Generalization in Human Category Learning: A Connectionist Account of Differences in Gradient after Discriminative and Non discriminative Training

1997 ◽  
Vol 50 (3) ◽  
pp. 607-630 ◽  
Author(s):  
A.J. Wills ◽  
I.P.L. McLaren
Keyword(s):  
Response Times ◽  
Discriminative Training ◽  
Network System ◽  
Significant Control ◽  
Decision Mechanism ◽  
Competitive Network ◽  
Comparable Effect ◽  
The Difference ◽  
Basic Prediction ◽  
Wagner Theory

Two experiments are reported that investigate the difference in gradient of generalization observed between one-category (non-discriminative) and two-category (discriminative) training. Extrapolating from the results of a number of animal learning studies, it was predicted that the gradient should be steeper under discriminative training. The first experiment confirms this basic prediction for the stimuli used, which were novel, prototype-structured, and constructed from 12 symbols positioned on a grid. An explanation for the effect, based on the Rescorla-Wagner theory of Pavlovian conditioning (Rescorla & Wagner, 1972), is that under non-discriminative training “incidental stimuli” have significant control over responding, whereas under discriminative training they do not. Incidental stimuli are those aspects of the stimulus, or the surrounding context, that are not differentially reinforced under discriminative training. This explanation leads to the prediction that a comparable effect of blocked versus intermixed discriminative training should also be found. This prediction is disconfirmed by the second experiment. An alternative model, still based on the Rescorla Wagner theory but with the addition of a decision mechanism comprising a threshold unit and a competitive network system, is proposed, and its ability to predict both the choice probabilities and the pattern of response times found is evaluated via simulation.

scholarly journals Bayesian confidence in optimal decisions

2020 ◽  
Author(s):  
Joshua Michael Calder-Travis ◽  
Lucie Charles ◽  
Rafal Bogacz ◽  
Nick Yeung
Keyword(s):  
Decision Making ◽  
Response Times ◽  
Perceptual Decision Making ◽  
Perceptual Decision ◽  
Decision Mechanism ◽  
Trial Basis ◽  
The Difference ◽  
Normative Models ◽  
The Brain ◽  
Quantitative Account

The drift diffusion model (DDM) provides an excellent account of decisions and response times. It also features the optimal property of tracking the difference in evidence between two options. However, the DDM struggles to account for human confidence reports, because responses are triggered when the difference in evidence reaches a set value, suggesting confidence in all decisions should be equal. Previously considered extensions to the DDM fall short of providing an adequate quantitative account of confidence. Possibly because of this, much confidence research has used non-normative models of the decision mechanism. Motivated by the idea that perceptual decision-making will reflect optimal computation, we consider 9 variants of the DDM. Motivated by the idea that the brain will not duplicate the representation of evidence, in all model variants confidence is read out from the decision mechanism. We compare the models to benchmark results, and make 4 qualitative predictions which we verify in a preregistered study. Modelling confidence on a trial-by-trial basis, we find that a subset of model variants provide an excellent account of the precise quantitative effects observed in confidence data. Specifically, models in which confidence reflects a miscalibrated Bayesian readout perform best. These results support the claim that confidence is based on the decision mechanism, which is itself optimal. Therefore, there is no need to abandon the idea that the implementation of perceptual decision-making will reflect optimal computation.

On the Difference Between Monkeys' and Humans' Response Times: Could It Be the Experimental Procedure?

2012 ◽  
Author(s):  
Guy E. Hawkins ◽  
Birte U. Forstmann ◽  
Eric-Jan Wagenmakers ◽  
Scott D. Brown
Keyword(s):  
Response Times ◽  
Experimental Procedure ◽  
The Difference

Development of a lightning model and implementation into a meteorological model developed in Japan~ Validation through the comparison with the ground base measurement

2021 ◽  
Author(s):  
Yousuke Sato ◽  
Syugo Hayashi ◽  
Akihiro Hashimoto
Keyword(s):  
Vertical Structure ◽  
Heavy Rain ◽  
Japan Meteorological Agency ◽  
Network System ◽  
Meteorological Model ◽  
Lightning Detection ◽  
Base Measurement ◽  
The Difference ◽  
Rain Events ◽  
The Vertical Distribution

<p>A lightning model was developed (Sato et al. 2019, 2021) and implemented into a community meteorological model in Japan (SCALE: Nishizawa et al. 2015, Sato et al. 2015). The lightning model coupled with SCALE was validated through the comparison with the ground base lightning measurement (LIghtning DEtection Network system: LIDEN) operated by Japan Meteorological Agency. For the validation, we conducted downscale simulations targeting on two heavy rain events, which occurred on July, 2017 and July, 2018. The heavy rainfall in both events were triggered by Baiu front system on July in Japan and cumulative precipitation exceeded 800 mm/48 hours, but lightning frequency in the 2017 case was much higher than that of the 2018 case.</p><p>Our results indicated that the model successfully reproduced the difference of the lightning frequency between the two heavy rain events. Our analyses elucidated that the difference in the lightning frequency was originated from the difference in the vertical distribution of the charged graupel, and as consequence, the vertical structure of the charge separation rate and the charge density.</p>

scholarly journals An Investigation of the Social Network System Competencies of High School Students in Japan

2018 ◽  
Vol 13 (05) ◽  
pp. 4 ◽  
Author(s):  
Masami Yoshida
Keyword(s):  
High School ◽  
High School Students ◽  
Social Network ◽  
Performance Criteria ◽  
Network System ◽  
School Students ◽  
Mean Values ◽  
The Social ◽  
Significant Difference ◽  
The Difference

We investigated the Social Network System (SNS) competencies of high school students in Japan. Student groups (from cities or regional areas) and the opinions of their teachers were compared. Twenty-five UNESCO criteria in three competency categories were selected. By two-way analysis of variance and paired-comparisons, we detected a significant difference in the opinions of students and teachers. Although the magnitude of the difference was small, by Dunnett’s multiple comparisons, the city and regional groups also differed from each other. Performance criteria items of risk awareness were valued the highest and most important in all groups; whereas technical skills and socio-cultural skills were reported as less proficient and less important by all groups. Classification of SNS-type was used, and the data of SNS sites with which the students were familiar and the mean values of related performance criteria items were applied to view the situation of students. By this approach, we confirmed that students are savvy in navigating socializing SNSs. Based on our findings, we propose important learning and societal-public activities relevant to SNSs.

Bilingual Representation of Discourse

1984 ◽  
Vol 54 (1) ◽  
pp. 83-90 ◽  
Author(s):  
R. Kim Guenther
Keyword(s):  
Response Times ◽  
The Other ◽  
The Difference

English-Persian bilingual subjects decided whether probes were true or false for some previously studied discourses written in either English or Persian. The response times to probes depicting explicit events were much faster when the probes were written in the same language as their discourses than when they were written in the other language. However, for probes depicting implicit or false events, the difference between response times to probes written in the same language and response times to probes written in the other language was substantially less. The results were consistent with the hypothesis that the form of the stored representation of the meaning of discourse is the same for both languages of the bilingual person.

Pore-Pressure-Coefficient Anisotropy Measurements for Intrinsic and Induced Anisotropy in Sandstone

2010 ◽  
Vol 13 (02) ◽  
pp. 265-274 ◽  
Author(s):  
Ashraf Al-Tahini ◽  
Younane Abousleiman
Keyword(s):  
Pore Pressure ◽  
Elastic Moduli ◽  
Pressure Coefficient ◽  
Induced Anisotropy ◽  
Transverse Anisotropy ◽  
Significant Control ◽  
Bedding Planes ◽  
Rock Structure ◽  
Stress Induced Anisotropy ◽  
The Difference

Summary In this study, we determine experimentally the effect of inherent and stress-induced anisotropy on stiffness components, elastic moduli, and Biot's pore-pressure coefficients (PPCs) for Lyons outcrop Colorado sandstone, which exhibits a clear transverse isotropic rock structure. Both dynamic and quasistatic methods were used under a nonhydrostatic state of stress to perform the measurements on dry core samples. Our assumption of apparent transverse anisotropy was confirmed initially with acoustic velocity measurements and at a later stage in the loading with experimental transverse anisotropic failure analysis. The objective of this study is to identify and isolate the effect of stress-induced anisotropy from the inherent transverse anisotropy on the measured stiffness components, elastic moduli, and Biot's PPCs. The effect of stress-induced anisotropy appears to have significant control on measured stiffness components, elastic moduli, and Biot's PPCs in comparison to the inherent-transverse-anisotropy effect. Our work shows that the stiffness components, Mij and thus the computed elastic moduli, are highly influenced by the stress-induced anisotropy, especially the off-diagonal stiffness components, M12 and M13, where the increase in their magnitudes from the dynamic measurements before failure is determined to be 100 and 81%, respectively. The difference in the magnitude between the axial and lateral Biot's PPCs in line with bedding planes and perpendicular to them is measured to be 24 and 16% from the quasistatic and dynamic methods, respectively; whereas, the effect of stress-induced anisotropy reduced the dynamic average magnitude of the Biot's PPCs along the bedding planes and transverse to these planes by 63% across a stress range of 145 MPa.

scholarly journals Determining Bounds on Assumption Errors in Operational Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Neal M. Bengtson
Keyword(s):  
Performance Measures ◽  
Response Times ◽  
Kkt Conditions ◽  
Tolerance Limits ◽  
Basic Principles ◽  
Mean Values ◽  
Operational Analysis ◽  
Error Measures ◽  
Time Period ◽  
The Difference

The technique of operational analysis (OA) is used in the study of systems performance, mainly for estimating mean values of various measures of interest, such as, number of jobs at a device and response times. The basic principles of operational analysis allow errors in assumptions to be quantified over a time period. The assumptions which are used to derive the operational analysis relationships are studied. Using Karush-Kuhn-Tucker (KKT) conditions bounds on error measures of these OA relationships are found. Examples of these bounds are used for representative performance measures to show limits on the difference between true performance values and those estimated by operational analysis relationships. A technique for finding tolerance limits on the bounds is demonstrated with a simulation example.

scholarly journals Qualitative speed-accuracy tradeoff effects that cannot be explained by the diffusion model under the selective influence assumption

2020 ◽  
Author(s):  
Farshad Rafiei ◽  
Dobromir Rahnev
Keyword(s):  
Diffusion Model ◽  
Discrimination Task ◽  
Drift Rate ◽  
Response Times ◽  
Perceptual Discrimination ◽  
The Difference ◽  
Speed Accuracy ◽  
Selective Influence ◽  
Accuracy Tradeoff ◽  
Rt Distributions

It is often thought that the diffusion model explains all effects related to the speed-accuracy tradeoff (SAT) but this has previously been examined with only a few SAT conditions or only a few subjects. Here we collected data from 20 subjects who performed a perceptual discrimination task with five different difficulty levels and five different SAT conditions (5,000 trials/subject). We found that the five SAT conditions produced robustly U-shaped curves for (i) the difference between error and correct response times (RTs), (ii) the ratio of the standard deviation and mean of the RT distributions, and (iii) the skewness of the RT distributions. Critically, the diffusion model where only drift rate varies with contrast and only boundary varies with SAT could not account for any of the three U-shaped curves. Further, allowing all parameters to vary across conditions revealed that both the SAT and difficulty manipulations resulted in substantial modulations in every model parameter, while still providing imperfect fits to the data. These findings demonstrate that the diffusion model cannot fully explain the effects of SAT and establishes three robust but challenging effects that models of SAT should account for.

scholarly journals Automatic Responses to Acoustically Rough Intervals: Evidence from a Word Evaluation task

2020 ◽  
Author(s):  
James Edward Armitage ◽  
Imre Lahdelma ◽  
Tuomas Eerola
Keyword(s):  
Response Times ◽  
Cognitive Task ◽  
Priming Effects ◽  
Priming Task ◽  
Evaluation Task ◽  
Recent Developments ◽  
Series Of Experiments ◽  
The Difference ◽  
Affective Priming Task ◽  
Simple Cognitive Task

The aim of the present study is to determine which acoustic components of harmonic consonance and dissonance influence automatic responses in a simple cognitive task. In a series of experiments, ten musical interval pairs were used to measure the influence of acoustic roughness and harmonicity on response times in an affective priming task conducted online. There was a significant correlation between the difference of roughness for each pair of intervals and a response time index. Harmonicity did not influence response times on the cognitive task. More detailed analysis suggests that the presence of priming in intervals is binary: in the negative primes that create congruency effects the intervals’ fundamentals and overtones coincide within the same equivalent rectangular bandwidth (i.e. the minor and major seconds). Intervals that fall outside this equivalent rectangular bandwidth do not elicit priming effects, regardless of their dissonance or cultural conventions of negative affect. The results are discussed in the context of recent developments in consonance/dissonance research and vocal similarity.

scholarly journals Equal evidence perceptual tasks suggest key role for interactive competition in decision-making

2019 ◽  
Author(s):  
Ryan Kirkpatrick ◽  
Brandon Turner ◽  
Per B. Sederberg
Keyword(s):  
Decision Making ◽  
Response Times ◽  
Sequential Sampling ◽  
The Past ◽  
Human Decision ◽  
Complex Decision Making ◽  
Complex Decision ◽  
The Difference ◽  
Best Fit ◽  
Made In

The dynamics of decision-making have been widely studied over the past several decades through the lens of an overarching theory called sequential sampling theory (SST). Within SST, choices are represented as accumulators, each of which races toward a decision boundary by drawing stochastic samples of evidence through time. Although progress has been made in understanding how decisionsare made within the SST framework, considerable debate centers on whether the accumulators exhibit dependency during the evidence accumulation process; namely whether accumulators are independent, fully dependent, or partially dependent. To evaluate which type of dependency is the most plausible representation of human decision-making, we applied a novel twist on two classic perceptual tasks; namely, in addition to the classic paradigm (i.e., the unequal-evidence conditions), we used stimuli that provided different magnitudes of equal-evidence (i.e., the equal-evidence conditions). In equal-evidence conditions, response times systematically decreased with increases in the magnitude of evidence, whereas in unequal evidence conditions, response times systematically increased as the difference in evidence between the two alternatives decreased. We designed a spectrum of models that ranged from independent accumulation to fully dependent accumulation, while also examining the effects of within-trial and between-trial variability. We then fit the set of models to our two experiments and found that models instantiating the principles of partial dependency provided the best fit to the data. Our results further suggest that mechanisms inducing partial dependency, such as lateral inhibition, are beneficial for understanding complex decision-making dynamics, even when the task is relatively simple.

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