Making heads or tails of probability: An experiment with random generators

Background. The equiprobability bias is a tendency for individuals to think of probabilistic events as ‘equiprobable’ by nature, and to judge outcomes that occur with different probabilities as equally likely. The equiprobability bias has been repeatedly found to be related to formal education in statistics, and it is claimed to be based on a misunderstanding of the concept of randomness. Aims. The aim of the present study was to examine whether experimenting with random generators would decrease the equiprobability bias. Sample. The participants were 108 psychology students whose performance was measured either immediately after taking part in a training session (n= 55), or without doing any training exercises (n= 53). Method. The training session consisted of four activities. These included generating random sequences of events, and learning about the law of large numbers. Subsequently, the participants were tested on a series of equiprobability problems, and a number of other problems with similar structure and content. Results. The results indicated that the training successfully decreased the equiprobability bias. However, this effect was moderated by participants’ cognitive ability (i.e., higher ability participants benefitted from the training more than participants with lower cognitive ability). Finally, the training session had the unexpected side effect of increasing students’ susceptibility to the representativeness heuristic. Conclusions. Experimenting with random generators has a positive effect on students’ general understanding of probability, but the same time it might increase their susceptibility to certain biases (especially, to the representativeness heuristic). These findings have important implications for using training methods to improve probabilistic reasoning performance.     

Feeling left out? The mediating role of perceived rejection on workgroup mistreatment and affective,behavioral, and organizational outcomes and the moderating role of organizational norms

This two‐study paper examines the detrimental impact of workgroup mistreatment and the mediating role of perceived rejection. In Study 1, perceived rejection emerged as a mediator between workgroup mistreatment and depression, organization‐based self‐esteem, organizational deviance, and organizational citizenship behaviors. In Study 2, the role of organizational norms was examined. Employees who experienced supportive organizational norms reported lower levels of perceived rejection, depression and turnover intentions, and higher levels of organization‐based self‐esteem and job satisfaction. Employees in the supportive norms condition reported that they were more likely to seek reconciliation after experiencing mistreatment than those who experienced low support. Perceived rejection also emerged as a mediator. Results, practical implications, and future research directions are discussed.     

Chronometric Analysis of the Posturo-Kinetic Programming of Voluntary Movement

Posturo-kinetic programming was investigated in a simple reaction time paradigm. Standing subjects performed voluntary upper limb elevations under three conditions differing by the importance of their destabilizing effect on the initial balance. Three indexes were considered: the reaction time (RT) corresponding to delay between the response signal (RS) and the onset of the upper limb acceleration at wrist level (Aw); the motor latency (ML) corresponding to delay between RS and onset of the earlier of the two accelerations at shank level (As) which was previously shown to indicate the onset of postural adjustments; and the postural anticipation (PA) corresponding to the delay between the onset of the earliest As and the onset of Aw. The results showed that the RT varied in relation to parameters of the forthcoming movement. RT variations were essentially due to differences in the PA. It appeared that the ML depended on cognitive factors while the PA depended on biomechanical ones. It is concluded that ML corresponds to the “true” reaction time while PA covers the earliest part of the motor response.     

Snoddy (1926) Revisited: Time Scales of Motor Learning

A new 3-stage model based on neuroimaging evidence is proposed by Chein and Schneider (2012). Each stage is associated with different brain regions, and draws on cognitive abilities: the first stage on creativity, the second on selective attention, and the third on automatic processing. The purpose of the present study was to scrutinize the validity of this model for 1 popular learning paradigm, visuomotor adaptation. Participants completed tests for creativity, selective attention and automated processing before attending in a pointing task with adaptation to a 60° rotation of visual feedback. To examine the relationship between cognitive abilities and motor learning at different times of practice, associations between cognitive and adaptation scores were calculated repeatedly throughout adaptation. The authors found no benefit of high creativity for adaptive performance. High levels of selective attention were positively associated with early adaptation, but hardly with late adaptation and de-adaptation. High levels of automated execution were beneficial for late adaptation, but hardly for early and de-adaptation. From this we conclude that Chein and Schneider's first learning stage is difficult to confirm by research on visuomotor adaptation, and that the other 2 learning stages rather relate to workaround strategies than to actual adaptive recalibration.     

Linguistic and nonlinguistic influences on the eyes' landing positions during reading

Two eye tracking experiments show that, for near launch sites, the eyes land nearer to the beginning of words with orthographically irregular than with regular initial letter sequences. In addition, the characteristics of words, at least at the level of orthography, influence the direction and length of within-word saccades. Importantly, these effects hold both for lower case and for visually less distinctive upper case text. Furthermore, contrary to previous evidence (Tinker & Paterson, 1939), there is little effect of type case on reading times. Additional analyses of oculomotor behaviour suggest that there is an inverted optimal viewing position for single fixation durations on words. Both the supplementary analyses and the effects of orthography on fixation positions are relevant to current models of eye movements in reading.     

Why is conversation so easy?

Traditional accounts of language processing suggest that monologue--presenting and listening to speeches--should be more straightforward than dialogue--holding a conversation. This is clearly not the case. We argue that conversation is easy because of an interactive processing mechanism that leads to the alignment of linguistic representations between partners. Interactive alignment occurs via automatic alignment channels that are functionally similar to the automatic links between perception and behaviour (the so-called perception-behaviour expressway) proposed in recent accounts of social interaction. We conclude that humans are "designed" for dialogue rather than monologue.     

FOXP2 in focus: what can genes tell us about speech and language?

The human capacity for acquiring speech and language must derive, at least in part, from the genome. In 2001, a study described the first case of a gene, FOXP2, which is thought to be implicated in our ability to acquire spoken language. In the present article, we discuss how this gene was discovered, what it might do, how it relates to other genes, and what it could tell us about the nature of speech and language development. We explain how FOXP2 could, without being specific to the brain or to our own species, still provide an invaluable entry-point into understanding the genetic cascades and neural pathways that contribute to our capacity for speech and language.     

Reaction Time Distribution Analysis of Neuropsychological Performance in an ADHD Sample

Differences in reaction time (RT) variability have been documented between children with and without Attention Deficit Hyperactivity Disorder (ADHD). Most previous research has utilized estimates of normal distributions to examine variability. Using a nontraditional approach, the present study evaluated RT distributions on the Conners’ Continuous Performance Test in children and adolescents from the Multimodal Treatment Study of ADHD sample compared to a matched sample of normal controls (n = 65 pairs). The ex-Gaussian curve was used to model RT and RT variability. Children with ADHD demonstrated faster RT associated with the normal portion of the curve and a greater proportion of abnormally slow responses associated with the exponential portion of the curve. These results contradict previous interpretation that children with ADHD have slower than normal responding and demonstrate why slower RT is found when estimates of variability assume normal Gaussian distributions. Further, results of this study suggest that the greater number of abnormally long RTs of children with ADHD reflect attentional lapses on some but not all trials.