Dena Lynn Norris Thesis M.Sc.Memorial University of Newfoundland

The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response by D

Get Access The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response by Dena Lynn Norris eBook in format PDF,ePub,Kindle and Audiobook

The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response

Author : Dena Lynn Norris

Publisher : Thesis (M.Sc.)--Memorial University of Newfoundland

Published : 1976

ISBN-10 :

ISBN-13 :

Number of Pages : 116 Pages

Language : en

Descriptions The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response

The present study investigated the phenomenon that under certain conditions the presentation of the conditioned stimulus (CS) alone leads to enhancement of the conditioned response (CR) rather than to extinction of the CR. It was further hypothesized that the personality dimensions of neuroticism and introversion were related to enhancement in that those persons high on these dimensions would tend to exhibit enhancement more than persons low on those dimensions. -- Thirty-four male subjects were used, there being eight subjects per group in two groups, and nine subjects per group in the remaining two groups. Three groups received CS (slide presentation)-UCS (a loud burst of white noise) pairings on a 76 per cent irregular reinforcement pattern. The groups differed by the duration of the CS-alone exposure each received one minute after conditioning--either 2, 60 or 300 seconds. The fourth group served as a control and received non-contingent CS and UCS presentations. At two extinction sessions held one and two weeks after conditioning the CR strength (magnitude and latency of the GSR and change in rate of Finger Pulse) was measured. The results showed: (a) that the experimental groups exhibited CR's on unreinforced CS presentations in the conditioning session with significantly higher SSR magnitudes than the control group (p .05); (b) that there was no evidence for enhancement since neither of the groups were responding differently on GSR magnitude in the first extinction session (p .05) nor were they responding differently on change in rate of Finger Pulse (p > .05); (c) significant main effects were found for Sessions and Trials and an interaction effect was found for Sessions x Trials on magnitude of the GSR (p

Keyword :

Read Online The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response pdf

Download The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response epub

The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response Audiobook Download

Listen The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response book

Download The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response Audiobook

An electronic book, also known as an e-book or eBook, is a book publication made available in digital form, consisting of text, images, or both, readable on the flat-panel display of computers or other electronic devices. Although sometimes defined as "an electronic version of a printed book",some e-books exist without a printed equivalent. E-books can be read on dedicated e-reader devices, but also on any computer device that features a controllable viewing screen, including desktop computers, laptops, tablets and smartphones.

Results The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response

Methods for time-varying exposure related problems in - Purpose: Lack of control for time-varying exposures can lead to substantial bias in estimates of treatment effects. The aim of this study is to provide an overview and guidance on some of the available methodologies used to address problems related to time-varying exposure and confounding in pharmacoepidemiology and other observational studies

CS-duration and partial-reinforcement effects counteract ... - PubMed - Two experiments used rats in a conditioned lick suppression preparation to investigate how the conditioned stimulus (CS)-duration and partial-reinforcement effects (, weakened responding due to conditioning with a CS of longer duration and presenting nonreinforced CSs intermingled with CS-unconditioned stimulus [US] pairings, respectively) interact with overshadowing

Time-Varying Exposure — zEpid documentation - Read the Docs - Time-Varying Exposure. In this section, we will go through some methods to estimate the average causal effect of a time-varying treatment / exposure on a specific outcome. The key problem we must overcome is time-varying confounding. Time-varying confounders are both a mediator and a confounder, depending on the causal path

PDF (3),258-260 Effectsof CS amounton conditioned taste ... - Springer - presents a paradox for learned safety theory. The paradox centers around the effects of experience with the CS on the acquisition of aversion. As defined by studies which involve repeated CS pre exposures or which vary the duration of CS pre exposure, "greater experience with the CS"·results in less (or at most equal) aversion being acquired

(PDF) CS-duration and partial-reinforcement effects counteract - The results support neither the view that the ratio between the total CS exposure and total time in the context determines the CS-duration and the partial-reinforcement effects nor the view that

The effect of varying CS exposure duration on paradoxical ... - CORE - The effect of varying CS exposure duration on paradoxical enhancement of a conditioned response. Authors. Dena Lynn Norris; Publication date January 1, 1976. ... The groups differed by the duration of the CS-alone exposure each received one minute after conditioning--either 2, 60 or 300 seconds

PDF CS-duration and partial-reinforcement effects counteract ... - Springer - observed only when both the absolute duration of total CS exposure and the US-US interval were short. The results support neither the view that the ratio between the total CS exposure and total time in the context deter-mines the CS-duration and the partial-reinforcement effects nor the view that these two effects arise from a loss

Confounders in Time-Series Regression - Columbia Public Health - Recent literature has demonstrated the utility of time series regression analysis towards understanding short-term association between time-varying exposures with outcomes. Thus, questions related to the effect of a daily measured common exposure by an individual or a city can be inferred through a time series regression analysis

Download The Effect of Varying CS Exposure Duration on Paradoxical - The Effect of Varying CS Exposure Duration on Paradoxical Enhancement of a Conditioned Response Summary The present study investigated the phenomenon that under certain conditions the presentation of the conditioned stimulus (CS) alone leads to enhancement of the conditioned response (CR) rather than to extinction of the CR

Methods for time‐varying exposure related problems in - The observations at each time point of the time-varying exposure and the time-varying confounder are indicated, respectively, with T 0, T 1, C 0, and C 1 since they are measured at time 0 and at time 1. The variable Y indicates the outcome. For simplicity of the graphical representations, in DAG A and in DAG B a variable representing the set of

Handling time varying confounding in observational research - Many exposures of epidemiological interest are time varying, and the values of potential confounders may change over time leading to time varying confounding. The aim of many longitudinal studies is to estimate the causal effect of a time varying exposure on an outcome that requires adjusting for time varying confounding. Time varying confounding affected by previous exposure often occurs in

The effect of varying CS exposure duration on paradoxical enhancement - Abstract. The present study investigated the phenomenon that under certain conditions the presentation of the conditioned stimulus (CS) alone leads to enhancement of the condition

Estimation of causal effects of a time-varying exposure at ... - PLOS - Structural mean models have previously been proposed for estimation of MR models with a time varying exposure. [21,22] The interpretation of the results from estimation of structural mean models will depend on the availability of data for the time-varying exposure, particularly how many time points data are available for. MVMR can be

Effects of conditioned stimulus pre-exposure on human ... - PubMed - The effects of conditioned stimulus (CS) pre-exposure and fear-relevance of the CS on human Pavlovian electrodermal conditioning were investigated. A differential delayed conditioning paradigm was used with a CS-unconditioned stimulus (US; shock) interval of 8 s. In Experiment 1, 64 subjects were ra …

Estimation of the Causal Effect of a Time-Varying Exposure on the - The greatest benefit comes with time-varying treat-ments, because then standard methods [like time-dependent proportional hazard and generalized estimating equations (GEE) regression modeling] can be biased even when the causal null is true and there are no unmeasured confounders (Robins 1986; Robins and Greenland 1994). Indeed, con-

Multiple Time-varying Exposures1 - Jstor - eling the potential interaction effects of multiple time-varying exposures. Models for time- varying exposure have also been an active focus in functional data analysis where functional coefficients from functional regression models are equivalent to the weight functions for time-varying exposures in WCE models with a difference of constant ratio

(PDF) Propensity score analysis for time-dependent exposure - ResearchGate - Because the exposure in the example is time-varying, , subjects can receive treatment at different observation period, the treatment effect can be estimated by using the

Variables that affect exposure - - The amount of light recorded by a camera depends on the size of the lens opening (called the aperture) and the amount of time light is allowed to strike the film or sensor chip (called the exposure time).The former is controlled by varying the f/stop, F-number, and the latter is controlled by varying the shutter speed

Survival analysis: time-dependent effects and time-varying risk factors - In the present paper, we describe (1) the interpretation of short-term and long-term effects of fixed risk factors on survival as well as (2) the effects of risk factors that vary over time in a time-dependent analysis. In the context of this paper, we use 'effects' and 'associations' interchangeably, and consistent with Rothman we

Digital resource - The effect of varying CS exposure duration on paradoxical enhancement of a conditioned response . Norris, Dena Lynn.. St. John's, Newfoundland : Memorial University of Newfoundland, 1976. File / Folder: Access Footnote * Norris_DenaLynn (PDF, 14.02 MB) Open Footnotes Footnote *

Paradoxical reaction - Wikipedia - Paradoxical reaction. A paradoxical reaction (or paradoxical effect) is an effect of a chemical substance, such as a medical drug, that is opposite to what would usually be expected. An example of a paradoxical reaction is pain caused by a pain relief medication. Paradoxical reactions may be more common in people with ADHD

Exposure Assessment - Boston University - Duration of exposure; Dose and frequency of exposure; Latency and critical window; Duration of Exposure. The duration of exposure may have an important impact on the likelihood of adverse consequences. Smoking one cigarette is unlikely to have long term adverse effects, but smoking a pack a day for 40 years is likely to have important adverse

Estimation of causal effects of a time-varying exposure at multiple - Estimation of causal effects of a time-varying exposure at multiple time points through multivariable mendelian randomization PLoS Genet. 2022 Jul 18 ... We explore the use of MVMR to estimate the direct effect of a single exposure at different time points in an individual's lifetime on an outcome. We use simulations to illustrate the

Estimation of the causal eﬀects of time-varying exposures - In this chapter we describe methods for the estimation of the causal eﬀect of a timevarying exposure on an outcome of interest from longitudinal data collected in an observational study. The terms "exposure" and "treatment" will be used synonymously and. interchangeably. We assume a ﬁxed study population, that is, a closed cohort

Estimation of time-varying causal effects with multivariable ... - medRxiv - Introduction For many exposures present across the lifecourse, the effect of the exposure may vary over time. Multivariable Mendelian randomization (MVMR) is an approach that can assess the effects of related risk factors using genetic variants as instrumental variables. Recently, multivariable Mendelian randomization has been used to estimate the effects of an exposure during distinct time

PDF Individual causal effects from observational longitudinal studies with - For known causal structures and time-varying expo-sures, the variability of the CWCE reduces with an increasing number of re-peated measurements. The CWCE becomes identiﬁable from observational data under the causal assumption of cross-world similarity of individual-effect modiﬁcation ( there exists an exposure strategy whose effect is af-

Modeling of cumulative effects of time-varying drug exposures on within - To account for the dosage, duration and timing of past exposures, we rely on a flexible weighted cumulative exposure methodology to model the cumulative effects of past drug use, as the weighted sum of past doses

PDF Chapter 9 - TIME VARYING (OR TIME-DEPENDENT) COVARIATES Survivor function: S(t;Z) = exp− t 0 exp(βZ(u)) λ 0(u)du and depends on the values of the time dependent variables over the interval from 0 to t. This is the classic formulation of the time varying Cox regression survival model. For Z(u) is step function with one change point at t 1

Exposure-time-varying hazard function ratios in case-control ... - PubMed - For many adverse effects of drugs, the instantaneous risk of an incident event per day of therapy (, the hazard function) varies by duration of therapy and by prior exposure. In cohort studies of adverse drug effects time-varying hazard functions are easily modeled using standard statistical sof …

The paradoxical effect of brief CS exposure on analogue - In formulating a theory of anxiety incubation, Eysenck (1968) has cited evidence from infrahuman and human aversive conditioning studies to suggest th…

The paradoxical effect of brief CS exposure on analogue - In both studies, short duration exposure to the CS subsequent to conditioning resulted in greater fear relative to zero or long exposure conditions. Furthermore, in support of an incubation effect, the latter study found increases in fear over post-conditioning base levels among brief exposure Ss

CS-duration and partial-reinforcement effects counteract - effect) or increment of the duration of CS-alone exposure (the CS-duration effect), which is shared by many associa-tive theories. Although the comparator hypothesis does not explicitly define the mechanism responsible for this loss of effectiveness of excitatory associations as a result of nonreinforced exposure, this mechanism is implicit

Methods for time-varying exposure related problems in - Several methods exist to address time-varying covariates, but the complexity of the most advanced approaches-eg, marginal structural models or structural nested failure time models-and the lack of user-friendly statistical packages have prevented broader adoption of these methods

The effect of varying CS exposure duration on paradoxical - Three groups received CS (slide presentation)-UCS (a loud burst of white noise) pairings on a 76 per cent irregular reinforcement pattern. The groups differed by the duration of the CS-alone exposure each received one minute after conditioning--either 2, 60 or 300 seconds

CS-duration and partial-reinforcement effects counteract - The results support neither the view that the ratio between the total CS exposure and total time in the context determines the CS-duration and the partial-reinforcement effects nor the view that these two effects arise from a loss of effectiveness of the excitatory CS-US association during CS-alone exposures in partial reinforcement or early …

Methods for time‐varying exposure related problems in - Is time-varying exposure and confounding a problem in Pharmacoepidemiology?