scholarly journals Monitoring Brain State and Behavioral Performance during Repetitive Visual Stimulation

2021 ◽  
Vol 11 (23) ◽  
pp. 11544
Author(s):  
Alexander K. Kuc ◽  
Semen A. Kurkin ◽  
Vladimir A. Maksimenko ◽  
Alexander N. Pisarchik ◽  
Alexander E. Hramov
Keyword(s):  
Visual Stimulation ◽  
Brain Activity ◽  
Decision Time ◽  
Task Demands ◽  
Brain State ◽  
Time On Task ◽  
Behavioral Performance ◽  
Task Effects ◽  
Perceptual Performance ◽  
Eeg Power

We tested whether changes in prestimulus neural activity predict behavioral performance (decision time and errors) during a prolonged visual task. The task was to classify ambiguous stimuli—Necker cubes; manipulating the degree of ambiguity from low ambiguity (LA) to high ambiguity (HA) changed the task difficulty. First, we assumed that the observer’s state changes over time, which leads to a change in the prestimulus brain activity. Second, we supposed that the prestimulus state produces a different effect on behavioral performance depending on the task demands. Monitoring behavioral responses, we revealed that the observer’s decision time decreased for both LA and HA stimuli during the task performance. The number of perceptual errors lowered for HA, but not for LA stimuli. EEG analysis revealed an increase in the prestimulus 9–11 Hz EEG power with task time. Finally, we found associations between the behavioral and neural estimates. The prestimulus EEG power negatively correlated with the decision time for LA stimuli and the erroneous responses rate for HA stimuli. The obtained results confirm that monitoring prestimulus EEG power enables predicting perceptual performance on the behavioral level. The observed different time-on-task effects on the LA and HA stimuli processing may shed light on the features of ambiguous perception.

scholarly journals An Analysis of the External Validity of EEG Spectral Power in an Uncontrolled Outdoor Environment during Default and Complex Neurocognitive States

2021 ◽  
Vol 11 (3) ◽  
pp. 330
Author(s):  
Dalton J. Edwards ◽  
Logan T. Trujillo
Keyword(s):  
External Validity ◽  
Spectral Power ◽  
Brain Activity ◽  
Outdoor Environment ◽  
Oscillatory Activity ◽  
Brain State ◽  
Beta Band ◽  
Eeg Spectral Power ◽  
Eeg Power ◽  
Human Participants

Traditionally, quantitative electroencephalography (QEEG) studies collect data within controlled laboratory environments that limit the external validity of scientific conclusions. To probe these validity limits, we used a mobile EEG system to record electrophysiological signals from human participants while they were located within a controlled laboratory environment and an uncontrolled outdoor environment exhibiting several moderate background influences. Participants performed two tasks during these recordings, one engaging brain activity related to several complex cognitive functions (number sense, attention, memory, executive function) and the other engaging two default brain states. We computed EEG spectral power over three frequency bands (theta: 4–7 Hz, alpha: 8–13 Hz, low beta: 14–20 Hz) where EEG oscillatory activity is known to correlate with the neurocognitive states engaged by these tasks. Null hypothesis significance testing yielded significant EEG power effects typical of the neurocognitive states engaged by each task, but only a beta-band power difference between the two background recording environments during the default brain state. Bayesian analysis showed that the remaining environment null effects were unlikely to reflect measurement insensitivities. This overall pattern of results supports the external validity of laboratory EEG power findings for complex and default neurocognitive states engaged within moderately uncontrolled environments.

The Eye Blink and Workload Considerations

1984 ◽  
Vol 28 (11) ◽  
pp. 942-944 ◽  
Author(s):  
John A. Stern ◽  
June J. Skelly
Keyword(s):  
Task Difficulty ◽  
Task Demands ◽  
High Fidelity ◽  
Time On Task ◽  
Blink Rate ◽  
Complex Environments ◽  
Eye Blink ◽  
Task Effects ◽  
Two Parameters ◽  
Task Modality

Two parameters of the eye blink, blink rate and blink duration, were used to assess workload in two independent operational studies. Both studies involved high fidelity strategic bomber mission simulations. The first study was an extended wartime mission where workload was evaluated during mission segments. The second study involved shorter, discrete training missions where task difficulty was systematically manipulated. Both studies produced complementary results. Results show that: (1) blink rate is significantly affected by task demands; (2) blink rate is sensitive to task modality; (3) blink duration is significantly affected by task modality and complexity; and (4) blink duration is a sensitive index of time on task effects. These data support the use of eye blink measurement in “noisy” complex environments as both a feasible and valuable assessment technique.

scholarly journals The Neural Architecture of Executive Functions Is Established by Middle Childhood

2018 ◽  
Author(s):  
Laura E. Engelhardt ◽  
K. Paige Harden ◽  
Elliot M. Tucker-Drob ◽  
Jessica A. Church
Keyword(s):  
Executive Functions ◽  
Middle Childhood ◽  
Cognitive Abilities ◽  
Functional Organization ◽  
Brain Activity ◽  
Brain Regions ◽  
Time On Task ◽  
Task Effects ◽  
Quantitative Changes ◽  
Functional Brain Activity

AbstractExecutive functions (EFs) are regulatory cognitive processes that support goal-directed thoughts and behaviors and that involve two primary networks of functional brain activity in adulthood. The current study assessed whether the same networks identified in adulthood underlie child EFs. Using task-based fMRI data from a diverse sample of N = 117 children and early adolescents (M age = 10.17 years), we assessed the extent to which neural activity was shared across three EF domains and whether these patterns reflected quantitative or qualitative differences relative to previously reported adult findings. Brain regions that were consistently engaged across switching, updating, and inhibition tasks closely corresponded to the cingulo-opercular and fronto-parietal networks identified in studies of adults. Isolating brain activity during more demanding task periods highlighted contributions of the dACC and anterior insular regions of the cingulo-opercular network. Results were independent of age and time-on-task effects. These results indicate that the two core brain networks that support EFs are in place by middle childhood. Improvement in EFs from middle childhood to adulthood, therefore, are likely due to quantitative changes in activity within these networks, rather than qualitative changes in the organization of the networks themselves. Improved knowledge of how the brain’s functional organization supports EF in childhood has critical implications for understanding the maturation of cognitive abilities.

An Adaptive and Learning System for Feedback-Controlled Evoked Response Studies

1981 ◽  
Vol 20 (03) ◽  
pp. 169-173
Author(s):  
J. Wagner ◽  
G. Pfurtscheixer
Keyword(s):  
Brain Activity ◽  
Evoked Response ◽  
Learning System ◽  
Time Interval ◽  
Electrical Brain Activity ◽  
Long Time ◽  
The Subject ◽  
Eeg Power ◽  
Stimulation System ◽  
Background Eeg

The shape, latency and amplitude of changes in electrical brain activity related to a stimulus (Evoked Potential) depend both on the stimulus parameters and on the background EEG at the time of stimulation. An adaptive, learnable stimulation system is introduced, whereby the subject is stimulated (e.g. with light), whenever the EEG power is subthreshold and minimal. Additionally, the system is conceived in such a way that a certain number of stimuli could be given within a particular time interval. Related to this time criterion, the threshold specific for each subject is calculated at the beginning of the experiment (preprocessing) and adapted to the EEG power during the processing mode because of long-time fluctuations and trends in the EEG. The process of adaptation is directed by a table which contains the necessary correction numbers for the threshold. Experiences of the stimulation system are reflected in an automatic correction of this table. Because the corrected and improved table is stored after each experiment and is used as the starting table for the next experiment, the system >learns<. The system introduced here can be used both for evoked response studies and for alpha-feedback experiments.

Learning to See Biological Motion: Brain Activity Parallels Behavior

2004 ◽  
Vol 16 (9) ◽  
pp. 1669-1679 ◽  
Author(s):  
Emily D. Grossman ◽  
Randolph Blake ◽  
Chai-Youn Kim
Keyword(s):  
Neural Activity ◽  
Biological Motion ◽  
Brain Activity ◽  
Daily Practice ◽  
Superior Temporal Sulcus ◽  
Fusiform Face Area ◽  
Face Area ◽  
Perceptual Performance ◽  
Trained Observers ◽  
Posterior Superior Temporal Sulcus

Individuals improve with practice on a variety of perceptual tasks, presumably reflecting plasticity in underlying neural mechanisms. We trained observers to discriminate biological motion from scrambled (nonbiological) motion and examined whether the resulting improvement in perceptual performance was accompanied by changes in activation within the posterior superior temporal sulcus and the fusiform “face area,” brain areas involved in perception of biological events. With daily practice, initially naive observers became more proficient at discriminating biological from scrambled animations embedded in an array of dynamic “noise” dots, with the extent of improvement varying among observers. Learning generalized to animations never seen before, indicating that observers had not simply memorized specific exemplars. In the same observers, neural activity prior to and following training was measured using functional magnetic resonance imaging. Neural activity within the posterior superior temporal sulcus and the fusiform “face area” reflected the participants' learning: BOLD signals were significantly larger after training in response both to animations experienced during training and to novel animations. The degree of learning was positively correlated with the amplitude changes in BOLD signals.

Time of day, time of sleep, and time on task effects on sleepiness and cognitive performance of bus drivers

2022 ◽  
Author(s):  
Maryam Maghsoudipour ◽  
Ramin Moradi ◽  
Sara Moghimi ◽  
Sonia Ancoli-Israel ◽  
Pamela N. DeYoung ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
Time Of Day ◽  
Time On Task ◽  
Bus Drivers ◽  
Task Effects

What can size tell us about abstract conceptual processing?

2021 ◽  
Author(s):  
Bo Yao ◽  
Jack Edward Taylor ◽  
Sara C Sereno
Keyword(s):  
Congruency Effect ◽  
Lexical Processing ◽  
Task Demands ◽  
Abstract Concepts ◽  
Physical Size ◽  
Conceptual Processing ◽  
Task Effects ◽  
Mental Worlds ◽  
Size Congruency

Embodied cognition theories propose that abstract concepts can be embodied via metaphorical extensions from experiences of the physical or the mental worlds. In three experiments, we explored how semantic size (e.g., the magnitude, dimension or extent of an object or a concept) of abstract concepts is mentally represented. We show that abstract size is metaphorically associated with the physical size of concrete objects (Experiment 1) and can produce a semantic-font size congruency effect comparable to that demonstrated in concrete words during online lexical processing (Experiment 2). Critically, this size congruency effect is large when a word is judged by its size but significantly smaller when it is judged by its emotionality (Experiment 3). Our results suggest that semantic size of abstract concepts can be represented in physical size and that such experiences are variably engaged under different task demands. The present findings advocate flexible embodiment of semantic representations, with an emphasis on the role of task effects on conceptual processing.

scholarly journals Stimulus-driven brain rhythms within the alpha band: The attentional-modulation conundrum

2018 ◽  
Author(s):  
Christian Keitel ◽  
Anne Keitel ◽  
Christopher SY Benwell ◽  
Christoph Daube ◽  
Gregor Thut ◽  
...  
Keyword(s):  
Spatial Attention ◽  
Visual Processing ◽  
Visual Stimulation ◽  
Brain Activity ◽  
Gain Control ◽  
Sensory Stimulation ◽  
Alpha Band ◽  
Visual Evoked Response ◽  
Brain Rhythms ◽  
Inhibitory Function

Two largely independent research lines use rhythmic sensory stimulation to study visual processing. Despite the use of strikingly similar experimental paradigms, they differ crucially in their notion of the stimulus-driven periodic brain responses: One regards them mostly as synchronised (entrained) intrinsic brain rhythms; the other assumes they are predominantly evoked responses (classically termed steady-state responses, or SSRs) that add to the ongoing brain activity. This conceptual difference can produce contradictory predictions about, and interpretations of, experimental outcomes. The effect of spatial attention on brain rhythms in the alpha-band (8-13 Hz) is one such instance: alpha-range SSRs have typically been found to increase in power when participants focus their spatial attention on laterally presented stimuli, in line with a gain control of the visual evoked response. In nearly identical experiments, retinotopic decreases in entrained alpha-band power have been reported, in line with the inhibitory function of intrinsic alpha. Here we reconcile these contradictory findings by showing that they result from a small but far-reaching difference between two common approaches to EEG spectral decomposition. In a new analysis of previously published EEG data, recorded during bilateral rhythmic visual stimulation, we find the typical SSR gain effect when emphasising stimulus-locked neural activity and the typical retinotopic alpha suppression when focusing on ongoing rhythms. These opposite but parallel effects suggest that spatial attention may bias the neural processing of dynamic visual stimulation via two complementary neural mechanisms.

scholarly journals Using experience to improve: how errors shape behavior and brain activity in monkeys

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5395
Author(s):  
Jose L. Pardo-Vazquez ◽  
Carlos Acuña
Keyword(s):  
Neuronal Activity ◽  
Decision Process ◽  
Brain Activity ◽  
Single Cells ◽  
Premotor Cortex ◽  
Strong Support ◽  
Behavioral Performance ◽  
Previous Trial ◽  
Current Trial ◽  
Future Behavior

Previous works have shown that neurons from the ventral premotor cortex (PMv) represent several elements of perceptual decisions. One of the most striking findings was that, after the outcome of the choice is known, neurons from PMv encode all the information necessary for evaluating the decision process. These results prompted us to suggest that this cortical area could be involved in shaping future behavior. In this work, we have characterized neuronal activity and behavioral performance as a function of the outcome of the previous trial. We found that the outcome of the immediately previous trial (n−1) significantly changes, in the current trial (n), the activity of single cells and behavioral performance. The outcome of trial n−2, however, does not affect either behavior or neuronal activity. Moreover, the outcome of difficult trials had a greater impact on performance and recruited more PMv neurons than the outcome of easy trials. These results give strong support to our suggestion that PMv neurons evaluate the decision process and use this information to modify future behavior.

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