Sources of bias and uncertainty in a visual temporal individuation task

Despite a clear ability to detect temporal modulations of visual stimuli in excess of 50 Hz, temporal individuation and serial order judgment tasks can be performed only when stimuli alternate at much slower rates, and the nature of such sluggishness remains unclear. One example of a task with a slow temporal limit is the individuation of a cued letter in a rapid serial visual presentation (RSVP) stream. The present study investigates the nature of the code used to perform such a slow temporal individuation task and the sources of uncertainty involved. The results demonstrate that temporal, rather than ordinal, position in the RSVP stream is critical in serial order estimation, suggesting the involvement of a noisy temporal code. In addition to variability in temporal coding, observers’ choices are also limited by a number of other factors, such as categorical errors and biases related to the position of the cue in the letters’ stream. Attentional filtering improves categorization, but crucially, it does not seem to increase the temporal precision of judgment. Generalizing the present results, I suggest that perception of order is limited by an internal temporal sampling instability that is distinct and independent from attention and that, similarly to temporal jitter in a clock, acts as a low-pass filter that hinders the judgment of the order of events that unfold too quickly.     

Attending to objects: costs or benefits?

The single-object advantage is said to occur when performance is faster and/or more accurate when the two targets to be compared appear on one object than when they appear on two different objects. The single-object advantage has been interpreted to suggest that attention can select objects rather than unparsed regions of visual space. In five experiments we explored whether directing attention to one object rather than two objects produces a benefit or a minor cost. Participants were required to compare two target features that belonged to one object, to two objects, or did not belong to any object. In addition, we varied the relevance to the task of object-related global information, such as symmetry of the object and perceptual cluttering of the background. Results showed that attending to one object in comparison to attending to no object produced a benefit only when object-related global information was relevant to the task. In contrast, when object-related global information was irrelevant to the task, attending to one object produced a cost. Thus, it can be concluded that attending to an object does not produce an absolute benefit, but rather produces a smaller cost than attending to two objects.     

It is all in good humor? Examining the impact of salesperson evaluations of leader humor on salesperson job satisfaction and job stress

Abstract

Salesperson job stress and job satisfaction have been identified as critical factors affecting job performance. Academic research suggests that sales managers can influence salesperson job stress and job satisfaction. Interestingly, a review of the sales literature finds very little research on the impact of sales leader humor usage on the stress and satisfaction of salespeople. Consequently, we explore how salespeople’s evaluation of their manager’s use of humor influences their individual levels of job stress and satisfaction. We investigate both the positive and negative roles of humor by analyzing the impact of salesperson evaluations of their managers’ use of affiliative and aggressive humor on their job stress and job satisfaction. Furthermore, we examine the mechanism by which these evaluations affect salesperson stress and satisfaction by identifying two critical mediating variables – social loneliness and willingness to cooperate. Using a sample of 299 professional salespeople, we empirically test this process model to find that affiliative humor usage by sales managers, as evaluated by salespeople, reduces social loneliness and stress for salespeople while also increasing followers’ acceptance of cooperation. Evaluations of aggressive humor, on the other hand, increase stress levels among salespeople. Both social loneliness and acceptance of cooperation, in turn, significantly affect job satisfaction.     

Una struttura algebrica per l’ontologia

Conclusioni La struttura a livelli modella il tutto e le sue parti con grande generalità. Lo dimostrano le argomentazioni teoriche (4.3), (4.4) e (4.5), e lo comprova la casistica che è stata aggiunta. Una tale struttura non presenta affatto i problemi a), b) e c) che sono tipici della struttura ad albero. Essa corregge inoltre deviazioni concettuali che sono diffuse nel settore informatico. L’immediatezza deviazioni concettuali che sono diffuse nel settore informatico. L’immediatezza visiva, infine, ne facilita la diffusione sul piano professionale e tecnico. Per concludere, ritengo che la struttura a livelli possa fornire un contributo anche alle ricerche di ontologia e in particolare possa favorire i tentativi di unificazione condotti sia sul piano teorico, sia su quello applicativo [Uschold 1996]. Le difficoltà ed i limiti che la teoria degli insiemi oppone ad un formalismo generale (ad esempio quando riduce la casistica della relazione concetto di livello possiede una valenza estremamente ampia e ciò lo predispone per gli auspicati sviluppi ontologici.     

Unique designs,errors and strategies in the Five-Point Test: The contribution of age,phonemic fluency and visuospatial abilities in Italian children aged 6–11 years

Performances on the Five-Point Test of 161 Italian children aged 6 to 11 years were investigated, along with phonemic fluency, visual-motor integration, visual perception, motor coordination, visuospatial memory, and fluid intelligence. Five-Point Test accuracy was significantly related to phonemic fluency and visual-motor integration, while phonemic fluency was linked to motor coordination. The two fluency measures increased linearly with age, but the developmental progression of Five-Point Test accuracy was less influenced by age. Different age effects were also found on the relationship between fluid intelligence and the two fluency measures. The inspection of qualitative aspects of Five-Point Test performance (errors and strategies) suggested that strategy usage enhanced both productivity and accuracy in children; age-related changes were observed in the relationship between the number of errors and the total number of designs produced.     

Frames of reference in spatial span

In four experiments, a computerized Corsi-like paradigm was used to assess which of the many reference frames are used in visuospatial short-term memory. By varying the relative orientation (slanted +/-45° or in an upright position) of the head and the displays, we modulate the utility of the allocentric, egocentric (eye- and head-centred), and template-centred reference frames. The results of all experiments showed the crucial importance of the gravitational allocentric reference frames while using visuospatial short-term memory to retain a spatial sequence of elements. The results also provide some support for a mental rotation process involved in recognition following angular displacement of a multi-item display.     

Component Models for Fuzzy Data

The fuzzy perspective in statistical analysis is first illustrated with reference to the “Informational Paradigm” allowing us to deal with different types of uncertainties related to the various informational ingredients (data, model, assumptions). The fuzzy empirical data are then introduced, referring to J LR fuzzy variables as observed on I observation units. Each observation is characterized by its center and its left and right spreads (LR₁ fuzzy number) or by its left and right “centers” and its left and right spreads (LR₂ fuzzy number). Two types of component models for LR₁ and LR₂ fuzzy data are proposed. The estimation of the parameters of these models is based on a Least Squares approach, exploiting an appropriately introduced distance measure for fuzzy data. A simulation study is carried out in order to assess the efficacy of the suggested models as compared with traditional Principal Component Analysis on the centers and with existing methods for fuzzy and interval valued data. An application to real fuzzy data is finally performed. We would like to express our gratitude to the Editor, the Associate Editor, and the Referees whose comments and suggestions improved significantly the quality of the paper.     

The effect of experience and of dots’ density and duration on the detection of coherent motion in dogs

Knowledge about the mechanisms underlying canine vision is far from being exhaustive, especially that concerning post-retinal elaboration. One aspect that has received little attention is motion perception, and in spite of the common belief that dogs are extremely apt at detecting moving stimuli, there is no scientific support for such an assumption. In fact, we recently showed that dogs have higher thresholds than humans for coherent motion detection (Kanizsar et al. in Sci Rep UK 7:11259, 2017). This term refers to the ability of the visual system to perceive several units moving in the same direction, as one coherently moving global unit. Coherent motion perception is commonly investigated using random dot displays, containing variable proportions of coherently moving dots. Here, we investigated the relative contribution of local and global integration mechanisms for coherent motion perception, and changes in detection thresholds as a result of repeated exposure to the experimental stimuli. Dogs who had been involved in the previous study were given a conditioned discrimination task, in which we systematically manipulated dot density and duration and, eventually, re-assessed our subjects’ threshold after extensive exposure to the stimuli. Decreasing dot duration impacted on dogs’ accuracy in detecting coherent motion only at very low duration values, revealing the efficacy of local integration mechanisms. Density impacted on dogs’ accuracy in a linear fashion, indicating less efficient global integration. There was limited evidence of improvement in the re-assessment but, with an average threshold at re-assessment of 29%, dogs’ ability to detect coherent motion remains much poorer than that of humans.