A biased-competition approach to spatial cueing: Combining empirical studies and computational modelling

We examined the effects of cue luminance on visual orienting. Experiment 1 established that the commonly-found early facilitation and late inhibition of return (IOR) effects were independent of cue luminance with single cues in terms of their amplitude, although IOR was delayed in the low compared to the high luminance cue condition. In contrast, Experiment 2 revealed that, with dual cues of mixed luminance, both facilitation and IOR effects were found only with bright cues. When cues had equal luminance, however, there were cueing effects for two cued locations but only when the cues were bright. The data were accommodated in a neural network model of biased competition in which cueing effects emerge at more than one location provided input activation is sufficient to overcome competitive damping of the selection system.     

Effects of varying target luminance and cue luminance on attentional effects of spatial cues

Attentional effects of letter cues on target processing were investigated in a bilateral spatial cueing paradigm. Luminance contrast of the cue stimuli and of the target stimuli were both manipulated. Consistent with predictions derived from theoretical models of visual attention, manipulating cue luminance and target luminance had very different effects on performance. In agreement with the dorsal stream attention hypothesis (Marrett et al., 2011) orienting effects were unaffected by changes in cue luminance; but in agreement with the work of Reynolds, Pasternak, and Desimone (2000) and Carrasco, Ling, and Read (2004) orienting effects were strongly modulated by changes in the luminance and perceptual quality of the target. Theoretical implications of the results are considered and the data are explained in terms of a sensory enhancement effect, whereby attention amplifies the neuronal responses for attended stimuli.     

Attention to distinguishing features in object recognition

This study advances the hypothesis that, in the course of object recognition, attention is directed to distinguishing features: visual information that is diagnostic of object identity in a specific context. In five experiments, observers performed an object categorization task involving drawings of fish (Experiments 1–4) and photographs of natural sea animals (Experiment 5). Allocation of attention to distinguishing and non-distinguishing features was examined using primed-matching (Experiment 1) and visual probe (Experiments 2, 4, 5) methods, and manipulated by spatial precuing (Experiment 3). Converging results indicated that in performing the object categorization task, attention was allocated to the distinguishing features in a context-dependent manner, and that such allocation facilitated performance. Based on the view that object recognition, like categorization, is essentially a process of discrimination between probable alternatives, the implications of the findings for the role of attention to distinguishing features in object recognition are discussed.     

Self-relevance enhances the benefits of attention on perception

ABSTRACT

Considerable efforts have focused on elucidating the influence that self-relevance exerts on perceptual decision-making. To explore this issue further, the current research explored the extent to which stimulus applicability facilitates the benefits of covert attention on early visual processing. In two experiments, we manipulated the personal-relevance of peripheral cues (i.e., geometric shapes) that preceded the appearance of target stimuli (i.e., Gabors) and asked participants to report the orientation of the stimulus with the highest contrast. The results revealed a significant effect of self-relevance on task performance. First, compared to cues associated with a friend or stranger, self-relevant cues enhanced the apparent contrast of a stimulus. Second, the benefits of self-relevance were most pronounced when cues pertained to identities that were significant (vs. trivial or irrelevant) to observers. Together, these findings demonstrate that self-relevance potentiates the benefits of transient attention on stimulus processing.     

Effects of divided attention and social categorization on the own-race bias in face recognition

Perceivers remember own-race faces more accurately than other-race faces (i.e., Own-Race Bias). In the current experiments, we manipulated participants' attentional resources and social group membership to explore their influence on own and other-race face recognition memory. In Experiment 1, Chinese participants viewed own-race and Caucasian faces, and between-subjects we manipulated whether participants attention was divided during face encoding. We found that divided attention eliminated the Own-Race Bias in memory due to a reduction of memory accuracy for own-race faces, implicating that attention allocation plays a role in creating the bias. In Experiment 2, Chinese participants completed an ostensible personality test. Some participants were informed that their personality traits were most commonly found in Caucasian (i.e., other-race) individuals, resulting in these participants sharing a group membership with other-race targets. In contrast, other participants were not told anything about the personality test, resulting in the default own-race group membership. The participants encoded the faces for a subsequent recognition memory test either with or without performing a concurrent arithmetic distracting task. Results showed that other-race group membership and reducing attention during encoding independently eliminated the typical Own-Race Bias in face memory. The implications of these findings on perceptual-expertise and social-categorization models are discussed.     

No templates for rejection: a failure to configure attention to ignore task-irrelevant features

ABSTRACT

Knowing the colour of an upcoming target allows one to bias attention towards objects of that colour. It is far less clear whether knowing the colour of an up-coming distractor can allow one to suppress attention to items of that colour. Arita, Carlisle, and Woodman (2012) suggest that people can create a template for rejection. However, the method used in Arita et al. may have allowed people to adopt a strategy of internally generating a positive cue for the target colour or target hemifield. Here we use a method very similar to theirs, but manipulate the display layouts and the number of un-cued colours in ways that should thwart such strategies. Across three experiments, we find a negative cuing benefit only in a very special circumstance that encourages a strategic shift to internally generating a positive cue (the same circumstance used by Arita et al.). We conclude that people are unable to use a negative feature-cue on a trial-by-trial basis to suppress attention to upcoming distractors, and attribute the finding in Arita et al. to a strategic shift rather than a template for rejection.     

Equally attending but still not seeing: An eye-tracking study of change detection in own- and other-race faces

The present study aimed to investigate whether the faster change detection in own-race faces in a change blindness paradigm, reported by Humphreys, Hodsoll, and Campbell (2005) and explained in terms of people's poorer ability to discriminate other-race faces, may be explained by people's preferential attention towards own-race faces. The study by Humphreys et al. was replicated using the same stimuli, while participants’ eye movements were recorded. These revealed that there was no attentional bias towards own-race faces (analysed in terms of fixation order, number, and duration), but people still detected changes in own-race faces faster than in other-race faces. The current results therefore give further support for the original claim that people are less sensitive to changes made in other-race faces, when own and other-race faces are equally attended.     

Are you with me? Probing the human capacity to recognize external/internal attention in others’ faces

ABSTRACT

Facial cues provide information about affective states and the direction of attention that is important for human social interaction. The present study examined how this capacity extends to judging whether attention is internally or externally directed. Participants evaluated a set of videos and images showing the face of people focused externally on a task, or internally while they performed a task in imagination. We found that participants could identify the focus of attention above chance in videos, and to a lesser degree in static images, but only when the eye region was visible. Self-reports further indicated that participants relied particularly on the eye region in their judgements. Interestingly, people engaged in demanding cognitive tasks were more likely judged to be externally focused independent of the actual focus of attention. These findings demonstrate that humans use information from the face and especially from the eyes of others not only to infer external goals or actions, but also to detect when others focus internally on their own thoughts and feelings.     

Meditators and non-meditators on sustained and executive attentional performance

In order to gain a deeper understanding of the mindfulness construct and the mental health benefits associated with mindfulness-based programmes, the relation between mindfulness and its proposed core component attention was studied. Buddhist and Western mindfulness meditators were compared with non-meditators on tasks of sustained (SART) and executive (the Stroop Task) attention. Relations between self-reported mindfulness (FFMQ) and sustained and executive attention were also analysed. No significant differences were found between meditators and non-meditators either in sustained or executive attention. High scores on the FFMQ total scale and on Describe were related to fewer SART errors. High scores on Describe were also related to low Stroop interference. Mindfulness meditators may have an increased awareness of internal processes and the ability to quickly attend to them but this type of refined attentional ability does not seem to be related to performance on attention tests requiring responses to external targets.     

Saccadic eye movements as indicators of cognitive function in older adults

Older adults appear to have greater difficulty ignoring distractions during day-to-day activities than younger adults. To assess these effects of age, the ability of adults aged between 50 and 80 years to ignore distracting stimuli was measured using the antisaccade and oculomotor capture tasks. In the antisaccade task, observers are instructed to look away from a visual cue, whereas in the oculomotor capture task, observers are instructed to look toward a colored singleton in the presence of a concurrent onset distractor. Index scores of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were compared with capture errors, and with prosaccade errors on the antisaccade task. A higher percentage of capture errors were made on the oculomotor capture tasks by the older members of the cohort compared to the younger members. There was a weak relationship between the attention index and capture errors, but the visuospatial/constructional index was the strongest predictor of prosaccade error rate in the antisaccade task. The saccade reaction times (SRTs) of correct initial saccades in the oculomotor capture task were poorly correlated with age, and with the neurospsychological tests, but prosaccade SRTs in both tasks moderately correlated with antisaccade error rate. These results were interpreted in terms of a competitive integration (or race) model. Any variable that reduces the strength of the top-down neural signal to produce a voluntary saccade, or that increases saccade speed, will enhance the likelihood that a reflexive saccade to a stimulus with an abrupt onset will occur.