The effects of stimulus magnitude and duration during pre‐trial delivery of preferred items to increase compliance

2020 ◽  
Author(s):  
Ansley C. Hodges ◽  
Ashley Shuler ◽  
David A. Wilder ◽  
Hallie Ertel
Keyword(s):  
Stimulus Magnitude

Are the dynamic response characteristics of brachial artery flow-mediated dilation sensitive to the magnitude of increase in shear stimulus?

2008 ◽  
Vol 105 (1) ◽  
pp. 282-292 ◽  
Author(s):  
K. E. Pyke ◽  
J. A. Hartnett ◽  
M. E. Tschakovsky
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Dynamic Response ◽  
Phase I ◽  
Brachial Artery ◽  
Flow Mediated Dilation ◽  
Final Phase ◽  
Stimulus Magnitude ◽  
Brachial Artery Diameter ◽  
Response Characteristics

The purpose of this study was to determine the dynamic characteristics of brachial artery dilation in response to step increases in shear stress [flow-mediated dilation (FMD)]. Brachial artery diameter (BAD) and mean blood velocity (MBV) (Doppler ultrasound) were obtained in 15 healthy subjects. Step increases in MBV at two shear stimulus magnitudes were investigated: large (L; maximal MBV attainable), and small (S; MBV at 50% of the large step). Increase in shear rate (estimate of shear stress: MBV/BAD) was 76.8 ± 15.6 s−1 for L and 41.4 ± 8.7 s−1 for S. The peak %FMD was 14.5 ± 3.8% for L and 5.7 ± 2.1% for S ( P < 0.001). Both the L (all subjects) and the S step trials (12 of 15 subjects) elicited a biphasic diameter response with a fast initial phase (phase I) followed by a slower final phase. Relative contribution of phase I to total FMD when two phases occurred was not sensitive to shear rate magnitude ( r2 = 0.003, slope P = 0.775). Parameters quantifying the dynamics of the FMD response [time delay (TD), time constant (τ)] were also not sensitive to shear rate magnitude for both phases (phase I: TD r2 = 0.03, slope P = 0.376, τ r2 = 0.04, slope P = 0.261; final phase: TD r2 = 0.07, slope P = 0.169, τ r2 = 0.07, slope P = 0.996). These data support the existence of two distinct mechanisms, or sets of mechanisms, in the human conduit artery FMD response that are proportionally sensitive to shear stimulus magnitude and whose dynamic response is not sensitive to shear stimulus magnitude.

scholarly journals Limitations of Proposed Signatures of Bayesian Confidence

2018 ◽  
Vol 30 (12) ◽  
pp. 3327-3354 ◽  
Author(s):  
William T. Adler ◽  
Wei Ji Ma
Keyword(s):  
Bayesian Model ◽  
Posterior Probability ◽  
Model Comparison ◽  
Sufficient Conditions ◽  
Internal Noise ◽  
Quantitative Model ◽  
Alternative Form ◽  
Stimulus Magnitude ◽  
Animal Data ◽  
Average Confidence

The Bayesian model of confidence posits that confidence reflects the observer's posterior probability that the decision is correct. Hangya, Sanders, and Kepecs ( 2016 ) have proposed that researchers can test the Bayesian model by deriving qualitative signatures of Bayesian confidence (i.e., patterns that one would expect to see if an observer were Bayesian) and looking for those signatures in human or animal data. We examine two proposed signatures, showing that their derivations contain hidden assumptions that limit their applicability and that they are neither necessary nor sufficient conditions for Bayesian confidence. One signature is an average confidence of 0.75 on trials with neutral evidence. This signature holds only when class-conditioned stimulus distributions do not overlap and when internal noise is very low. Another signature is that as stimulus magnitude increases, confidence increases on correct trials but decreases on incorrect trials. This divergence signature holds only when stimulus distributions do not overlap or when noise is high. Navajas et al. ( 2017 ) have proposed an alternative form of this signature; we find no indication that this alternative form is expected under Bayesian confidence. Our observations give us pause about the usefulness of the qualitative signatures of Bayesian confidence. To determine the nature of the computations underlying confidence reports, there may be no shortcut to quantitative model comparison.

scholarly journals Duration estimation is affected by stimulus magnitude information in non-temporal dimensions

2010 ◽  
Vol 6 (6) ◽  
pp. 1009-1009
Author(s):  
X. Chen ◽  
B. Xuan ◽  
D. Zhang ◽  
S. He
Keyword(s):  
Stimulus Magnitude ◽  
Temporal Dimensions ◽  
Duration Estimation

Event-related potentials to inspiratory flow-resistive loads in young adults: stimulus magnitude effects

1998 ◽  
Vol 49 (1-2) ◽  
pp. 165-186 ◽  
Author(s):  
Elisabeth Bloch-Salisbury ◽  
Andrew Harver ◽  
Nancy K Squires
Keyword(s):  
Young Adults ◽  
Event Related Potentials ◽  
Inspiratory Flow ◽  
Stimulus Magnitude ◽  
Related Potentials ◽  
Resistive Loads

Noise Increases Anchoring Effects

2021 ◽  
pp. 095679762110242
Author(s):  
Chang-Yuan Lee ◽  
Carey K. Morewedge
Keyword(s):  
Theoretical Framework ◽  
Stimulus Feature ◽  
Stimulus Magnitude ◽  
Point Estimates ◽  
Plausible Values ◽  
Anchoring Effects ◽  
Anchoring Bias ◽  
Reservation Prices ◽  
Scalar Variability

We introduce a theoretical framework distinguishing between anchoring effects, anchoring bias, and judgmental noise: Anchoring effects require anchoring bias, but noise modulates their size. We tested this framework by manipulating stimulus magnitudes. As magnitudes increase, psychophysical noise due to scalar variability widens the perceived range of plausible values for the stimulus. This increased noise, in turn, increases the influence of anchoring bias on judgments. In 11 preregistered experiments ( N = 3,552 adults), anchoring effects increased with stimulus magnitude for point estimates of familiar and novel stimuli (e.g., reservation prices for hotels and donuts, counts in dot arrays). Comparisons of relevant and irrelevant anchors showed that noise itself did not produce anchoring effects. Noise amplified anchoring bias. Our findings identify a stimulus feature predicting the size and replicability of anchoring effects—stimulus magnitude. More broadly, we show how to use psychophysical noise to test relationships between bias and noise in judgment under uncertainty.

Effect of unconditioned stimulus magnitude on the emergence of conditioned responding.

2006 ◽  
Vol 32 (4) ◽  
pp. 371-385 ◽  
Author(s):  
Richard W. Morris ◽  
Mark E. Bouton
Keyword(s):  
Unconditioned Stimulus ◽  
Stimulus Magnitude ◽  
Conditioned Responding

Efficiency of Learning When Both Incidental and Intentional Learning Occur Simultaneously

1970 ◽  
Vol 31 (2) ◽  
pp. 367-370 ◽  
Author(s):  
David B. Cohen
Keyword(s):  
Test Performance ◽  
Verbal Learning ◽  
Visual Stimuli ◽  
Intentional Learning ◽  
Stimulus Magnitude

This project investigated the effect of incidental visual stimuli on the efficiency of learning factual material. Verbal learning situations were employed to investigate whether tachistoscopically presented incidental word stimuli, intended to facilitate learning, would result in test performance which was: (1) improved and (2) related to stimulus magnitude, (3) sex, (4) color, or (5) the method of control of the presentation of focal material and cue word. The results imply that it may be possible to improve the efficiency of the learning of factual material in the classroom by as much as 42% if incidental and intentional learning occur simultaneously.

scholarly journals Limitations of proposed signatures of Bayesian confidence

2017 ◽  
Author(s):  
William T. Adler ◽  
Wei Ji Ma
Keyword(s):  
Bayesian Model ◽  
Model Comparison ◽  
Sufficient Conditions ◽  
Internal Noise ◽  
Quantitative Model ◽  
Alternative Form ◽  
Stimulus Magnitude ◽  
Animal Data ◽  
Average Confidence ◽  
Distribution Type

The Bayesian model of confidence posits that confidence is the observer’s posterior probability that the decision is correct. It has been proposed that researchers can gain evidence in favor of the Bayesian model by deriving qualitative signatures of Bayesian confidence, i.e., patterns that one would expect to see if an observer was Bayesian, and looking for those signatures in human or animal data. We examine two proposed qualitative signatures, showing that their derivations contain hidden assumptions that limit their applicability, and that they are neither necessary nor sufficient conditions for Bayesian confidence. One signature is an average confidence of 0.75 for trials with neutral evidence. This signature only holds when class-conditioned stimulus distributions do not overlap and internal noise is very low. Another signature is that, as stimulus magnitude increases, confidence increases on correct trials but decreases on incorrect trials. This signature is also dependent on stimulus distribution type. There is an alternative form of this signature that has been applied in the literature; we find no indication that it is expected under Bayesian confidence, which resolves an ostensible discrepancy. We conclude that, to determine the nature of the computations underlying confidence reports, there may be no shortcut to quantitative model comparison.

Respiratory effects of brief baroreceptor stimuli in the anesthetized dog

1985 ◽  
Vol 59 (4) ◽  
pp. 1258-1265 ◽  
Author(s):  
E. L. Dove ◽  
P. G. Katona
Keyword(s):  
Stimulus Onset ◽  
Base Line ◽  
Stimulus Magnitude ◽  
Carotid Bodies ◽  
Baroreceptor Stimulation ◽  
Before And After ◽  
Anesthetized Dogs ◽  
Line Pressure ◽  
Alpha Chloralose ◽  
Cardiovascular Variables

To quantify the immediate isocapnic respiratory response to baroreceptor stimulation, pressure in the isolated externally perfused carotid sinuses (CS) of 24 vagotomized alpha-chloralose-anesthetized dogs was increased selectively during either inspiration or expiration as a step (from time of onset to end of respiratory phase) or a pulse (500 ms). The rise time (150 ms), base-line pressure (80 mmHg), and stimulus magnitude (40 mmHg) were similar for the two stimuli. The time of stimulus onset (delay), expressed as a percent of control time of inspiration (TI) or expiration (TE), was varied. TI, TE, and tidal volume (VT) were expressed as percent changes from control. Stimuli delivered early in inspiration lengthened TI [23.5 +/- 6.4% (SE) for step and 11.7 +/- 6.3% for pulse stimuli at 5% delay] more effectively than late stimuli. VT was essentially unaltered. In contrast, step stimuli delivered during expiration caused a lengthening of TE (32.7 +/- 6.3% at 5% delay) that did not depend on the delay (up to 75%). Very late (85%) pulse stimuli lengthened TE (15.2 +/- 5.7%) more effectively than early stimuli. For both stimuli, the expiratory VT was unaltered. When the responses are compared before and after separation of the blood supply of the carotid bodies from the CS region and when they are compared before and after inhibition of reflex systemic hypotension by ganglionic blockade, the observed responses were shown to be due solely to CS baroreceptor stimulation and not to alterations in carotid body blood flow or reflex changes in systemic cardiovascular variables.

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