Naïve and Robust: Class‐Conditional Independence in Human Classification Learning

Humans excel in categorization. Yet from a computational standpoint, learning a novel probabilistic classification task involves severe computational challenges. The present paper investigates one way to address these challenges: assuming class‐conditional independence of features. This feature independence assumption simplifies the inference problem, allows for informed inferences about novel feature combinations, and performs robustly across different statistical environments. We designed a new Bayesian classification learning model (the dependence‐independence structure and category learning model, DISC‐LM) that incorporates varying degrees of prior belief in class‐conditional independence, learns whether or not independence holds, and adapts its behavior accordingly. Theoretical results from two simulation studies demonstrate that classification behavior can appear to start simple, yet adapt effectively to unexpected task structures. Two experiments—designed using optimal experimental design principles—were conducted with human learners. Classification decisions of the majority of participants were best accounted for by a version of the model with very high initial prior belief in class‐conditional independence, before adapting to the true environmental structure. Class‐conditional independence may be a strong and useful default assumption in category learning tasks.     

A FURTHER EVALUATION OF PICTURE PROMPTS DURING AUDITORY‐VISUAL CONDITIONAL DISCRIMINATION TRAINING

This study was a systematic replication and extension of Fisher, Kodak, and Moore (2007 ), in which a picture prompt embedded into a least‐to‐most prompting sequence facilitated acquisition of auditory‐visual conditional discriminations. Participants were 4 children who had been diagnosed with autism; 2 had limited prior receptive skills, and 2 had more advanced receptive skills. We used a balanced design to compare the effects of picture prompts, pointing prompts, and either trial‐and‐error learning or a no‐reinforcement condition. In addition, we assessed the emergence of vocal tacts for the 2 participants who had prior tact repertoires. Picture prompts enhanced acquisition for all participants, but there were no differential effects on tact emergence. The results support a generality of the effect reported by Fisher et al. and suggest that a variety of learners may benefit from the incorporation of picture prompts into auditory‐visual conditional discrimination training.     

充分条件句语义关系知觉对条件推理的影响

作者通过实验考察了大学生被试对五种充分条件句语义关系知觉对其条件推理的影响。两个实验的结果表明,被试对条件句中前后件之间语义关系的知觉理解影响和调节其相应的条件推理的成绩。实验1新发现,被试对充分条件句后件对前件必要性的知觉理解存在难易差异,对许可句和定义句的后件必要性容易知觉,对偶然句、义务句和因果句的后件必要性难以知觉。实验2新发现,被试对充分条件句后件对前件必要性的知觉理解的难易差异导致被试在否定后件式推理成绩上的差异,对许可句和定义句的否定后件式推理成绩显著高于对偶然句、义务句和因果句的否定后件式推理成绩,对充分条件句否定后件式推理成绩随对后件必要性知觉增加而增加。     

The logic sense: exploring the role of executive functioning in belief and logic-based judgments

Abstract

The Default Interventionist account suggests that by default, we often generate belief-based responses when reasoning and find it difficult to draw the logical inference. Recent research, however, shows that in some instances belief judgments take longer, are more prone to error and are more affected by cognitive load. One interpretation is that some logical inferences are available automatically and require intervention in order to respond according to beliefs. In two experiments, we investigate the effortful nature of belief judgments and the automaticity of logical inferences by increasing the inhibitory demands of the task. Participants were instructed to judge conclusion validity, believability and either font colour or font style, to increase the number of competing responses. Results showed that conflict more strongly affects judgments of believability than validity and when inhibitory demands are increased, the validity of an argument impacts more on belief judgments. These findings align with the new Parallel Processing model of belief bias.     

The Effects of Time and Distance on Accuracy of Target-Directed Locomotion

Dual adaptation to different amounts or directions of prismatic displacement, or both, can be acquired and maintained with little mutual interference. Associative recalibration of the regional task- or workspace, contingent on differentiation of distinguishing sensory information, can explain such adaptation. In contrast, nonassociative realignment restores dimensional mapping among spatial representations. Methods for measuring the separate contributions of those 2 kinds of prism adaptation are identified in the present article. On the basis of a critique of dual-adaptation studies, the authors suggest that recalibration can explain the data but that the method used in those experiments confounded realignment and might have obscured the effectiveness of dual-calibration training.     

Flat intentions – crazy dispositions?

Future-directed intentions, it is widely held, involve behavioral dispositions. But of what kind? Suppose you now intend to Φ at future time t. Are you thereby now disposed to Φ at t no matter what? If so, your intention disposes you to Φ even if around t you will come to believe that Φ-ing would be crazy. And would not that be a crazy intention to have? – Like considerations have led Luca Ferrero and others to believe that only intentions with strong internal conditions are capable of rationality. This paper explores in how far a broadly dispositional view of intention supports their claims. Its first point will come as a surprise: Intentions indeed involve dispositions toward follies in plenty. Natural objections against this bizarre-sounding claim are shown to fail, and standard counterfactual analyses of disposition locutions are shown to underpin it further. However, since the dispositions at issue are pro tanto dispositions, the consequences are not as odd as might be expected: When hedged by reasonable habits to reconsider one’s intentions, dispositions toward follies do not entail any actual crazy behavior. On balance, unconditional intention is therefore found rational after all. Dispositions toward crazy actions need not be crazy dispositions.