Irrelevant Incentive Learning during Instrumental Conditioning: The Role of the Drive-Reinforcer and Response-Reinforcer Relationships

1983 ◽  
Vol 35 (3b) ◽  
pp. 249-263 ◽  
Author(s):  
Anthony Dickinson ◽  
D. J. Nicholas
Keyword(s):  
Lever Press ◽  
Instrumental Conditioning ◽  
Convincing Evidence ◽  
Incentive Learning ◽  
Instrumental Performance ◽  
Test Drive ◽  
Sodium Appetite ◽  
Drive State ◽  
Sodium Solution

Four experiments investigated the processes by which a motivationally-induced change in the value of the training reinforcer affects instrumental performance. Initially, thirsty rats were trained to lever press for either a sodium or non-sodium solution. In Experiment I sodium-trained rats responded faster in extinction following the induction of a sodium appetite, but not following either food or water deprivation. Thus, enhanced extinction performance depends upon the relevance of the training reinforcer to the test drive state. The remaining experiments examined the role of the instrumental contingency. Animals received response-contingent presentations of one solution alternated either within (Experiments II and III) or between sessions (Experiment IV) with non-contingent presentations of another solution. Neither procedure yielded convincing evidence that contingent sodium presentations generated more responding in extinction under a sodium appetite than did non-contingent sodium presentations. On the basis of these results, we argue that the instrumental contingency itself does not play a major role in this irrelevant incentive effect.

The Effects of a Signal for free or for Earned Reward: Implications for the Role of Response-Reinforcer Associations in Instrumental Performance

1981 ◽  
Vol 33 (2b) ◽  
pp. 95-107 ◽  
Author(s):  
Geoffrey Hall ◽  
Stephen Channell ◽  
John M. Pearce
Keyword(s):  
Lever Press ◽  
Response Rate ◽  
Variable Interval ◽  
Free Food ◽  
Food Delivery ◽  
Instrumental Performance ◽  
Lever Pressing ◽  
Light Flashes

Pearce and Hall (1978) investigated the effects of making a brief flash of light contingent upon response in rats lever-pressing for food on a variable-interval (VI) schedule. When this signal occurred in conjunction only with reinforced responses the response rate was lowered with respect to a condition in which an equal number of light flashes occurred uncorrelated with reinforcement. The experiments reported here compared these effects with those produced by signalling “free” food deliveries in a similar way. Experiments I and II compared the effects of presenting correlated and uncorrelated schedules of light and food to rats given no opportunity to lever-press. The different schedules did not produce differences in response rate when the levers were made available. In Experiment III, free food was delivered to rats responding on a VI schedule. Signalling the delivery of earned food pellets produced a low response rate in comparison with a condition in which the free pellets were signalled. It is concluded that signalling food delivery is effective only when the rat must respond to earn the food and it is argued that the signal has its effect by overshadowing a response-reinforcer association.

Irrelevant Incentive Learning during Training on Ratio and Interval Schedules

1983 ◽  
Vol 35 (3b) ◽  
pp. 235-247 ◽  
Author(s):  
Anthony Dickinson ◽  
D. J. Nicholas
Keyword(s):  
Test Performance ◽  
Lever Press ◽  
Relative Size ◽  
Interval Schedule ◽  
Instrumental Performance ◽  
Incentive Effect ◽  
Sodium Appetite ◽  
Aversion Conditioning ◽  
The Difference ◽  
Sodium And Potassium

Two experiments investigated the effect of a motivationally-induced change in the value of the training reinforcer on instrumental performance. Initially, thirsty rats were trained to lever press for either a sodium or a potassium solution. Responding in an extinction test was then measured following the induction of sodium appetite. In Experiment I sodium-trained rats responded faster in a test given one day following the end of instrumental training. Furthermore, the relative size of this irrelevant incentive effect did not depend upon whether a ratio or interval schedule was employed during training. Delaying the test for eight days following the end of training abolished the difference between the test performance of sodium- and potassium-trained animals. Experiment II provided a further study of the effect of the training schedule when the introduction of the sodium reinforcer was delayed until responding was well established. Again the relative size of the difference between the performance of sodium- and potassium-trained animals was comparable following training on ratio and interval schedules. The insensitivity of this irrelevant incentive effect to the training contingency is in marked contrast to previous failures to detect an effect of reinforcer revaluation brought about by aversion conditioning following training on an interval schedule (Dickinson, Nicholas and Adams, 1983).

scholarly journals A triple combination of treatments on moderate COVID-19

Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 769-772
Author(s):  
ChunMiao Bao ◽  
BinBin Li ◽  
YuFeng Zhou
Keyword(s):  
Medical Records ◽  
Clinical Characteristics ◽  
Smoking Status ◽  
Length Of Hospital Stay ◽  
Convincing Evidence ◽  
Triple Combination ◽  
Viral Shedding ◽  
Null Effect ◽  
Treatment Start

Abstract Objective A triple combination of interferon (IFN) α-2b, lopinavir tablets, and umifenovir was used to treat COVID-19 patients. It is important to explore whether the benefit of this therapy is time dependent. Methods A cohort of moderate COVID-19 patients (n = 54) was admitted for hospitalization. The demographic (age, gender, and smoking status) and clinical characteristics (epidemiological trace and comorbidity) were collected from the digital medical records. The length of hospital stay (LOS) and the viral shedding time (VST) were set as the outcomes for COVID-19 cases. Results After control for age, sex, epidemiological trace, smoking, and comorbidity, the time of treatment start had null effect on VST (IRR = 1.09; 95% CI = 0.91–1.30; p = 0.33) or LOS (IRR = 1.10; 95% CI = 0.94–1.28; p = 0.23). Conclusion There is no convincing evidence to support a pivotal role of the timing of the therapy in the prognosis of moderate COVID-19 cases.

REVIEW ARTICLE

PEDIATRICS ◽  
1954 ◽  
Vol 14 (3) ◽  
pp. 269-279
Author(s):  
CHARLES D. MAY
Keyword(s):  
Vitamin B6 ◽  
Convincing Evidence ◽  
Human Nutrition ◽  
Nutritional Factors ◽  
Dietary Requirement ◽  
The Past ◽  
The Status ◽  
Metabolic Reactions ◽  
Convulsive Seizures

WITHIN the past year a dramatic outbreak of a singular type of convulsive seizures in babies has provided convincing evidence of an essential role for Vitamin B6 in human nutrition under natural circumstances. This is a general review of the circumstances surrounding this outbreak and of the present state of our knowledge of vitamin B6. But it is also important that this episode be considered as a reminder of the complex interrelationships which permeate studies of nutritional factors and as a warning against hasty conclusions. It also serves as an illustration of the hazard in premature or uncontrolled application to human nutrition of isolated fragments of knowledge concerning nutritional factors. The existence of Vitamin B6 was discovered in 1934 by experiments with rats. Symptoms of deficiency of this vitamin were soon described in several species of animals but not in man. Within a few years the chemistry of the vitamin was determined and the synthesis achieved. Considerable information as to the metabolic reactions affected by a deficiency of Vitamin B6 was rapidly accumulated. Only recently, 16 years after the discovery of Vitamin B6, the Council on Pharmacy and Chemistry of the American Medical Association reviewing the status of our knowledge of the role of Vitamin B6 in human nutrition reached only a cautious acceptance of an essential dietary requirement for Vitamin B6 in the human. The original observations which called attention to the problem of unusual convulsions in infants and pointed the way to its solution were made by a doctor in practice, just as were similar observations which led a few years ago to an appreciation of the circumstances producing a deficiency of folic acid in infancy.

The Role of Addington V Texas on Involuntary Civil Commitment

1989 ◽  
Vol 65 (3_suppl2) ◽  
pp. 1211-1215 ◽  
Author(s):  
J. Ray Hays
Keyword(s):  
United States ◽  
No Reduction ◽  
Burden Of Proof ◽  
United States Supreme Court ◽  
The United States ◽  
Convincing Evidence ◽  
Involuntary Commitment ◽  
United States Supreme ◽  
Linear Fashion

The United States Supreme Court in 1979 set the standard for involuntary commitment. This decision, styled Addington v Texas, raised the burden of proof required to commit persons from the usual civil burden of proof of “preponderance of the evidence” to “clear and convincing” evidence. There was no reduction in the rates of commitment as a result of the decision. The proportion of patients committed in Texas grew in almost linear fashion during the years 1972–1986. Various economic, sociological, and treatment factors may have more influence on commitment of patients than does a court decision.

scholarly journals Uterine Notch2 facilitates pregnancy recognition and corpus luteum maintenance via upregulating decidual Prl8a2

PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009786
Author(s):  
Haili Bao ◽  
Yang Sun ◽  
Ningjie Yang ◽  
Na Deng ◽  
Zhangli Ni ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Corpus Luteum ◽  
Convincing Evidence ◽  
Progesterone Level ◽  
Dopamine Receptor Agonist ◽  
Serum Progesterone ◽  
Pregnancy Recognition ◽  
Pituitary Prolactin ◽  
In Pregnancy

The maternal recognition of pregnancy is a necessary prerequisite for gestation maintenance through prolonging the corpus luteum lifespan and ensuring progesterone production. In addition to pituitary prolactin and placental lactogens, decidual derived prolactin family members have been presumed to possess luteotropic effect. However, there was a lack of convincing evidence to support this hypothesis. Here, we unveiled an essential role of uterine Notch2 in pregnancy recognition and corpus luteum maintenance. Uterine-specific deletion of Notch2 did not affect female fertility. Nevertheless, the expression of decidual Prl8a2, a member of the prolactin family, was downregulated due to Notch2 ablation. Subsequently, we interrupted pituitary prolactin function to determine the luteotropic role of the decidua by employing the lipopolysaccharide-induced prolactin resistance model, or blocking the prolactin signaling by prolactin receptor-Fc fusion protein, or repressing pituitary prolactin release by dopamine receptor agonist bromocriptine, and found that Notch2-deficient females were more sensitive to these stresses and ended up in pregnancy loss resulting from abnormal corpus luteum function and insufficient serum progesterone level. Overexpression of Prl8a2 in Notch2 knockout mice rescued lipopolysaccharide-induced abortion, highlighting its luteotropic function. Further investigation adopting Rbpj knockout and DNMAML overexpression mouse models along with chromatin immunoprecipitation assay and luciferase analysis confirmed that Prl8a2 was regulated by the canonical Notch signaling. Collectively, our findings demonstrated that decidual prolactin members, under the control of uterine Notch signaling, assisted pituitary prolactin to sustain corpus luteum function and serum progesterone level during post-implantation phase, which was conducive to pregnancy recognition and maintenance.

scholarly journals Medycyna w ujęciu Jędrzeja Śniadeckiego

2019 ◽  
Vol 26 ◽  
pp. 7-19
Author(s):  
Ryszard W. Gryglewski
Keyword(s):  
Clinical Medicine ◽  
Clinical Work ◽  
Convincing Evidence ◽  
Clinical Model ◽  
Highly Educated ◽  
Pathological Model ◽  
The Subject ◽  
The 19Th Century ◽  
Derived Data

Medicine in terms of Jędrzej Śniadecki Jędrzej Śniadecki (1768–1838) remains one of most eminent scholars of his times. Remembered as a founder of modern chemistry in Poland, one of early pioneers in anthropology and social sciences, and author of the two volume book Theory of organic being (Teoria jestestw organicznych), in which the modern metabolic concept of life processes can be considered as grounded; he was also a highly educated and gifted physician. This paper aims to show the importance of medicine in Śniadecki’s theory of life, in its physiological and pathological manifestations in regard to the clinical model and the medical practice which he followed. It deals with the concept of illness as described in Śniadecki’s writings, focusing on the role of irritation and organic reaction as the major components of his proposed pathological model. The dynamic and variable conditions of diseases are explained by means of metabolic changes, which was a truly pioneering concept, already described in Śniadecki’s earlier theoretical works on the subject of life and nature. The paper discusses the problem of influence in terms of the leading medical doctrines at the end of the 18th and the beginning of the 19th century, namely those of John Brown (1735–1788) and François Broussais (1772–1838), on Śniadecki as a researcher and practitioner. For practical (clinical) medicine his reserve towards auscultation and percussion, then a slowly gaining field in clinical subjects, is clearly present in Śniadecki’s writings and teaching. His passive and, as far as we can tell, sceptical attitude is explained by the lack of convincing evidence, based on empirical and experimental data, which would enable to connect the physical signs of a diagnosis fulfilled by means of stethoscope to that of the percussion process. It must be remembered that the books by Adam Raciborski (1809–1871) and Joseph Škoda (1805–1881) were both published in the 1830s, where modern diagnosing methods were established using a suitable scientific background to explain their importance. This was too late to influence the clinical work of Śniadecki. The same scepticism, with an obvious demand for strict and experimentally derived data, is probably responsible for the conservative therapy present in Śniadecki’s teaching.

scholarly journals Do anesthesiologists need epidural anesthesia and do surgeons need an anesthesiologist?

2016 ◽  
Vol 10 (3) ◽  
pp. 155-164
Author(s):  
Alexei M. Ovechkin
Keyword(s):  
Epidural Anesthesia ◽  
Critical Analysis ◽  
Risk Groups ◽  
Convincing Evidence ◽  
Major Surgery ◽  
Minimally Invasive Techniques ◽  
Thoracic And Abdominal ◽  
Invasive Techniques ◽  
Infiltration Analgesia

Presented paper reviews up-to-date often contradictive concepts about the role of epidural anesthesia in anesthesiological support of patients undergone major surgery. The author performed critical analysis of the arguments of the opponents of the wide use of epidural analgesia who propose to substitute the epidural anesthesia with minimally invasive techniques in particular infiltration analgesia with local anesthetics. The article includes convincing evidence in favour of continuous epidural anesthesia remains the method of choice for open major thoracic and abdominal surgery especially in patients from high risk groups.

Sign in / Sign up

Export Citation Format

Share Document