Two good reasons to say ‘change!’ – ensemble representations as well as item representations impact standard measures of VWM capacity

Visual working memory (VWM) is a central bottleneck in human information processing. Its capacity is most often measured in terms of how many individual‐item representations VWM can hold (k). In the standard task employed to estimate k, an array of highly discriminable colour patches is maintained and, after a short retention interval, compared to a test display (change detection). Recent research has shown that with more complex, structured displays, change‐detection performance is, in addition to individual‐item representations, supported by ensemble representations formed as a result of spatial subgroupings. Here, by asking participants to additionally localize the change, we reveal indication for an influence of ensemble representations even in the very simple, unstructured displays of the colour‐patch change‐detection task. Critically, pure‐item models from which standard formulae of k are derived do not consider ensemble representations and, therefore, potentially overestimate k. To gauge this overestimation, we develop an item‐plus‐ensemble model of change detection and change localization. Estimates of k from this new model are about 1 item (~30%) lower than the estimates from traditional pure‐item models, even if derived from the same data sets.     

Exhaled breath analysis in evaluation of psychological stress: A short literature review

Physiological stress is pervasive in today's society. Its detection is normally performed through several unobtrusive methods, driving both caregivers and patients to take measures to reduce the burden of this condition on human health. Among the methods for assessing stress, exhaled breath analysis represents a non‐invasive, real‐time alternative to classic laboratory tests. Therefore, a literature review was performed to assess the presence of altered parameters, related to psychological stress, in exhaled breath. Most studies in our review measured nitric oxide (NO), whose concentration was often correlated, either positively or negatively, with psychological stress, with reasonable scientific support. Other compounds (isoprene, terpene and so on) were rarely studied and with mixed evidence. Further investigations are needed to elucidate the involvement and the pathophysiological role of NO in stress, possibly including a greater number of individuals, as sample size actually represents the main limitation of the work published to date.     

Psychometric Qualities and Measurement Invariance of the Modified Self‐Rated Creativity Scale

The 13‐item self‐rated creativity scale (SRCS) initially developed for supervisory rating of employees’ creativity was modified by some researchers and used as a self‐report of creativity. However, it is not clear if the modified SRCS is psychometrically sound. The present study addressed this gap in three studies (N = 1,033). The exploratory factor analysis (Study 1) revealed a two‐factor solution after removing Item 9 due to low factor loading. Confirmatory factor analysis was then used in Study 2 to examine and compare the conceptual one‐factor model with 13 items (Model 1), one‐factor model with 12 items (Model 2), two‐factor model with 12 items (Model 3), and the 12‐item bifactor model with one general factor and two specific factors (Model 4). The results indicated that Model 4 is more superior to all the competing models. Study 3 further confirmed that the bifactor model, showed support to the reliability and convergent validity, and found partial metric invariance across Chinese and Malay undergraduates. Taken together, the modified (12‐item) SRCS is a psychometrically sound tool for self‐rated creativity in the Malaysian context.     

Baseline training sequence affects speed of emergent conditional discriminations

We examined the effects of baseline training sequence on the emergence of conditional discriminations in an intraverbal naming task. Thirty‐two college students were randomly assigned to two groups. The tact‐intraverbal (TI) group first learned to vocally tact eight visual stimuli using a unique verbal label for each stimulus, and then to intraverbally relate four pairs of verbal labels. The intraverbal‐tact (IT) group received the same training but in the opposite sequence. Both groups then received a match‐to‐sample test involving the visual stimuli alone. On average, the TI group had significantly shorter reaction times than the IT group throughout all four test blocks, even when controlling for intraverbal retention, which was lower in the IT group. Accuracy on the MTS test did not differ significantly between groups when controlling for intraverbal retention. However, MTS accuracy and intraverbal retention were strongly correlated in the IT group but uncorrelated in the TI group. We suggest the effect of training sequence reflects different sources of stimulus control available to subjects in different groups when confronted with the novel MTS trials.     

Basic‐Know And Super‐Know

Sometimes a proposition is ‘opaque’ to an agent: (s)he doesn't know it, but (s)he does know something about how coming to know it should affect his or her credence function. It is tempting to assume that a rational agent's credence function coheres in a certain way with his or her knowledge of these opaque propositions, and I call this the ‘Opaque Proposition Principle’. The principle is compelling but demonstrably false. I explain this incongruity by showing that the principle is ambiguous: the term ‘know’ as it appears in the principle can be interpreted in two different ways, as either basic‐know or super‐know. I use this distinction to construct a plausible version of the principle, and then to similarly construct plausible versions of the Reflection Principle and the Sure‐Thing Principle.     

Automatic semantic activation is no myth: semantic context effects on the N400 in the letter-search task in the absence of response time effects

The claim that semantic activation is an automatic process was recently called a myth, on the basis of the finding that if letter search is performed on a prime word, semantic priming effects on response time are eliminated, whereas repetition effects are preserved. The absence of semantic activation, however, cannot be validly inferred from the lack of response time effects, and converging evidence is needed. To this end, we examined the event-related potential correlate of priming, the N400 amplitude modulation, in a letter-search priming paradigm. Our experiment replicated the response time effects and demonstrated that the N400 amplitude successfully differentiates cross-case repetition priming, semantic priming, and neutral conditions. The results clearly indicate that the meaning of the prime word was processed and that semantic activation indeed was present in the letter-search task. The notion that semantic activation is an automatic process should not be abandoned prematurely.     

What happens next? The predictability of natural behaviour viewed through CCTV cameras

Can potentially antisocial or criminal behaviour be predicted? Our study aimed to ascertain (a) whether observers can successfully predict the onset of such behaviour when viewing real recordings from CCTV; (b) where, in the sequence of events, it is possible to make this prediction; and (c) whether there may be a difference between na?ve and professional observers. We used 100 sample scenes from UK urban locations. Of these, 18 led to criminal behaviour (fights or vandalism). A further 18 scenes were matched as closely as possible to the crime examples, but did not lead to any crime, and 64 were neutral scenes chosen from a wide variety of noncriminal situations. A signal-detection paradigm was used in conjunction with a 6-point rating scale. Data from fifty na?ve and fifty professional observers suggest that (a) observers can distinguish crime sequences from neutral sequences and from matches; (b) there are key types of behaviour (particularly gestures and body position) that allow predictions to be made; (c) the performance of na?ve observers is comparable to that of experts. However, because the experts were predominantly male, the absence of an effect of experience may have been due to gender differences, which were investigated in a subsidiary experiment. The results of experiment 2 leave open the possibility that females perform better than males at such tasks.