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1. Individual and collective foraging in autonomous search agents with human intervention

   https://doi.org/10.1038/s41598-021-87717-7  

   Schloesser, Daniel S.; Hollenbeck, Derek; Kello, Christopher T. (December 2021, Scientific Reports)

   null (Ed.)

   Abstract Humans and other complex organisms exhibit intelligent behaviors as individual agents and as groups of coordinated agents. They can switch between independent and collective modes of behavior, and flexible switching can be advantageous for adapting to ongoing changes in conditions. In the present study, we investigated the flexibility between independent and collective modes of behavior in a simulated social foraging task designed to benefit from both modes: distancing among ten foraging agents promoted faster detection of resources, whereas flocking promoted faster consumption. There was a tradeoff between faster detection versus faster consumption, but both factors contributed to foraging success. Results showed that group foraging performance among simulated agents was enhanced by  loose coupling  that balanced distancing and flocking among agents and enabled them to fluidly switch among a variety of groupings. We also examined the effects of more sophisticated cognitive capacities by studying how human players improve performance when they control one of the search agents. Results showed that human intervention further enhanced group performance with loosely coupled agents, and human foragers performed better when coordinating with loosely coupled agents. Humans players adapted their balance of independent versus collective search modes in response to the dynamics of simulated agents, thereby demonstrating the importance of adaptive flexibility in social foraging. 

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2. Impaired and Spared Auditory Category Learning in Developmental Dyslexia

   https://doi.org/10.1177/09567976231151581  

   Gabay, Yafit; Roark, Casey L.; Holt, Lori L. (January 2023, Psychological Science)

   Categorization has a deep impact on behavior, but whether category learning is served by a single system or multiple systems remains debated. Here, we designed two well-equated nonspeech auditory category learning challenges to draw on putative procedural (information-integration) versus declarative (rule-based) learning systems among adult Hebrew-speaking control participants and individuals with dyslexia, a language disorder that has been linked to a selective disruption in the procedural memory system and in which phonological deficits are ubiquitous. We observed impaired information-integration category learning and spared rule-based category learning in the dyslexia group compared with the neurotypical group. Quantitative model-based analyses revealed reduced use of, and slower shifting to, optimal procedural-based strategies in dyslexia with hypothesis-testing strategy use on par with control participants. The dissociation is consistent with multiple category learning systems and points to the possibility that procedural learning inefficiencies across categories defined by complex, multidimensional exemplars may result in difficulty in phonetic category acquisition in dyslexia. 

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3. The transfer effect of mental rotation training on arithmetic skill: The role of state anxiety and arithmetic strategy use.

   https://doi.org/10.1037/dev0002040  

   Zhang, Xinhe; Gunderson, Elizabeth A (August 2025, Developmental Psychology)

   Spatial skills in early childhood are key predictors of mathematical achievement. Previous studies have found that training mental rotation can transfer to arithmetic skills; however, some studies have failed to replicate this transfer effect, or observed transfer effects only in certain types of arithmetic problems. Even in studies where transfer effects were observed, the underlying mechanisms of this transfer have not been explored. This study focused on the effect of short-duration (i.e., single-session) spatial training on arithmetic skills, and tested two underlying mechanisms. First, based on the spatial modeling account, short-duration spatial training may prime spatial processing, leading to a reduction in the use of counting strategies and an increase in spatially-related strategies following spatial training. Second, from a social-psychological account, short-duration spatial training may reduce children’s state anxiety, thus allowing them more cognitive resources in spatial and arithmetic tasks. We tested these mechanisms among 80 U.S. second- and third-graders using a pretest-intervention-posttest design, with 40 children in the spatial training group and 40 in an active control group. Short-duration spatial training improved children’s overall arithmetic performance; this effect did not differ by problem type (conventional, missing-term, or two-step problems). Spatial training also reduced children’s use of counting strategies. However, we did not find a significant increase in spatially-related strategies, nor did we observe a significant reduction in state anxiety. This study makes an important contribution to understanding the mechanisms underlying the transfer effects of short-duration spatial training on arithmetic skills, providing partial support for the spatial modeling account. 

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4. Long-distance vocalizations of spotted hyenas contain individual, but not group, signatures

   https://doi.org/10.1098/rspb.2022.0548  

   Lehmann, Kenna D.; Jensen, Frants H.; Gersick, Andrew S.; Strandburg-Peshkin, Ariana; Holekamp, Kay E. (July 2022, Proceedings of the Royal Society B: Biological Sciences)

   In animal societies, identity signals are common, mediate interactions within groups, and allow individuals to discriminate group-mates from out-group competitors. However, individual recognition becomes increasingly challenging as group size increases and as signals must be transmitted over greater distances. Group vocal signatures may evolve when successful in-group/out-group distinctions are at the crux of fitness-relevant decisions, but group signatures alone are insufficient when differentiated within-group relationships are important for decision-making. Spotted hyenas are social carnivores that live in stable clans of less than 125 individuals composed of multiple unrelated matrilines. Clan members cooperate to defend resources and communal territories from neighbouring clans and other mega carnivores; this collective defence is mediated by long-range (up to 5 km range) recruitment vocalizations, called whoops. Here, we use machine learning to determine that spotted hyena whoops contain individual but not group signatures, and that fundamental frequency features which propagate well are critical for individual discrimination. For effective clan-level cooperation, hyenas face the cognitive challenge of remembering and recognizing individual voices at long range. We show that serial redundancy in whoop bouts increases individual classification accuracy and thus extended call bouts used by hyenas probably evolved to overcome the challenges of communicating individual identity at long distance. 

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5. Limit Theorems for Some Long Range Random Walks on Torsion Free Nilpotent Groups

   Chen, Zhen-Qing; Kumagai, Takashi; Saloff-Coste, Laurent; Wang, Jian; Zheng, Tianyi (July 2023, Springer)

   This book develops limit theorems for a natural class of long range random walks on finitely generated torsion free nilpotent groups. The limits in these limit theorems are Lévy processes on some simply connected nilpotent Lie groups. Both the limit Lévy process and the limit Lie group carrying this process are determined by and depend on the law of the original random walk. The book offers the first systematic study of such limit theorems involving stable-like random walks and stable limit Lévy processes in the context of (non-commutative) nilpotent groups. 

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