The need to explain

How do reasoners deal with inconsistencies? James (1907) believed that the rational solution is to revise your beliefs and to do so in a minimal way. We propose an alternative: You explain the origins of an inconsistency, which has the side effect of a revision to your beliefs. This hypothesis predicts that individuals should spontaneously create explanations of inconsistencies rather than refute one of the assertions and that they should rate explanations as more probable than refutations. A pilot study showed that participants spontaneously explain inconsistencies when they are asked what follows from inconsistent premises. In three subsequent experiments, participants were asked to compare explanations of inconsistencies against minimal refutations of the inconsistent premises. In Experiment 1, participants chose which conclusion was most probable; in Experiment 2 they rank ordered the conclusions based on their probability; and in Experiment 3 they estimated the mean probability of the conclusions' occurrence. In all three studies, participants rated explanations as more probable than refutations. The results imply that individuals create explanations to resolve an inconsistency and that these explanations lead to changes in belief. Changes in belief are therefore of secondary importance to the primary goal of explanation.     

Just passing through? Inhibition of return in saccadic sequences

Responses tend to be slower to previously fixated spatial locations, an effect known as “inhibition of return” (IOR). Saccades cannot be assumed to be independent, however, and saccade sequences programmed in parallel differ from independent eye movements. We measured the speed of both saccadic and manual responses to probes appearing in previously fixated locations when those locations were fixated as part of either parallel or independent saccade sequences. Saccadic IOR was observed in independent but not parallel saccade sequences, while manual IOR was present in both parallel and independent sequence types. Saccadic IOR was also short-lived, and dissipated with delays of more than ～1500?ms between the intermediate fixation and the probe onset. The results confirm that the characteristics of IOR depend critically on the response modality used for measuring it, with saccadic and manual responses giving rise to motor and attentional forms of IOR, respectively. Saccadic IOR is relatively short-lived and is not observed at intermediate locations of parallel saccade sequences, while attentional IOR is long-lasting and consistent for all sequence types.     

Anticipatory Planning of Sequential Hand and Finger Movements

ABSTRACT

Hand movements may be anticipatorily planned to reach an immediate target and at the same time facilitate movements to subsequent targets. Researchers have proposed that in anticipatory planning, information about subsequent targets needs to be processed to engage in the planning of the next movement. To test this hypothesis, the authors varied the information 48 participants had about to-be-executed two-step hand and finger movement sequences prior to a choice reaction signal. Movements were initialized faster if participants had advance information about the second target of the sequence than if participants had no advance information at all. The results imply that movement segments to late targets in a movement sequence may be at least partially planned, even if information about earlier targets is not yet available.     

Memory for Movement in Blind Children

The author assessed the mechanisms underlying skilled production of keying sequences in the discrete sequence-production task by examining the effect of sequence length on mean element execution rate (i.e., the rate effect). To that end, participants (N = 9) practiced fixed movement sequences consisting of 2, 4, and 6 key presses for a total of 588 trials per sequence. In the subsequent test phase, the sequences were executed with and without a verbal short-term memory task in both simple and choice reaction time (RT) paradigms. The rate effect was obtained in the discrete sequence-production task—including the typical quadratic increase in sequence execution time (SET, which excludes RT) with sequence length. The rate effect resulted primarily from 6-key sequences that included 1 or 2 relatively slow elements at individually different serial positions. Slowing of the depression of the 2nd response key (R₂) in the 2-key sequence reduced the rate effect in the memory task condition, and faster execution of the 1st few elements in each sequence amplified the rate effect in simple RT. Last, the time to respond to random cues increased with position, suggesting that the mechanisms that underlie the rate effect in new sequences and in familiar sequences are different. The data were in line with the notion that coding of longer keying sequences involves motor chunks for the individual sequence segments and information on how those motor chunks are to be concatenated.     

Do we map remembrances to the left/back and expectations to the right/front of a mental timeline? Space–time congruency effects with retrospective and prospective verbs

Recent experimental studies have shown that people code time in terms of a mental timeline which typically runs from left to right or from back to front. Determining the cognitive function of this mental timeline for language processing, however, is still an unsettled issue. Whereas the studies of Ulrich and Maienborn (2010) and Ulrich et al. (2012) argue against an automatic activation of the mental timeline for the interpretation of tense and temporal adverbials at sentence level, Sell and Kaschak (2011) observe an automatic activation for the processing of past- and future-related sentences in small stories. The present paper reports the results of three experiments which examine the processing of sentences with retrospective and prospective verbs (e.g., to remember, to regret vs. to expect, to announce) in present tense, which locate a second, embedded event in the past or the future. When temporal information was task-relevant, a space–time congruency effect emerged (Experiment 1). This suggests that the mental timeline is not only linked to overtly deictic linguistic material but may also be construed in a more intricate way through the compositional construction of sentence meaning. The congruency effect disappeared, however, when temporal information was task-irrelevant (Experiments 2 and 3), suggesting that the mental timeline is not functionally involved in the cognitive processing of these especially demanding two-event sentences. The results of the present study support the conclusion that the relevant factor driving an automatic activation of the mental timeline is not the number of linguistically expressed events, but might rather be the number of sentential units.     

The Acquisition of Time Properties Associated with a Sequential Motor Skill

Three experiments are reported that examined the relative importance of phasing and duration training in the motor learning of a sequential task. In all three experiments, the task involved knocking down three barriers in a specified order. The Phasing task required the subject to contact each of the barriers in a particular goal time interval, that is, each segment had a particular movement-time goal. The Duration task required the subject to contact the final barrier in a total elapsed-time goal defined by the experimenter. Following training, half of the subjects in each training condition transferred to either a novel Duration or a novel Phasing task. Phasing-trained subjects, compared to Duration-trained subjects, produced equivalent transfer performance on the Duration transfer task but superior performance on the Phasing transfer task. These results suggest that phasing serves as a higher-order source of information for the performer in a sequential motor task. In addition, these experiments complement and extend previous work by Shapiro (1977) and Summers (1975) which demonstrated that learned phasing patterns were not modified despite changes in the overall rate of performing a motor sequence. Our experiments indicate that phasing training increases the performer’s sensitivity to phasing patterns such that novel temporal patterns can be produced when they are well-defined.     

热手谬误？赌徒谬误？ ——随机序列知觉中近因效应的格式塔现象研究

通过两个实验来探讨随机序列中的近因效应。在实验1中,采用传统实验范式,让被试进行一系列的抛掷硬币结果的猜测并给予反馈,结果发现：（1）在最近连续几次硬币呈现的结果不同时,人们通常把各个结果分别作为独立的单元来看待,大部分情况下做出随机性的预期;（2）在最近连续几次硬币呈现的结果相同时,人们通常把连续几次相同的结果作为一个认知单元来看待,在最近猜测对错两种情况下分别出现了截然相反的两种近因效应。当最近1次猜对时,对下一结果的预期出现正近因效应即热手谬误,但是最近几次连续猜对时谬误减少乃至消失;当最近1次猜错时,对下一结果的预期出现负近因效应即赌徒谬误,并且最近几次连续猜错时负近因效应并未受到太大影响。实验2在实验1范式的基础上,把硬币抛掷的结果人为分组,发现被试对每一组的第一个结果做出预期时,实验1中的各种效应均消失,该现象支持关于随机序列知觉的“格式塔理论”。     

Some Remarks on Ultrafilter and Normality Logics

The paper presents the main ideas of Ultrafilter Logic (UL), as introduced by Veloso and others. A new proposal, Normality Logic (NL), is outlined for expanding the expressive power of UL. The system NL appears to offer a simpler solution to the problem of expressive power than the sorting strategy of Carnielli and Veloso. Interpretations of NL are discussed and an important point of contact to Hansson's notion of non-prioritized belief revision is observed. This revised version was published online in August 2006 with corrections to the Cover Date.     

System JLZ – rational default reasoning by minimal ranking constructions

We present a powerful quasi-probabilistic default formalism for graded defaults based on a well-motivated canonical ranking construction procedure, System JLZ. It implements the minimal construction paradigm and verifies the major inference principles and inheritance desiderata, including rational monotony for propositions and structured cumulativity for default conditionals. With help from a structured ranking semantics for defaults, it also avoids some drawbacks of semi-qualitative entropy maximization and other competing accounts.