scholarly journals Disentangling sources of interference in the N-back task

2021 ◽  
Author(s):  
Long Ni ◽  
Wei Ji Ma
Keyword(s):  
Working Memory ◽  
Cognitive Tasks ◽  
Optimal Decision ◽  
Decision Strategy ◽  
Substitution Model ◽  
Decision Variables ◽  
Substitution Models ◽  
Target Performance ◽  
The One ◽  
Back Task

The N-back task is a common working memory paradigm: subjects judge whether the current item in a sequence (the probe) matches the one presented N items ago (the target). Performance in the N-back task is susceptible to interference from intervening items (distractors), especially when the probe and the distractor are similar. However, the categorical stimuli usually used in the classic N-back task are not suitable for distinguishing possible causes of interference. Here, we instead used parametric stimuli (varying in orientation or color) to measure the amount of interference induced in a 2-back task by the 1-back distractor. As expected, we find that interference was larger when the feature distance between the probe and the distractor was smaller. To investigate the source of the interference, we fitted four mathematical models to the data. In the No interference model, the observer utilizes an optimal decision strategy. In the Early pooling model, the ob- server has access only to a mixed measurement of the target and distractor, but employs an optimal de-mixing strategy. In the Late pooling model, the observer mixes decision variables that are optimal for the target and distractor separately. In the Substitution model, the observer swaps the target with the distractor on some proportion of trials, and decides optimally otherwise. The No interference and the Early pooling models described the data substantially worse than the Late pooling and the Substitution models. However, we were not able to distinguish the Late pooling and Substitution models. Our modeling results suggest that interference in the 2-back task results either from the pooling of decision variables based the “target” and “distractor” separately, or from the substitution of the distractor for the target. Our study opens the door to parametrically examining the sources of interference in similar cognitive tasks.

Slow Wave Activity Related to Working Memory Maintenance in the N-Back Task

2016 ◽  
Vol 30 (4) ◽  
pp. 141-154 ◽  
Author(s):  
Kira Bailey ◽  
Gregory Mlynarczyk ◽  
Robert West
Keyword(s):  
Working Memory ◽  
Slow Wave ◽  
Time Course ◽  
Relevant Information ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Response Accuracy ◽  
Functional Neuroanatomy ◽  
Stimulus Interval ◽  
Back Task

Abstract. Working memory supports our ability to maintain goal-relevant information that guides cognition in the face of distraction or competing tasks. The N-back task has been widely used in cognitive neuroscience to examine the functional neuroanatomy of working memory. Fewer studies have capitalized on the temporal resolution of event-related brain potentials (ERPs) to examine the time course of neural activity in the N-back task. The primary goal of the current study was to characterize slow wave activity observed in the response-to-stimulus interval in the N-back task that may be related to maintenance of information between trials in the task. In three experiments, we examined the effects of N-back load, interference, and response accuracy on the amplitude of the P3b following stimulus onset and slow wave activity elicited in the response-to-stimulus interval. Consistent with previous research, the amplitude of the P3b decreased as N-back load increased. Slow wave activity over the frontal and posterior regions of the scalp was sensitive to N-back load and was insensitive to interference or response accuracy. Together these findings lead to the suggestion that slow wave activity observed in the response-to-stimulus interval is related to the maintenance of information between trials in the 1-back task.

Pattern of Near Transfer Effects Following Working Memory Training With a Dual N-Back Task

2017 ◽  
Vol 64 (4) ◽  
pp. 240-252 ◽  
Author(s):  
Anna Soveri ◽  
Eric P. A. Karlsson ◽  
Otto Waris ◽  
Petra Grönholm-Nyman ◽  
Matti Laine
Keyword(s):  
Working Memory ◽  
Controlled Trial ◽  
Composite Score ◽  
Memory Training ◽  
Interference Control ◽  
Transfer Effects ◽  
Near Transfer ◽  
Randomized Controlled ◽  
Transfer Tasks ◽  
Back Task

Abstract. In a randomized controlled trial, we investigated the pattern of near transfer effects of working memory (WM) training with an adaptive auditory-visuospatial dual n-back training task in healthy young adults. The results revealed significant task-specific transfer to an untrained single n-back task, and more general near transfer to a WM updating composite score plus a nearly significant effect on a composite score measuring interference control in WM. No transfer effects were seen on Active or Passive WM composites. The results are discussed in the light of cognitive versus strategy-related overlap between training and transfer tasks.

Quasi-Periodic Control Technique for Minimizing Fuel Consumption During Record Vehicle Competition

2013 ◽  
Vol 60 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Paweł Sulikowski ◽  
Ryszard Maronski
Keyword(s):  
Fuel Consumption ◽  
Optimal Control Theory ◽  
Slope Angle ◽  
Control Technique ◽  
Decision Variables ◽  
Aeronautical Engineering ◽  
The One ◽  
Optimal Driving ◽  
The Given ◽  
Engine Power

The problem of the optimal driving technique during the fuel economy competition is reconsidered. The vehicle is regarded as a particle moving on a trace with a variable slope angle. The fuel consumption is minimized as the vehicle covers the given distance in a given time. It is assumed that the run consists of two recurrent phases: acceleration with a full available engine power and coasting down with the engine turned off. The most fuel-efficient technique for shifting gears during acceleration is found. The decision variables are: the vehicle velocities at which the gears should be shifted, on the one hand, and the vehicle velocities when the engine should be turned on and off, on the other hand. For the data of students’ vehicle representing the Faculty of Power and Aeronautical Engineering it has been found that such driving strategy is more effective in comparison with a constant speed strategy with the engine partly throttled, as well as a strategy resulting from optimal control theory when the engine is still active.

Effects of urban noise variability on cognitive abilities in indoor spaces: Gender differences

2021 ◽  
pp. 095745652110307
Author(s):  
Massimiliano Masullo ◽  
Gennaro Ruggiero ◽  
Daniel Alvarez Fernandez ◽  
Tina Iachini ◽  
Luigi Maffei
Keyword(s):  
Working Memory ◽  
Verbal Memory ◽  
Cognitive Abilities ◽  
Cognitive Domain ◽  
Cognitive Tasks ◽  
Indoor Environments ◽  
Urban Noise ◽  
Male And Female ◽  
Open Window ◽  
Indoor Spaces

Previous evidence has shown that exposure to urban noise negatively influences some cognitive abilities (i.e. verbal fluency and delayed recall of prose memory) of people in indoor spaces. However, long-standing literature in the cognitive domain has reported that men and women can show different performance on cognitive tasks. Here, we aimed to investigate if and how different patterns of perceived urban noises in indoor environments could affect male and female participants’ cognitive abilities. Ambisonic sound recordings representing scenarios with varying noise patterns (low, medium and high variability) were acquired with an open window at three dwellings in a southern Italian city. As a control condition, the recordings were caught inside a quiet room. While exposed to theses four auditory conditions, participants had to perform cognitive tasks assessing free verbal memory recall, auditory–verbal recognition and working memory. The results show that male and female participants have a different tolerance to noise patterns. Women overperform men on verbal tasks, while the contrary effect emerges with men outperforming women on visuospatial working memory tasks.

scholarly journals Abnormal brain activity patterns during spatial working memory task in patients with end-stage renal disease on maintenance hemodialysis: a fMRI study

2020 ◽  
Author(s):  
Jinzhuang Huang ◽  
Lei Xie ◽  
Ruiwei Guo ◽  
Jinhong Wang ◽  
Jinquan Lin ◽  
...  
Keyword(s):  
Working Memory ◽  
Frontal Cortex ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Activity Patterns ◽  
Parietal Lobule ◽  
Stage Renal Disease ◽  
End Stage ◽  
Esrd Patients ◽  
Back Task

Abstract Hemodialysis (HD) is associated with cognitive impairment in patients with end-stage renal disease (ESRD). However, the neural mechanism of spatial working memory (SWM) impairment in HD-ESRD patients remains unclear. We investigated the abnormal alterations in SWM-associated brain activity patterns in HD-ESRD patients using blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) technique during n-back tasks. Twenty-two HD-ESRD patients and 22 well-matched controls underwent an fMRI scan while undergoing a three-load n-back tasks with different difficulty levels. Cognitive and mental states were assessed using a battery of neuropsychologic tests. The HD-ESRD patients exhibited worse memory abilities than controls. Compared with the control group, the HD-ESRD patient group showed lower accuracy and longer response time under the n-back tasks, especially in the 2-back task. The patterns of brain activation changed under different working memory loads in the HD-ESRD patients, showing decreased activity in the right medial frontal gyrus and inferior frontal gyrus under 0-back and 1-back task, while more decreased activation in the bilateral frontal cortex, parietal lobule, anterior/posterior cingulate cortex and insula cortex under 2-back task. With the increase of task difficulty, the activation degree of the frontal and parietal cortex decreased. More importantly, we found that lower activation in frontal cortex and parietal lobule was associated with worse cognitive function in the HD-ESRD patients. These results demonstrate that the abnormal brain activity patterns of frontal cortex and parietal lobule may reflect the neural mediation of SWM impairment.

scholarly journals The Effect of Single Bout of Acute Exercise on Working Memory Performance

2018 ◽  
Vol 3 (2) ◽  
pp. 484-487
Author(s):  
Santosh Kumar Deo ◽  
Kopila Agrawal ◽  
Prem Bhattrai ◽  
Raju Kumar Chaudhary
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Acute Exercise ◽  
Test Procedure ◽  
Step Test ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Moderate Intensity Exercise ◽  
Single Bout ◽  
Back Task

Introduction: Working memory is a kind of short term memory important for reasoning and guiding decision-making and behavioral process.Objective: The goal of the present research was to study the outcome of single bout of acute moderate-intensity exercise on working memory.Methodology: Twenty two male subjects were asked to perform working memory task by 2n back task in baseline resting, immediately after exercise and after five minute of exercise session. 3 minute step test procedure was used as a moderate intensity exercise intervention.Results: The percentage correctness of 2n back task of working memory was found to be 64.36% for baseline resting condition, 78.01 % for immediately after 3-minute step test and 80.70% for 5 minute after the exercise. In both exercise session (i.e. immediately after exercise and after 5 minute of exercise), significant improvement (p value <0.05) in working memory was seen as compared to the baseline resting session while no such significant beneficial improvement was seen when compared between immediately after exercise and after 5 minute of exercise.Conclusion: Improvement in working memory after moderate exercise intervention was seen, which is important for learning and memory and decision-making.  BJHS 2018;3(2)6:484-487.

scholarly journals Possible Effect of Headphone Usage on Working Memory Among Students in Faculty of Medicine, Ahmadu Bello University, Zaria‒Nigeria

2019 ◽  
pp. 1-4
Author(s):  
Yushau Yusuf ◽  
Muhammad U.A ◽  
Isah F.A
Keyword(s):  
Working Memory ◽  
Signal Processing ◽  
Cognitive Abilities ◽  
Healthy Subjects ◽  
Significant Difference ◽  
Stored Information ◽  
Age Range ◽  
The Relationship ◽  
The Brain ◽  
Back Task

Working memory is a system that is responsible for transient holding and processing of new and already stored information. It also involves processing for reasoning, comprehension, learning and memory updating. Headphones are a pair of small loudspeakers that are designed to be held in place close to a user’s ear. They are electroacoustic transducers which convert electrical signals to a corresponding sound in the user’s ear. Several studies have recently shown a link between cognitive abilities and response to hearing aid and signal processing in the brain. Therefore, the relationship between headphone usage among healthy subjects become pertinent. This study is aimed at evaluating the effect of headphone on working memory using N-back task. One hundred (100) participants (55 headphone users and 45 non-headphone user’s) within the age range of 18-31 years were assessed. Participants were instructed to keep in memory, a series of letters and say “target” whenever there was a repetition of letter with exactly one intervening letter and to remain silent when any other letter appeared. The results of this study showed that there was no statistically significant difference in working memory between headphone and non-headphone users with p>0.05. In conclusion, this study revealed headphone use has no effect on working memory of the participants subjected to N–back test.

Prefrontal Hemodynamics of Physical Activity and Environmental Complexity During Cognitive Work

2017 ◽  
Vol 59 (1) ◽  
pp. 147-162 ◽  
Author(s):  
Ryan McKendrick ◽  
Ranjana Mehta ◽  
Hasan Ayaz ◽  
Melissa Scheldrup ◽  
Raja Parasuraman
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Selective Attention ◽  
Memory Performance ◽  
Physical Work ◽  
Environmental Complexity ◽  
Cognitive States ◽  
Executive Processing ◽  
Cognitive Work ◽  
Back Task

Objective: The aim of this study was to assess performance and cognitive states during cognitive work in the presence of physical work and in natural settings. Background: Authors of previous studies have examined the interaction between cognitive and physical work, finding performance decrements in working memory. Neuroimaging has revealed increases and decreases in prefrontal oxygenated hemoglobin during the interaction of cognitive and physical work. The effect of environment on cognitive-physical dual tasking has not been previously considered. Method: Thirteen participants were monitored with wireless functional near-infrared spectroscopy (fNIRS) as they performed an auditory 1-back task while sitting, walking indoors, and walking outdoors. Results: Relative to sitting and walking indoors, auditory working memory performance declined when participants were walking outdoors. Sitting during the auditory 1-back task increased oxygenated hemoglobin and decreased deoxygenated hemoglobin in bilateral prefrontal cortex. Walking reduced the total hemoglobin available to bilateral prefrontal cortex. An increase in environmental complexity reduced oxygenated hemoglobin and increased deoxygenated hemoglobin in bilateral prefrontal cortex. Conclusion: Wireless fNIRS is capable of monitoring cognitive states in naturalistic environments. Selective attention and physical work compete with executive processing. During executive processing loading of selective attention and physical work results in deactivation of bilateral prefrontal cortex and degraded working memory performance, indicating that physical work and concomitant selective attention may supersede executive processing in the distribution of mental resources. Application: This research informs decision-making procedures in work where working memory, physical activity, and attention interact. Where working memory is paramount, precautions should be taken to eliminate competition from physical work and selective attention.

Perception of Simple and Complex Visual Stimuli: Decision Strategies and Hemispheric Differences in Same—Different Judgments

Perception ◽  
1995 ◽  
Vol 24 (7) ◽  
pp. 787-809 ◽  
Author(s):  
R John Irwin ◽  
Margaret A Francis
Keyword(s):  
Visual Field ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Visual Stimuli ◽  
Optimal Decision ◽  
Hemispheric Differences ◽  
Decision Strategy ◽  
Decision Strategies ◽  
Visual Patterns ◽  
Rating Method

The accuracy with which observers could judge whether two visual stimuli were the same or different was measured with the rating method of detection theory. For judgments of whether two pictures referred to natural or manufactured things, the shape of the obtained receiver operating characteristic (ROC) was consistent with the observers adopting an optimal decision strategy. A similar result was found for judgments of complex but meaningless visual patterns. For judgments of whether two colours that differed along a simple sensory dimension were the same or different, however, the resulting ROC was consistent with the observers adopting a suboptimal differencing strategy. The accuracy of the judgments did not depend on the visual field to which the stimuli were presented.

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