Gender differences on the semantic flanker task using transposed-letter target words

Previous research has demonstrated that men and women are differentially influenced by irrelevant distractors. Other lines of evidence have suggested that increasing the perceptual load of a task reduces distractor interference for participants generally. The present study examined these effects using a semantic version of the flanker task; participants made speeded responses to category target words that were flanked by irrelevant distractors. The response mapping between the target and flanker words was either congruent (mapped to the same motor response) or incongruent (target word mapped to a different motor response to that of the flankers). Target words were presented either normally (e.g., table: low perceptual load) or with the beginning letters transposed (e.g., atble: high perceptual load). The results revealed that women showed a larger congruency effect than men but this was not due to greater interference on incongruent trials. While men and women made faster responses to normal than to transposed target words, this was similar in magnitude. The magnitude of the flanker effect for normal and transposed target words was significantly correlated in men but not in women. These findings are consistent with the view that women may process target words to a deeper level than men and therefore may engage in more conflict monitoring then men.     

What you say matters: Exploring visual–verbal interactions in visual working memory

The aim of this study was to explore whether the content of a simple concurrent verbal load task determines the extent of its interference on memory for coloured shapes. The task consisted of remembering four visual items while repeating aloud a pair of words that varied in terms of imageability and relatedness to the task set. At test, a cue appeared that was either the colour or the shape of one of the previously seen objects, with participants required to select the object's other feature from a visual array. During encoding and retention, there were four verbal load conditions: (a) a related, shape–colour pair (from outside the experimental set, i.e., “pink square”); (b) a pair of unrelated but visually imageable, concrete, words (i.e., “big elephant”); (c) a pair of unrelated and abstract words (i.e., “critical event”); and (d) no verbal load. Results showed differential effects of these verbal load conditions. In particular, imageable words (concrete and related conditions) interfered to a greater degree than abstract words. Possible implications for how visual working memory interacts with verbal memory and long-term memory are discussed.     

Working memory capacity and visual attention: Top-down and bottom-up guidance

Previous studies have indicated that working memory capacity (WMC) is related to visual attention when selection of critical information must be made in the face of distraction. The present study examines whether WMC-related differences in flanker task performance might be decreased by displays that are designed to support bottom-up guidance of attention. Participants were required to respond to a centrally located target while ignoring a peripheral flanker. In one condition, bottom-up support was provided by embedding the target in a row of zeros. In another condition, the zeros were removed, thus emphasizing the role of top-down attention in selecting spatially defined information. It was found that the inclusion of zeros led to the elimination of WMC-related flanker effects. We conclude that bottom-up attentional guidance can attenuate the role of WMC in selective attention.     

Individual differences in autistic trait load in the general population predict visual working memory performance

Prior studies have reported instances of both intact and impaired working memory (WM) performance in people with autism spectrum disorder (ASD). In order to investigate the relation between autistic traits that extend into the normal population and WM, 104 normal college-aged students who varied in their levels of autistic traits were tested. The loading of ASD-associated traits in the normal population leads to differing predictions about WM performance. ASD traits related to a local processing style (or “attention to detail”) might enhance WM while ASD-associated traits related to difficulty switching attention and reorienting focus (or “social interaction”) might impair WM performance. To assess these predictions, participants filled out the Autism Spectrum Quotient (AQ) and performed a working memory task with both visual and verbal variants. AQ scores were then broken into “attention to detail” and “social interaction” factors, as proposed by Hoekstra and colleagues. The results showed that AQ scores did not predict verbal WM performance but they did predict visual WM performance. The social interaction and attention to detail factors of the AQ had opposing relationships with visual WM performance: A higher level of social difficulty was associated with significantly poorer visual WM performance while a higher level of attention to detail was associated with enhanced visual WM performance. Further investigation of the relation between AQ and WM using the original five-factor model proposed by Baron-Cohen and colleagues (2001) revealed an association between impoverished imagination and visual WM overall.     

When being narrow minded is a good thing: Locally biased people show stronger contextual cueing

Repeated contexts allow us to find relevant information more easily. Learning such contexts has been proposed to depend upon either global processing of the repeated contexts, or alternatively processing of the local region surrounding the target information. In this study, we measured the extent to which observers were by default biased to process towards a more global or local level. The findings showed that the ability to use context to help guide their search was strongly related to an observer's local/global processing bias. Locally biased people could use context to help improve their search better than globally biased people. The results suggest that the extent to which context can be used depends crucially on the observer's attentional bias and thus also to factors and influences that can change this bias.     

Basic processes in reading aloud and colour naming: Towards a better understanding of the role of spatial attention

Whether or not lexical access from print requires spatial attention has been debated intensively for the last 30 years. Studies involving colour naming generally find evidence that “unattended” words are processed. In contrast, reading-based experiments do not find evidence of distractor processing. One theory ascribes the discrepancy to weaker attentional demands for colour identification. If colour naming does not capture all of a subject's attention, the remaining attentional resources can be deployed to process the distractor word. The present study combined exogenous spatial cueing with colour naming and reading aloud separately and found that colour naming is less sensitive to the validity of a spatial cue than is reading words aloud. Based on these results, we argue that colour naming studies do not effectively control attention so that no conclusions about unattended distractor processing can be drawn from them. Thus we reiterate the consistent conclusion drawn from reading aloud and lexical decision studies: There is no word identification without (spatial) attention.     

The transference of visual search between two unrelated tasks: Measuring the temporal characteristics of carry-over

Investigations into the persistence of top-down control settings do not accurately reflect the nature of dynamic tasks. They typically involve extended practice with an initial task, and this initial task usually shares similar stimuli with a second task. Recent work shows that visual attention and search can be affected by limited exposure to a preceding, unrelated task, and the current study explored the temporal characteristics of this “carry-over” effect. Thirty-four participants completed one, four, or eight simple letter searches and then searched a natural scene. The spatial layout of letters influenced spread of search in the pictures, and this was further impacted by the time spent in the initial task, yet the carry-over effect diminished quickly. The results have implications for theories of top-down control and models that attempt to predict search in natural scenes. They are also relevant to real-world tasks in which performance is closely related to visual attention and search.     

The loss of residual visual memories over the passage of time

There has been extensive discussion of the causes of short-term forgetting. Some accounts suggest that time plays an important role in the loss of representations, whereas other models reject this notion and explain all forgetting through interference processes. The present experiment used the recent-probes task to investigate whether residual visual information is lost over the passage of time. On each trial, three unusual target objects were displayed and followed by a probe stimulus. The task was to determine whether the probe matched any of the targets, and the next trial commenced after an intertrial interval lasting 300?ms, 3.3?s, or 8.3?s. Of critical interest were recent negative (RN) trials, on which the probe matched a target from the previous trial. These were contrasted against nonrecent negative (NRN) trials, in which the probe had not been seen in the recent past. RN trials damaged performance and slowed reaction times in comparison to NRN trials, highlighting interference. However, this interfering effect diminished as the intertrial interval was lengthened, suggesting that residual visual information is lost as time passes. This finding is difficult to reconcile with interference-based models and suggests that time plays some role in forgetting.     

Attention capture while switching search strategies: Evidence for a breakdown in top-down attentional control

Whereas capture experiments typically repeat a single task many times, real world cognition is characterized by frequent switching. Lien, Ruthruff, and Johnston (2010) reported that the attentional control system can rapidly and fully switch between different search settings (e.g., red to green), with no carryover and no intertrial priming. The present study examined whether this impressive flexibility is possible even when the switch is not between different features along the same dimension, but between mutually incompatible search modes. On each trial, participants were prompted to find and identify the letter that was in a specific colour (feature search mode) or was uniquely coloured (singleton search mode). Within each block, search mode was either pure or mixed; the mixed blocks contained a fixed AABB search sequence (singleton-singleton-feature-feature) in Experiment 1 and a random sequence in Experiment 2. The target display was preceded by a noninformative cue display containing a nontarget colour singleton. In pure feature search blocks, these irrelevant singleton cues were generally unable to capture attention, replicating previous findings of “contingent capture”. In mixed blocks, however, irrelevant colour singletons captured attention on feature search trials. This breakdown indicates a limitation in the sharpness of attentional control following mode switches, which might be common in the real world.