Anna S. Law

Attention capture by faces

We report three experiments that investigate whether faces are capable of capturing attention when in competition with other non-face objects. In Experiment 1a participants took longer to decide that an array of objects contained a butterfly target when a face appeared as one of the distracting items than when the face did not appear in the array. This irrelevant face effect was eliminated when the items in the arrays were inverted in Experiment 1b ruling out an explanation based on some low-level image-based properties of the faces. Experiment 2 replicated and extended the results of Experiment 1a. Irrelevant faces once again interfered with search for butterflies but, when the roles of faces and butterflies were reversed, irrelevant butterflies no longer interfered with search for faces. This suggests that the irrelevant face effect is unlikely to have been caused by the relative novelty of the faces or arises because butterflies and faces were the only animate items in the arrays. We conclude that these experiments offer evidence of a stimulus-driven capture of attention by faces.

Multitasking: multiple, domain-specific cognitive functions in a virtual environment

Multitasking among three or more different tasks is a ubiquitous requirement of everyday cognition, yet rarely is it addressed in research on healthy adults who have had no specific training in multitasking skills. Participants completed a set of diverse subtasks within a simulated shopping mall and office environment, the Edinburgh Virtual Errands Test (EVET). The aim was to investigate how different cognitive functions, such as planning, retrospective and prospective memory, and visuospatial and verbal working memory, contribute to everyday multitasking. Subtasks were chosen to be diverse, and predictions were derived from a statistical model of everyday multitasking impairments associated with frontal-lobe lesions (Burgess, Veitch, de Lacy Costello, & Shallice, 2000b). Multiple regression indicated significant independent contributions from measures of retrospective memory, visuospatial working memory, and online planning, but not from independent measures of prospective memory or verbal working memory. Structural equation modelling showed that the best fit to the data arose from three underlying constructs, with Memory and Planning having a weak link, but with both having a strong directional pathway to an Intent construct that reflected implementation of intentions. Participants who followed their preprepared plan achieved higher scores than those who altered their plan during multitask performance. This was true regardless of whether the plan was efficient or poor. These results substantially develop and extend the Burgess et al. (2000b) model to healthy adults and yield new insight into the poorly understood area of everyday multitasking. The findings also point to the utility of using virtual environments for investigating this form of complex human cognition.

A comparison of graphical and textual presentations of time series data to support medical decision making in the neonatal intensive care unit.

Objective. To compare expert-generated textual summaries of physiological data with trend graphs, in terms of their ability to support neonatal Intensive Care Unit (ICU) staff in making decisions when presented with medical scenarios. Methods. Forty neonatal ICU staff were recruited for the experiment, eight from each of five groups – junior, intermediate and senior nurses, junior and senior doctors. The participants were presented with medical scenarios on a computer screen, and asked to choose from a list of 18 possible actions those they thought were appropriate. Half of the scenarios were presented as trend graphs, while the other half were presented as passages of text. The textual summaries had been generated by two human experts and were intended to describe the physiological state of the patient over a short period of time (around 40 minutes) but not to interpret it. Results. In terms of the content of responses there was a clear advantage for the Text condition, with participants tending to choose more of the appropriate actions when the information was presented as text rather than as graphs. In terms of the speed of response there was no difference between the Graphs and Text conditions. There was no significant difference between the staff groups in terms of speed or content of responses. In contrast to the objective measures of performance, the majority of participants reported a subjective preference for the Graphs condition. Conclusions. In this experimental task, participants performed better when presented with a textual summary of the medical scenario than when it was presented as a set of trend graphs. If the necessary algorithms could be developed that would allow computers automatically to generate descriptive summaries of physiological data, this could potentially be a useful feature of decision support tools in the intensive care unit.

Event-based prospective remembering in a virtual world

Most laboratory-based prospective memory (PM) paradigms pose problems that are very different from those encountered in the real world. Several PM studies have reported conflicting results when comparing laboratory- with naturalistic-based studies (e.g., Bailey, Henry, Rendell, Phillips, & Kliegel, 2010). One key contrast is that for the former, how and when the PM cue is encountered typically is determined by the experimenter, whereas in the latter case, cue availability is determined by participant actions. However, participant-driven access to the cue has not been examined in laboratory studies focused on healthy young adults, and its relationship with planned intentions is poorly understood. Here we report a study of PM performance in a controlled, laboratory setting, but with participant-driven actions leading to the availability of the PM cue. This uses a novel PM methodology based upon analysis of participant movements as they attempted a series of errands in a large virtual building on the computer screen. A PM failure was identified as a situation in which a participant entered and exited the “cue” area outside an errand related room without performing the required errand whilst still successfully remembering that errand post test. Additional individual difference measures assessed retrospective and working memory capacity, planning ability and PM. Multiple regression analysis showed that the independent measures of verbal working memory span, planning ability, and PM were significant predictors of PM failure. Correlational analyses with measures of planning suggest that sticking with an original plan (good or bad) is related to better overall PM performance.

Investigating Multitasking in High-Functioning Adolescents with Autism Spectrum Disorders Using the Virtual Errands Task

Using a modified version of the Virtual Errands Task (VET; McGeorge et al. in Presence-Teleop Virtual Environ 10(4):375–383, 2001), we investigated the executive ability of multitasking in 18 high-functioning adolescents with ASD and 18 typically developing adolescents. The VET requires multitasking (Law et al. in Acta Psychol 122(1):27–44, 2006) because there is a limited amount of time in which to complete the errands. ANCOVA revealed that the ASD group completed fewer tasks, broke more rules and rigidly followed the task list in the order of presentation. Our findings suggest that executive problems of planning inflexibility, inhibition, as well as difficulties with prospective memory (remembering to carry out intentions) may lie behind multitasking difficulties in ASD.

Assessing the impact of verbal and visuospatial working memory load on eye-gaze cueing

Observers tend to respond more quickly to peripheral stimuli that are being gazed at by a centrally presented face, than to stimuli that are not being gazed at. While this gaze-cueing effect was initially seen as reflexive, there have also been some indications that top-down control processes may be involved. Therefore, the present investigation employed a dual-task paradigm to attempt to disrupt the putative control processes involved in gaze cueing. Two experiments examined the impact of working memory load on gaze cueing. In Experiment 1, participants were required to hold a set of digits in working memory during each gaze trial. In Experiment 2, the gaze task was combined with an auditory task that required the manipulation and maintenance of visuospatial information. Gaze cueing effects were observed, but they were not modulated by dual-task load in either experiment. These results are consistent with traditional accounts of gaze cueing as a highly reflexive process.

The impact of working memory load on task execution and online plan adjustment during multitasking in a virtual environment

Three experiments investigated the impact of working memory load on online plan adjustment during a test of multitasking in young, nonexpert, adult participants. Multitasking was assessed using the Edinburgh Virtual Errands Test (EVET). Participants were asked to memorize either good or poor plans for performing multiple errands and were assessed both on task completion and on the extent to which they modified their plans during EVET performance. EVET was performed twice, with and without a secondary task loading a component of working memory. In Experiment 1, articulatory suppression was used to load the phonological loop. In Experiment 2, oral random generation was used to load executive functions. In Experiment 3, spatial working memory was loaded with an auditory spatial localization task. EVET performance for both good- and poor-planning groups was disrupted by random generation and sound localization, but not by articulatory suppression. Additionally, people given a poor plan were able to overcome this initial disadvantage by modifying their plans online. It was concluded that, in addition to executive functions, multiple errands performance draws heavily on spatial, but not verbal, working memory resources but can be successfully completed on the basis of modifying plans online, despite a secondary task load.

Looking back at the stare-in-the-crowd effect: Staring eyes do not capture attention in visual search

The stare-in-the crowd effect refers to the finding that a visual search for a target of staring eyes among averted-eyes distracters is more efficient than the search for an averted-eyes target among staring distracters. This finding could indicate that staring eyes are prioritized in the processing of the search array so that attention is more likely to be directed to their location than to any other. However, visual search is a complex process, which not only depends upon the properties of the target, but also the similarity between the target of the search and the distractor items and between the distractor items themselves. Across five experiments, we show that the search asymmetry diagnostic of the stare-in-the-crowd effect is more likely to be the result of a failure to control for the similarity among distracting items between the two critical search conditions rather than any special attention-grabbing property of staring gazes. Our results suggest that, contrary to results reported in the literature, staring gazes are not prioritized by attention in visual search.

Preliminary evidence that glucose ingestion facilitates prospective memory performance

Previous research has found that the ingestion of glucose boosts task performance in the memory domain (including tasks tapping episodic, semantic, and working memory). The present pilot study tested the hypothesis that glucose ingestion would enhance performance on a test of prospective memory. In a between-subjects design, 56 adults ranging from 17 to 80 years of age performed a computerized prospective memory task and an attention (filler) task after 25 g of glucose or a sweetness-matched placebo. Blood glucose measurements were also taken to assess the impact of individual differences on glucose regulation. After the drink containing glucose, cognitive facilitation was observed on the prospective memory task after excluding subjects with impaired fasting glucose level. Specifically, subjects receiving glucose were 19% more accurate than subjects receiving a placebo, a trend that was marginally nonsignificant, F₁,₄₁ = 3.4, P = .07, but that had a medium effect size, d = 0.58. Subjects receiving glucose were also significantly faster on the prospective memory task, F₁,₃₅ = 4.8, P < .05, d = 0.6. In addition, elevated baseline blood glucose (indicative of poor glucose regulation) was associated with slower prospective memory responding, F₁,₃₅ = 4.4, P < .05, d = 0.57. These data add to the growing body of evidence suggesting that both memory and executive functioning can benefit from the increased provision of glucose to the brain.

Prospective memory in a virtual environment: Beneficial effects of cue saliency

Prospective Memory (PM) research focuses on how the cognitive system successfully encodes and retains an intention, before retrieving it at a particular future time or in response to a particular future event. Previous work using 2D text stimuli has shown that increasing the saliency of the retrieval cue can improve performance. In this work, we investigated the effect of increased cue saliency in a more ecologically valid 3D virtual environment. The findings indicate that increased perceptual saliency of the cue does benefit PM in a dynamic and visually rich environment but that the impact of cue saliency does not interact with attentional load.