Evoked potential correlates of visual selective attention

Atypical visual selective attention in children with dyslexia: evidence from N2pc and PD.

BACKGROUND:Cerebral ischemia or stroke is the second leading cause of death in the world, and most surviving patients suffer from long-term physical and cognitive disabilities, which create many social and economic problems for them and society. Visual attention impairment is a common cognitive complication among patients with cerebral ischemia, especially in the Middle Cerebral Artery (MCA). One way to improve attention in these patients is cognitive rehabilitation. RehaCom software is one of the computer-based tools to rehabilitate visual attention in these patients. The purpose of this study was to evaluate RehaCom cognitive rehabilitation on different aspects of visual attention in patients with middle cerebral artery ischemia.METHODS:In this single-blind randomized clinical trial, 30 patients with cerebral ischemia in MCA territories were selected and randomly divided into control (n=15) and intervention (n=15) groups. Visual attention of both groups was assessed before the treatments using the Integrated Visual-Auditory test (IVA). Then the intervention group was rehabilitated for 8 sessions of 45 minutes each with RehaCom cognitive software, according to our selected modules, while the control group was only under intervention by non-targeted computer games. After applying the treatments, visual attention in the two groups was assessed using the IVA test.RESULTS:There were no significant differences in visual focus attention between the intervention and control groups before the intervention (29.20±30.06 and 49.53±29.69, P value >0.05). In addition, there were no significant differences in visual selective attention in both groups before the study (23.07±24.73, 39.27±27.08, P value >0.05). However, significant differences were found in visual sustained attention, visual alternating attention, and visual divided attention at baseline (P value <0.05). After the intervention, visual focus attention in the intervention group was significantly higher than in the control group (84.67±26.51, 57.20±31.44, P value <0.05). RehaCom cognitive software intervention increased visual divided attention in the intervention group (88.40±14.85 versus 72.70±25.73, P value <0.05).CONCLUSION:These results demonstrate that using RehaCom cognitive software can improve focus attention and visual attention in the intervention group. Cognitive rehabilitation with RehaCom was able to improve visual attention deficits in patients with middle cerebral artery ischemia.

A growing body of research shows that video games may be used to enhance cognitive skills, with particular reference to attentional abilities. This research study explored the effects of video game playing on visual selective attention in a young adult sample. A secondary research objective explored the possibility that gender acted as a moderating variable with regard to their visual selective attention. This was achieved by means of a quantitative research design, which consisted of a survey research and a quasi-experimental research design. Participants were sampled using purposive sampling ( n = 80), and to test the effects of video game playing and gender on visual selective attention, participants were exposed to a computerised version of the Stroop task. Data were analysed using a two-way between-group analysis of variance (ANOVA) and results indicated a statistically significant difference in visual selective attention abilities between video game players and the non-players. Video gamers thus exhibited more advanced attentional skills than non-players. There were no interaction effects between video game playing and gender, and gender did not have a statistically significant main effect on participants’ visual selective attention.

The main question motivating this study was to which extent overt visual selective attention depends on personality traits and on whether the participant is performing a linguistic or non-linguistic task. To answer this question, this study investigated the effects of personality traits and task demands (i.e., categorising and naming pictures) on visual selective attention. The visual selective attention of 64 Dutch participants was assessed using eye-tracking. Their personality traits were measured using the Big-Five model (BFI-2-S). The results indicated that higher degrees of extraversion, open-mindedness and agreeableness affect visual selective attention during language production tasks. That is, more extraverted, more open-minded and more agreeable people could be more distracted by their partners’ pictures more than conscientious as well as emotionally negative people could be. Those who have more degrees of the latter personality traits selectively attend to their own pictures and overlook their partners’. Thus, this study contributed to the considerable number of studies investigating the effect of individual differences on cognitive processing demonstrating that some personality traits could affect selective visual attention in picture naming/categorising tasks.

Outcomes of actions, in the form of rewards and punishments, are known to shape behavior. For example, an action followed by reward will be more readily elicited on subsequent encounters with the same stimuli and context -- a phenomenon known as the law of effect. These consequences of rewards (and punishments) are important because they reinforce adaptive behaviors at the expense of competing ones, thus increasing fitness of the organism in its environment. However, it is unknown whether similar influences regulate covert mental processes, such as visual selective attention. Visual selective attention allows privileged processing of task-relevant information, while inhibiting distracting contextual elements. Using variable monetary rewards as arbitrary feedback on performance, we tested whether acts of attentional selection, and in particular the resulting aftereffects, can be modulated by their consequences. Results show that the efficacy of visual selective attention can be sensibly adjusted by external feedback. Specifically, although lingering inhibition of distractors is robust after highly rewarded selections, it is eliminated after poorly rewarded selections. This powerful feature of visual selective attention provides attentive processes with both flexibility and self-regulation properties.

Treatment Effects of Methylphenidate on Cognitive Functioning in Children With Mental Retardation and ADHD

Static presentation and coarse information bring great challenge to human who has limited attention resource. To reduce the cognitive loading, a dynamic information presentation method has been put forward in this paper which calculates the utility of the information and presents it based on the visual selective attention. With this method, the presentation can adapt to the user and environment automatically. By organizing the information in small unit and calculating the utility of each unit, the amount of useless information has been reduced greatly. Different information piece has different utility, if the information with high utility would get more attention resource, the decision might be made more easily. After analyzing the current selective visual attention theory, a new presentation style based on user's visual attention also put forward in this paper. This model arranges information presentation according to the movement of sightline. Through visual attention control, the user can allocate his limited attention resource reasonably.

A more babyfaced individual is perceived as more child-like and this impression from babyface, as known as babyface effect, has an impact on social life among various age groups. In this study, the influence of babyfaces on visual selective attention was tested by cognitive task, demonstrating that the female babyface and male mature face would draw participants’ attention so that they take their eyes off more slowly. In Experiment 1, a detection task was applied to test the influence of babyfaces on visual selective attention. In this experiment, a babyface and a mature face with the same gender were presented simultaneously with a letter on one of them. The reaction time was shorter when the target letter was overlaid with a female babyface or male mature face, suggesting an attention capture effect. To explore how this competition influenced by attentional resources, we conducted Experiment 2 with a spatial cueing paradigm and controlled the attentional resources by cueing validity and inter-stimulus interval. In this task, the female babyface and male mature face prolonged responses to the spatially separated targets under the condition of an invalid and long interval pre-cue. This observation replicated the result of Experiment 1. This indicates that the female babyface and male mature face glued visual selective attention once attentional resources were directed to them. To further investigate the subliminal influence from a babyface, we used continuous flash suppression paradigm in Experiment 3. The results, again, showed the advantage of the female babyfaces and male mature faces: they broke the suppression faster than other faces. Our results provide primary evidence that the female babyfaces and male mature faces can reliably glue the visual selective attention, both supra- and sub-liminally.

The auditory efferent system comprises descending projections from the cerebral cortex to subcortical nuclei, reaching the cochlear receptor through olivocochlear fibres. One of the functions attributed to this corticofugal system is to suppress irrelevant sounds during selective attention to visual stimuli. Medial olivocochlear neurons can also be activated by sounds through a brainstem reflex circuit. Whether the individual variability of this reflex is related to the cognitive capacity to suppress auditory stimuli is still controversial. Here we propose that the individual strength per animal of the olivocochlear reflex is correlated with the ability to suppress auditory distractors during visual attention in awake chinchillas. The olivocochlear reflex was elicited with a contralateral broad-band noise at ~ 60 dB and ipsilateral distortion product otoacoustic emissions were obtained at different frequencies (1–8 kHz). Fourteen chinchillas were evaluated in a behavioural protocol of visual attention with broad-band noise and chinchilla vocalizations as auditory distractors. Results show that the behavioural performance was affected by both distractors and that the magnitudes of the olivocochlear reflex evaluated at multiple frequencies were relevant for behavioural performance during visual discrimination with auditory distractors. These results stress the ecological relevance of the olivocochlear system for suppressing natural distractors.

Besides visual salience and observers' current intention, prior learning experience may influence deployment of visual attention. Associative learning models postulate that observers pay more attention to stimuli previously experienced as reliable predictors of specific outcomes. To investigate the impact of learning experience on deployment of attention, we combined an associative learning task with a visual search task and measured event-related potentials of the EEG as neural markers of attention deployment. In the learning task, participants categorized stimuli varying in color/shape with only one dimension being predictive of category membership. In the search task, participants searched a shape target while disregarding irrelevant color distractors. Behavioral results showed that color distractors impaired performance to a greater degree when color rather than shape was predictive in the learning task. Neurophysiological results show that the amplified distraction was due to differential attention deployment (N2pc). Experiment 2 showed that when color was predictive for learning, color distractors captured more attention in the search task (ND component) and more suppression of color distractor was required (PD component). The present results thus demonstrate that priority in visual attention is biased toward predictive stimuli, which allows learning experience to shape selection. We also show that learning experience can overrule strong top-down control (blocked tasks, Experiment 3) and that learning experience has a longer-term effect on attention deployment (tasks on two successive days, Experiment 4).

Neural evidence reveals the rapid effects of reward history on selective attention

Task-relevant and physically salient features influence visual selective attention. In the present study, we investigated the influence of task-irrelevant and physically nonsalient reward-associated features on visual selective attention. Two hypotheses were tested: One predicts that the effects of target-defining task-relevant and task-irrelevant features interact to modulate visual selection; the other predicts that visual selection is determined by the independent combination of relevant and irrelevant feature effects. These alternatives were tested using a visual search task that contained multiple targets, placing a high demand on the need for selectivity, and that was data-limited and required unspeeded responses, emphasizing early perceptual selection processes. One week prior to the visual search task, participants completed a training task in which they learned to associate particular colors with a specific reward value. In the search task, the reward-associated colors were presented surrounding targets and distractors, but were neither physically salient nor task-relevant. In two experiments, the irrelevant reward-associated features influenced performance, but only when they were presented in a task-relevant location. The costs induced by the irrelevant reward-associated features were greater when they oriented attention to a target than to a distractor. In a third experiment, we examined the effects of selection history in the absence of reward history and found that the interaction between task relevance and selection history differed, relative to when the features had previously been associated with reward. The results indicate that under conditions that demand highly efficient perceptual selection, physically nonsalient task-irrelevant and task-relevant factors interact to influence visual selective attention.

The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio–visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio–visual selective attention modulates the primate brain, identify sources for “lost” attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals.

We recorded ERPs to investigate whether the visual memory load can bias visual selective attention. Participants memorized one or four letters and then responded to memory-matching letters presented in a relevant color while ignoring distractor letters or letters in an irrelevant color. Stimuli in the relevant color elicited larger frontal selection positivities (FSP) and occipital selection negativities (OSN) compared to irrelevant color stimuli. Only distractors elicited a larger FSP in the high than in the low memory load task. Memory load prolonged the OSN for all letters. Response mapping complexity was also modulated but did not affect the FSP and OSN. Together, the FSP data suggest that high memory load increased distractability. The OSN data suggest that memory load sustained attention to letters in a relevant color until working memory processing was completed, independently of whether the letters were in working memory or not.

Chapter 12 - Visual Selective Attention to Object Features