Redundant-target Task Research Articles

Examining the relationship between aerobic fitness and cognitive control processes: An SFT and ERP study

Previous studies have demonstrated a positive relationship between aerobic fitness and cognitive control, the ability to inhibit distractions (conflict control) or impulsive actions (response inhibition). However, it is unknown whether these sub-processes and their underlying information processing capacity are differentially related to aerobic fitness. To address this question, we employed a go/no-go version of the redundant-target task, which was administered concurrently with the recording of event-related potentials (ERPs) and the use of a reaction-time based diagnostic tool known as system factorial technology (SFT). Our sample consisted of 46 young male adults with varying levels of aerobic fitness: the high-fit group (n = 23; aged 21.33 ± 2.44 years; VO2max 58.83 ± 6.93 ml/kg/min) and the low-fit group (n = 23; aged 22.30 ± 1.40 years; VO2max 41.90 ± 4.01 ml/kg/min). The results showed that the high-fit group exhibited a lower false-alarm rate compared to the low-fit group. However, there was no difference in processing speed between the two groups. The SFT analysis revealed that the high-fit group had more efficient information processing for earlier responses, but not later responses, compared to the low-fit group. Analysis of the ERPs indicated that the high-fit group had larger N2d amplitudes and shorter P3d latencies during conflict control compared to the low-fit group, while there were no such effects for the process of response inhibition. These findings suggest that aerobic fitness may be differentially related to the temporal dynamics and sub-processes of cognitive control.

Protective effect of aerobic fitness on the detrimental influence of exhaustive exercise on information processing capacity

Although aerobic fitness has been thought to protect against the detrimental cognitive effects following exhaustive exercise, available evidence from studies using traditional mean behavioral measures remain somewhat equivocal. PurposeThis study aimed to reconcile this discrepancy by using a novel theory-driven diagnostic tool, the Systems Factorial Technology (SFT). MethodsSixty-six healthy young adults aged from 18 to 30 years old with different levels of aerobic fitness (n = 33 for the higher-fit and lower-fit groups) completed a go/nogo version of redundant-target task before and after a graded exercise test (GXT) until exhaustion. SFT was used to calculate the resilience capacity, which reflects the information processing capacity underlying inhibitory control. ResultsFollowing the GXT, both higher-fit and lower-fit groups showed faster responses while leaving accuracy unchanged as compared to the performance at the pretest. On the other hand, the resilience capacity decreased for the lower-fit group but was maintained for the higher-fit group. ConclusionThe present findings suggest that aerobic fitness may modulate the individual difference in decisional mechanism following exhaustive exercise. In sum, this study offers an alternative mechanistic explanation regarding cognitive individual differences in response to exhaustive exercise and provides novel insights into the significance of maintaining a state of high physical fitness for those who need to perform cognitively challenging tasks under physically stressful conditions (e.g., elite athletes).

Acute effects of aerobic exercise on conflict suppression, response inhibition, and processing efficiency underlying inhibitory control processes: An ERP and SFT study.

Aerobic exercise has been identified as an effective strategy for transiently enhancing inhibitory control, an ability to suppress irrelevant distractors while focusing on relevant information in facilitating the implementation of goal-directed behavior. The purpose of this study was to employ a go/no-go version of the redundant-target task and event-related potential to further determine whether inhibitory control at the perceptual and response levels as well as their underlying processing capacity and neuroelectric alterations are differentially affected by a single bout of aerobic exercise. Twenty-seven young adults completed the redundant-target task while electroencephalogram was recorded before and after one 20-min bout of moderate-intensity aerobic exercise and a sitting control condition on separate days in counterbalanced order. Although behavioral outcomes of mean-level performance did not differ between intervention conditions, time-related decreases in processing capacity for the faster responses were only observed following rest. Aerobic exercise resulted in maintained P3b amplitude from pretest to posttest for all trial types while decreased P3b amplitude from pretest to posttest during single-target and redundant-target trials was observed following rest. Further, the time-related changes in P3b amplitude were positively correlated with improvements in task performance following exercise. These findings suggest that a short bout of aerobic exercise selectively counteracts the time-related decrements in processing capacity as well as neuroelectric processing of attention and conflict suppression that contribute to behavioral outcomes of inhibitory control.

Neural correlates of cognitive processing capacity in elite soccer players

Although great progress has been made in our understanding of perceptual-cognitive expertise in team sports, the neurocognitive mechanisms underlying such cognitive advantage in the face of multiple, sometimes conflicting, channels of information are not well understood. Two electroencephalographic indices associated with perceptual decisions, the P3 component of event-related potential and alpha inter-trial phase coherence (ITPC), were measured and compared across elite soccer players and non-athletic controls while performing a redundant-target task. Specifically, we adopted an effective diagnostic tool, Systems Factorial Technology, to assess participants’ workload capacity. Soccer players exhibited larger workload capacity while making faster decisions compared with controls. Moreover, this larger workload capacity was associated with modulations of P3 and alpha ITPC when processing two targets relative to one target and one distractor, an effect that was not observed in controls. Together, the present findings offer a possible mechanistic explanation of perceptual-cognitive expertise in the context of team sports.

Dual-Task Redundant-Target Processing: The Case of the Limited Capacity Parallel Model

We examined the effect of a central tracking task on visual target processing efficiency in a combined target detection / manual tracking paradigm. Participants performed a redundant-target task by itself, and concurrently with the tracking task. A measure of workload capacity gauged target processing efficiency. Processing was less efficient than predicted by a standard parallel race model under both levels of task load. However, data suggested no difference in processing efficiency between the single-and dual-task conditions. Our findings provide further evidence that processing capacity for peripheral visual targets is consistently limited but robust against changes to concurrent task load.

Audiovisual integration in depth: multisensory binding and gain as a function of distance

The integration of information across sensory modalities is dependent on the spatiotemporal characteristics of the stimuli that are paired. Despite large variation in the distance over which events occur in our environment, relatively little is known regarding how stimulus-observer distance affects multisensory integration. Prior work has suggested that exteroceptive stimuli are integrated over larger temporal intervals in near relative to far space, and that larger multisensory facilitations are evident in far relative to near space. Here, we sought to examine the interrelationship between these previously established distance-related features of multisensory processing. Participants performed an audiovisual simultaneity judgment and redundant target task in near and far space, while audiovisual stimuli were presented at a range of temporal delays (i.e., stimulus onset asynchronies). In line with the previous findings, temporal acuity was poorer in near relative to far space. Furthermore, reaction time to asynchronously presented audiovisual targets suggested a temporal window for fast detection—a range of stimuli asynchronies that was also larger in near as compared to far space. However, the range of reaction times over which multisensory response enhancement was observed was limited to a restricted range of relatively small (i.e., 150 ms) asynchronies, and did not differ significantly between near and far space. Furthermore, for synchronous presentations, these distance-related (i.e., near vs. far) modulations in temporal acuity and multisensory gain correlated negatively at an individual subject level. Thus, the findings support the conclusion that multisensory temporal binding and gain are asymmetrically modulated as a function of distance from the observer, and specifies that this relationship is specific for temporally synchronous audiovisual stimulus presentations.

Redundant-target processing is robust against changes to task load

Monitoring visual displays while performing other tasks is commonplace in many operational environments. Although dividing attention between tasks can impair monitoring accuracy and response times, it is unclear whether it also reduces processing efficiency for visual targets. Thus, the current three experiments examined the effects of dual-tasking on target processing in the visual periphery. A total of 120 undergraduate students performed a redundant-target task either by itself (Experiment 1a) or in conjunction with a manual tracking task (Experiments 1b–3). Target processing efficiency was assessed using measures of workload resilience. Processing of redundant targets in Experiments 1–2 was less efficient than predicted by a standard parallel race model, giving evidence for limited-capacity, parallel processing. However, when stimulus characteristics forced participants to process targets in serial (Experiment 3), processing efficiency became super-capacity. Across the three experiments, dual-tasking had no effect on target processing efficiency. Results suggest that a central task slows target detection in the display periphery, but does not change the efficiency with which multiple concurrent targets are processed.

Multisensory temporal function and EEG complexity in patients with epilepsy and psychogenic nonepileptic events.

Cognitive and perceptual comorbidities frequently accompany epilepsy and psychogenic nonepileptic events (PNEE). However, and despite the fact that perceptual function is built upon a multisensory foundation, little knowledge exists concerning multisensory function in these populations. Here, we characterized facets of multisensory processing abilities in patients with epilepsy and PNEE, and probed the relationship between individual resting-state EEG complexity and these psychophysical measures in each patient. We prospectively studied a cohort of patients with epilepsy (N=18) and PNEE (N=20) patients who were admitted to Vanderbilt's Epilepsy Monitoring Unit (EMU) and weaned off of anticonvulsant drugs. Unaffected age-matched persons staying with the patients in the EMU (N=15) were also recruited as controls. All participants performed two tests of multisensory function: an audio-visual simultaneity judgment and an audio-visual redundant target task. Further, in the cohort of patients with epilepsy and PNEE we quantified resting state EEG gamma power and complexity. Compared with both patients with epilepsy and control subjects, patients with PNEE exhibited significantly poorer acuity in audiovisual temporal function as evidenced in significantly larger temporal binding windows (i.e., they perceived larger stimulus asynchronies as being presented simultaneously). These differences appeared to be specific for temporal function, as there was no difference among the three groups in a non-temporally based measure of multisensory function - the redundant target task. Further, patients with PNEE exhibited more complex resting state EEG patterns as compared to their patients with epilepsy, and EEG complexity correlated with multisensory temporal performance on a subject-by-subject manner. Taken together, findings seem to indicate that patients with PNEE bind information from audition and vision over larger temporal intervals when compared with control subjects as well as patients with epilepsy. This difference in multisensory function appears to be specific to the temporal domain, and may be a contributing factor to the behavioral and perceptual alterations seen in this population.

Unchanging Capacity

Complex workspaces often require operators to divide attention between information within the visual periphery and a visual central task. For an air traffic controller, for example, monitoring complex displays while also watching for potential hazards is essential for avoiding aircraft collisions. In such environments, fast and accurate detection of peripheral events may be critical for safe performance. Presenting targets redundantly offers a potential way of speeding up target detection (Little, Eidels, Fific, & Wang, 2015; Townsend & Eidels, 2011). It remains unclear, however, whether redundant-target processing remains efficient with a concurrent central task. A series of experiments examined the effects of dual-tasking on peripheral redundant-target processing, either between- (Experiments 1a & 1b) or within-participants (Experiment 4). Furthermore, Experiments 2 and 3 manipulated target-distractor discriminability and distractor presence to examine the effects of target salience on dual-task processing efficiency. One hundred and one undergraduate students ( N =20 in each of Experiments 1a to 3; N = 21 in Experiment 4) performed a redundant-target task either by itself (Experiment 1a) or whilst performing a manual tracking task (Experiments 1b-4). The tracking task required participants to maneuver a joystick using both hands to align a cursor with a moving red target. The detection task required participants to press a joystick button bimanually whenever a target appeared at a location in the peripheral visual field. Experiments 1a, 1b, and Experiment 4 employed “T” as the target item and “L” as distractor items that appeared randomly rotated in 90° steps. In Experiment 2, target salience was increased by employing “X” as the target item and “O” for the distractor items. Experiment 3 tested peripheral target processing in the absence of distractors; hence, only the target item “T” was employed. Processing efficiency in the target-detection task was calculated using measures of resiliency (Little et al., 2015) or workload capacity (Townsend & Eidels, 2011). In all five experiments, processing of redundant targets was less efficient than predicted by a standard parallel race model (Raab, 1962; Townsend & Eidels, 2011). Surprisingly, processing efficiency differed negligibly between the single and dual-task conditions. Capacity may be protected from task-load effects due to separate information-processing resource pools within the central and peripheral visual fields (Wickens, 2002). Neither increasing the discriminability between targets and distractors, nor removing distractors entirely, had any effect on redundant-target processing efficiency. Results suggest target processing in the visual periphery is capacity-limited, but that processing efficiency is robust against changes to concurrent task load or target salience.