Abstract: Abstract There is a sense in which the symbols used in mathematical expressions and formulas are arbitrary. After all, arithmetic would be no different if we would replace the symbols ‘+’ or ‘8’ by different symbols. Nevertheless, the shape of many mathematical symbols is in fact well motivated in practice. In the case of symbols that were introduced a long time ago, the original motivations remain mostly inaccessible to us. Accordingly, motivations that are discussed in the literature are only ascribed retrospectively and should be considered as post‐hoc rationalizations. For more recent introductions of new symbols (e.g., in symbolic logic), however, we sometimes do have first‐hand accounts by the authors that inform us of the reasons behind their notational choices. In this paper, I present a systematic overview of possible motivations for the design of mathematical symbols, which include practical (such as ease of writing and reuse of previously used symbols) as well as cognitive aspects (such as indicating relations to other symbols or to their intended meanings).

Abstract: Cognitive technologies are socially shared and culturally evolved systems whose function is principally cognitive. Throughout human history and prehistory, they have aided in classifying, organizing, or managing information and knowledge, including ideas, language, and material culture. They range in scope from the highly artifactual (e.g., maps, scientific instruments, weights and measures) to the more abstract and conceptual (e.g., taxonomies, linguistic frameworks). Cognitive technologies thus scaffold many of the complex activities common to all human societies. Because they are both dynamic and culturally embedded, cognitive technologies, therefore, have histories, and are thus amenable not only to contemporary experimental methods, but also a range of historical and evolutionary approaches, including those from outside disciplines traditionally considered parts of cognitive science, such as classics and other humanistic disciplines. While the study of cognitive technologies is hardly new, many pre-existing studies can now be brought together under this framework in recognition that the field has been insufficiently integrated. This issue brings together a disciplinarily diverse range of scholars whose work employs the methods and concepts of specific disciplines while orienting itself around contemporary cognitive-scientific frameworks. The value of this integrative approach is to form a nexus around which a broader range of future interdisciplinary cognitive scholarship can coalesce, in which humanists and scientists have much to learn from one another through collaboration and shared concepts.

Abstract: It has been argued that fungi have cognitive capacities, and even conscious experiences. While these arguments risk ushering in unproductive disputes about how words like "mind," "cognitive," "sentient," and "conscious" should be used, paying close attention to key properties of fungal life can also be uncontroversially productive for cognitive science. Attention to fungal life can, for example, inspire new, potentially fruitful directions of research in cognitive science. Here, I introduce a concept of cognitive symbiosis whose significance for cognitive science becomes salient when we consider the centrality of symbioses in the life of fungi. Like fungi, virtually all cognitive systems live in close association with other kinds of cognitive systems, and this living together can have substantive psychological consequences. Expanding the scope of cognitive science to study a wide variety of cognitive symbioses underwrites the importance of biology and evolution in understanding minds.

Abstract: Engraved ochres and ostrich eggshells from the South African Blombos Cave and Diepkloof Rock Shelter are among the earliest expressions of human symbolic behavior. They appear to document a continuous practice of mark-making across ∼40,000 years. During this time, the engraved markings change from simpler, unstructured patterns to more complex markings such as cross-hatchings. Previous work examining the cognitive implications of these changes concluded that the engravings were likely used as decorations and may have served as group identity markers, but not as denotational symbols. To inform discussions of the emergence of symbolic behavior, we conducted a two-part experimental study inspired by these engravings and based on the assumption that artifact use will motivate incremental adaptive refinements. Part 1 combined a delayed reproduction task with a transmission chain design to simulate an enduring mark-making practice. Eleven transmission chains were seeded with four drawings derived from the early Blombos and Diepkloof engravings and reproduced over eight generations. Transmission chain drawings showed a tendency to become increasingly regular, organized, and symmetric. Part 2 subjected a sample of the transmission chain drawings to a suite of psychophysical experiments to assess the cognitive implications of the accumulated structural changes. We found that the drawings became easier to discriminate, looked more like they had been intentionally made, and became easier to remember and reproduce, but there was no evidence of a systematic change in saliency or stylistic properties. Finally, we compared the results from the transmission chains with a similar analysis of the drawings derived from the original engravings. Although we observe interesting qualitative similarities between the original engravings and the experimental drawings, our findings suggest that cognitive biases and working memory constraints are not sufficient to generate the patterns observed in the archaeological record, highlighting the significance of social and functional contexts in shaping early symbolic artifacts. By integrating archaeological and experimental research, we can better inform inferences on sparse records of early symbolic behavior. Our study thus leads to a broader consideration of the role, strengths, and potential limitations of the transmission chain approach in analyzing trajectories of early symbolic behavior.

Abstract: When and how do children come to understand various kinds of visual media (e.g., pictures, videos, scale models), and how does early experience contribute to variation in the development of visual media comprehension across global contexts? In this selective review, we show that while researchers have investigated how children from Western convenience samples understand visual media, less is known about how this comprehension varies across children in global contexts. Indeed, prior work investigating picture comprehension suggests that children in different contexts may understand pictures at different developmental time points, potentially due to variation in their early picture experiences. These findings demonstrate the need for more research investigating children's comprehension of additional kinds of visual media across contexts. The experience-dependence of visual media comprehension could provide important insight into these abilities' origins, as well as the appropriateness of cross-cultural use of visual media in early childhood measurement.

Abstract: Abstract Numerical notation found on multiple slates from Early Medieval Visigothic Iberia remains undeciphered. Previous studies have proposed that they simply represent Roman numerals. However, the comparative study of the numbers on the written and numerical slates suggests that they do not in fact represent the same graphic code. This paper analyzes the use of the numbers on these slates through the lens of human cognitive architecture and cognitive extension. The results of the study suggest that the Roman numerals on the written slates coexist alongside the notational system used on the numerical slates rather than that both types belonging to the same system. Whereas written slates worked as asynchronous code to facilitate dual communication, numerical slates could be used as a memory aid to assist with individual cognition. These results shed important light on who was using numerals in early medieval Iberia and for what purposes.

Abstract: Abstract Predictive Processing has been proposed as the single unifying computation underlying all of cognition, and proponents argue that all psychological phenomena can be explained as consequences of this principle. This theoretical framework has inspired many cognitive scientists and neuroscientists, but it currently has no developmental mechanism that would explain how infants begin to perceive and learn about the world. Rather, it treats human cognition as if it exists in a fully developed adult with a history of observations and world knowledge. In its current formulation, Predictive Processing only allows for perception of incoming stimuli given the existence of expectations based on previous experiences and as such does not allow for an infant to ever make a first observation. In this paper, we propose a possible starting point from which the infant can begin to develop predictive models, as well as a toolkit necessary to allow the infant to perform the range of cognitive operations on predictive models necessary for learning. The starting point we propose is a set of low‐precision, low level‐of‐detail predictions with little or no hierarchical structure, which is very rapidly updated to reflect the infant's early environment. The toolkit contains a range of operations referred to collectively as structure learning, which are applied to models in order to allow for building adult‐like hierarchical models. These modifications are necessary for developmental scientists to be able to adopt the Predictive Processing framework and benefit from its advantages, but also for Predictive Processing to be able to explain all human cognition, which inherently must include development.

Abstract: Abstract Are people able to tell apart a random configuration of lines and dots from a work of art? Previous studies have shown that untrained viewers can distinguish between abstract art made by professional artists, children, or apes. Pieces made by artists were perceived as more intentionally made and organized than the rest. However, these studies used paintings by prominent abstract artists (e.g., Mark Rothko) as stimuli, which in any case showed that people were able to recognize high‐quality paintings made by trained artists, not “any” human. In this study, we presented participants with artworks by untrained human artists versus artworks made by captive chimpanzees in a visual discrimination task. In Study 1, participants viewed sets of human‐ and non‐human‐made paintings and were asked to identify the artist as human or ape. In Study 2, they rated the paintings on several criteria: intentionality, organization, balance, and complexity. We found that participants: (1) successfully distinguished between human‐made and non‐human‐made paintings; (2) reported perceiving more balance, organization, and intentionality in human‐made paintings; (3) preferred stimuli, which ranked higher in intentionality. We also identified balance, complexity, and organization as key features that influence preference for abstract artworks. Overall, our results show that even non‐figurative paintings made by adults untrained in the visual arts are perceived as intentionally made, suggesting people spontaneously produce and perceive cues of intentionality, generating an implicit human signature in visual art.

Abstract: Abstract It is well known that context‐dependent decisions incur mental costs. While previous research has sought to formalize these costs at various levels of analysis, we still lack basic insight into the nature of mental costs, including the underlying cognitive resources being consumed. Moreover, many computational models assume that mental costs scale linearly with the cognitive resource being used, an assumption of convenience that has yet to be systematically tested. To address these gaps, we build on rate‐distortion theory by formalizing an information‐theoretic notion of mental costs. Specifically, we define the cost of policies—the mappings from states to actions—as a function of the mutual information between states and actions, the policy complexity . Across four decision‐making experiments featuring diverse task manipulations, we find that this mental cost formulation offers a parsimonious description of how humans adaptively adjust their policy complexity across different tasks. Notably, a quadratic mental cost formulation, where increases in policy complexity incur supralinear costs, provides the best fit. These findings highlight the meta‐cognitive ability of humans to account for mental costs when forming decision strategies, and pave the way toward a domain‐general quantification of mental effort.

Abstract: Abstract Mushrooms are a ubiquitous and essential component in our biological environment and have been of interest to humans around the globe for millennia. Knowledge about mushrooms represents a prime example of cumulative culture, one of the key processes in human evolution. Based on a review of available research, we argue that the cognitive mechanisms of cultural transmission impact this knowledge in a twofold manner. First and foremost, they secure the accumulation of (folk‐)mycological knowledge, with the principal objective to capture reliable information on edibility and means for safe distinction. However, they also shape attitudes toward mushrooms, practices involved in foraging and consumption, and appraisals of edibility in distinct ways, with even regression and eventual loss of knowledge as one possible outcome. In using the domain of mushrooms as an example for expounding this dual role that culture plays during knowledge transmission, our paper contributes to theoretical debates around the cognitive and cultural mechanisms involved in human evolution.

Abstract: Abstract Whereas cognitive models of learning often assume direct experience with both the features of an event and with a true label or outcome, much of everyday learning arises from hearing the opinions of others, without direct access to either the experience or the ground‐truth outcome. We consider how people can learn which opinions to trust in such scenarios by extending the hedge algorithm : a classic solution for learning from diverse information sources. We first introduce a semi‐supervised variant we call the delusional hedge capable of learning from both supervised and unsupervised experiences. In two experiments, we examine the alignment between human judgments and predictions from the standard hedge, the delusional hedge, and a heuristic baseline model. Results indicate that humans effectively incorporate both labeled and unlabeled information in a manner consistent with the delusional hedge algorithm—suggesting that human learners not only gauge the accuracy of information sources but also their consistency with other reliable sources. The findings advance our understanding of human learning from diverse opinions, with implications for the development of algorithms that better capture how people learn to weigh conflicting information sources.

Abstract: Abstract Humans can make moral inferences from multiple sources of input. In contrast, computational moral inference in artificial intelligence typically relies on language models with textual input. However, morality is conveyed through modalities beyond language. We present a computational framework that supports moral inference from natural images, demonstrated in two related tasks: (1) inferring human moral judgment toward visual images and (2) analyzing patterns in moral content communicated via images from public news. We find that models based on text alone cannot capture the fine‐grained human moral judgment toward visual stimuli, but language‐vision fusion models offer better precision in visual moral inference. Furthermore, applications of our framework to news data reveal implicit biases in news categories and geopolitical discussions. Our work creates avenues for automating visual moral inference and discovering patterns of visual moral communication in public media.