Tubes,tables and traps: great apes solve two functionally equivalent trap tasks but show no evidence of transfer across tasks

Previous studies on tool using have shown that presenting subjects with certain modifications in the experimental setup can substantially improve their performance. However, procedural modifications (e.g. trap table task) may not only remove task constraints but also simplify the problem conceptually. The goal of this study was to design a variation of the trap-table that was functionally equivalent to the trap-tube task. In this new task, the subjects had to decide where to insert the tool and in which direction the reward should be pushed. We also administered a trap-tube task that allowed animals to push or rake the reward with the tool to compare the subjects' performance on both tasks. We used a larger sample of subjects than in previous studies and from all the four species of great apes (Gorilla gorilla, Pan troglodytes, Pan paniscus, and Pongo pygmaeus). The results showed that apes performed better in the trap-platform task than in the trap-tube task. Subjects solved the tube task faster than in previous studies and they also preferred to rake in rather than to push the reward out. There was no correlation in the level of performance between both tasks, and no indication of interspecies differences. These data are consistent with the idea that apes may possess some specific causal knowledge of traps but may lack the ability to establish analogical relations between functional equivalent tasks.     

Action understanding as inverse planning

Humans are adept at inferring the mental states underlying other agents’ actions, such as goals, beliefs, desires, emotions and other thoughts. We propose a computational framework based on Bayesian inverse planning for modeling human action understanding. The framework represents an intuitive theory of intentional agents’ behavior based on the principle of rationality: the expectation that agents will plan approximately rationally to achieve their goals, given their beliefs about the world. The mental states that caused an agent’s behavior are inferred by inverting this model of rational planning using Bayesian inference, integrating the likelihood of the observed actions with the prior over mental states. This approach formalizes in precise probabilistic terms the essence of previous qualitative approaches to action understanding based on an “intentional stance” [Dennett, D. C. (1987). The intentional stance. Cambridge, MA: MIT Press] or a “teleological stance” [Gergely, G., Nádasdy, Z., Csibra, G., & Biró, S. (1995). Taking the intentional stance at 12 months of age. Cognition, 56, 165-193]. In three psychophysical experiments using animated stimuli of agents moving in simple mazes, we assess how well different inverse planning models based on different goal priors can predict human goal inferences. The results provide quantitative evidence for an approximately rational inference mechanism in human goal inference within our simplified stimulus paradigm, and for the flexible nature of goal representations that human observers can adopt. We discuss the implications of our experimental results for human action understanding in real-world contexts, and suggest how our framework might be extended to capture other kinds of mental state inferences, such as inferences about beliefs, or inferring whether an entity is an intentional agent.     

Causal perception of action-and-reaction sequences in 8- to 10-month-olds

Four experiments with 202 8- to 10-month-old infants studied their sensitivity to causation-at-a-distance in schematic events seen as goal-directed action and reaction by adults and whether this depends on attributes associated with animate agents. In Experiment 1, a red square moved toward a blue square without making contact; in “reaction” events blue moved away while red was approaching, whereas in “delay” events blue started after red stopped. Infants were habituated to one event and then tested on its reversal. Spatiotemporal features reversed for both events, but causal roles changed only in reversed reactions. Infants dishabituated more to reversed reaction events than to reversed delay events. Squares moved rigidly or in a nonrigid animal-like fashion. Infants discriminated these, but motion pattern did not affect responses to reversal. Infants also discriminated reactions from launching and dishabituated to reversed reactions lacking self-initiated motion. These results suggest that sensitivity to causation-at-a-distance depends on the event structure but not pattern or onset typical of animal motion.     

Statistical inference and sensitivity to sampling in 11-month-old infants

Research on initial conceptual knowledge and research on early statistical learning mechanisms have been, for the most part, two separate enterprises. We report a study with 11-month-old infants investigating whether they are sensitive to sampling conditions and whether they can integrate intentional information in a statistical inference task. Previous studies found that infants were able to make inferences from samples to populations, and vice versa [Xu, F., & Garcia, V. (2008). Intuitive statistics by 8-month-old infants. Proceedings of the National Academy of Sciences of the United States of America, 105, 5012-5015]. We found that when employing this statistical inference mechanism, infants are sensitive to whether a sample was randomly drawn from a population or not, and they take into account intentional information (e.g., explicitly expressed preference, visual access) when computing the relationship between samples and populations. Our results suggest that domain-specific knowledge is integrated with statistical inference mechanisms early in development.     

利/害条件下归纳推理的心理效应分离

研究设计了两类包含内容的归纳推理任务, 一类是对获得收益的可能性的推理; 另一类是避免伤害的推理。实验显示, 不同内容的归纳推理结果有显著差异。其中, 避免伤害的归纳推理表现出将伤害可能过度推延的特点; 而获得收益的归纳推理则表现出对收益可能推延不足。此外, 不同的自我卷入水平——自我卷入式推理或者非自我卷入式推理——也会对推理产生显著影响。在避害条件下, 自我卷入式推理比非自我卷入式推理表现出更强烈的过度推延的特点; 在获利条件下, 自我卷入式推理比非自我卷入式推理表现出更严重的推延不足。研究经过分析提出, 这种差异可能暗示了归纳推理的领域特殊性特征。     

Flickers of Freedom and Modes of Action: A Reply to Timpe

In recent years, many incompatibilists have come to reject the traditional association of moral responsibility with alternative possibilities. Kevin Timpe argues that one such incompatibilist, Eleonore Stump, ultimately fails in her bid to sever this link. While she may have succeeded in dissociating responsibility from the freedom to perform a different action, he argues, she ends up reinforcing a related link, between responsibility and the freedom to act under a different mode. In this paper, I argue that Timpe’s response to Stump exploits concessions she need not have made. The upshot is that, contrary to what Timpe maintains, there is no reason to doubt that Stump's brand of incompatibilism is a genuine alternative to the traditional variety.

Causal relations drive young children's induction, naming, and categorization

A number of recent models and experiments have suggested that evidence of early category-based induction is an artifact of perceptual cues provided by experimenters. We tested these accounts against the prediction that different relations (causal versus non-causal) determine the types of perceptual similarity by which children generalize. Young children were asked to label, to infer novel properties, and to project future appearances of a novel animal that varied in two opposite respects: (1) how much it looked like another animal whose name and properties were known, and (2) how much its parents looked like parents of another animal whose name and properties were known. When exemplar origins were known, children generalized to exemplars with similar origins rather than with similar appearances; when origins were unknown, children generalized to exemplars with similar appearances. Results indicate even young children possess the cognitive control to choose the similarities that best predict accurate generalizations.     

Predictive coding: an account of the mirror neuron system

Is it possible to understand the intentions of other people by simply observing their actions? Many believe that this ability is made possible by the brain’s mirror neuron system through its direct link between action and observation. However, precisely how intentions can be inferred through action observation has provoked much debate. Here we suggest that the function of the mirror system can be understood within a predictive coding framework that appeals to the statistical approach known as empirical Bayes. Within this scheme the most likely cause of an observed action can be inferred by minimizing the prediction error at all levels of the cortical hierarchy that are engaged during action observation. This account identifies a precise role for the mirror system in our ability to infer intentions from actions and provides the outline of the underlying computational mechanisms.     

文本阅读中预期推理激活与编码的语境条件研究

本研究通过三个实验考察了语义联系和因果制约对文本阅读中预期推理激活和编码的贡献。结果表明,预期语境与预期事件间的语义联系不能使预期推理在文本阅读过程中得到激活和编码,语境与预期事件间的强因果关系是文本阅读过程中预期推理激活与编码的必要条件;提示阅读过程中的预期是因果预期而非联想预期。结果为建构主义推理观提供了实验依据。