Selective contributions of executive function ability to the P3.

The P3 component (P300, P3b) is considered to be an effective index of attention and categorization processes when elicited in a visual oddball task, specifically reflecting the selection of a rare target item among frequent non-targets. Researchers have proposed that target categorization is guided by representations of target features held in working memory (WM), thus guiding attention and categorization processes to distinguish targets from non-targets. Although WM is theorized to have visuospatial, verbal and executive function components, most studies do not investigate how these WM components contribute to the P3. This study uses an individual differences approach to determine whether correlations between WM capabilities and P3 amplitudes indicate a common underlying cognitive construct. Participants (n = 140) completed an 80/20 visual oddball task to elicit the P3 as well as independent visual working memory (VWM), spatial working memory (SPWM), and executive function (task switching (TS) and digit symbol substitution (DSS)) tests. Results indicated that measures of executive function, DSS and TS, but not VWM or SPWM ability, correlated with and predicted faster task response times and greater P3 amplitudes. RT and WM measures were not correlated with P3 fractional area latencies. These results support context updating theory. Executive function WM availability, whether as a property of the participant's processing system or based on task demands, plays a functional role in the P3 and an important role in efficient visual categorization and goal-directed learning.

Open science as a path to education of new psychophysiologists.

There is a pressing need for resources to train the next generation of psychophysiologists. Psychophysiology, and especially the subfield of cognitive electrophysiology, poses challenges for educators because it requires an understanding of complex concepts and experimental design, advanced analysis and programming skills, and access to specialized software and equipment. These challenges are common to other STEM fields as well. We present PURSUE (Preparing Undergraduates for Research in STEM Using Electrophysiology - www.PursueERP.com) as an example initiative that engages open educational practices to create and share freely available electrophysiology training materials. This model uses evidence-based pedagogy to create accessible and flexible materials, an open database with supporting lab-based training resources, and also provides instructor support during implementation. This model can be used for other areas within STEM. We review benefits and challenges of using open science research and publishing practices for training. Open science resources have benefits for both course-based undergraduate research experiences and other types of training by increasing access to publications, software, and code for conducting experiments and analyses, as well as access to data for those who do not have access to research equipment. Further, we argue that coordinated open educational practices are necessary to take full advantage of open science resources for training students. Open educational practices such as open educational resources, collaborative course building, and implementation support greatly enhance the ability to incorporate these open science resources into a curriculum.

Individual Differences in Working Memory and the N2pc.

The lateralized ERP N2pc component has been shown to be an effective marker of attentional object selection when elicited in a visual search task, specifically reflecting the selection of a target item among distractors. Moreover, when targets are known in advance, the visual search process is guided by representations of target features held in working memory at the time of search, thus guiding attention to objects with target-matching features. Previous studies have shown that manipulating working memory availability via concurrent tasks or within task manipulations influences visual search performance and the N2pc. Other studies have indicated that visual (non-spatial) vs. spatial working memory manipulations have differential contributions to visual search. To investigate this the current study assesses participants' visual and spatial working memory ability independent of the visual search task to determine whether such individual differences in working memory affect task performance and the N2pc. Participants (n = 205) completed a visual search task to elicit the N2pc and separate visual working memory (VWM) and spatial working memory (SPWM) assessments. Greater SPWM, but not VWM, ability is correlated with and predicts higher visual search accuracy and greater N2pc amplitudes. Neither VWM nor SPWM was related to N2pc latency. These results provide additional support to prior behavioral and neural visual search findings that spatial WM availability, whether as an ability of the participant's processing system or based on task demands, plays an important role in efficient visual search.

Attentional set and the gradient of visual spatial attention.

There are a number of factors that may influence the shape and scope of the gradient of visual attention. This study examined the role of attentional set in determining the scope and presence of suppression in the gradient of visual selective attention observed in the P1 event related potential waveform. Twenty-two participants were asked to attend to a specific location and respond to a target stimulus. However, thirty percent of the time, the stimulus could also appear at one of 7 other locations (three ipsilateral to the attended location and four contralateral). Attentional set was varied by changes in the instructions to avoid confounds created by changing the stimuli. In half of the study participants were asked to respond only to stimuli that appeared at the designated location. In the other half of the study participants were asked to attend to the designated location but respond to all stimuli. Results demonstrate a significant main effect of attentional set, with greater processing when participants were asked to respond to all stimuli as compared to when they were only asked to respond to stimuli at the designated location. Additionally a significant interaction between visual field and location shows greater differences in processing (i.e. an attentional effect) at locations closer to the designated location. Findings are discussed in relation to the scope and gradient of attention.

Visual search and the N2pc in children.

While there is growing understanding of visual selective attention in children, some aspects such as selection in the presence of distractors are not well understood. Adult studies suggest that when presented with a visual search task, an enhanced negativity is seen beginning around 200 ms (the N2pc) that reflects selection of a target item among distractors. However, it is not known if similar selective attention-related activity is seen in children during visual search. This study was designed to investigate the presence of the N2pc in children. Nineteen children (ages 9-12 years) and 21 adults (ages 18-22 years) completed a visual search task in which they were asked to attend to a fixation surrounded by both a target and a distractor stimulus. Three types of displays were analyzed at parietal electrodes P7 and P8; lateral target/lateral distractor, lateral target/midline distractor, and midline target/lateral distractor. Both adults and children showed a significant increased negativity contralateral compared to ipsilateral to the target (reflected in the N2pc) in both displays with a lateral target while no such effect was seen in displays with a midline target. This suggests that children also utilized additional resources to select a target item when distractors are present. These findings demonstrate that the N2pc can be used as a marker of attentional object selection in children.

Perceptual load influences selective attention across development.

Research suggests that visual selective attention develops across childhood. However, there is relatively little understanding of the neurological changes that accompany this development, particularly in the context of adult theories of selective attention, such as N. Lavie's (1995) perceptual load theory of attention. This study examined visual selective attention across development from 7 years of age to adulthood. Specifically, the author examined if changes in processing as a function of selective attention are similarly influenced by perceptual load across development. Participants were asked to complete a task at either low or high perceptual load while processing of an unattended probe stimulus was examined using event related potentials. Similar to adults, children and teens showed reduced processing of the unattended stimulus as perceptual load increased at the P1 visual component. However, although there were no qualitative differences in changes in processing, there were quantitative differences, with shorter P1 latencies in teens and adults compared with children, suggesting increases in the speed of processing across development. In addition, younger children did not need as high a perceptual load to achieve the same difference in performance between low and high perceptual load as adults. Thus, this study demonstrates that although there are developmental changes in visual selective attention, the mechanisms by which visual selective attention is achieved in children may share similarities with adults.

Visual search and contextual cueing: differential effects in 10-year-old children and adults.

The development of contextual cueing specifically in relation to attention was examined in two experiments. Adult and 10-year-old participants completed a context cueing visual search task (Jiang & Chun, The Quarterly Journal of Experimental Psychology, 54A(4), 1105-1124, 2001) containing stimuli presented in an attended (e.g., red) and unattended (e.g., green) color. When the spatial configuration of stimuli in the attended and unattended color was invariant and consistently paired with the target location, adult reaction times improved, demonstrating learning. Learning also occurred if only the attended stimuli's configuration remained fixed. In contrast, while 10 year olds, like adults, showed incrementally slower reaction times as the number of attended stimuli increased, they did not show learning in the standard paradigm. However, they did show learning when the ratio of attended to unattended stimuli was high, irrespective of the total number of attended stimuli. Findings suggest children show efficient attentional guidance by color in visual search but differences in contextual cueing.

Implicit learning modulates selective attention at sensory levels of perceptual processing.

Electrophysiological evidence suggests that attention can be modulated as early as 100 msec after stimulus presentation. However, it is not clear whether these changes are based primarily on stimulus properties such as perceptual load (i.e., the level of perceptual difficulty), or other properties, such as general attentional set or learned expectations concerning perceptual load. Using event-related potentials, this study examined how implicit learning of perceptual load conditions modulates selective attention at sensory levels of perceptual analysis. The results show significant differences in P1 amplitude recorded over occipital areas of the brain as a function of learned expectations of perceptual load, only when perceptual load could be reliably predicted by the preceding stimuli. Moreover, differences in processing were found when both low and high perceptual load conditions could be predicted. These findings suggest that implicit learning modulates the allocation of attention at early stages of perceptual processing.

Regulation of cognitive resources during sustained attention and working memory in 10-year-olds and adults.

We examined differences between 10-year-olds and young adults in resource recruitment and regulation during tasks of sustained attention and spatial working memory. We administered participants spatial 0- and 1-back tasks and used pupillary dilation as a measure of resource recruitment. Repeated administration of 0-back led to smaller pupillary dilations and greater response time (RT) variability, revealing a vigilance decrement. Effects of repeated administration of 0-back and differences between 0- and 1-back in d' and RTs were similar between ages. Results further suggested that the children may not have been as effective as adults in extracting frequency information. Thus, on simple tasks of sustained attention and working memory, children recruit resources in a manner similar to adults. Finally, d' was correlated with RT variability on both tasks at both ages, highlighting the role of attentional fluctuations on both tasks.

Attention allocation in the dual-task paradigm as measured through behavioral and psychophysiological responses.

We investigated attention allocation in a dual-task paradigm using behavioral and pupillary measures. We used an auditory digit span (DS) and a simple visual response time (RT) task. Participants were administered four conditions in which they performed neither task (no-task), a single task (DS or RT only), or both tasks (dual). Dependent variables were DS accuracy, RT, and task-evoked pupillary responses (TEPRs) to digits as estimates of mental effort. Participants maintained almost the same level of DS accuracy on dual as on DS only and sacrificed speed on the RT task. As expected, TEPRs increased linearly with memory load in both DS only and dual. Although TEPRs were initially higher in dual than in DS only, the slope of the increase was shallower in dual. Results suggest that TEPRs can elucidate mechanisms of attention allocation by distinguishing between effectiveness (level of behavioral performance) and efficiency (the costs of that performance in mental effort).