The change probability effect: incidental learning, adaptability, and shared visual working memory resources

Statistical properties in the visual environment can be used to improve performance on visual working memory (VWM) tasks. The current study examined the ability to incidentally learn that a change is more likely to occur to a particular feature dimension (shape, color, or location) and use this information to improve change detection performance for that dimension (the change probability effect). Participants completed a change detection task in which one change type was more probable than others. Change probability effects were found for color and shape changes, but not location changes, and intentional strategies did not improve the effect. Furthermore, the change probability effect developed and adapted to new probability information quickly. Finally, in some conditions, an improvement in change detection performance for a probable change led to an impairment in change detection for improbable changes.     

任务情境与概率知识经验对中学生合取判断的影响研究

本研究采用了一套由不同任务情境(数字情境和日常情境)组成的合取判断问卷与一套概率基础知识问卷,对106名中学生的合取判断情况进行调查,结果显示:(1)无论在哪种任务情境下,概率知识经验均未对合取判断成绩产生显著影响。(2)不同概率知识经验的被试在数字任务情境下采用的策略有所不同。     

Nature and facts about natural and artifactual categories: Sex differences in the semantic priming paradigm

There is abundant evidence from behavioral and neurophysiological experiments for the distinction of natural versus artifactual categories and a gender-specific difference: women’s performances in cognitive tasks increase when natural categories are used, whereas men’s performances increase with artifactual categories. Here, we used the semantic priming paradigm to study retrieval processes by presenting category labels as primes and exemplars as targets. Overall, in two experiments we found larger priming effects for natural than for artifactual categories. In addition, females showed positive priming effects for natural but negative effects for artifactual categories, whereas males showed positive priming effects for both categories. This pattern matches with that from other tasks and can be interpreted as evidence that the findings from these other tasks are, at least partially, indeed due to different representations or processing modes for males and females and not (exclusively) due to—for example—different familiarity with a category. In a further experiment, we showed that the found pattern for females can be manipulated by focusing on perceptual vs. functional features. The results can be interpreted as first evidence that there are (eventually in addition to different “crystallized” semantic structures) specific default processing modes that differ for males and females.     

Intolerance of uncertainty and perceived threat

The present study examined the relations between dimensions of intolerance of uncertainty (i.e., desire for predictability and uncertainty paralysis) and perceptions of threat (i.e., perceptions of the probabilities and costs of future undesirable outcomes) in a sample of 239 college students. Uncertainty paralysis was positively associated with both perceived probabilities and perceived costs for negative outcomes. Desire for predictability was positively associated with perceived costs for negative outcomes but was not associated with perceived probabilities for negative outcomes. When probability estimates for low base rate outcomes were examined separately, desire for predictability was negatively associated with perceived probabilities. Finally, perceived threat partially mediated the relations between dimensions of intolerance of uncertainty and worry. The results of the present study suggest mechanisms through which dimensions of intolerance of uncertainty might lead to excessive worry.     

Violations of coherence in subjective probability: a representational and assessment processes account

Coherent judgment is a cardinal feature of rational cognition. Six experiments revealed systematic violations of coherence in probability judgment in which participants assigned different probabilities to mathematically equiprobable events. Experiments 1-5 revealed a strict refocusing effect: Compared to an occurrence frame, a non-occurrence frame resulted in higher estimates if base-rate evidence favored occurrence, lower estimates if evidence favored non-occurrence, and similar estimates if evidence supported indifference. Moreover, Experiments 5 and 6 revealed a pessimistic bias in which the less favorable of two equiprobable events was assigned greater probability. The findings support a Representational and Assessment Processes account (RAP) in which subjective probability is influenced by the perceived compatibility between representations of focal events and representations of evidence.     

Not so above average after all: When people believe they are worse than average and its implications for theories of bias in social comparison

Recent research calls into question the generally accepted conclusion that people believe themselves to be better than average. This paper reviews the new theories that have been proposed to explain the fact that better-than-average effects are isolated to common behaviors and abilities, and that people believe themselves to be below average with respect to rare behaviors and uncommon abilities. These new theories are then used to revisit prior findings of better-than-average effects. When viewed in light of recent work, the evidence suggests that prior findings overstated the degree to which people engage in self-enhancement by believing that they are better than others when in fact they are not. Prior studies have often confounded desirability with commonness and have used subjective measures of comparative judgment that capitalize on people’s tendency to conflate relative with absolute self-evaluation.     

The development of possibility judgment within and across domains

The ability to differentiate possible events from impossible ones is an invaluable skill when reasoning about claims that transcend the perceptual evidence at hand, yet preschool-aged children do not readily make this differentiation when reasoning about physically extraordinary events [Shtulman, A., &; Carey, S. (2007). Improbable or impossible? How children reason about the possibility of extraordinary claims. Child Development, 78, 1015–1032]. The present study sought to determine whether this failure stems from deficits in domain-specific knowledge or deficits in the domain-general procedure by which possibility judgments are made. Participants (48 children aged 4-9 years olds and 16 adults) were asked to judge the possibility of three types of extraordinary events – physical, psychological, and biological – and to justify their judgments of impossibility. Developmental changes in the ability to differentiate improbable events from impossible events were qualitatively similar across domains. Moreover, participants’ propensity to judge improbable events possible was significantly correlated with the quality of their justifications, both within and across domains. These findings suggest that modal development involves a domain-general change in how modal claims are evaluated.     

Quantity judgments of sequentially presented food items by capuchin monkeys (Cebus apella)

Recent assessments have shown that capuchin monkeys, like chimpanzees and other Old World primate species, are sensitive to quantitative differences between sets of visible stimuli. In the present study, we examined capuchins’ performance in a more sophisticated quantity judgment task that required the ability to form representations of food quantities while viewing the quantities only one piece at a time. In three experiments, we presented monkeys with the choice between two sets of discrete homogeneous food items and allowed the monkeys to consume the set of their choice. In Experiments 1 and 2, monkeys compared an entirely visible food set to a second set, presented item-by-item into an opaque container. All monkeys exhibited high accuracy in choosing the larger set, even when the entirely visible set was presented last, preventing the use of one-to-one item correspondence to compare quantities. In Experiment 3, monkeys compared two sets that were each presented item-by-item into opaque containers, but at different rates to control for temporal cues. Some monkeys performed well in this experiment, though others exhibited near-chance performance, suggesting that this species’ ability to form representations of food quantities may be limited compared to previously tested species such as chimpanzees. Overall, these findings support the analog magnitude model of quantity representation as an explanation for capuchin monkeys’ quantification of sequentially presented food items.

Reasoning about the future: Doom and Beauty

According to the Doomsday Argument we have to rethink the probabilities we assign to a soon or not so soon extinction of mankind when we realize that we are living now, rather early in the history of mankind. Sleeping Beauty finds herself in a similar predicament: on learning the date of her first awakening, she is asked to re-evaluate the probabilities of her two possible future scenarios. In connection with Doom, I argue that it is wrong to assume that our ordinary probability judgements do not already reflect our place in history: we justify the predictive use we make of the probabilities yielded by science (or other sources of information) by our knowledge of the fact that we live now, a certain time before the possible occurrence of the events the probabilities refer to. Our degrees of belief should change drastically when we forget the date—importantly, this follows without invoking the “Self Indication Assumption”. Subsequent conditionalization on information about which year it is cancels this probability shift again. The Doomsday Argument is about such probability shifts, but tells us nothing about the concrete values of the probabilities—for these, experience provides the only basis. Essentially the same analysis applies to the Sleeping Beauty problem. I argue that Sleeping Beauty “thirders” should be committed to thinking that the Doomsday Argument is ineffective; whereas “halfers” should agree that doom is imminent—but they are wrong.     

On the alleged impossibility of coherence

If coherence is to have justificatory status, as some analytical philosophers think it has, it must be truth-conducive, if perhaps only under certain specific conditions. This paper is a critical discussion of some recent arguments that seek to show that under no reasonable conditions can coherence be truth-conducive. More specifically, it considers Bovens and Hartmann’s and Olsson’s “impossibility results,” which attempt to show that coherence cannot possibly be a truth-conducive property. We point to various ways in which the advocates of a coherence theory of justification may attempt to divert the threat of these results.