scholarly journals Optimizing Design Efficiency of Free Recall Events for fMRI

2010 ◽  
Vol 22 (10) ◽  
pp. 2238-2250 ◽  
Author(s):  
Ilke Öztekin ◽  
Nicole M. Long ◽  
David Badre
Keyword(s):  
Free Recall ◽  
Recall Performance ◽  
Memory Search ◽  
Data Sets ◽  
Neural Activation ◽  
Design Efficiency ◽  
Recall Latency ◽  
Optimizing Design ◽  
And Performance ◽  
Latency Distributions

Free recall is a fundamental paradigm for studying memory retrieval in the context of minimal cue support. Accordingly, free recall has been extensively studied using behavioral methods. However, the neural mechanisms that support free recall have not been fully investigated due to technical challenges associated with probing individual recall events with neuroimaging methods. Of particular concern is the extent to which the uncontrolled latencies associated with recall events can confer sufficient design efficiency to permit neural activation for individual conditions to be distinguished. The present study sought to rigorously assess the feasibility of testing individual free recall events with fMRI. We used both theoretically and empirically derived free recall latency distributions to generate simulated fMRI data sets and assessed design efficiency across a range of parameters that describe free recall performance and fMRI designs. In addition, two fMRI experiments empirically assessed whether differential neural activation in visual cortex at onsets determined by true free recall performance across different conditions can be resolved. Collectively, these results specify the design and performance parameters that can provide comparable efficiency between free recall designs and more traditional jittered event-related designs. These findings suggest that assessing BOLD response during free recall using fMRI is feasible, under certain conditions, and can serve as a powerful tool in understanding the neural bases of memory search and overt retrieval.

Decoding Episodic Retrieval Processes: Frontoparietal and Medial Temporal Lobe Contributions to Free Recall

2016 ◽  
Vol 28 (1) ◽  
pp. 125-139 ◽  
Author(s):  
James E. Kragel ◽  
Sean M. Polyn
Keyword(s):  
Free Recall ◽  
Temporal Lobe ◽  
Parietal Cortex ◽  
Medial Temporal Lobe ◽  
Posterior Parietal Cortex ◽  
Activity Patterns ◽  
Memory Search ◽  
Correct Identification ◽  
Neural Activation ◽  
Posterior Parietal

Neuroimaging studies of recognition memory have identified distinct patterns of cortical activity associated with two sets of cognitive processes: Recollective processes supporting retrieval of information specifying a probe item's original source are associated with the posterior hippocampus, ventral posterior parietal cortex, and medial pFC. Familiarity processes supporting the correct identification of previously studied probes (in the absence of a recollective response) are associated with activity in anterior medial temporal lobe (MTL) structures including the perirhinal cortex and anterior hippocampus, in addition to lateral prefrontal and dorsal posterior parietal cortex. Here, we address an open question in the cognitive neuroscientific literature: To what extent are these same neurocognitive processes engaged during an internally directed memory search task like free recall? We recorded fMRI activity while participants performed a series of free recall and source recognition trials, and we used a combination of univariate and multivariate analysis techniques to compare neural activation profiles across the two tasks. Univariate analyses showed that posterior MTL regions were commonly associated with recollective processes during source recognition and with free recall responses. Prefrontal and posterior parietal regions were commonly associated with familiarity processes and free recall responses, whereas anterior MTL regions were only associated with familiarity processes during recognition. In contrast with the univariate results, free recall activity patterns characterized using multivariate pattern analysis did not reliably match the neural patterns associated with recollective processes. However, these free recall patterns did reliably match patterns associated with familiarity processes, supporting theories of memory in which common cognitive mechanisms support both item recognition and free recall.

scholarly journals Using metamemory measures and memory tests to estimate eyewitness free recall performance

2019 ◽  
Author(s):  
Renan Benigno Saraiva ◽  
LORRAINE HOPE ◽  
Robert Horselenberg ◽  
James Ost ◽  
James D. Sauer ◽  
...  
Keyword(s):  
Free Recall ◽  
Recall Performance ◽  
Memory Capacity ◽  
Cued Recall ◽  
General Knowledge ◽  
Memory Tests ◽  
Subjective Assessments ◽  
Dependent Variables ◽  
And Performance ◽  
Mock Crime

Using a mock witness methodology, we investigated the predictive value of metamemory measures and objective memory tests as indicators of eyewitness free recall performance. Participants (n = 208) first completed a metamemory assessment that included assessments of self-rated memory capacity, memory development and use of strategies. In a separate session, participants watched a mock crime video and provided a free recall account, followed by one out of four independent memory tests (i.e., free recall, cued recall, face recognition and general knowledge). Accuracy, amount of details reported, confidence and over/underconfidence in the eyewitness free recall were the main dependent variables. Results indicated three main findings: (1) subjective assessments of memory capacity were not related to eyewitness free recall performance; (2) although individual confidence and over/underconfidence was somewhat stable across different memory tests, accuracy was less stable; and (3) individuals with higher self-rated memory capacity had a slightly stronger confidence-accuracy relation in free recall. These results are discussed with respect to metamemory assessments and performance stability across memory tests of different domains.

Limitations to the Spacing Effect

2005 ◽  
Vol 52 (4) ◽  
pp. 257-263 ◽  
Author(s):  
Peter P. J. L. Verkoeijen ◽  
Remy M. J. P. Rikers ◽  
Henk G. Schmidt
Keyword(s):  
Free Recall ◽  
Phase Retrieval ◽  
Incidental Learning ◽  
Factor Model ◽  
Recall Performance ◽  
Spacing Effect ◽  
Word List ◽  
Intentional Learning ◽  
Study Phase ◽  
Learning Condition

Abstract. The spacing effect refers to the finding that memory for repeated items improves when the interrepetition interval increases. To explain the spacing effect in free-recall tasks, a two-factor model has been put forward that combines mechanisms of contextual variability and study-phase retrieval (e.g., Raaijmakers, 2003 ; Verkoeijen, Rikers, & Schmidt, 2004 ). An important, yet untested, implication of this model is that free recall of repetitions should follow an inverted u-shaped relationship with interrepetition spacing. To demonstrate the suggested relationship an experiment was conducted. Participants studied a word list, consisting of items repeated at different interrepetition intervals, either under incidental or under intentional learning instructions. Subsequently, participants received a free-recall test. The results revealed an inverted u-shaped relationship between free recall and interrepetition spacing in both the incidental-learning condition and the intentional-learning condition. Moreover, for intentionally learned repetitions, the maximum free-recall performance was located at a longer interrepetition interval than for incidentally learned repetitions. These findings are interpreted in terms of the two-factor model of spacing effects in free-recall tasks.

Articulatory Rehearsal Is More Than Refreshing Memory Traces

2013 ◽  
Vol 60 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Ryoji Nishiyama ◽  
Jun Ukita
Keyword(s):  
Free Recall ◽  
Recall Performance ◽  
Verbal Working Memory ◽  
Verbal Information ◽  
Free Recall Task ◽  
Study Item ◽  
Phonological Representations ◽  
Memory Traces ◽  
Short Period ◽  
Serial Position Curves

This study examined whether additional articulatory rehearsal induced temporary durability of phonological representations, using a 10-s delayed nonword free recall task. Three experiments demonstrated that cumulative rehearsal between the offset of the last study item and the start of the filled delay (Experiments 1 and 3) and a fixed rehearsal of the immediate item during the subsequent interstimulus interval (Experiments 2 and 3) improved free recall performance. These results suggest that an additional rehearsal helps to stabilize phonological representations for a short period. Furthermore, the analyses of serial position curves suggested that the frequency of the articulation affected the durability of the phonological representation. The significance of these findings as clues of the mechanism maintaining verbal information (i.e., verbal working memory) is discussed.

A Reliability-Based Approach to Assess Fatigue Behaviour Based on Small Incomplete Data Sets

2008 ◽  
Vol 44-46 ◽  
pp. 871-878 ◽  
Author(s):  
Chu Yang Luo ◽  
Jun Jiang Xiong ◽  
R.A. Shenoi
Keyword(s):  
Incomplete Data ◽  
Standard Procedure ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Small Sample ◽  
Data Sets ◽  
Safe Life ◽  
A New Technique ◽  
And Performance

This paper outlines a new technique to address the paucity of data in determining fatigue life and performance based on reliability concepts. Two new randomized models are presented for estimating the safe life and pS-N curve, by using the standard procedure for statistical analysis and dealing with small sample numbers of incomplete data. The confidence level formulations for the safe and p-S-N curve are also given. The concepts are then applied for the determination of the safe life and p-S-N curve. Two sets of fatigue tests for the safe life and p-S-N curve are conducted to validate the presented method, demonstrating the practical use of the proposed technique.

scholarly journals Using Learning Analytics to Assess Student Learning in Online Courses

2016 ◽  
Vol 13 (3) ◽  
pp. 110-130 ◽  
Author(s):  
Florence Martin ◽  
◽  
Abdou Ndoye ◽  
Keyword(s):  
Learning Analytics ◽  
Data Analytics ◽  
Qualitative Data ◽  
Online Courses ◽  
Instructional Designers ◽  
Data Sets ◽  
Online Assessments ◽  
Visualization Tools ◽  
And Performance ◽  
Analyze Data

Learning analytics can be used to enhance student engagement and performance in online courses. Using learning analytics, instructors can collect and analyze data about students and improve the design and delivery of instruction to make it more meaningful for them. In this paper, the authors review different categories of online assessments and identify data sets that can be collected and analyzed for each of them. Two different data analytics and visualization tools were used: Tableau for quantitative data and Many Eyes for qualitative data. This paper has implications for instructors, instructional designers, administrators, and educational researchers who use online assessments.

A Real-Time Log Analyzer Based on MongoDB

2014 ◽  
Vol 571-572 ◽  
pp. 497-501 ◽  
Author(s):  
Qi Lv ◽  
Wei Xie
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Performance Comparison ◽  
Log Analysis ◽  
Data Sets ◽  
Time Data ◽  
Real Time Analysis ◽  
Large Scale Data ◽  
Implementation Approach ◽  
And Performance

Real-time log analysis on large scale data is important for applications. Specifically, real-time refers to UI latency within 100ms. Therefore, techniques which efficiently support real-time analysis over large log data sets are desired. MongoDB provides well query performance, aggregation frameworks, and distributed architecture which is suitable for real-time data query and massive log analysis. In this paper, a novel implementation approach for an event driven file log analyzer is presented, and performance comparison of query, scan and aggregation operations over MongoDB, HBase and MySQL is analyzed. Our experimental results show that HBase performs best balanced in all operations, while MongoDB provides less than 10ms query speed in some operations which is most suitable for real-time applications.

Operation Diagnosis of a Combined Cycle Based on the Structural Theory of Thermoeconomics

1999 ◽  
Author(s):  
Luis Correas ◽  
Ángel Martínez ◽  
Antonio Valero
Keyword(s):  
Power Plants ◽  
Poor Quality ◽  
Structural Theory ◽  
Combined Cycle ◽  
Data Reconciliation ◽  
Data Sets ◽  
Component Level ◽  
Performance Diagnosis ◽  
Field Instrumentation ◽  
And Performance

Abstract Diagnosis of the performance of energy was theoretically developed based on the Structural Theory (Valero, Serra and Lozano, 1993), and traditionally Thermoeconomics have usually been applied to the design of power plants and comparison between alternatives. However, the application of thermoeconomic techniques to actual power plants has always to face the generally poor quality of measurement readings from the standard field instrumentation as an unavoidable first step. The proposed methodology focuses on measurement uncertainty estimation and performance calculation by means of data reconciliation techniques, in order to obtain the most confident plant balance upon the available instrumentation. The formulation of the Structural Theory has been applied to a combined cycle, where the Fuel-Product relationships at the component level must be optimally defined for a correct malfunction interpretation. This set of relationships determines the ability to diagnose and the level of the diagnostics obtained. The paper reports the application of the methodology to a 280 MW rated combined cycle, where performance diagnosis is illustrated with results from a collection of actual operation data sets. The results show that data reconciliation yields sufficient accuracy to conduct a thermoeconomic analysis, and how the estimated impact on fuel correlates with physical causes. Hence the feasibility of thermoeconomic analysis of plant operation is demonstrated.

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