Time course of selective attention in clinically depressed young adults: an eye tracking study

Depressed individuals display biased attention for emotional information when stimuli are presented for relatively “long” (e.g., 1 s) durations. The current study examined whether attentional biases are sustained over a much longer period. Specifically, clinically depressed and never depressed young adults simultaneously viewed images from four emotion categories (sad, threat, positive, neutral) for 30 s while line of visual gaze was assessed. Depressed individuals spent significantly more time viewing dysphoric images and less time viewing positive images than their never depressed counterparts. Time course analyses indicated that these biases were maintained over the course of the trial. Results suggest that depressed participants' attentional biases for dysphoric information are sustained for relatively long periods even when other emotional stimuli are present. Mood congruent information-processing biases appear to be a robust feature of depression and may have an important role in the maintenance of the disorder.     

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.     

Effects of Attention on the Strength of Lexical Influences on Speech Perception: Behavioral Experiments and Computational Mechanisms

The effects of lexical context on phonological processing are pervasive and there have been indications that such effects may be modulated by attention. However, attentional modulation in speech processing is neither well documented nor well understood. Experiment 1 demonstrated attentional modulation of lexical facilitation of speech sound recognition when task and critical stimuli were identical across attention conditions. We propose modulation of lexical activation as a neurophysiologically plausible computational mechanism that can account for this type of modulation. Contrary to the claims of critics, this mechanism can account for attentional modulation without violating the principle of interactive processing. Simulations of the interactive TRACE model extended to include two different ways of modulating lexical activation showed that each can account for attentional modulation of lexical feedback effects. Experiment 2 tested conflicting predictions from the two implementations and provided evidence that is consistent with bias input as the mechanism of attentional control of lexical activation.     

Investigating sustained attention ability in the elderly by using two different approaches: Inhibiting ongoing behavior versus responding on rare occasions

Previous studies on sustained attention ability in the elderly produced inconsistent results. The aim of this study was to evaluate sustained attention performance in younger and older individuals by using, in a within-subjects design, two versions of the same task (the sustained attention to response task, SART) in which only in the response mode differed: in a traditionally formatted task (TFT), subjects had to respond to rare targets, and in a Go/No-Go task they had to withhold response to rare targets. Results showed that in the TFT SART only the older group exhibited a vigilance decrement. On the contrary, only young individuals showed a vigilance decrement in the Go/No-Go SART. These results showed that older individuals, who also reported less mind wandering and a higher level of motivation, exhibited preserved sustained attention ability in the Go/No-Go SART, which could be explained by increased engagement of cognitive control mechanisms in this population. The discrepancy in performance depending on the approach used also underlines the need for further studies on the nature of attention failures and their underlying mechanisms.     

Parallel averaging of size is possible but range-limited: A reply to Marchant,Simons, and De Fockert

In their recent paper, Marchant, Simons, and De Fockert (2013) claimed that the ability to average between multiple items of different sizes is limited by small samples of arbitrarily attended members of a set. This claim is based on a finding that observers are good at representing the average when an ensemble includes only two sizes distributed among all items (regular sets), but their performance gets worse when the number of sizes increases with the number of items (irregular sets). We argue that an important factor not considered by Marchant et al. (2013) is the range of size variation that was much bigger in their irregular sets. We manipulated this factor across our experiments and found almost the same efficiency of averaging for both regular and irregular sets when the range was stabilized. Moreover, highly regular sets consisting only of small and large items (two-peaks distributions) were averaged with greater error than sets with small, large, and intermediate items, suggesting a segmentation threshold determining whether all variable items are perceived as a single ensemble or distinct subsets. Our results demonstrate that averaging can actually be parallel but the visual system has some difficulties with it when some items differ too much from others.     

Temperamental contributions to children's performance in an emotion-word processing task: a behavioral and electrophysiological study

Seven-year-old children (N=65) participating in a study of the influence of infant temperament on socioemotional development performed an auditory selective attention task involving words that varied in both affective (positive vs. negative) and social (social vs. nonsocial) content. Parent report of contemporaneous child temperament was also collected, and individual differences in self-regulation in the affective (soothability) and cognitive (attentional control) domains were noted. Overall, children showed slower responses to stimuli that were either social or negative in content, with the largest effect elicited by words that possessed both traits. Children rated high in soothability and attentional control showed slower responses to social negative words. The other children showed little to no differential response patterns across the word categories. ERPs collected during the task indicated that processing differences were evident in the later more cognitive components of the ERP, especially in children low in attentional control. These findings indicate that performance on an auditory selective attention task can assist in identifying underlying patterns of affective processing.     

Flanker compatibility effects in patients with Parkinson's disease: impact of target onset delay and trial-by-trial stimulus variation

Parkinson’s disease (PD) patients and healthy controls were administered a flanker task that consisted of the presentation of colored targets and distractors. Participants were required to attend to the center target and identify its color. The stimulus displays were either congruent (i.e., the target and flankers were the same color) or incongruent. The time between the onset of the flanker and the target color (the target onset delay) was either short or long. Results indicated that PD patients and controls did not differ in the magnitude of the flanker effect within individual trials in that both groups demonstrated a typical flanker effect at the short target onset delay and neither group demonstrated a flanker effect at the longer delay. However, when performance was examined on a trial-by-trial basis, PD patients demonstrated a slowing of reaction time relative to controls when having to make the same response across consecutive trials at longer inter-trial intervals when the flankers were incongruent across consecutive trials and the display on the second of two trials was incongruent. These results indicate that PD patients are impaired in inhibiting the distractors over an extended delay and that this deficit may impact motor responding in these patients, suggesting that the basal ganglia contribute to the interface of attention and action.     

Rumination and attention in major depression

Up until recently, it had been assumed that attentional biases for negative information do not exist in depression. However studies using post-conscious exposure durations have produced contradictory results. The limitations of common attentional tasks, suitability of stimulus materials and differences in stimulus duration times may have contributed to these inconsistencies. We aimed to address many of these issues and examine attentional responses in major depression at two post-conscious exposure times. We also investigated possible roles for rumination and distraction in increasing and lessening attentional biases for negative information. We used a fully controlled experimental design to test the effects of both induced and trait rumination and distraction on attention in patients with major depression and healthy controls. Attention was assessed using the dot-probe task. The findings revealed an attentional bias for negative information in depressed patients only at the longer post-conscious exposure duration. Furthermore although this bias was not influenced by either induced or trait distraction, it was related to trait rumination. Overall, the results showed that depression is associated with a strategic attentional bias towards negative information and that this bias is stronger in individuals who habitually ruminate.     

Effects of route guidance variable message signs (VMS) on driver behaviour

Effects of route guidance Variable Message Signs (VMS) on speed and route choice were investigated in a field study on two sites on motorways. Two VMS were used in the study, which displayed information about a closed road section downstream on the motorways and recommendations for alternative routes. Route choice, speed and braking behaviour were compared between vehicles approaching the VMS while they displayed messages and while they were left blank without message. There was high compliance with the messages on the VMS. About every fifth vehicle changed route choice according to the recommendation, and almost none drove as far as the closed road section. Speed measurements of 3342 vehicles showed large speed reductions, and video observations showed that large proportions of vehicles braked while approaching the VMS. The speed reductions and braking manoeuvres can partly be attributed to attention overload or distraction due to the information on the VMS. However, a proportion of the speed reductions was due to chain reactions where one vehicle braked and forced the following vehicles to brake or change lanes in order to avoid collisions. Safety problems may result directly from distraction, or indirectly from the reactions of the drivers to the distraction.     

Visual attention capacity: a review of TVA-based patient studies

Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity, and measurements are highly reliable. As the method is theoretically founded, it also has high validity. TVA-based assessment has recently been used to investigate a broad range of neuropsychological and neurological conditions. We present the method, including the experimental paradigm and practical guidelines to patient testing, and review existing TVA-based patient studies organized by lesion anatomy. Lesions in three anatomical regions affect visual capacity: The parietal lobes, frontal cortex and basal ganglia, and extrastriate cortex. Visual capacity thus depends on large, bilaterally distributed anatomical networks that include several regions outside the visual system. The two visual capacity parameters are functionally separable, but seem to rely on largely overlapping brain areas.