scholarly journals Modeling the influence of working memory, reinforcement, and action uncertainty on reaction time and choice during instrumental learning

2020 ◽  
Author(s):  
Samuel D. McDougle ◽  
Anne G. E. Collins
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
Instrumental Learning

scholarly journals Modeling the influence of working memory, reinforcement, and action uncertainty on reaction time and choice during instrumental learning

2019 ◽  
Author(s):  
Samuel McDougle ◽  
Anne Collins
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Reaction Time ◽  
Process Model ◽  
Task Complexity ◽  
Sequential Sampling ◽  
Instrumental Learning ◽  
Decision Dynamics ◽  
Reward Contingencies ◽  
And Task

What determines the speed of our decisions? Various models of decision-making have focused on perceptual evidence, past experience, and task complexity as important factors determining the degree of deliberation needed for a decision. Here, we build on a sequential sampling decision-making framework to develop a new model that captures a range of reaction time (RT) effects by accounting for both working memory and instrumental learning processes. The model captures choices and RTs at various stages of learning, and in learning environments with varying complexity. Moreover, the model generalizes from tasks with deterministic reward contingencies to probabilistic ones. The model succeeds in part by incorporating prior uncertainty over actions when modeling RT. This straightforward process model provides a parsimonious account of decision dynamics during instrumental learning and makes unique predictions about internal representations of action values.

scholarly journals Hot and cold cognitive disturbances in antidepressant-free patients with major depressive disorder: a NeuroPharm study

2020 ◽  
pp. 1-10
Author(s):  
V. H. Dam ◽  
D. S. Stenbæk ◽  
K. Köhler-Forsberg ◽  
C. Ip ◽  
B. Ozenne ◽  
...  
Keyword(s):  
Working Memory ◽  
Major Depressive Disorder ◽  
Reaction Time ◽  
Depressive Disorder ◽  
Healthy Controls ◽  
Cognitive Profiles ◽  
Depression Severity ◽  
Major Depressive ◽  
Depressed Patients ◽  
Cognitive Disturbances

Abstract Background Cognitive disturbances are common and disabling features of major depressive disorder (MDD). Previous studies provide limited insight into the co-occurrence of hot (emotion-dependent) and cold (emotion-independent) cognitive disturbances in MDD. Therefore, we here map both hot and cold cognition in depressed patients compared to healthy individuals. Methods We collected neuropsychological data from 92 antidepressant-free MDD patients and 103 healthy controls. All participants completed a comprehensive neuropsychological test battery assessing hot cognition including emotion processing, affective verbal memory and social cognition as well as cold cognition including verbal and working memory and reaction time. Results The depressed patients showed small to moderate negative affective biases on emotion processing outcomes, moderate increases in ratings of guilt and shame and moderate deficits in verbal and working memory as well as moderately slowed reaction time compared to healthy controls. We observed no correlations between individual cognitive tasks and depression severity in the depressed patients. Lastly, an exploratory cluster analysis suggested the presence of three cognitive profiles in MDD: one characterised predominantly by disturbed hot cognitive functions, one characterised predominantly by disturbed cold cognitive functions and one characterised by global impairment across all cognitive domains. Notably, the three cognitive profiles differed in depression severity. Conclusion We identified a pattern of small to moderate disturbances in both hot and cold cognition in MDD. While none of the individual cognitive outcomes mapped onto depression severity, cognitive profile clusters did. Overall cognition-based stratification tools may be useful in precision medicine approaches to MDD.

scholarly journals Reaction time, inhibition, working memory and ‘delay aversion’ performance: genetic influences and their interpretation

2006 ◽  
Vol 36 (11) ◽  
pp. 1613-1624 ◽  
Author(s):  
JONNA KUNTSI ◽  
HANNAH ROGERS ◽  
GREER SWINARD ◽  
NORBERT BÖRGER ◽  
JAAP van der MEERE ◽  
...  
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
Performance Test ◽  
Genetic Influences ◽  
Moderate Degree ◽  
Delay Aversion ◽  
Retest Reliability ◽  
Combining Data ◽  
Heritability Estimates ◽  
Test Retest Reliability

Background. For candidate endophenotypes to be useful for psychiatric genetic research, they first of all need to show significant genetic influences. To address the relative lack of previous data, we set to investigate the extent of genetic and environmental influences on performance in a set of theoretically driven cognitive-experimental tasks in a large twin sample. We further aimed to illustrate how test–retest reliability of the measures affects the estimates.Method. Four-hundred 7- to 9-year-old twin pairs were assessed individually on tasks measuring reaction time, inhibition, working memory and ‘delay aversion’ performance. Test–retest reliability data on some of the key measures were available from a previous study.Results. Several key measures of reaction time, inhibition and working-memory performance indicated a moderate degree of genetic influence. Combining data across theoretically related tasks increased the heritability estimates, as illustrated by the heritability estimates of 60% for mean reaction time and 50% for reaction-time variability. Psychometric properties (reliability or ceiling effects) had a substantial influence on the estimates for some measures.Conclusions. The data support the usefulness of several of the variables for endophenotype studies that aim to link genes to cognitive and motivational processes. Importantly, the data also illustrate specific conditions under which the true extent of genetic influences may be underestimated and hence the usefulness for genetic mapping studies compromised, and suggest ways to address this.

scholarly journals Cognitive impairment as a function of sleep quality and gender

2019 ◽  
pp. 4
Author(s):  
R. Akhil ◽  
B.P. Nair
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
Sleep Quality ◽  
Sustained Attention ◽  
Divided Attention ◽  
Poor Sleep ◽  
Poor Sleep Quality ◽  
Vigilance Test ◽  
And Gender ◽  
Good Sleep

Background: The study aims at finding whether there is any significant difference between sub-groups classified on the basis of sleep quality (good sleep quality and poor sleep quality) and gender in the performance of various cognitive functioning tests like Visual N Back Test (N Back 1and N Back 2 test) for working memory, Triad test for divided attention, Digit Vigilance Test for sustained attention and Reaction time test (simple reaction time and choice reaction time). Materials and methods: The sample consisted of 30 participants, both males (N=13) and females (N=17) in the age range between 18 to 30 years, randomly drawn from Thiruvananthapuram and Kollam districts of Kerala. The participants of the study are screened and categorized into two groups of 15 members each on the basis of the scores obtained in the Pittsburgh Sleep Quality Index (PSQI). t-test and two-way ANOVA were performed to test the significance of the hypotheses. Results: The results showed that the participants with poor sleep quality significantly differed from those with good sleep quality and committed more number of errors in the triad test of divided attention and took more time and committed more errors in the completion of the digit vigilance test of sustained attention. Conclusion: A gender advantage favoring females was seen on the test of working memory, test for sustained attention and the test for choice reaction time. An interaction between sleep quality and gender was noticed only on the test of divided attention. It was seen that males with poor sleep quality are more impaired in divided attention tasks than females with poor sleep quality.

scholarly journals Functional Interaction Between NMDA and mGlu5 Receptors: Effects on Working Memory, Instrumental Learning, Motor Behaviors, and Dopamine Release

2004 ◽  
Vol 29 (7) ◽  
pp. 1259-1269 ◽  
Author(s):  
Houman Homayoun ◽  
Mark R Stefani ◽  
Barbara W Adams ◽  
Gilles D Tamagan ◽  
Bita Moghaddam
Keyword(s):  
Working Memory ◽  
Dopamine Release ◽  
Instrumental Learning ◽  
Functional Interaction ◽  
Motor Behaviors ◽  
Mglu5 Receptors

scholarly journals Can we measure working memory via the Internet? The reliability and factorial validity of an online n-back task

2016 ◽  
Vol 47 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Konrad Kulikowski ◽  
Katarzyna Potasz-Kulikowska
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
The Internet ◽  
Memory Research ◽  
Measurement Models ◽  
Home Computers ◽  
Confirmatory Factor ◽  
Accuracy Indices ◽  
First Time ◽  
Back Task

Abstract The aim of this study was to check whether an online n-back task conducted in the uncontrolled environment of the Internet can yield valid and reliable data. For this purpose, 169 participants completed an online n-back task with n1, n2 and n3 blocks on their home computers. The results have shown acceptable reliability for overall accuracy and reaction time indices across n1, n2, n3 blocks, as well as for reaction time indices for each n block. Unacceptable reliability has been found for separate n levels accuracy indices and for response bias indices. Confirmatory factor analysis has revealed that, among 8 proposed measurement models, the best fit for the data collected is a model with two uncorrelated factors: accuracy consisting of n1, n2, n3 indices and reaction time consisting of n2, n3 indices. The results of this study have demonstrated for the first time that a reliable administration of online n-back task is possible and may therefore give rise to new opportunities for working memory research.

scholarly journals Effects of SuperUlam on Supporting Concentration and Mood: A Randomized, Double-Blind, Placebo-Controlled Crossover Study

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jay K Udani
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
Cognitive Function ◽  
Executive Functioning ◽  
Crossover Study ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Study Product ◽  
Total Mood Disturbance ◽  
Significant Difference

Background. SuperUlam is a proprietary blend of natural ingredients aimed at supporting brain health. We aimed to evaluate the effect of SuperUlam on attention and mood in healthy adults.Methods. Twenty healthy individuals aged 35–65 were enrolled in this randomized, double-blind, placebo-controlled, crossover study. Study duration was 3 weeks and consisted of 3 visits. Measurement of cognitive function included computer-based testing of reaction time, complex attention, working memory, sustained attention, and executive functioning. Mood testing was performed via the profile of mood states (POMS) survey and the Chalder fatigue scale.Results. Cognitive function testing demonstrated a significant improvement from baseline in executive functioning, cognitive flexibility, reaction time, and working memory in the product group only (P<0.05). When comparing the study product to placebo, the data demonstrated a significant decrease in tension, depression, and anger (P<0.05). There was no significant difference between the product and placebo in the other measures of mood, including vigor, fatigue, confusion, and total mood disturbance. No adverse events were reported.Conclusions.Supplementation with SuperUlam is safe to consume with potential benefits to cognitive function and mood.

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