Three layers of working memory: Focus-switch costs and retrieval dynamics as revealed by the N-count task

Two experiments explored the process of switching items in and out of the focus of attention using a new paradigm, the N-count task (adapted from Garavan, 1998; N varied from 1 to 4). This task yielded a focus size of one, indicated by a substantial focus-switch cost for 2-count. Additionally, the focus-switch costs in response time increased with working memory load, indicating an effortful search process occurring at a speed of about 240 ms/item. Maintaining and switching to and from a passive load did not increase the focus-switch costs or decrease memory accuracy, indicating that there is no crosstalk between passive and active items. The results support a concentric theory of working memory: a small focus at its core, a surrounding area of (at least) three readily available items referred to as the outer store, and a still wider region of passive storage, possibly more long-term memory than working memory.     

A focused attention intervention for coping with ostracism

Ostracism—being excluded and ignored—thwarts satisfaction of four fundamental needs: belonging, self-esteem, control, and meaningful existence. The current study investigated whether training participants to focus their attention on the here-and-now (i.e., focused attention) reduces distress from an ostracism experience. Participants were first trained in either focused or unfocused attention, and then played Cyberball, an online ball-tossing game for which half the participants were included or ostracized. Participants reported their levels of need satisfaction during the game, and after a short delay. Whereas both training groups experienced the same degree of need-threat in the immediate measure, participants who were trained in focused attention showed more recovery for the delayed measure. We reason that focused attention would not reduce the distress during the ostracism experience, but it aided in recovery by preventing participants from reliving the ostracism experience after it concludes.     

Self-efficacy moderates the relationship between stress appraisal and quality of life among rescue workers

Abstract

Rescue workers are frequently exposed to highly stressful situations during their everyday work activity. Stress and coping theory emphasizes the interaction between primary and secondary appraisal in determining coping responses to stressful events and quality of life. According to Social Cognitive Theory, stress reactions depend on self-appraisal of coping capabilities.

The present study investigated whether self-efficacy moderates the relationship between stress appraisal and professional quality of life. A self-administered questionnaire was submitted to a sample of 451 Italian rescue workers (firefighters, paramedics, and medical technicians), including the Professional Quality of Life Scale, which measures three dimensions of emergency workers' quality of working life: compassion fatigue, burnout, and compassion satisfaction. Multiple regression analyses indicated that the relationship between stress appraisal and professional quality of life was significant only among rescue workers with low levels of self-efficacy but not among those with higher levels of self-efficacy. These results confirmed the expectations based on Social Cognitive Theory that self-efficacy buffers the impact of perceived stressful encounters on professional quality of life. Results suggest the usefulness of interventions aimed at increasing rescue workers' psychosocial skills.     

Sustained attention can create an (illusory) experience of seeing dynamic change

Recent studies speculated that two types of change detection exist, one involving the experience of seeing dynamic change (change over brief interval), the other involving detecting a completed change (change over long interval), with only the former requiring sustained attention. To examine this supposition, a flicker change detection task was conducted in which the spatial location of objects was manipulated (shift, no-shift). In shift conditions, changed image display appeared in different locations than they did in the original display. The time interval separating images was manipulated (200 or 1000 ms). Results showed that a shift led to poor change detection only in the short interval condition. The performance decline by the image shift was not attenuated even when participants knew beforehand whether or not a shift would occur. Results indicate that sustained attention, which is sustained for a brief time, is related to the experience of seeing dynamic change.     

Masked partial priming of letter perception

In three experiments testing 178 subjects, letter targets were preceded by briefly presented, pattern-masked primes formed by deleting pixels in a larger or smaller version of the target stimulus. In Experiment 1A (alphabetic decision)and Experiment 1B (letter naming) a slight advantage was observed for global primes (alternate pixels deleted) compared with junction primes (midsegment information removed). This advantage was stronger at 50 ms prime exposures than at 30 ms exposures in the naming task. In Experiment 2 (letter naming), midsegment primes (with junction information removed) produced faster latencies than did junction primes. This result was replicated in a third experiment and was shown to be independent of target letter case and the relative size of prime and target stimuli. The same midsegment and junction primes did not facilitate performance compared to neutral primes in the alphabetic decision task. These results suggest that masked partial priming of letter naming can be usefully applied to the study of basic processes in letter perception.     

A new form of human spatial attention: Automated symbolic orienting

The control of human attention is typically conceptualized either in terms of exogenous automatic processes that are driven by external sensory stimulation or endogenous strategic processes that are driven by internal expectancies about events in the environment. However, this classic dichotomy has struggled to explain a wealth of new data demonstrating that behaviourally and biologically relevant visual stimuli, like arrow and eye direction, elicit shifts of spatial attention that on the one hand, appear exogenous, and on the other hand, endogenous. To address this issue, we used a double-cueing task that combined arrows with classic cues known to invoke either exogenous or endogenous orienting. Our data suggest that behaviourally relevant directional cues, like arrows, engage a new form of cortically mediated orienting—automated symbolic orienting—that operates independent of, and in parallel with, the two classic forms of exogenous and endogenous spatial attention.     

Visual target detection is impaired at event boundaries

Boundaries between meaningful events are key moments in comprehending human action. At these points, viewers may focus on the event's contents at the expense of other information. We tested whether visual detection was impaired at those moments perceivers judged to be boundaries between events. Short animated football clips were used as stimulus material, and event boundaries were imposed by having the ball change possession. In a first experiment, we found that possession changes were perceived to be event boundaries. In a second experiment, participants were asked to keep track of 4 of 10 players and to watch for 120 ms probes appearing either at an event boundary or a nonboundary. Probe detection was less accurate at event boundaries. This result suggests that the segmentation of ongoing activity into events corresponds with the regulation of attention over time.     

Look who's talking? Sound changes gaze behaviour in a dynamic social scene

Humans often look at other people in natural scenes, and previous research has shown that these looks follow the conversation and that they are sensitive to sound in audiovisual speech perception. In the present experiment, participants viewed video clips of four people involved in a discussion. By removing the sound, we asked whether auditory information would affect when speakers were fixated, how fixations between different observers were synchronized, and whether the eyes or mouth were looked at most often. The results showed that sound changed the timing of looks—by alerting observers to changes in conversation and attracting attention to the speaker. Clips with sound also led to greater attentional synchrony, with more observers fixating the same regions at the same time. However, looks towards the eyes of the people continued to dominate and were unaffected by removing the sound. These findings provide a rich example of multimodal social attention.     

No difference in flanker effects for sad and happy schematic faces: A parametric study of temporal parameters

Flanker effects with schematic faces have been reported to be larger for happy than for sad faces, allegedly because sad faces restrict the focus of spatial attention. We report a parametric study that fails to replicate this effect. Participants performed speeded identifications of happy or sad faces accompanied by compatible or incompatible flanker faces. We varied the temporal interval between presentation of central target and flanker faces because differential attentional effects of happy and sad faces should critically depend on this variable. In contradiction to the literature, we found large compatibility effects that were modulated by temporal parameters, but not by the emotional valence of the faces, and not in the way consistent with differential attentional modulation. We conclude that previously reported asymmetries in flanker tasks with schematic faces are not due to changes in attentional scope (mediated by emotion or otherwise), but rather to perceptual low-level differences.     

Contextual cueing in multiple object tracking

In this study, we examined whether visual context can be learned through a dynamic display and whether it can facilitate sustained attentional tracking by combining a multiple object tracking (MOT) task and a contextual cueing procedure. The trajectories of the targets and distractors in the MOT task were made invariant by repeatedly presenting them. The results revealed that when the targets were repeatedly displayed, tracking performance implicitly improved, and this effect was enhanced when the unattended distractors in the displays were also repeated. However, the repetition of the distractors alone did not produce any effect. Interestingly, when the targets and distractors were switched in a display in which the distractors had been previously repeated, the tracking performance was impaired as compared with that in the case of nonrepeated displays. We concluded that the contextual information in a dynamic display facilitates attentional tracking and that different types of contextual modulations occurred in MOT processes, such as facilitation for attended targets and inhibition for ignored distractors.