O-43 Data-driven selection of active iEEG channels during verbal memory task performance

2019 ◽  
Vol 130 (7) ◽  
pp. e35
Author(s):  
Çağdaş Topçu ◽  
Victoria S. Marks ◽  
Michal T. Kucewicz
Keyword(s):  
Task Performance ◽  
Verbal Memory ◽  
Memory Task ◽  
Data Driven ◽  
O 43 ◽  
Selection Of

Understanding Driver Behavior after Concussion: A Machine-Learning Approach

2020 ◽  
Vol 64 (1) ◽  
pp. 1911-1915
Author(s):  
Maryam Daniali ◽  
Dario D. Salvucci ◽  
Maria T. Schultheis
Keyword(s):  
Machine Learning ◽  
Task Performance ◽  
Verbal Memory ◽  
Driving Simulator ◽  
Cognitive Impairments ◽  
Driver Behavior ◽  
Memory Task ◽  
Learning Approach ◽  
Behavioral Task ◽  
Machine Learning Approach

Concussions are common cognitive impairments, but their effects on task performance in general, and on driving in particular, are not well understood. To better understand the effects of concussion on driving, we investigated previously gathered data on twenty-two people with a concussion, driving in a virtual-reality driving simulator (VRDS), and twenty-two non-concussed matched drivers. Participants were asked to per-form a behavioral task (either coin sorting or a verbal memory task) while driving. In this study, we chose a few common metrics from the VRDS and tracked their changes through time for each participant. Our pro-posed method—namely, the use of convolutional neural networks for classification and analysis—can accu-rately classify concussed driving and extract local features on driving sequences that translate to behavioral driving signatures. Overall, our method improves identification and understanding of clinically relevant driv-ing behaviors for concussed individuals and should generalize well to other types of impairments.

Individual Differences in Secondary Task Performance and Subjective Estimation of Workload

1985 ◽  
Vol 56 (1) ◽  
pp. 311-322 ◽  
Author(s):  
Kathryn A. Bloem ◽  
Diane L. Damos
Keyword(s):  
Individual Differences ◽  
Task Performance ◽  
Verbal Memory ◽  
Secondary Task ◽  
Subjective Experience ◽  
Memory Task ◽  
Primary Task ◽  
Classification Task ◽  
Residual Capacity ◽  
Task Differences

This experiment had two purposes. First, it attempted to replicate the easy-to-hard prediction for residual capacity described by Lansman and Hunt (1982) for two complex task combinations. Second, it examined the relation between individual differences in resource capacity, as indicated by the easy-to-hard prediction, and the subjective experience of workload. One task combination involved a verbal-memory task paired with a vowel-consonant classification task. The other combination involved a paired-associate task with a name-classification task. The easy-to-hard prediction was not replicated for either task combination; easy primary task performance provided a better prediction of hard primary task performances than did secondary task performance. Measures of residual capacity were not related to subjective ratings of workload, however, the workload scales were sensitive to between-task differences.

Clinical and Cognitive Factors Associated With Verbal Memory Task Performance in Patients With Schizophrenia

2001 ◽  
Vol 158 (5) ◽  
pp. 758-764 ◽  
Author(s):  
Gildas Brébion ◽  
Jack M. Gorman ◽  
Dolores Malaspina ◽  
Zafar Sharif ◽  
Xavier Amador
Keyword(s):  
Task Performance ◽  
Verbal Memory ◽  
Memory Task ◽  
Cognitive Factors ◽  
Factors Associated

scholarly journals Incorporating radiomics into clinical trials: expert consensus on considerations for data-driven compared to biologically driven quantitative biomarkers

2021 ◽  
Author(s):  
Laure Fournier ◽  
Lena Costaridou ◽  
Luc Bidaut ◽  
Nicolas Michoux ◽  
Frederic E. Lecouvet ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Quantitative Imaging ◽  
A Priori ◽  
External Validation ◽  
Data Driven ◽  
Imaging Biomarkers ◽  
Clinical Validation ◽  
Biological Processes ◽  
Imaging Data ◽  
Selection Of

Abstract Existing quantitative imaging biomarkers (QIBs) are associated with known biological tissue characteristics and follow a well-understood path of technical, biological and clinical validation before incorporation into clinical trials. In radiomics, novel data-driven processes extract numerous visually imperceptible statistical features from the imaging data with no a priori assumptions on their correlation with biological processes. The selection of relevant features (radiomic signature) and incorporation into clinical trials therefore requires additional considerations to ensure meaningful imaging endpoints. Also, the number of radiomic features tested means that power calculations would result in sample sizes impossible to achieve within clinical trials. This article examines how the process of standardising and validating data-driven imaging biomarkers differs from those based on biological associations. Radiomic signatures are best developed initially on datasets that represent diversity of acquisition protocols as well as diversity of disease and of normal findings, rather than within clinical trials with standardised and optimised protocols as this would risk the selection of radiomic features being linked to the imaging process rather than the pathology. Normalisation through discretisation and feature harmonisation are essential pre-processing steps. Biological correlation may be performed after the technical and clinical validity of a radiomic signature is established, but is not mandatory. Feature selection may be part of discovery within a radiomics-specific trial or represent exploratory endpoints within an established trial; a previously validated radiomic signature may even be used as a primary/secondary endpoint, particularly if associations are demonstrated with specific biological processes and pathways being targeted within clinical trials. Key Points • Data-driven processes like radiomics risk false discoveries due to high-dimensionality of the dataset compared to sample size, making adequate diversity of the data, cross-validation and external validation essential to mitigate the risks of spurious associations and overfitting. • Use of radiomic signatures within clinical trials requires multistep standardisation of image acquisition, image analysis and data mining processes. • Biological correlation may be established after clinical validation but is not mandatory.

scholarly journals Working Memory Performance under a Negative Affect Is More Susceptible to Higher Cognitive Workloads with Different Neural Haemodynamic Correlates

2021 ◽  
Vol 11 (7) ◽  
pp. 935
Author(s):  
Ying Xing Feng ◽  
Masashi Kiguchi ◽  
Wei Chun Ung ◽  
Sarat Chandra Dass ◽  
Ahmad Fadzil Mohd Hani ◽  
...  
Keyword(s):  
Working Memory ◽  
Task Performance ◽  
Memory Performance ◽  
Affective State ◽  
Memory Task ◽  
Interactive Effects ◽  
Functional Near Infrared Spectroscopy ◽  
Affective Factors ◽  
Related Stress ◽  
Haemodynamic Activity

The effect of stress on task performance is complex, too much or too little stress negatively affects performance and there exists an optimal level of stress to drive optimal performance. Task difficulty and external affective factors are distinct stressors that impact cognitive performance. Neuroimaging studies showed that mood affects working memory performance and the correlates are changes in haemodynamic activity in the prefrontal cortex (PFC). We investigate the interactive effects of affective states and working memory load (WML) on working memory task performance and haemodynamic activity using functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants. We seek to understand if haemodynamic responses could tell apart workload-related stress from situational stress arising from external affective distraction. We found that the haemodynamic changes towards affective stressor- and workload-related stress were more dominant in the medial and lateral PFC, respectively. Our study reveals distinct affective state-dependent modulations of haemodynamic activity with increasing WML in n-back tasks, which correlate with decreasing performance. The influence of a negative effect on performance is greater at higher WML, and haemodynamic activity showed evident changes in temporal, and both spatial and strength of activation differently with WML.

Does Secondary Task Measure Outcome Conflict or Resource Allocation?

1992 ◽  
Vol 36 (18) ◽  
pp. 1398-1402
Author(s):  
Pamela S. Tsang ◽  
Tonya L. Shaner
Keyword(s):  
Resource Allocation ◽  
Task Performance ◽  
Dual Task ◽  
Secondary Task ◽  
Tracking Error ◽  
Memory Task ◽  
Primary Task ◽  
Memory Probe ◽  
Temporal Predictability ◽  
Task Measure

The secondary task technique was used to test two alternative explanations of dual task decrement: outcome conflict and resource allocation. Subjects time-shared a continuous tracking task and a discrete Sternberg memory task. The memory probes were presented under three temporal predictability conditions. Dual task performance decrements in both the tracking and memory tasks suggested that the two tasks competed for some common resources, processes, or mechanisms. Although performance decrements were consistent with both the outcome conflict and resource allocation explanations, the two explanations propose different mechanisms by which the primary task could be protected from interference from the concurrent secondary task. The primary task performance could be protected by resource allocation or by strategic sequencing of the processing of the two tasks in order to avoid outcome conflict. In addition to examining the global trial means, moment-by-moment tracking error time-locked to the memory probe was also analyzed. There was little indication that the primary task was protected by resequencing of the processing of the two tasks. This together with the suggestion that predictable memory probes led to better protected primary task performance than less predictable memory probes lend support for the resource explanation.

scholarly journals Frontal Midline Theta Reflects Individual Task Performance in a Working Memory Task

2014 ◽  
Vol 28 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Urs Maurer ◽  
Silvia Brem ◽  
Martina Liechti ◽  
Stefano Maurizio ◽  
Lars Michels ◽  
...  
Keyword(s):  
Working Memory ◽  
Task Performance ◽  
Memory Task ◽  
Frontal Midline Theta ◽  
Individual Task

scholarly journals How Does Physical Demand Affect Cognitive Performance? Interference Between Outdoor Running And Narrative Memory

2018 ◽  
Vol 62 (1) ◽  
pp. 237-241
Author(s):  
Samantha L. Epling ◽  
Graham K. Edgar ◽  
Paul N. Russell ◽  
William S. Helton
Keyword(s):  
High Risk ◽  
Task Performance ◽  
Cognitive Performance ◽  
Real World ◽  
Dual Task ◽  
Memory Task ◽  
Search And Rescue ◽  
Dual Tasking ◽  
Physical Demand ◽  
Dual Task Paradigm

Dual-tasking situations are common in military, firefighting, search and rescue, and other high risk operations. Cognitive and physical demands can occur at the same time, but little is known about the specific demands of real world tasks or how they might interfere with one another. It is well known that attempting simultaneous tasks will divide and divert attention, but to what extent? In this experiment, a narrative memory task was paired with an outdoor running task, and as expected, memory task performance declined when participants were asked to run at the same time. It is suggested that more cognitively demanding physical tasks be used within this dual-task paradigm for a better understanding of the human cognitive resource structure, i.e., how and why certain tasks interfere.

scholarly journals Phenomenology of Visuo-spatial Working Memory Task Performance

2021 ◽  
Author(s):  
Aleš Oblak ◽  
Anka Slana Ozimič ◽  
Grega Repovš ◽  
Urban Kordeš
Keyword(s):  
Working Memory ◽  
Cognitive Psychology ◽  
Task Performance ◽  
Present Article ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Bodily Feelings ◽  
Psychological Tasks

In experimental cognitive psychology, objects of inquiry have typically been operationalized with psychological tasks. If we are interested in measuring the target phenomena, we must inquire into the validity of the task; that is, to what extent does the task elicit the phenomenon in question. If we subscribe to the second view, evaluating the validity and the interpretation of the gathered data can be supplemented by understanding the experience of solving psychological tasks. The aim of the present article is to investigate how individuals experience performing a psychological task, specifically, a visuo-spatial working memory task. We present ethnographic descriptions of different ways individuals can experience the same task. We focus on aspects of experience that comprise the overall sense of experience (e.g., bodily feelings, emotional atmosphere, mood). We discuss the methodological implications of our findings and the possibility of conducting a neurophenomenology of visuo-spatial working memory.

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