The role of modality: Auditory and visual distractors in Stroop interference

As a commonly used measure of selective attention, it is important to understand the factors contributing to interference in the Stroop task. The current research examined distracting stimuli in the auditory and visual modalities to determine whether the use of auditory distractors would create additional interference, beyond what is typically observed in the print-based Stroop task. Research by Cowan and Barron supported the additive effects of auditory and visual distractors; however, there is only one empirical demonstration of this finding to date. Using different versions of the Stroop colour-naming task, behavioural analyses of reaction times (RT) were conducted, along with distributional RT analyses. The results indicated that a combination of visual and auditory distraction did not lead to a larger interference effect than visually based distraction alone. These findings suggest that methodological issues may have influenced the prior finding of additive effects of the two modalities, and are discussed in relation to the word production architecture account of Stroop effects.     

Effects of resource demanding processing on context memory for context-related versus context-unrelated items

In two experiments, context memory was compared between conditions of higher versus lower cognitive load. The ease of the item–context binding was manipulated using words whose meaning was preexperimentally related versus unrelated to context (colour). Experiment 1 showed that an item generation task may lead to a decrease in memory for font colour without enhancing item recognition. Experiment 2 used a dual-task paradigm, that is, participants performed a concurrent task during the study phase of the memory task. The divided-attention condition decreased both item and context memory. However, in both experiments, the influence of resource demanding conditions on context memory was apparent only when the item–context binding process was not facilitated by preexperimental associations.     

The types of stimuli loaded in memory can modulate its effects on visual search

The effects of memory load in visual search (VS) have shown a diversity of results from the absence through beneficial and detrimental effects of a concurrent memory load in VS performance. One of the hypotheses intended to explain the heterogeneity of results follows the idea proposed by certain models in the context of VS that the contents of working memory (WM) can modulate the attentional processes involved in VS (Desimone & Duncan, 1995; Duncan & Humphreys, 1989). In four experiments, we manipulated the similarity of information maintained in WM and those materials playing the role of target and distractors in the VS task. The results showed a beneficial effect in the first two experiments, where the materials in WM matched the target in VS. However, when they matched the distractors in the attentional task there is no effect in the slope of the search function. Present results strengthen those theories supporting that visual working memory is fractionated to allow for maintenance of items not essential to the attentional task (Downing & Dodds, 2004).     

Magnocellular facilitation of flanked-letter identification disappears with strong flanker interference

Previously, we obtained evidence to suggest that the magnocellular system may reduce interference from flankers during flanked-letter identification. To understand this phenomenon better, we combined the data of our previous experiments, which all used the same flanking letter, and focused on the different target letters that were used. The new analysis showed that after an initial increase, magnocellular facilitation decreased and ultimately disappeared, as the target–flanker combination's level of interference increased. The initial increase was partly while the later decrease was fully replicated in two new experiments that focused on two different target letters while manipulating flanker identity. The outcome of a third new experiment studying the type of interference reduced suggested that although crowding contributed to total interference, it was insensitive to magnocellular mediation. Our results may be understood to reflect the involvement of the magnocellular system in an attentional-selection mechanism that is silenced by surround suppression.     

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.     

Explicit feedback maintains implicit knowledge

The role of feedback was investigated with respect to conscious and unconscious knowledge acquired during artificial grammar learning (AGL). After incidental learning of training sequences, participants classified further sequences in terms of grammaticality and reported their decision strategy with or without explicit veridical feedback. Sequences that disobeyed the learning structure conformed to an alternative structure. Feedback led to an increase in the amount of reported conscious knowledge of structure (derived rules and recollections) but did not increase its accuracy. Conversely, feedback maintained the accuracy of unconscious knowledge of structure (intuition or familiarity-based responses) which otherwise degraded. Results support a dual-process account of AGL. They suggest that implicit learning of the to-be-rejected structure at test contaminates familiarity-based classifications whereas feedback allows competing familiarity signals to be contextualised, which is incompatible with theories that consider familiarity context-insensitive.     

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.     

Highly correlated stimuli do not necessarily facilitate the measurement of unconscious perception: Exclusion failure is hard to find in forced-choice tasks

Persaud and McLeod (2008) report that unconscious perception is easier to measure with forced-choice exclusion tasks when the stimuli are highly similar, such as choosing between the letters ‘h’ and ‘b’. The high degree of stimulus similarity may decrease conscious awareness of the target stimuli while leaving unconscious cognition intact. The present experiments used forced-choice exclusion tasks (i.e., choosing the opposite of a masked target stimulus) with the aim of replicating these findings. No evidence of relevant perception – either conscious or unconscious – was obtained with short duration targets. The forced-choice exclusion task was correctly performed at longer target durations (25 ms and higher), which suggests conscious perception of the target stimuli. We conclude that increasing stimulus similarity does not reliably produce exclusion failure effects and does not appear to facilitate the measurement of unconscious cognition.     

The contributions of arousal and self-focused attention to avoidance in social anxiety

Abstract

Fear of blushing is a specific syndrome generally subsumed under the diagnostic category of social anxiety disorder (SAD). This study aims at gathering preliminary data about an intensive weekend intervention specifically designed for individuals with fear of blushing as the predominant complaint. Treatment consisted of a combination of attention training and behavioral therapy. Thirty-one blushing-fearful individuals meeting the criteria for SAD following the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) were treated in three groups. The study was conducted as an open trial. Full assessments were performed before treatment, six weeks after treatment, and at six-month follow-up. Only fear of blushing, the main outcome criterion, was assessed immediately before and after the treatment weekend. The intensive therapy program was well accepted. Fear of blushing and SAD were significantly reduced and reductions remained stable. At follow-up, nearly two-thirds of the participants achieved significant changes in fear of blushing. Despite the preliminary nature of this study, the condensed format of weekend therapy for treating fear of blushing calls for further investigation.     

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.