Open Mind最新文献

Infants experience language in the context of a dynamic environment in which many cues co-occur. However, experimenters often reduce language input to individual cues a priori without considering how children themselves may experience incoming information, leading to potentially inaccurate conclusions about how learning works outside of the lab. Here, we examined the shared temporal dynamics of two historically separated cues that are thought to support word learning: repetition of the same word in nearby utterances, and isolation of individual word tokens (i.e., single-word utterances). In a large database of North American English, we found that word repetition and isolation frequently co-occurred in children's natural language experiences, and the extent to which they did so was linked to words' earlier age of acquisition. This investigation emphasizes children's experiences in time as a way to understand the learning cues in the language environment, which may help researchers build learning theories that are grounded in real-world structure.

There is a growing interest in the use of webcams to conduct eye-tracking experiments over the internet. We assessed the performance of two webcam-based eye-tracking techniques for behavioral research: manual annotation of webcam videos (manual eye-tracking) and the automated WebGazer eye-tracking algorithm. We compared these methods to a traditional infrared eye-tracker and assessed their performance in both lab and web-based settings. In both lab and web experiments, participants completed the same battery of five tasks, selected to trigger effects of various sizes: two visual fixation tasks and three visual world tasks testing real-time (psycholinguistic) processing effects. In the lab experiment, we simultaneously collected infrared eye-tracking, manual eye-tracking, and WebGazer data; in the web experiment, we simultaneously collected manual eye-tracking and WebGazer data. We found that the two webcam-based methods are suited to capture different types of eye-movement patterns. Manual eye-tracking, similar to infrared eye-tracking, detected both large and small effects. WebGazer, however, showed less accuracy in detecting short, subtle effects. There was no notable effect of setting for either method. We discuss the trade-offs researchers face when choosing eye-tracking methods and offer advice for conducting eye-tracking experiments over the internet.

Starting in early infancy, our perception and predictions are rooted in strong expectations about the behavior of everyday objects. These intuitive physics expectations have been demonstrated in numerous behavioral experiments, showing that even pre-verbal infants are surprised when something impossible happens (e.g., when objects magically appear or disappear). However, it remains unclear whether and how physical expectations shape different aspects of moment-by-moment online visual scene processing, unrelated to explicit physical reasoning. In two EEG experiments, people watched short videos like those used in behavioral studies with adults and infants, and more recently in AI benchmarks. Objects moved on a stage, and were briefly hidden behind an occluder, with the scene either unfolding as expected, or violating object permanence (adding or removing an object). We measured the contralateral delay activity, an electrophysiological marker of online processing, to examine participants' working memory (WM) representations, as well as their ability to continuously track the objects in the scene. We found that both types of object permanence violations disrupted tracking, even though violations involved perceptually non-salient events (magical vanishing) or new objects that weren't previously tracked (magical creation). Physical violations caused WM to reset, i.e., to discard the original scene representation before it could recover and represent the updated number of items. Providing a physical explanation for the violations (a hole behind the occluder) restored object tracking, and we found evidence that WM continued to represent items that disappeared 'down the hole'. Our results show how intuitive physical expectations shape online representations, and form the basis of dynamic object tracking.

The discovery of a new kind of experience can teach an agent what that kind of experience is like. Such a discovery can be epistemically transformative, teaching an agent something they could not have learned without having that kind of experience. However, learning something new does not always require new experience. In some cases, an agent can merely expand their existing knowledge using, e.g., inference or imagination that draws on prior knowledge. We present a computational framework, grounded in the language of partially observable Markov Decision Processes (POMDPs), to formalize this distinction. We propose that epistemically transformative experiences leave a measurable "signature" distinguishing them from experiences that are not epistemically transformative. For epistemically transformative experiences, learning in a new environment may be comparable to "learning from scratch" (since prior knowledge has become obsolete). In contrast, for experiences that are not transformative, learning in a new environment can be facilitated by prior knowledge of that same kind (since new knowledge can be built upon the old). We demonstrate this in a synthetic experiment inspired by Edwin Abbott's Flatland, where an agent learns to navigate a 2D world and is subsequently transferred either to a 3D world (epistemically transformative change) or to an expanded 2D world (epistemically non-transformative change). Beyond the contribution to understanding epistemic change, our work shows how tools in computational cognitive science can formalize and evaluate philosophical intuitions in new ways.

Pronoun production involves at least two processes: (i) deciding to refer to a referent with a pronoun instead of a full NP and (ii) determining the pronoun's form. In the present study, we assess whether the second of these processes occurs as a by-product of the first process-namely, does accessing the message-level representation of the referent provide access to the features required to determine pronoun form, meaning that pronouns should be robust to errors, or are pronoun features determined through an agreement operation with the antecedent, in which case they may be susceptible to agreement attraction, similar to subject-verb agreement. Prior lab experiments suggest that pronouns display number attraction at a similar rate to verbs. However, in contrast to verb attraction errors, there is no documentation of systematic pronoun attraction errors in corpora of natural speech. Our study builds upon prior lab work by eliciting pronoun sentences using a scene description paradigm that engages the pronominalization processes involved in natural speech. Across three experiments, we observed small but reliable number attraction effects for pronouns, suggesting that pronoun form is not always determined from the message-level representation of the referent. The elicited error rates were smaller than those previously observed for verbs in a similar scene-description paradigm; this smaller error rate helps to reconcile the apparent discrepancy between pronoun number attraction error rates observed in and outside the lab. The results suggest that pronoun form is determined (at least at times) through an agreement process referencing the features of the linguistic antecedent.

Pragmatic theories assume that during communicative exchanges humans strive to be optimally informative and spontaneously adjust their communicative signals to satisfy their addressee's inferred epistemic needs. For instance, when necessary, adults flexibly and appropriately modify their communicative gestures to provide their partner the relevant information she lacks about the situation. To investigate this ability in infants, we designed a cooperative task in which 18-month-olds were asked to point at the target object they wanted to receive. In Experiment 1, we found that when their desired object was placed behind a distractor object, infants appropriately modified their prototypical pointing to avoid mistakenly indicating the distractor to their partner. When the objects were covered, and their cooperative partner had no information (Experiment 2) or incorrect information (Experiment 3) about the target's location - as opposed to being knowledgeable about it - infants pointed differentially more often at the target and employed modified pointing gestures more frequently as a function of the amount of relevant information that their partner needed to retrieve their desired object from its correct location. These findings demonstrate that when responding to a verbal request in a cooperative task 18-month-old infants can take into account their communicative partner's epistemic states and when necessary provide her with the relevant information she lacks through sufficiently informative deictic gestures. Our results indicate that infants possess an early emerging, species-unique cognitive adaptation specialized for communicative mindreading and pragmatic inferential communication which enable the efficient exchange of relevant information between communicating social partners in cooperative contexts.

People derive contrastive inferences when interpreting adjectives (e.g., inferring that 'the short pencil' is being contrasted with a longer one). However, classic eye-tracking studies revealed contrastive inferences with scalar and material adjectives, but not with color adjectives. This was explained as a difference in listeners' informativity expectations, since color adjectives are often used descriptively (hence not warranting a contrastive interpretation). Here we hypothesized that, beyond these pragmatic factors, perceptual factors (i.e., the relative perceptibility of color, material and scalar contrast) and semantic factors (i.e., the difference between gradable and non-gradable properties) also affect the real-time derivation of contrastive inferences. We tested these predictions in three languages with prenominal modification (English, Hindi, and Hungarian) and found that people derive contrastive inferences for color and scalar adjectives, but not for material adjectives. In addition, the processing of scalar adjectives was more context dependent than that of color and material adjectives, confirming that pragmatic, perceptual and semantic factors affect the derivation of contrastive inferences.

Whereas decades of research have cataloged striking errors in physical reasoning, a resurgence of interest in intuitive physics has revealed humans' remarkable ability to successfully predict the unfolding of physical scenes. A leading interpretation intended to resolve these opposing results is that physical reasoning recruits a general-purpose mechanism that reliably models physical scenarios (explaining recent successes), but overly contrived tasks or impoverished and ecologically invalid stimuli can produce poor performance (accounting for earlier failures). But might there be tasks that persistently strain physical understanding, even in naturalistic contexts? Here, we explore this question by introducing a new intuitive physics task: evaluating the strength of knots and tangles. Knots are ubiquitous across cultures and time-periods, and evaluating them correctly often spells the difference between safety and peril. Despite this, 5 experiments show that observers fail to discern even very large differences in strength between knots. In a series of two-alternative forced-choice tasks, observers viewed a variety of simple "bends" (knots joining two pieces of thread) and decided which would require more force to undo. Though the strength of these knots is well-documented, observers' judgments completely failed to reflect these distinctions, across naturalistic photographs (E1), idealized renderings (E2), dynamic videos (E3), and even when accompanied by schematic diagrams of the knots' structures (E4). Moreover, these failures persisted despite accurate identification of the topological differences between the knots (E5); in other words, even when observers correctly perceived the underlying structure of the knot, they failed to correctly judge its strength. These results expose a blindspot in physical reasoning, placing new constraints on general-purpose theories of scene understanding.

The vocabularies of natural languages harbour many instances of iconicity, where words show a perceived resemblance between aspects of form and meaning. An open challenge in this domain is how to reconcile different operationalizations of iconicity and link them to an empirically grounded theory. Here we combine three ways of looking at iconicity using a set of 239 iconic words from 5 spoken languages (Japanese, Korean, Semai, Siwu and Ewe). Data on guessing accuracy serves as a baseline measure of probable iconicity and provides variation that we seek to explain and predict using structure-mapping theory and iconicity ratings. We systematically trace a range of cross-linguistically attested form-meaning correspondences in the dataset, yielding a word-level measure of cumulative iconicity that we find to be highly predictive of guessing accuracy. In a rating study, we collect iconicity judgments for all words from 78 participants. The ratings are well-predicted by our measure of cumulative iconicity and also correlate strongly with guessing accuracy, showing that rating tasks offer a scalable method to measure iconicity. Triangulating the measures reveals how structure-mapping can help open the black box of experimental measures of iconicity. While none of the methods is perfect, taken together they provide a well-rounded way to approach the meaning and measurement of iconicity in natural language vocabulary.

Children learn their first number words gradually over the course of many months, which is surprising given their ability to discriminate small numerosities. One potential explanation for this is that children are sensitive to the numerical features of stimuli, but don't consider exact cardinality as a primary hypothesis for novel word meanings. To test this, we trained 144 children on a number word they hadn't yet learned, and contrasted this with a condition in which they were merely required to attend to number to identify the word's referent, without encoding number as its meaning. In the first condition, children were trained to find a "giraffe with three spots." In the second condition, children were instead trained to find "Mr. Three", which also named a giraffe with three spots. In both conditions, children had to attend to number to identify the target giraffe, but, because proper nouns refer to individuals rather than their properties, the second condition did not require children to encode number as the meaning of the expression. We found that children were significantly better at identifying the giraffe when it had been labeled with the proper noun than with the number word. This finding contrasted with a second experiment involving color words, in which children (n = 56) were equally successful with a proper noun ("Mr. Purple") and an adjective ("the giraffe with purple spots"). Together, these findings suggest that, for number, but not for color, children's difficulty acquiring new words cannot be solely attributed to problems with attention or perception, but instead may be due to difficulty selecting the correct meaning from their hypothesis space for learning unknown words.