The present research measured participants' event-related brain activity while they performed a Stroop-priming task that induced the implementation of expectancy-based strategic processes. Participants identified a colored (red vs. green) target patch preceded by a prime word (GREEN or RED), with incongruent prime-target pairings being more frequent (75 %) than congruent pairs (25 %).
View Article and Find Full Text PDFClinical and subclinical (trait) anxiety impairs decision making and interferes with learning. Less understood are the effects of temporary anxious states on learning and decision making in healthy populations, and whether these can serve as a model for clinical anxiety. Here we test whether anxious states in healthy individuals elicit a pattern of aberrant behavioural, neural, and physiological responses comparable with those found in anxiety disorders-particularly when processing uncertainty in unstable environments.
View Article and Find Full Text PDFAction preparation can facilitate performance in tasks of visual perception, for instance by speeding up responses to action-relevant stimulus features. However, it is unknown whether this facilitation reflects an influence on early perceptual processing, or instead post-perceptual processes. In three experiments, a combination of psychophysics and electroencephalography was used to investigate whether visual features are influenced by action preparation at the perceptual level.
View Article and Find Full Text PDFDevelopmental coordination disorder (DCD) is a neurodevelopmental condition affecting motor coordination in children and adults. Here, EEG signals elicited by visual and tactile stimuli were recorded while adult participants with and without probable DCD (pDCD) performed a motor task. The task cued reaching movements towards a location in visible peripersonal space as well as an area of unseen personal space.
View Article and Find Full Text PDFParticipants made speeded categorization decisions regarding a famous person (politician or film star) accompanied by a peripheral distracter face (either the same or from the opposite category). The first experiment found that processing a peripheral distracter face is independent of load when the search set contains name strings. The search set in the second experiment consisted of faces.
View Article and Find Full Text PDFThe present research examined whether imposing a high (or low) working memory (WM) load in different types of non-verbal WM tasks could affect the implementation of expectancy-based strategic processes in a sequential verbal Stroop task. Participants had to identify a colored (green vs. red) target patch that was preceded by a prime word (GREEN or RED), which was either incongruent or congruent with the target color on 80% and 20% of the trials, respectively.
View Article and Find Full Text PDFWe present the first empirical evidence that experience alters lightness perception. The role of experience in lightness perception was investigated through a cross-cultural comparison of 2 visual contrast phenomena: simultaneous lightness contrast and White's illusion. The Himba, a traditional seminomadic group known to have a local bias in perception, showed enhanced simultaneous lightness contrast but reduced White's illusion compared with groups that have a more global perceptual style: Urban-dwelling Himba and Westerners.
View Article and Find Full Text PDFPreparing to grasp objects facilitates visual processing of object location, orientation and size, compared to preparing actions such as pointing. This influence of action on perception reflects mechanisms of selection in visual perception tuned to current action goals, such that action relevant sensory information is prioritized relative to less relevant information. In three experiments, rather than varying movement type (grasp vs point), the magnitude of a prepared movement (power vs precision grasps) was manipulated while visual processing of object size, as well as local/global target detection was measured.
View Article and Find Full Text PDFDespite evidence that Sensorimotor Rhythm (SMR) and beta1 neurofeedback have distinct cognitive enhancement effects, it remains unclear whether their amplitudes can be independently enhanced. Furthermore, demands for top-down attention control, postural restraint and maintenance of cognitive set processes, all requiring low-beta frequencies, might masquerade as learning and confound interpretation. The feasibility of selectively enhancing SMR and beta1 amplitudes was investigated with the addition of a random frequency control condition that also requires the potentially confounding cognitive processes.
View Article and Find Full Text PDFWe investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2).
View Article and Find Full Text PDFThe present study investigated whether a differential availability of cognitive control resources as a result of varying working memory (WM) load could affect the capacity for expectancy-based strategic actions. Participants performed a Stroop-priming task in which a prime word (GREEN or RED) was followed by a colored target (red vs. green) that participants had to identify.
View Article and Find Full Text PDFFront Psychol
September 2016
Previous research using flanker paradigms suggests that peripheral distracter faces are automatically processed when participants have to classify a single central familiar target face. These distracter interference effects disappear when the central task contains additional anonymous (non-target) faces that load the search for the face target, but not when the central task contains additional non-face stimuli, suggesting there are face-specific capacity limits in visual processing. Here we tested whether manipulating the format of non-target faces in the search task affected face-specific capacity limits.
View Article and Find Full Text PDFThe effects of spatial attention and part-whole configuration on recognition of repeated objects were investigated with behavioral and event-related potential (ERP) measures. Short-term repetition effects were measured for probe objects as a function of whether a preceding prime object was shown as an intact image or coarsely scrambled (split into two halves) and whether or not it had been attended during the prime display. In line with previous behavioral experiments, priming effects were observed from both intact and split primes for attended objects, but only from intact (repeated same-view) objects when they were unattended.
View Article and Find Full Text PDFThis study examined the properties of ERP effects elicited by unattended (spatially uncued) objects using a short-lag repetition-priming paradigm. Same or different common objects were presented in a yoked prime-probe trial either as intact images or slightly scrambled (half-split) versions. Behaviourally, only objects in a familiar (intact) view showed priming.
View Article and Find Full Text PDFBehavioural and electrophysiological evidence has demonstrated that preparation of goal-directed actions modulates sensory perception at the goal location before the action is executed. However, previous studies have focused on sensory perception in areas of peripersonal space. The present study investigated visual and tactile sensory processing at the goal location of upcoming movements towards the body, much of which is not visible, as well as visible peripersonal space.
View Article and Find Full Text PDFThe development of visual context effects in the Ebbinghaus illusion in the United Kingdom and in remote and urban Namibians (UN) was investigated (N = 336). Remote traditional Himba children showed no illusion up until 9-10 years, whereas UK children showed a robust illusion from 7 to 8 years of age. Greater illusion in UK than in traditional Himba children was stable from 9 to 10 years to adulthood.
View Article and Find Full Text PDFRecent studies have suggested that individuals with eating disorders show a stronger local processing bias and/or a weaker global bias in visual processing than typical individuals. In this study, healthy participants with varying scores on the Eating Disorder Examination Questionnaire (EDE-Q) performed the Navon task, a standard task of local and global visual processing, whilst electrophysiological measures were recorded. Global stimuli were presented that were made up of many local parts, and the information between levels was either compatible or incompatible.
View Article and Find Full Text PDFA new study reveals that the integration of multiple visual depth cues in visual cortex develops surprisingly late in human childhood.
View Article and Find Full Text PDFFront Hum Neurosci
October 2014
There are multiple ways in which working memory can influence selective attention. Aside from the content-specific effects of working memory on selective attention, whereby attention is more likely to be directed towards information that matches the contents of working memory, the mere level of load on working memory has also been shown to have an effect on selective attention. Specifically, high load on working memory is associated with increased processing of irrelevant information.
View Article and Find Full Text PDFThe neural correlates of intraindividual response variability were investigated in a serial choice reaction time (CRT) task. Reaction times (RTs) from the faster and slower portions of the RT distribution for the task were separately aggregated and associated P300 event-related potentials computed. Independent behavioral measures of executive function and IQ were also recorded.
View Article and Find Full Text PDFIn this study, we investigated the time course of attentional bias for threat-related (angry) facial expressions under conditions of high versus low cognitive (working memory) load. Event-related potential (ERP) and reaction time (RT) data were recorded while participants viewed pairs of faces (angry paired with neutral face) displayed for 500 ms and followed by a probe. Participants were required to respond to the probe while performing a concurrent task of holding in working memory a sequence of digits that were either in the same order (low memory load) or in a random mixed order (high memory load).
View Article and Find Full Text PDFNegative moods have been associated with a tendency to prioritise local details in visual processing. The current study investigated the relation between depression and visual processing using the Navon task, a standard task of local and global processing. In the Navon task, global stimuli are presented that are made up of many local parts, and the participants are instructed to report the identity of either a global or a local target shape.
View Article and Find Full Text PDFThe present research examined the role of working memory in the pursuit of qualitatively different achievement goals. Pursuit of a mastery-approach goal entails a focus on developing self-referential competence while a performance-approach goal entails a focus on demonstrating normative competence. Across two experiments it was found that, when working memory is loaded, individuals pursuing a mastery-approach goal experienced larger performance decrements than individuals pursuing a performance-approach goal or those in a no-goal control.
View Article and Find Full Text PDFThe perceptual load and dilution models differ fundamentally in terms of the proposed mechanism underlying variation in distractibility during different perceptual conditions. However, both models predict that distracting information can be processed beyond perceptual processing under certain conditions, a prediction that is well-supported by the literature. Load theory proposes that in such cases, where perceptual task aspects do not allow for sufficient attentional selectivity, the maintenance of task-relevant processing depends on cognitive control mechanisms, including working memory.
View Article and Find Full Text PDFObservers can accurately perceive and evaluate the statistical properties of a set of objects, forming what is now known as an ensemble representation. The accuracy and speed with which people can judge the mean size of a set of objects have led to the proposal that ensemble representations of average size can be computed in parallel when attention is distributed across the display. Consistent with this idea, judgments of mean size show little or no decrement in accuracy when the number of objects in the set increases.
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