What do (most of) our dispersion measures measure (most)? Dispersion?

This paper discusses the degree to which most of the most widely-used measures of dispersion in corpus linguistics are not particularly valid in the sense of actually measuring dispersion rather than some amalgam of a lot of frequency and a little dispersion. The paper demonstrates these issues on the basis of data from a variety of corpora. I then outline how to design a dispersion measure that only measures dispersion and show that (i) it indeed measures information that is different from frequency in an intuitive way and (ii) has a higher degree of predictive power of lexical decision times from the MALD database than nearly all other measures in nearly all corpora tested.

Abstract Action Language Processing in Eleven-Year-Old Children: Influence of Upper Limb Movement on Sentence Comprehension

Regarding the embodiment of language processing in adults, there is evidence of a close connection between sensorimotor brain areas and brain areas relevant to the processing of action verbs. This thesis is hotly debated and has therefore been thoroughly studied in adults. However, there are still questions concerning its development in children. The present study deals with the processing of action verbs in concrete and abstract sentences in 60 eleven-year-olds using a decision time paradigm. Sixty-five children mirrored arm movements or sat still and rated the semantic plausibility of sentences. The data of the current study suggest that eleven-year-olds are likely to misunderstand the meaning of action verbs in abstract contexts. Their decision times were faster and their error rates for action verbs in concrete sentences were lower. However, the gender of the children had a significant influence on the decision time and the number of errors, especially when processing abstract sentences. Females were more likely to benefit from an arm movement before the decision, while males were better if they sat still beforehand. Overall, children made quite a few errors when assessing the plausibility of sentences, but the female participants more often gave plausibility assessments that deviated from our expectations, especially when processing abstract sentences. It can be assumed that the embodiment of language processing plays some role in 11-year-old children, but is not yet as mature as it is in adults. Especially with regard to the processing of abstract language, the embodied system still has to change and mature in the course of child development.

The Limits of Defaults: The Influence of Decision Time on Default Effects

The stability of default effects to contextual features is critical to their use in policy. In this paper, decision time was investigated as a contextual factor that may pose limits on the efficacy of defaults. Consistent with the hypothesis that time constraints may increase reliance on contextual cues, four experiments, including a preregistered one of a nationally representative sample, and a meta-analysis that included four additional pilot experiments, indicated that short decision times increased the advantage of action defaults (i.e., the default option automatically endorsed the desired behavior) and that the default advantage was trivial or nonexistent when decision times were longer. These effects replicated for naturalistic as well as externally induced decision times and were present even when participants were unaware that time was limited. This research has critical implications for psychological science and allied disciplines concerned with policy in the domains of public health, finance and economics, marketing, and environmental sciences.

Affective Valence of Words Differentially Affects Visual and Auditory Word Recognition

Recognizing written or spoken words involves a sequence of processing stages, transforming sensory features into lexical-semantic representations. While the later processing stages are common across modalities, the initial stages are modality-specific. In the visual modality, previous studies have shown that words with positive valence are recognized faster than neutral words. Here, we examined whether the effects of valence on word recognition are specific to the visual modality or are common across visual and auditory modalities. To address this question, we analyzed multiple large databases of visual and auditory lexical decision tasks, relating the valence of words to lexical decision times while controlling for a large number of variables, including arousal and frequency. We found that valence differentially influenced visual and auditory word recognition. Valence had an asymmetric effect on visual lexical decision times, primarily speeding up recognition of positive words. By contrast, valence had a symmetric effect on auditory lexical decision times, with both negative and positive words speeding up word recognition relative to neutral words. The modality-specificity of valence effects were consistent across databases and were observed when the same set of words were compared across modalities. We interpret these findings as indicating that valence influences word recognition partly at the sensory-perceptual stage. We relate these effects to the effects of positive (reward) and negative (punishment) reinforcers on perception.

Charting closed-loop collective cultural decisions: from book best sellers and music downloads to Twitter hashtags and Reddit comments

Charts are used to measure relative success for a large variety of cultural items. Traditional music charts have been shown to follow self-organizing principles with regard to the distribution of item lifetimes, the on-chart residence times. Here we examine if this observation holds also for (a) music streaming charts (b) book best-seller lists and (c) for social network activity charts, such as Twitter hashtags and the number of comments Reddit postings receive. We find that charts based on the active production of items, like commenting, are more likely to be influenced by external factors, in particular by the 24 h day–night cycle. External factors are less important for consumption-based charts (sales, downloads), which can be explained by a generic theory of decision-making. In this view, humans aim to optimize the information content of the internal representation of the outside world, which is logarithmically compressed. Further support for information maximization is argued to arise from the comparison of hourly, daily and weekly charts, which allow to gauge the importance of decision times with respect to the chart compilation period.

Mid-frontal Theta during Conflict in a Value-based Decision Task

Mid-frontal theta is a sensitive marker for cognitive conflict. However, most research focuses on cognitive control paradigms (e.g., the Flanker task). Here, we ask if mid-frontal theta is also sensitive to response conflicts within value-based decision-making. We recorded electroencephalography activity during a value-based binary decision task. In this task, participants collect rewards in a virtual two-dimensional world. In each trial, we present two reward options that are either quick to collect but are smaller in value, or take longer to collect but are larger in value. The subjective value of each option is driven by the options' value and how quickly they can be reached. We used this task to investigate three types of potential conflicts: choice ambiguity, choice repetitions, and temporal delay. We investigated choice repetition by biasing participants toward one option for two trials and then testing how that affects the subsequent decision. We manipulated choice ambiguity by varying the subjective values of the decision options, and temporal delay by making one option quick to collect and one longer to collect. The behavioral results showed the expected effects: Decision times were shorter for unambiguous choices, participants showed a tendency to repeat the previous choice and decision times were shorter for repetitions, and decision times were shorter for earlier available choices. Response-locked mid-frontal theta power was increased for choice switches as compared to choice repetitions, and for the later available as compared to the earlier available option, but we found no effect of ambiguity.

Covert attention leads to fast and accurate decision making

Decision makers are regularly faced with more choice information than they can directly gaze at in a limited amount of time. Many theories assume that because decision makers attend to information sequentially and overtly that is, with direct gaze, they must respond to information overload by trading off between speed and decision accuracy. By re-analyzing four published studies, we show that participants, besides using overt attention, also use covert attention that is, attend to information without direct gaze, to evaluate choice attributes that lead them to either choose the best or reject the worst option. We show that the use of covert attention is common for most participants and more so when information is easily identifiable in the peripheral visual field due to being large or visually salient. Covert choices are associated with faster decision times suggesting that participants process multiple pieces of information simultaneously using distributed attention. Our findings highlight the importance of covert attention in decision making and show how decision makers may be gaining speed without sacrificing accuracy. We discuss implications of our findings for both existing and future theories of decision making.

Stress-sensitive inference of task controllability

ABSTRACTEstimating environmental controllability enables agents to better predict upcoming events and decide when to engage controlled action selection. How does the human brain estimate environmental controllability? Trial-by-trial analysis of choices, decision times and neural activity in an explore-and-predict task demonstrate that humans solve this problem by comparing the predictions of an “actor” model with those of a reduced “spectator” model of their environment. Neural BOLD responses within striatal and medial prefrontal areas tracked the instantaneous difference in the prediction errors generated by these two statistical learning models. BOLD activity in the posterior cingulate, parietal and prefrontal cortices covaried with changes in estimated controllability. Exposure to inescapable stressors biased controllability estimates downward and increased reliance on the spectator model in an anxiety-dependent fashion. Taken together, these findings provide a mechanistic account of controllability inference and its distortion by stress exposure.

Forced choices reveal a trade-off between cognitive effort and physical pain

Cognitive effort is described as aversive, and people will generally avoid it when possible. This aversion to effort is believed to arise from a cost–benefit analysis of the actions available. The comparison of cognitive effort against other primary aversive experiences, however, remains relatively unexplored. Here, we offered participants choices between performing a cognitively demanding task or experiencing thermal pain. We found that cognitive effort can be traded off for physical pain and that people generally avoid exerting high levels of cognitive effort. We also used computational modelling to examine the aversive subjective value of effort and its effects on response behaviours. Applying this model to decision times revealed asymmetric effects of effort and pain, suggesting that cognitive effort may not share the same basic influences on avoidance behaviour as more primary aversive stimuli such as physical pain.