) with eight videos of single-category objects which vary in colour and other perceptual features. The objects were either accompanied by a word and/or an action that is being performed on the object. Infants in the word and action condition showed a decrease in looking over the course of the familiarization phase indicating habituation to the category, but infants in the word-action condition did not. At test, infants saw a novel object of the just-learned category and a novel object from another category side-by-side on the screen. There was some evidence for an advantage for words in shaping early object categorization, although we note that this was not robust across analyses.

The many benefits of online research and the recent emergence of open-source eye-tracking libraries have sparked an interest in transferring time-consuming and expensive eye-tracking studies from the lab to the web. In the current study, we validate online webcam-based eye-tracking by conceptually replicating three robust eye-tracking studies (the cascade effect, n = 134, the novelty preference, n = 45, and the visual world paradigm, n = 32) online using the participant\'s webcam as eye-tracker with the WebGazer.js library. We successfully replicated all three effects, although the effect sizes of all three studies shrank by 20-27%. The visual world paradigm was conducted both online and in the lab, using the same participants and a standard laboratory eye-tracker. The results showed that replication per se could not fully account for the effect size shrinkage, but that the shrinkage was also due to the use of online webcam-based eye-tracking, which is noisier. In conclusion, we argue that eye-tracking studies with relatively large effects that do not require extremely high precision (e.g., studies with four or fewer large regions of interest) can be done online using the participant\'s webcam. We also make recommendations for how the quality of online webcam-based eye-tracking could be improved.

This study investigates infants\' enculturation to music in a bicultural musical environment. We tested 49 12- to 30-month-old Korean infants on their preference for Korean or Western traditional songs played by haegeum and cello. Korean infants have access to both Korean and Western music in their environment as captured on a survey of infants\' daily exposure to music at home. Our results show that infants with less daily exposure to any kind of music at home listened longer to all music types. The infants\' overall listening time did not differ between Korean and Western music and instruments. Rather, those with high exposure to Western music listened longer to Korean music played with haegeum. Moreover, older toddlers (aged 24-30 months) maintained a longer interest in songs of an origin with which they are less familiar, indicating an emerging orientation towards novelty. Early orientation of Korean infants toward the novel experience of music listening is likely driven by perceptual curiosity, which drives exploratory behavior that diminishes with continued exposure. On the other hand, older infants\' orientation towards novel stimuli is led by epistemic curiosity, which motivates an infant to acquire new knowledge. Korean infants\' lack of differential listening likely reflects their protracted period of enculturation to ambient music due to complex input. Further, older infants\' novelty-orientation is consistent with findings in bilingual infants\' orientation towards novel information. Additional analysis showed a long-term effect of music exposure on infants\' vocabulary development. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=Kllt0KA1tJk RESEARCH HIGHLIGHTS: Korean infants showed novelty-oriented attention to music such that infants with less daily exposure to music at home showed longer listening times to music. 12- to 30-month-old Korean infants did not show differential listening to Korean versus Western music or instruments, suggesting a protracted period of perceptual openness. 24- to 30-month-old Korean toddlers\' listening behavior indicated emerging novelty-preference, exhibiting delayed enculturation to ambient music compared to Western infants reported in earlier research. 18-month-old Korean infants with a greater weekly exposure to music had higher CDI scores a year later, consistent with the well-known music-to-language transfer effect.

It is now well-established that the hippocampal CA2 region plays an important role in social recognition memory in adult mice. The CA2 is also important for the earliest social memories, including those that mice have for their mothers and littermates, which manifest themselves as a social preference for familiarity over novelty. The role of the CA2 in the development of social memory for recently encountered same-age conspecifics, that is, peers, has not been previously reported. Here, we used a direct social interaction test to characterize the emergence of novelty preference for peers during development and found that at the end of the second postnatal week, pups begin to significantly prefer novel over familiar peers. Using chemogenetic inhibition at this time, we showed that CA2 activity is necessary for the emergence of novelty preference and for the ability to distinguish never encountered from recently encountered peers. In adulthood, the CA2 region is known to integrate a large number of inputs from various sources, many of which participate in social recognition memory, but previous studies have not determined whether these afferents are present at adult levels by the end of the second postnatal week. To explore the development of CA2 inputs, we used immunolabeling and retrograde adenovirus circuit tracing and found that, by the end of the second postnatal week, the CA2 is innervated by many regions, including the dentate gyrus, supramammillary nucleus of the hypothalamus, the lateral entorhinal cortex, and the median raphe nucleus. Using retroviral labeling of postnatally generated granule cells in the dentate gyrus, we found that mossy fiber projections to the CA2 mature faster during development than those generated in adulthood. Together, our findings indicate that the CA2 is partially mature in afferent connectivity by the end of the second postnatal week, connections that likely facilitate the emergence of social recognition memory and preference for novel peers.

In many species, the allocation of exploration and exploitation responses to environmental stimuli is important for survival. In this exploratory study, we determined whether dogs (Canis familiaris) explored novel stimuli in a visual discrimination task using food reinforcers. Initially, the dogs were trained with two pairs of simultaneous visual discrimination tasks. Having achieved the learning criterion, the dogs were presented with a pair of stimuli including a novel stimulus and a previously reinforced stimulus in the probe trials (familiar stimulus). Dogs were reinforced by 50% for novel stimuli and 100% for familiar stimuli. The proportions of responses to novel and familiar stimuli in the probe trials were considered to reflect the propensity for exploration and exploitation, respectively. The five dogs tested selected the novel stimulus more frequently (in 22 of the 30 probe trials; binomial test, P = 0.016). Therefore, dogs prefer novel stimuli over familiar ones, suggesting that this species, which is less neophobic than wolves (Canis lupus), would likely allocate more responses to exploration. Comparisons among breeds or with wolves are warranted in future studies.

In two experiments with 47 4-month-olds, we investigated attention to key aspects of events in which an object moved along a partly occluded path that contained an obstruction. Infants were familiarized with a ball rolling behind an occluder to be revealed resting on an end wall, and on test trials an obstruction wall was placed in the ball\'s path. In Experiment 1, we did not find longer looking when the object appeared in an impossible location beyond the obstruction, and infants did not selectively fixate the object in this location. In Experiment 2, after rolling one or two balls, we measured infants\' fixations of a two-object outcome with one ball in a novel but possible resting position and the other in a familiar but impossible location beyond the obstruction. Infants looked longer at the ball in the possible but novel location, likely reflecting a looking preference for location novelty. Thus we obtained no evidence that infants reasoned about obstruction and identified a violation on that basis.

BACKGROUND: Risk factors for drug addiction include genetics, environment, and behavioral traits such as impulsivity and novelty preference (NP), which have been related to deficits in striatal dopamine (DA) D2/3-receptors (D2/3R) and heightened amphetamine (AMPH)-induced DA release. However, the influence of the early rearing environment on these behavioral and neurochemical variables is not clear.
OBJECTIVE: We investigated the influence of early rearing environment on striatal D2/3R availabilities and AMPH-induced DA release in relation to impulsivity, NP, and propensity to drug self-administration (SA) in \"addiction-prone\" Roman high- (RHA) and \"addiction-resistant\" Roman low-avoidance (RLA) rats.
METHODS: Animals were reared post-weaning in either environmental enrichment (EE) or impoverishment (EI) and were assessed at adulthood for impulsivity, NP, and propensity to cocaine SA. EE and EI rats were also scanned using single-photon emission computed tomography to concurrently measure in vivo striatal D2/3R availability and AMPH-induced DA release.
RESULTS: EE vs. EI was associated with heightened impulsivity and a lack of NP in both rat lines. Higher dorsal striatal D2/3R densities were found in RHA EE and higher AMPH-induced DA release in RLA EE. Both impulsivity and NP were negatively correlated to dorsal striatal D2/3R availabilities and positively correlated with AMPH-induced DA release in EI but not in EE. EE vs. EI was related to a faster rate of cocaine intake and elevated active timeout responses in RHAs.
CONCLUSIONS: Our results suggest non-monotonic, environment-dependent, relationships between impulsivity, NP, and D2/3R-mediated signaling, and suggest that EI vs. EE may decrease the reinforcing effects of psychostimulants in predisposed individuals.

Impulsivity and novelty preference are both associated with an increased propensity to develop addiction-like behaviors, but their relationship and respective underlying dopamine (DA) underpinnings are not fully elucidated.
We evaluated a large cohort (n = 49) of Roman high- and low-avoidance rats using single photon emission computed tomography to concurrently measure in vivo striatal D2/3 receptor (D2/3R) availability and amphetamine (AMPH)-induced DA release in relation to impulsivity and novelty preference using a within-subject design. To further examine the DA-dependent processes related to these traits, midbrain D2/3-autoreceptor levels were measured using ex vivo autoradiography in the same animals.
We replicated a robust inverse relationship between impulsivity, as measured with the 5-choice serial reaction time task, and D2/3R availability in ventral striatum and extended this relationship to D2/3R levels measured in dorsal striatum. Novelty preference was positively related to impulsivity and showed inverse associations with D2/3R availability in dorsal striatum and ventral striatum. A high magnitude of AMPH-induced DA release in striatum predicted both impulsivity and novelty preference, perhaps owing to the diminished midbrain D2/3-autoreceptor availability measured in high-impulsive/novelty-preferring Roman high-avoidance animals that may amplify AMPH effect on DA transmission. Mediation analyses revealed that while D2/3R availability and AMPH-induced DA release in striatum are both significant predictors of impulsivity, the effect of striatal D2/3R availability on novelty preference is fully mediated by evoked striatal DA release.
Impulsivity and novelty preference are related but mediated by overlapping, yet dissociable, DA-dependent mechanisms in striatum that may interact to promote the emergence of an addiction-prone phenotype.