scholarly journals Divergent effects of absolute evidence magnitude on decision accuracy and confidence in perceptual judgements

2021 ◽  
Author(s):  
Yiu Hong Ko ◽  
Daniel C Feuerriegel ◽  
William Turner ◽  
Helen Overhoff ◽  
Eva Niessen ◽  
...  
Keyword(s):  
Judgment Task ◽  
Sources Of Information ◽  
Decision Accuracy ◽  
Decision Confidence ◽  
Initial Decision ◽  
Confidence Judgments ◽  
Sensory Evidence ◽  
The Mean ◽  
Perceptual Judgement ◽  
Mean Luminance

Whether people change their mind after making a perceptual judgement may depend on how confident they are in their initial decision. Recently, it was shown that, when making perceptual judgements about stimuli containing high levels of 'absolute evidence' (i.e., the overall magnitude of sensory evidence across choice options), people make less accurate initial decisions and are also slower to change their mind and correct their mistakes. Here we report two studies that investigated whether high levels of absolute evidence also lead to increased decision confidence. We used a luminance judgment task in which participants decided which of two dynamic, flickering stimuli was brighter. After making a decision, participants rated their confidence. We manipulated relative evidence (i.e., the mean luminance difference between the two stimuli) and absolute evidence (i.e., the summed luminance of the two stimuli). In the first experiment, we found that higher absolute evidence was associated with decreased decision accuracy but increased decision confidence. In the second experiment, we additionally manipulated the degree of luminance variability to assess whether the observed effects were due to differences in perceived evidence variability. We replicated the results of the first experiment but did not find substantial effects of luminance variability on confidence ratings. Our findings support the view that decisions and confidence judgments are based on partly dissociable sources of information, and suggest that decisions initially made with higher confidence may be more resistant to subsequent changes of mind.

scholarly journals Domain-general idiosyncratic anchoring of metacognition

2017 ◽  
Author(s):  
Hebah Foda ◽  
Kristina Barger ◽  
Joaquin Navajas ◽  
Bahador Bahrami
Keyword(s):  
Task Difficulty ◽  
Correct Choice ◽  
Decision Confidence ◽  
Confidence Judgments ◽  
Initial Location ◽  
Informational Uncertainty ◽  
The Mean ◽  
State Of The Environment ◽  
New Evidence

Recent studies in the field of metacognition and decision-making have found that confidence judgments are influenced by numerous post-decisional factors. Anchoring is a post-decisional factor whose effects on decisions have been widely documented but little is known about its possible impact on decision confidence. In two experiments, participants made categorical decisions about the mean of a sequence of visual (oriented gratings) or numerical stimuli and rated their confidence on a Likert scale. By randomizing the initial location of the indicator across trials, we demonstrated the effects of anchoring in metacognitive confidence judgments. The effect was (a) consistent across two domains of visual perception and mathematical cognition and (b) independent of informational uncertainty and task difficulty. Our findings provide new evidence for the post-decisional accounts of confidence that recognize the role of idiosyncratic, domain-general, trait-like factors (e.g. susceptibility to an anchor). Our data are inconsistent with the normative accounts that confine confidence to reflecting statistical variance (in the external state of the environment) or probability of correct choice (subjective to the agent).

Canine visual acuity: retinal and cortical field potentials evoked by pattern stimulation

1983 ◽  
Vol 245 (5) ◽  
pp. R637-R641 ◽  
Author(s):  
J. V. Odom ◽  
N. M. Bromberg ◽  
W. W. Dawson
Keyword(s):  
Neuromuscular Block ◽  
Pattern Detection ◽  
Field Potentials ◽  
Retinal Processing ◽  
Pattern Stimulation ◽  
Last Stage ◽  
The Mean ◽  
The Difference ◽  
Mean Luminance ◽  
Cortical Field

The visual acuities (i.e., visual thresholds for pattern detection) of four dogs under neuromuscular block were measured using visually evoked cortical potentials (VECP) and/or pattern-evoked retinal potentials (PERR). Stimuli were phase-reversing square-wave gratings with a mean luminance of 86 cd/m2 and 70% contrast. The mean of the VECP thresholds of two dogs tested was 12.59 cycles per degree (cycles/deg). The mean of the PERR thresholds of four dogs tested was 11.61 cycles/deg. The difference between VECP and PERR thresholds was not statistically significant. VECP acuities appear to be determined at or before the last stage of retinal processing (PERR). Our estimates of canine acuity are 1.3–2 times those reported for cats and 0.2–0.4 times those reported for primates when tested under comparable luminance and contrast conditions.

scholarly journals Changes of mind and absolute evidence

2019 ◽  
Author(s):  
William Turner ◽  
Daniel Feuerriegel ◽  
Milan Andrejevic ◽  
Robert Hester ◽  
Stefan Bode
Keyword(s):  
Decision Process ◽  
Initial Response ◽  
Luminance Ratio ◽  
Noise Sources ◽  
Initial Decision ◽  
Luminance Difference ◽  
The World ◽  
Sensory Evidence

To navigate the world safely, we often need to rapidly ‘change our mind’ about decisions. Current models assume that initial decisions and change-of-mind decisions draw upon common sources of sensory evidence. In two-choice scenarios, this evidence may be ‘relative’ or ‘absolute’. For example, when judging which of two objects is the brightest, the luminance difference and luminance ratio between the two objects are sources of ‘relative’ evidence, which are invariant across additive and multiplicative luminance changes. Conversely, the overall luminance of the two objects combined is a source of ‘absolute’ evidence, which necessarily varies across symmetric luminance manipulations. Previous studies have shown that initial decisions are sensitive to both relative and absolute evidence; however, it is unknown whether change-of-mind decisions are sensitive to absolute evidence. Here, we investigated this question across two experiments. In each experiment participants indicated which of two flickering greyscale squares was brightest. Following an initial decision, the stimuli remained on screen for a brief period and participants could change their response. To investigate the effect of absolute evidence, the overall luminance of the two squares was varied whilst either the luminance difference (Experiment 1) or luminance ratio (Experiment 2) was held constant. In both experiments we found that increases in absolute evidence led to faster, less accurate initial responses and slower changes of mind. Change-of-mind accuracy decreased when the luminance difference was held constant, but remained unchanged when the luminance ratio was fixed. The initial response effects could be explained by the presence of input-dependent noise within the decision process, varying either within or across trials. However, the change-of-mind effects could not be captured by existing models, nor by two modified models which included input-dependent noise sources. This suggests that that the continued integration of sensory evidence following an initial decision operates differently to that described in existing theoretical accounts.

scholarly journals Pre-stimulus alpha activities predict the confidence in subjective judgment by modulating post-stimulus theta oscillation

2021 ◽  
Author(s):  
Haoyue Qian ◽  
Yang Lu ◽  
Zhiyuan Liu ◽  
Xue Weng ◽  
Xiuyan Guo ◽  
...  
Keyword(s):  
Judgment Task ◽  
Neural Oscillation ◽  
Brain Areas ◽  
Subjective Judgment ◽  
Alpha Oscillations ◽  
Evidence Accumulation ◽  
Decision Confidence ◽  
Boundary Process ◽  
Specific Pathway ◽  
The Brain

AbstractEven when making arbitrary decisions, people tend to feel varying levels of confidence, which is associated with the pre-stimulus neural oscillation of the brain. We investigated varying confidence in a pure subjective judgment task, and how this confidence was predicted by pre-stimulus alpha oscillations. Participants made pure subjective judgments where their prior experience seems to be helpful but actually useless, and their fluctuating confidence was related to the choice boundary process rather than the evidence accumulation process, suggesting participants underwent varying confidence resulting from the internal signals. With EEG and MEG analyses, we not only revealed the linkage between confidence and pre-stimulus alpha activities, but also successfully located this linkage onto decision-making relevant brain areas, i.e. MCC/PCC and SMA. Moreover, we unveiled a specific pathway underlying such linkage, that is, the influence of pre-stimulus alpha activities on decision confidence was fulfilled through modulating post-stimulus theta activities of SMA.

scholarly journals Estimation of peak discharges of historical floods

2014 ◽  
Vol 11 (5) ◽  
pp. 5463-5485 ◽  
Author(s):  
J. Herget ◽  
T. Roggenkamp ◽  
M. Krell
Keyword(s):  
Flood Frequency ◽  
River Channels ◽  
Sources Of Information ◽  
Mean Flow ◽  
General Outline ◽  
One Dimensional ◽  
Flood Level ◽  
Alternative Approaches ◽  
The Mean ◽  
Generalized Statement

Abstract. There is no doubt, that the hazard assessment of future floods especially under consideration of the recent environmental change can be significantly improved by the consideration of historic flood events. While flood frequency inventories on local, regional and even European scale are already developed and published, the estimation of their magnitudes indicated by discharges is still challenging. Such data are required due to significant human impact on river channels and floodplains though historic flood levels cannot be related to recent ones or recent discharges. Based on own experiences from single local key studies the general outline of an approach to estimate the discharge of the previous flood based on handed down flood level and topographic data is presented. The model for one-dimensional steady flow is based on the empirical Manning equation for the mean flow velocity. Background and potential sources of information, acceptable simplifications and data transformation for each element of the model-equation are explained and discussed. Preliminary experiences on the accuracy of ±10% are documented and potential approaches for the validation of individual estimations given. A brief discussion on benefits and limitations including a generalized statement on alternative approaches closes the review presentation of the approach.

scholarly journals Estimation of peak discharges of historical floods

2014 ◽  
Vol 18 (10) ◽  
pp. 4029-4037 ◽  
Author(s):  
J. Herget ◽  
T. Roggenkamp ◽  
M. Krell
Keyword(s):  
Human Impacts ◽  
Flood Frequency ◽  
River Channels ◽  
Sources Of Information ◽  
Mean Flow ◽  
General Outline ◽  
Flood Level ◽  
Alternative Approaches ◽  
The Mean ◽  
Generalized Statement

Abstract. There is no doubt that the hazard assessment of future floods, especially under consideration of recent environmental change, can be significantly improved by the consideration of historic flood events. While flood frequency inventories on local, regional and even European scale have already been developed and published, the estimation of their magnitudes indicated by discharges is still challenging. Such data are required due to significant human impacts on river channels and floodplains, though historic flood levels cannot be related to recent ones or recent discharges. Based on experiences from single local key studies, we present the general outline of an approach to estimate the discharge of the previous flood based on handed-down flood level and topographic data. The model for one-dimensional steady flow is based on the empirical Manning equation for the mean flow velocity. Background and potential sources of information, acceptable simplifications and data transformation for each element of the model equation are explained and discussed. Preliminary experiences regarding the accuracy of ±10% are documented, and potential approaches for the validation of individual estimations are given. A brief discussion of benefits and limitations, including a generalized statement on alternative approaches, concludes the review of the approach.

scholarly journals Gain control of synaptic transfer from second- to third-order neurons of cockroach ocelli.

1996 ◽  
Vol 107 (1) ◽  
pp. 121-131 ◽  
Author(s):  
M Mizunami
Keyword(s):  
Synaptic Transmission ◽  
Characteristic Curve ◽  
Gain Control ◽  
Second Order ◽  
The Body ◽  
Intensity Change ◽  
Third Order ◽  
The Mean ◽  
Mean Luminance ◽  
Nonlinear Nature

Synaptic transmission from second- to third-order neurons of cockroach ocelli occurs in an exponentially rising part of the overall sigmoidal characteristic curve relating pre- and postsynaptic voltage. Because of the nonlinear nature of the synapse, linear responses of second-order neurons to changes in ligh intensity are half-wave rectified, i.e., the response to a decrement in light is amplified whereas that to an increment in light is compressed. Here I report that the gain of synaptic transmission from second- to third-order neurons changes by ambient light levels and by wind stimulation applied to the cerci. Transfer characteristics of the synapse were studied by simultaneous intracellular recordings of second- and third-order neurons. Potential changes were evoked in second-order neurons by a sinusoidally modulated light with various mean luminances. With a decrease in the mean luminance (a) the mean membrane potential of second-order neurons was depolarized, (b) the synapse between the second- and third-order neurons operated in a steeper range of the exponential characteristic curve, where the gain to transmit modulatory signals was higher, and (c) the gain of third-order neurons to detect a decrement in light increased. Second-order neurons were depolarized when a wind or tactile stimulus was applied to various parts of the body including the cerci. During a wind-evoked depolarization, the synapse operated in a steeper range of the characteristic curve, which resulted in an increased gain of third-order neurons to detect light decrements. I conclude that the nonlinear nature of the synapse between the second- and third-order neurons provides an opportunity for an adjustment of gain to transmit signals of intensity change. The possibility that a similar gain control occurs in other visual systems and underlies a more advanced visual function, i.e., detection of motion, is discussed.

scholarly journals Confidence Predictions Affect Performance Confidence and Neural Preparation in Perceptual Decision Making.

2017 ◽  
Author(s):  
Anne-Marike Schiffer ◽  
Annika Boldt ◽  
Florian Waszak ◽  
Nick Yeung
Keyword(s):  
Decision Making ◽  
Color Discrimination ◽  
Sources Of Information ◽  
Perceptual Decision Making ◽  
Multiple Sources ◽  
Behavioral Measures ◽  
Confidence Judgments ◽  
Source Of Information ◽  
Preparation And Evaluation ◽  
Confidence Estimate

The decisions we make are usually accompanied by a feeling of being wrong or right – a confidence estimate regarding the correctness of our decisions. The questions which information this confidence estimate is based on, and what confidence is used for, have increasingly become a focus of research into decision-making. This research has largely focused on confidence regarding current or past decisions, and successfully identified for example how characteristics of the stimulus affect confidence, and how communicating confidence can affect group decisions. Here, we report two studies which implemented a color-discrimination task which introduced a novel metacognitive measure: predictions of confidence for future perceptual decisions. Using behavioral measures, computational modeling, and EEG, we tested the hypothesis that experience-based confidence predictions are one source of information which affects how confident we are in future decision-making and that one key purpose of confidence is to prepare future encounters of a task. Results from both studies show that participants develop precise confidence predictions informed by confidence experienced in past trials. Notably, our results show a bi-directional link between predicted and experienced (performance) confidence: confidence predictions are not only informed by, but can also modulate performance confidence; this finding supports our recent proposal that confidence judgments are based on multiple sources of information, including expectations. We found further support for this bi-directional link in neural correlates of stimulus-preparation and processing. EEG measures of preparatory neural activity (contingent negative variation; CNV) and evidence accumulation (centro-parietal positivity; CPP) show that predicted confidence affects neural preparation for stimulus processing, supporting the proposal that one purpose of confidence judgments may be to learn about performance for future encounters and prepare accordingly.Taken together, our results suggest that confidence integrates information from various sources, and affects neural processing profoundly. The bi-directional link between performance confidence and predicted confidence suggests that confidence signals are exploited to increase precision in preparation and evaluation of future decisions.

scholarly journals Using confidence inferred from pupil-size to dissect perceptual task-strategy: support for a bounded decision-formation process

2018 ◽  
Author(s):  
Katsuhisa Kawaguchi ◽  
Stephane Clery ◽  
Paria Pourriahi ◽  
Lenka Seillier ◽  
Ralf Haefner ◽  
...  
Keyword(s):  
Pupil Size ◽  
Neuronal Response ◽  
Perceptual Task ◽  
Neural Basis ◽  
Decision Confidence ◽  
Attractor Dynamics ◽  
Task Strategy ◽  
Decision Area ◽  
Sensory Evidence ◽  
Account Due

During perceptual decisions subjects often rely more strongly on early rather than late sensory evidence even in tasks when both are equally informative about the correct decision. This early psychophysical weighting has been explained by an integration-to-bound decision process, in which the stimulus is ignored after the accumulated evidence reaches a certain bound, or confidence level. Here, we derive predictions about how the average temporal weighting of the evidence depends on a subject’s decision-confidence in this model. To test these predictions empirically, we devised a method to infer decision-confidence from pupil size in monkeys performing a disparity discrimination task. Our animals’ data confirmed the integration-to-bound predictions, with different internal decision-bounds accounting for differences between animals. However, the data could not be explained by two alternative accounts for early psychophysical weighting: attractor dynamics either within the decision area or due to feedback to sensory areas, or a feedforward account due to neuronal response adaptation. This approach also opens the door to using confidence more broadly when studying the neural basis of decision-making.

scholarly journals Patterns of lymphoma in Misan city, Iraq: A retrospective observational study

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1733
Author(s):  
Haider Saadoon Qasim Alhilfi ◽  
Omer Mansib Kassid ◽  
Husam Jihad Imran Jihad ◽  
Ahmed Salih Hussien Alshewered
Keyword(s):  
Hodgkin’S Lymphoma ◽  
Stage Iv ◽  
B Cell Lymphoma ◽  
Hodgkin's Lymphoma ◽  
Sources Of Information ◽  
Female Ratio ◽  
Single Center Study ◽  
The Mean ◽  
Male To Female ◽  
Oncology Center

Background: Lymphomas represent a biologically and clinically heterogeneous group of neoplasms. They have historically and clinically been divided into two groups, Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL). This study aimed to identify patterns in lymphomas in Misan city, Iraq, and evaluate the characteristics of this disease. Methods: A retrospective, observational, single-center study was conducted at Al-Shifaa Oncology Center, Al-Sadder Teaching Hospital, Misan city, Iraq, between 1 April 2016 and 30 April 2018. A total of 80 Misanian participants (48 (60%) men and 32 (40%) women) who had lymphoma were involved in this study. The sources of information were patient files, histopathology reports, and patients’ oncologist reports. Results: The mean age (±SD) of participants was 36 ±12.8 years. The male to female ratio was 1.5:1. NHL cases were three times more prevalent than HL. The most frequent stage at presentation was stage IV, in 34 (42.5%) participants. The classical subtypes of HL were present in 14 (70%) of HL cases. The diffuse large B-cell lymphoma (DLBCL) subtype was the most common NHL subtype, being recorded for 44 (73.3%) of participants. Conclusion: Lymphomas were more frequent in men. NHL was more common than HL; one HL case was diagnosed for every three NHL cases. The most common histopathology of HL was mixed cellularity, while DLBCL was the most common subtype of NHL. Most cases presented at an advanced stage, resulting in a late diagnosis.

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