scholarly journals A decision-time account of individual variability in context-dependent orientation estimation

2019 ◽  
Author(s):  
Ron Dekel ◽  
Dov Sagi
Keyword(s):  
Decision Making ◽  
Visual Processing ◽  
Initial Conditions ◽  
Decision Time ◽  
Individual Variability ◽  
Perceptual Bias ◽  
Large Individual ◽  
List Type ◽  
Tilt Aftereffect ◽  
Context Dependent

AbstractFollowing exposure to an oriented stimulus, the perceived orientation is slightly shifted, a phenomenon termed the tilt aftereffect (TAE). This estimation bias, as well as other context-dependent biases, is speculated to reflect statistical mechanisms of inference that optimize visual processing. Importantly, although measured biases are extremely robust in the population, the magnitude of individual bias can be extremely variable. For example, measuring different individuals may result in TAE magnitudes that differ by a factor of 5. Such findings appear to challenge the accounts of bias in terms of learned statistics: is inference so different across individuals? Here, we found that a strong correlation exists between reaction time and TAE, with slower individuals having much less TAE. In the tilt illusion, the spatial analogue of the TAE, we found a similar, though weaker, correlation. These findings can be explained by a theory predicting that bias, caused by a change in the initial conditions of evidence accumulation (e.g., prior), decreases with decision time (Dekel & Sagi, 2019b). We contend that the context-dependence of visual processing is more homogeneous in the population than was previously thought, with the measured variability of perceptual bias explained, at least in part, by the flexibility of decision-making. Homogeneity in processing might reflect the similarity of the learned statistics.HighlightsThe tilt aftereffect (TAE) exhibits large individual differences.Reduced TAE magnitudes are found in slower individuals.Reduced TAE in slower decisions can be explained by the reduced influence of prior.Therefore, individual variability can reflect decision making flexibility.

scholarly journals Temporal experience modifies future thoughts: Manipulation of Libet’s W influences difficulty assessment during a decision-making task

2020 ◽  
Author(s):  
Eve A. Isham
Keyword(s):  
Decision Making ◽  
Subjective Experience ◽  
Decision Time ◽  
List Type ◽  
Temporal Experience ◽  
Temporal Index ◽  
Perceived Difficulty ◽  
The Moment ◽  
Decision Difficulty

Past studies have employed the subjective experience of decision time (Libet’s W) as an index of consciousness, marking the moment at which the agent first becomes aware of a decision. In the current study, we examined whether the temporal experience of W affects subsequent experience related to the action. Specifically, we tested whether W influenced the perception of difficulty in a decision-making task, hypothesizing that temporal awareness of W might influence the sense of difficulty. Consistent with our predictions, when W was perceived as early or late, participants subsequently rated the decision difficulty to be easy or difficult, respectively (Exp.1). Further investigation showed that perceived difficulty, however, did not influence W (Exp.2). Together, our findings suggest a unidirectional relationship such that W plays a role in the metacognition of difficulty evaluation. The results imply that subjective temporal experience of decision time modifies the consequential sense of difficulty.HighlightsPerceived timing of decision (W) can bias the metacognition of difficulty evaluation in a decision-making task.Defined as a temporal index of consciousness, time W’s influence on difficulty evaluation reflects the possibility that the role of consciousness is to modify subsequent thoughts and behaviors.Explicit attention is necessary for the timing of decision (W) to be consciously experienced and effectively influential on subsequent thoughts.

scholarly journals Interaction of contexts in context-dependent orientation estimation

2019 ◽  
Author(s):  
Ron Dekel ◽  
Dov Sagi
Keyword(s):  
Visual Processing ◽  
Combined Effect ◽  
List Type ◽  
Contextual Influences ◽  
Tilt Aftereffect ◽  
Tilt Illusion ◽  
Contextual Influence ◽  
Non Linear ◽  
Selection For ◽  
Visual History

AbstractThe processing of a visual stimulus is known to be influenced by the statistics in recent visual history and by the stimulus’ visual surround. Such contextual influences lead to perceptually salient phenomena, such as the tilt aftereffect and the tilt illusion. Despite much research on the influence of an isolated context, it is not clear how multiple, possibly competing sources of contextual influence interact. Here, using psychophysical methods, we compared the combined influence of multiple contexts to the sum of the isolated context influences. The results showed large deviations from linear additivity for adjacent or overlapping contexts, and remarkably, clear additivity when the contexts were sufficiently separated. Specifically, for adjacent or overlapping contexts, the combined effect was often lower than the sum of the isolated component effects (sub-additivity), or was more influenced by one component than another (selection). For contexts that were separated in time (600 ms), the combined effect measured the exact sum of the isolated component effects (in degrees of bias). Overall, the results imply an initial compressive transformation during visual processing, followed by selection between the processed parts.HighlightsNon-linear sub-additivity for increased context area or contrastNon-linear selection between overlapping or adjacent, dissimilar contextsLinear additivity for combinations of temporally separated contexts

STUDIES IN CONGENITAL GENERALIZED LIPODYSTROPHY

1973 ◽  
Vol 72 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Oddmund Søvik ◽  
Svein Oseid
Keyword(s):  
Biological Activity ◽  
Insulin Response ◽  
Epididymal Adipose Tissue ◽  
Large Individual ◽  
Immunoreactive Insulin ◽  
List Type ◽  
Glucose Load ◽  
Congenital Generalized Lipodystrophy ◽  
The One

ABSTRACT The biological activity of plasma insulin from 4 cases of congenital generalized lipodystrophy has been studied, using rat diaphragm and epididymal adipose tissue in vivo. The results are compared with previous data on plasma immunoreactive insulin obtained in these patients. 2 of the 4 cases exhibited unusually high biological insulin activities during the fasting state as well as after an intravenous (iv) glucose load. In the fat pad assay activities as high as 10 000 μU insulin per ml were observed. During childhood the biological insulin activities were generally high, although there were large individual variations. However, in the one case studied after the age of puberty, the insulin response to a glucose load was negligible. Taken together, the biological and immunological activities observed strongly suggest the presence of pancreatic insulin in these patients. It appears that the circulating insulin has a fully biological activity. The decreasing insulin activities after cessation of growth are in agreement with the appearance of frank diabetes at this time.

7 Exploring healthcare professionals’ attitudes to future care planning with older adults in hospital: qualitative research co-design through multi-professional patient and carer involvement

2018 ◽  
Vol 8 (3) ◽  
pp. 362.2-362
Author(s):  
Anna-Maria Bielinska ◽  
Stephanie Archer ◽  
Catherine Urch ◽  
Ara Darzi
Keyword(s):  
Older Adults ◽  
Decision Making ◽  
End Of Life Care ◽  
Healthcare Professionals ◽  
List Type ◽  
Care Planning ◽  
Life Care ◽  
Topic Guide ◽  
Future Care ◽  
Advance Care

IntroductionDespite evidence that advance care planning in older hospital inpatients improves the quality of end-of-life care (Detering 2010) future care planning (FCP) with older adults remains to be normalised in hospital culture. It is therefore crucial to understand the attitudes of healthcare professionals to FCP in older patients in the hospital setting. Co-design with patients carers and healthcare professionals can generate more detailed meaningful data through better conversations.AimsTo co-design a semi-structured interview (SSI) topic guide to explore healthcare professionals’ attitudes to FCP with older adults in hospital.MethodsA multi-professional research group including a panel of patient and carer representatives co-designed an in-depth topic guide for a SSI exploring healthcare professionals’ attitudes to FCP with older adults in hospital.ResultsThe co-designed topic guide encourages participants to explore personal and system-level factors that may influence attitudes to FCP and practice in hospital amongst healthcare staff. Co-designed topics for inclusion in the SSI schedule include:Potential differences between specialist and generalist approaches to FCPThe influence of perceived hierarchy and emergency–decision making ability in professionals on FCP discussionsThe relevance to transitions of careAttitudes to FCP beyond the biomedical paradigm including perceived well–being and psychosocial aspects of careDigital FCP tools including patient–led FCP.ConclusionCo-designing qualitative research with older people and multi-disciplinary professionals may narrow translational gaps in implementing FCP by setting joint research priorities. Data generated from a co-designed study may expand understanding of hospital-based anticipatory decision-making with older adults.Reference. Detering KM, Hancock AD, Reade MC, Silvester W. The impact of advance care planning on end of life care in elderly patients: randomised controlled trial. BMJ23 March 2010;340:c1345.

The Legislative Decision-Making Process

1982 ◽  
Vol 32 ◽  
pp. 7-8
Author(s):  
Richard DeGraw ◽  
Bette F. DeGraw
Keyword(s):  
Decision Making ◽  
American Indians ◽  
Undergraduate Students ◽  
Community Organization ◽  
Role Play ◽  
The Political ◽  
Decision Making Process ◽  
List Type ◽  
Provision Of Services ◽  
Legislative Decision

The Legislative Decision Making Process is an educational role play for graduate or undergraduate students concerning the political and pressure relationships involved in the political decision-making process. The role play reviews the implications of the decision-making processes upon the provision of services by governmental agencies.The role play engages from twenty to sixty students in a simulated budget-making and lobbying experience and utilizes this experience to teach students:1.The values and pressures considered by bureaucracies and the Legislature in decision-making;2.The relationships which exist between clients, community groups, administrators and politicians;3.The various techniques of Community Organization for lobbying and Legislative influence.The role play consists of various groups of students in roles which include legislators, administrators of three major state departments, two minor state departments, parent groups, Concerned Citizen groups, American Indians disabled individuals and ex-clients.

scholarly journals Cognitive Control of Working Memory: A Model-Based Approach

2021 ◽  
Vol 11 (6) ◽  
pp. 721
Author(s):  
Russell J. Boag ◽  
Niek Stevenson ◽  
Roel van Dooren ◽  
Anne C. Trutti ◽  
Zsuzsika Sjoerds ◽  
...  
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Cognitive Control ◽  
Relevant Information ◽  
Decision Time ◽  
Control Processes ◽  
Prepotent Response ◽  
New Information ◽  
Empirical Performance ◽  
Flow Of Information

Working memory (WM)-based decision making depends on a number of cognitive control processes that control the flow of information into and out of WM and ensure that only relevant information is held active in WM’s limited-capacity store. Although necessary for successful decision making, recent work has shown that these control processes impose performance costs on both the speed and accuracy of WM-based decisions. Using the reference-back task as a benchmark measure of WM control, we conducted evidence accumulation modeling to test several competing explanations for six benchmark empirical performance costs. Costs were driven by a combination of processes, running outside of the decision stage (longer non-decision time) and showing the inhibition of the prepotent response (lower drift rates) in trials requiring WM control. Individuals also set more cautious response thresholds when expecting to update WM with new information versus maintain existing information. We discuss the promise of this approach for understanding cognitive control in WM-based decision making.

scholarly journals Interannual comparison of core taxa and community composition of the blow microbiota from East Australian humpback whales

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
C Vendl ◽  
B C Ferrari ◽  
T Thomas ◽  
E Slavich ◽  
E Zhang ◽  
...  
Keyword(s):  
Multiple Stressors ◽  
Physiological State ◽  
Temporal Stability ◽  
Individual Variability ◽  
Habitat Destruction ◽  
Humpback Whales ◽  
Large Individual ◽  
Rrna Gene ◽  
Alpha And Beta Diversity ◽  
Transient Nature

ABSTRACT Cetacean represent vulnerable species impacted by multiple stressors, including reduction in prey species, habitat destruction, whaling and infectious disease. The composition of blow microbiota has been claimed to provide a promising tool for non-invasive health monitoring aiming to inform conservation management. Still, little is known about the temporal stability and composition of blow microbiota in whales. We used East Australian humpback whales (Megaptera novaeangliae) as a model species and collected blow and control samples in August 2016 and 2017 for an interannual comparison. We analysed the blow by barcode tag sequencing of the bacterial 16S rRNA gene. We found that the microbial communities in 2016 and 2017 were statistically similar regarding alpha and beta diversity but distinct to seawater. Zero-radius operational taxonomic units (zOTUs) shared by both groups accounted for about 50% of all zOTUs present. Still, the large individual variability in the blow microbiota resulted in a small number of core taxa (defined as present in at least 60% of whales). We conclude that the blow microbiota of humpback whales is either generally limited and of transient nature or the reduced airway microbiota is the symptom of a compromised physiological state potentially due to the challenges of the whales‘ annual migration.

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