scholarly journals Bias effects in a two-stage recognition paradigm: A challenge for ‘pure’ threshold and signal detection models

2021 ◽  
Author(s):  
Qiuli Ma ◽  
Jeffrey Joseph Starns ◽  
David Kellen
Keyword(s):  
Signal Detection ◽  
Forced Choice ◽  
Dual Process ◽  
High Threshold ◽  
Word Target ◽  
Choice Data ◽  
Two Stage ◽  
Unequal Variance ◽  
Single Item

We explored a two-stage recognition memory paradigm in which people first make single-item “studied”/“not studied” decisions and then have a chance to correct their errors in forced-choice trials. Each forced-choice trial included one studied word (“target”) and one non-studied word (“lure”) that received the same previous single-item response. For example, a “studied”-“studied” trial would have a target that was correctly called “studied” and a lure that was incorrectly called “studied.” The two-high-threshold (2HT) model and the unequal-variance signal detection (UVSD) model predict opposite effects of biasing the initial single-item responses on subsequent forced-choice accuracy. Results from two experiments showed that the bias effect is actually near zero and well out of the range of effects predicted by either model. Follow-up analyses showed that the model failures were not a function of experiment artifacts like changing memory states between the two types of recognition trials. Follow-up analyses also showed that the dual process signal detection (DPSD) model made better predictions for the forced-choice data than 2HT and UVSD models.

scholarly journals Evidence for the Contribution of A Threshold Retrieval Process to Semantic Memory

2017 ◽  
Vol 70 (10) ◽  
pp. 2026-2047 ◽  
Author(s):  
Maria Kempnich ◽  
Josephine A. Urquhart ◽  
Akira R. O'Connor ◽  
Chris J.A. Moulin
Keyword(s):  
Signal Detection ◽  
Semantic Memory ◽  
Target Identification ◽  
Dual Process ◽  
Semantic Retrieval ◽  
Retrieval Process ◽  
Operating Characteristics ◽  
Semantic Task ◽  
Unequal Variance ◽  
Detection Model

It is widely held that episodic retrieval can recruit two processes: a threshold context retrieval process (recollection) and a continuous signal strength process (familiarity). Conversely the processes recruited during semantic retrieval are less well specified. We developed a semantic task analogous to single-item episodic recognition to interrogate semantic recognition receiver-operating characteristics (ROCs) for a marker of a threshold retrieval process. We fitted observed ROC points to three signal detection models: two models typically used in episodic recognition (unequal variance and dual-process signal detection models) and a novel dual-process recollect-to-reject (DP-RR) signal detection model that allows a threshold recollection process to aid both target identification and lure rejection. Given the nature of most semantic questions, we anticipated the DP-RR model would best fit the semantic task data. Experiment 1 (506 participants) provided evidence for a threshold retrieval process in semantic memory, with overall best fits to the DP-RR model. Experiment 2 (316 participants) found within-subjects estimates of episodic and semantic threshold retrieval to be uncorrelated. Our findings add weight to the proposal that semantic and episodic memory are served by similar dual-process retrieval systems, though the relationship between the two threshold processes needs to be more fully elucidated.

scholarly journals Pre-experimental Familiarization Increases Hippocampal Activity for Both Targets and Lures in Recognition Memory: An fMRI Study

2011 ◽  
Vol 23 (12) ◽  
pp. 4164-4173 ◽  
Author(s):  
Greig I. de Zubicaray ◽  
Katie L. McMahon ◽  
Lydia Hayward ◽  
John C. Dunn
Keyword(s):  
Signal Detection ◽  
Dual Process ◽  
Memory Strength ◽  
High Confidence ◽  
Unequal Variance ◽  
Detection Model ◽  
Parahippocampal Cortex ◽  
Hippocampal Activity ◽  
Model Account ◽  
List Discrimination

In the present study, items pre-exposed in a familiarization series were included in a list discrimination task to manipulate memory strength. At test, participants were required to discriminate strong targets and strong lures from weak targets and new lures. This resulted in a concordant pattern of increased “old” responses to strong targets and lures. Model estimates attributed this pattern to either equivalent increases in memory strength across the two types of items (unequal variance signal detection model) or equivalent increases in both familiarity and recollection (dual process signal detection [DPSD] model). Hippocampal activity associated with strong targets and lures showed equivalent increases compared with missed items. This remained the case when analyses were restricted to high-confidence responses considered by the DPSD model to reflect predominantly recollection. A similar pattern of activity was observed in parahippocampal cortex for high-confidence responses. The present results are incompatible with “noncriterial” or “false” recollection being reflected solely in inflated DPSD familiarity estimates and support a positive correlation between hippocampal activity and memory strength irrespective of the accuracy of list discrimination, consistent with the unequal variance signal detection model account.

Constructing and model-fitting receiver operator characteristics using continuous data.

2018 ◽  
Author(s):  
Josephine Ann Urquhart ◽  
Akira O'Connor
Keyword(s):  
Signal Detection ◽  
Least Squares Method ◽  
Model Fitting ◽  
Simulated Data ◽  
Continuous Variable ◽  
Continuous Data ◽  
Model Parameters ◽  
Operating Characteristics ◽  
Unequal Variance ◽  
Discrete Discrimination

Receiver operating characteristics (ROCs) are plots which provide a visual summary of a classifier’s decision response accuracy at varying discrimination thresholds. Typical practice, particularly within psychological studies, involves plotting an ROC from a limited number of discrete thresholds before fitting signal detection parameters to the plot. We propose that additional insight into decision-making could be gained through increasing ROC resolution, using trial-by-trial measurements derived from a continuous variable, in place of discrete discrimination thresholds. Such continuous ROCs are not yet routinely used in behavioural research, which we attribute to issues of practicality (i.e. the difficulty of applying standard ROC model-fitting methodologies to continuous data). Consequently, the purpose of the current article is to provide a documented method of fitting signal detection parameters to continuous ROCs. This method reliably produces model fits equivalent to the unequal variance least squares method of model-fitting (Yonelinas et al., 1998), irrespective of the number of data points used in ROC construction. We present the suggested method in three main stages: I) building continuous ROCs, II) model-fitting to continuous ROCs and III) extracting model parameters from continuous ROCs. Throughout the article, procedures are demonstrated in Microsoft Excel, using an example continuous variable: reaction time, taken from a single-item recognition memory. Supplementary MATLAB code used for automating our procedures is also presented in Appendix B, with a validation of the procedure using simulated data shown in Appendix C.

scholarly journals An empirical example of analysis using a two-stage modeling approach: within-subject association of outdoor context and physical activity predicts future daily physical activity levels

2020 ◽  
Author(s):  
Chih-Hsiang Yang ◽  
Jaclyn P Maher ◽  
Aditya Ponnada ◽  
Eldin Dzubur ◽  
Rachel Nordgren ◽  
...  
Keyword(s):  
Physical Activity ◽  
Vigorous Physical Activity ◽  
Wearable Sensors ◽  
Activity Levels ◽  
Two Stage ◽  
Modeling Approach ◽  
Source Program ◽  
Modeling Strategy ◽  
Stage Modeling

Abstract People differ from each other to the extent to which momentary factors, such as context, mood, and cognitions, influence momentary health behaviors. However, statistical models to date are limited in their ability to test whether the association between two momentary variables (i.e., subject-level slopes) predicts a subject-level outcome. This study demonstrates a novel two-stage statistical modeling strategy that is capable of testing whether subject-level slopes between two momentary variables predict subject-level outcomes. An empirical case study application is presented to examine whether there are differences in momentary moderate-to-vigorous physical activity (MVPA) levels between the outdoor and indoor context in adults and whether these momentary differences predict mean daily MVPA levels 6 months later. One hundred and eight adults from a multiwave longitudinal study provided 4 days of ecological momentary assessment (during baseline) and accelerometry data (both at baseline and 6 month follow-up). Multilevel data were analyzed using an open-source program (MixWILD) to test whether momentary strength between outdoor context and MVPA during baseline was associated with average daily MVPA levels measured 6 months later. During baseline, momentary MVPA levels were higher in outdoor contexts as compared to indoor contexts (b = 0.07, p < .001). Participants who had more momentary MVPA when outdoors (vs. indoors) during baseline (i.e., a greater subject-level slope) had higher daily MVPA at the 6 month follow-up (b = 0.09, p < .05). This empirical example shows that the subject-level momentary association between specific context (i.e., outdoors) and health behavior (i.e., physical activity) may contribute to overall engagement in that behavior in the future. The demonstrated two-stage modeling approach has extensive applications in behavioral medicine to analyze intensive longitudinal data collected from wearable sensors and mobile devices.

scholarly journals Long-term outcomes of two-stage, immediate and delayed breast reconstruction with polyurethane-covered versus textured implants: protocol of a prospective, multicentre randomised controlled trial (TIPI trial)

BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e044219
Author(s):  
J X Harmeling ◽  
Kevin Peter Cinca ◽  
Eleni-Rosalina Andrinopoulou ◽  
Eveline M L Corten ◽  
M A Mureau
Keyword(s):  
Randomised Controlled Trial ◽  
Breast Reconstruction ◽  
Controlled Trial ◽  
Capsular Contracture ◽  
Tissue Expander ◽  
Complication Rates ◽  
Two Stage ◽  
Randomised Controlled

IntroductionTwo-stage implant-based breast reconstruction is the most commonly performed postmastectomy reconstructive technique. During the first stage, a tissue expander creates a sufficiently large pocket for the definite breast implant placed in the second stage. Capsular contracture is a common long-term complication associated with implant-based breast reconstruction, causing functional complaints and often requiring reoperation. The exact aetiology is still unknown, but a relationship between the outer surface of the implant and the probability of developing capsular contracture has been suggested. The purpose of this study is to determine whether polyurethane-covered implants result in a different capsular contracture rate than textured implants.Methods and analysisThe Textured Implants versus Polyurethane-covered Implants (TIPI) trial is a multicentre randomised controlled trial with a 1:1 allocation rate and a follow-up of 10 years. A total of 321 breasts of female adults undergoing a two-stage breast reconstruction will be enrolled. The primary outcome is capsular contracture at 10-year follow-up which is graded with the modified Baker classification. It is analysed with survival analysis using a frailty model for clustered interval-censored data, with both an intention-to-treat and per-protocol approach. Secondary outcomes are other complication rates, surgical revision rate, patient satisfaction and quality of life and user-friendliness. Outcomes are measured 2 weeks, 6 months, 1, 2, 3, 5 and 10 years postoperatively. Interim analysis is performed when 1-year, 3-year and 5-year follow-up is completed.Ethics and disseminationThe trial has been reviewed and approved by the Medical Research Ethics Committee of the Erasmus MC, University Medical Centre Rotterdam (MEC-2018-126) and locally by each participating centre. Written informed consent will be obtained from each study participant. The results will be disseminated by publication in peer-reviewed journals.Trial registrationNTR7265.

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