Escape Behavior as a Function of Delay of Negative Reinforcement

1973 ◽  
Vol 32 (1) ◽  
pp. 63-70
Author(s):  
Frank C. Leeming ◽  
Joel E. Robinson
Keyword(s):  
Negative Reinforcement ◽  
Escape Behavior ◽  
Escape Latency ◽  
Shock Termination ◽  
Shuttle Box ◽  
Group 4 ◽  
Delay Of Reinforcement ◽  
Group 16 ◽  
The Moment

Rats in a shuttle box were reinforced by shock termination after delays of 0, 1, 2, 4, 8, or 16 sec. All Ss received 100 training trials and Ss in Groups 0, 1, and 4 received an additional 30 test trials on which shock termination was delayed for 20 sec. During training and testing, escape latency, and Ss' location in the compartment at the moment of shock termination were recorded. Number of trials required to reach criterion was directly related to length of delay. The differences between asymptotic response levels were small and, with the exception of Group 16, nonsignificant. Ss in Groups 2, 4, and 8 showed a significant increase in location consistency during training. During resting Groups 0 and 1 showed marked decrements in performance while Group 4 showed no increase in escape latency. Group 4 also showed significantly higher location consistency than Groups 0 and 1. These findings were discussed in relation to Spence's theories of delay of reinforcement and extinction.

Contiguous Approach Conditioning: A Model for Negative Reinforcement

1975 ◽  
Vol 37 (3) ◽  
pp. 851-856 ◽  
Author(s):  
Ernest G. Maples ◽  
Phillip D. Tomporowski ◽  
Maury M. Haraway
Keyword(s):  
Test Trial ◽  
Negative Reinforcement ◽  
Shock Termination ◽  
Single Test ◽  
Empirical Basis ◽  
Equivalent Number ◽  
The Difference

The study was designed to provide an empirical basis for Denny's account of negative reinforcement by showing that stimuli contiguously paired with shock termination can become conditioned elicitors of approach. 20 experimental Ss received 15 trials in which the onset of a 6-w light was paired with the termination of a 30-sec., 1-ma. scrambled shock, independently of Ss' behavior. 20 control Ss received an equivalent number of light and shock presentations, but these were unpaired. On a single test trial, S was exposed to a 6 w light in one arm (randomly selected) of a modified T-maze. 17 of 20 experimental Ss approached the light whereas only 11 of 20 control Ss approached the light. The difference between proportions was significant ( p = .05).

Delay of Shock-Escape with and without Stimulus Change

1971 ◽  
Vol 29 (1) ◽  
pp. 315-318
Author(s):  
Jesse B. Milby
Keyword(s):  
Negative Reinforcement ◽  
Stimulus Change ◽  
Secondary Reinforcement ◽  
Response Rates ◽  
Shock Termination ◽  
Control Procedure ◽  
Escape Conditioning ◽  
Background Stimulus ◽  
Shock Escape ◽  
Secondary Reinforcing

Effects of a stimulus change presented with delay of shock-escape were examined in escape conditioning. Where a stimulus change occurred with the delay, greater response rates were found before delay and lower rates during the delay. Results are interpreted as providing evidence for the efficacy of a stimulus change in maintaining behavior with delay of negative reinforcement. Results are consistent with an information account of secondary reinforcement. Data from a control procedure suggest the possibility that stimuli paired with shock termination might have two opposite properties, secondary reinforcing and conditioced aversive, depending upon the background stimulus conditions prevailing at testing.

scholarly journals Return-To-Practice Roadmap In Orthopedic Surgery Of A Spanish Military Hospital After Covid-19 Pandemic

2020 ◽  
Author(s):  
Diana Crego Vita ◽  
Carlos Rodríguez-Moro ◽  
José Adolfo Orelana Gómez-Rico ◽  
Rafael García-Cañas ◽  
Monica Huecas Martínez ◽  
...  
Keyword(s):  
Orthopedic Surgery ◽  
Emergency Situation ◽  
Military Hospital ◽  
Protection Measures ◽  
Group 4 ◽  
Orthopedic Surgeons ◽  
Individual Protection ◽  
The Moment ◽  
Surgery Department ◽  
The Impact

Abstract Background The impact of the COVID-19 pandemic In Spain, especially in Madrid, suddenly affected all the activity of the hospital including the suspension of all non-urgent surgical procedures. What´s more crucial, the urgent procedures were seriously obstructed by to factors: the mandatory protection measures (individual protection clothes, facemasks, and their initial stockout, etc), the redesigned flow of the patients in and out the operation room specially because the advisable diagnosis study of severe acute respiratory syndrome related Coronavirus 2 in each patient.Methods We review the patients treated in our orthopedic department during the outbreak of Coronavirus disease 19. Based in our early experience and the emergency situation with high contagious rate in Madrid, Spain, we have built a list of considerations and recommendations to guide orthopaedic units in their resumption of their regular activity, focusing at the moment of reintroduce elective surgeries, during the contained epidemic phases.Results The mortality rate in Coronavirus disease 19 patients was 3/9 and in the non Coronavirus disease group 4/23 developed pneumonia by Coronavirus2 (1 dead). There are no guidelines in literature for orthopedic surgeons in the postpandemic phase.Conclusion Coronavirus disease 19 patients have an elevated morbidity and mortality, surgery during this pandemia can facilitate pneumonia by Coronavirus2. The return-to-practice measures in the orthopedic units must take into account this fact. We recommend for each orthopedic surgery department to create a flowchart, as ours, in order to restart surgical activity.

scholarly journals Numerical model of beam-to-column composite connection between slim floor system and composite column

2020 ◽  
Vol 13 (2) ◽  
pp. 348-379
Author(s):  
R. F. F. KOCHEM ◽  
S. de NARDIN
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Composite Beam ◽  
Negative Reinforcement ◽  
Numerical Approach ◽  
Steel Tube ◽  
The Moment ◽  
Composite Connections ◽  
Floor System ◽  
Good Agreement

Abstract The slim floor system has been used mainly due to the structural and constructive advantages of it, such as the capacity to overcome large spans with the low height of the composite floor system. There is a lack of finite element modelling researches of composite connections between the slim floor system and columns, especially with the concrete infilled steel tube columns. This paper presents the numerical approach based on the solid modelling, for the simulation of the nonlinear structural behavior of composite connection between partially encased composite beam and concrete infilled steel tube column; in this model, the composite beam represents the slim floor. The ABAQUS finite element code was used to investigate the behavior of composite connection that consists of a shear steel plate and negative reinforcement of the composite slab. In this paper, the authors discusses the procedures to the numerical model construction including finite elements and boundary conditions. Besides, the influence of stress-strain relationships for concrete and steel and the parameters that defines each model are presented and discussed, as well as the different steel to concrete interface conditions. Based on the results obtained, the effectiveness of the numerical model developed was verified against experimental results showing a good agreement response for the Moment vs. Rotation response, as well as the moment resistance of the composite connection.

scholarly journals Nitrate and nitrite exposure increases anxiety-like behavior and alters brain metabolomic profile in zebrafish

2020 ◽  
Author(s):  
Manuel García-Jaramillo ◽  
Laura M. Beaver ◽  
Lisa Truong ◽  
Elizabeth R. Axton ◽  
Rosa M. Keller ◽  
...  
Keyword(s):  
Executive Function ◽  
Associative Learning ◽  
Cognitive Performance ◽  
Predator Avoidance ◽  
Negative Reinforcement ◽  
Shuttle Box ◽  
Treatment Groups ◽  
Multiple Parameters ◽  
Nitrate And Nitrite ◽  
The Brain

AbstractIntroductionDietary nitrate lowers blood pressure and improves athletic performance in humans, yet data supporting observations that it may increase cerebral blood flow and improve cognitive performance are mixed. Here we tested the hypothesis that nitrate and nitrite treatment would improve indicators of learning and cognitive performance in a zebrafish (Danio rerio) model. We also explored the extent to which nitrate and nitrite treatment affected the brain metabolome in order to understand how nitrate and nitrite supplementation may affect indices of cognitive function.MethodsFish were exposed to sodium nitrate (606.9 mg/L), sodium nitrite (19.5 mg/L), or control water for 2-4 weeks and free swim, startle response, innate predator avoidance, social cohesion, and shuttle box assays were performed.ResultsNitrate and nitrite treatment did not change fish weight, length, predator avoidance, or distance and velocity traveled in an unstressed environment. Nitrate- and nitrite-treated fish initially experienced more negative reinforcement and increased time to decision in the shuttle box assay, which is consistent with a decrease in associative learning or executive function however, over multiple trials, all treatment groups demonstrated behaviors associated with learning. Nitrate and nitrite treatment significantly increased anxiety-like behavior but did not alter epinephrine, norepinephrine or dopamine levels. Targeted LC-MS/MS analysis revealed no significant increase in brain nitrate or nitrite concentrations with treatment. An untargeted metabolomics analysis found 47 metabolites whose abundance was significantly altered in the brain with nitrate and nitrite treatment including an 18-19% reduction in the neurotransmitter γ-aminobutyric acid (GABA), and 17-22% reduction in its precursor, glutamine, which may contribute to the increased anxiety-like behavior.ConclusionNitrate and nitrite treatment did not adversely affect multiple parameters of zebrafish health but was associated with mild anxiety-like behavior, changes in the brain metabolome, and caused a short-term decrease in executive function or associative learning.

scholarly journals O Jato de Ar Quente Como um Estímulo Aversivo em Contingências de Fuga em Ratos

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Marcus Bentes de Carvalho Neto ◽  
Thrissy Collares Maestri ◽  
Maria Helena Leite Hunziker
Keyword(s):  
Escape Response ◽  
Negative Reinforcement ◽  
Aversive Stimulus ◽  
Laboratory Research ◽  
Air Blast ◽  
Shuttle Box ◽  
Aversive Control ◽  
Aversive Stimuli ◽  
Hot Air ◽  
Negative Reinforcer

To increase the number of aversive stimuli that are available for laboratory research, the hot air blast (HAB) was tested as a negative reinforcer in two escape contingencies. Sixteen naïve rats were exposed to 30 or 60 HAB presentations. For half of the subjects, the escape response was jumping in a shuttle box; for the others, the HAB was interrupted after a nose poke response. The results showed that seven of eight subjects (87.5%) in each group learned the required escape response. These data confirm the negative reinforcing function of the HAB, which may be an alternative aversive stimulus to be adopted in research with nonhumans subjects.Keywords: escape; negative reinforcement; hot air blast; aversive control.

scholarly journals Nitrate and nitrite exposure leads to mild anxiogenic-like behavior and alters brain metabolomic profile in zebrafish

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0240070
Author(s):  
Manuel García-Jaramillo ◽  
Laura M. Beaver ◽  
Lisa Truong ◽  
Elizabeth R. Axton ◽  
Rosa M. Keller ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
Negative Reinforcement ◽  
Inhibitory Neurotransmitter ◽  
Shuttle Box ◽  
Multiple Parameters ◽  
Nitrate Treatment ◽  
Liquid Chromatography Tandem Mass ◽  
Nitrate And Nitrite ◽  
The Brain ◽  
Metabolomics Analysis

Dietary nitrate lowers blood pressure and improves athletic performance in humans, yet data supporting observations that it may increase cerebral blood flow and improve cognitive performance are mixed. We tested the hypothesis that nitrate and nitrite treatment would improve indicators of learning and cognitive performance in a zebrafish (Danio rerio) model. We utilized targeted and untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to examine the extent to which treatment resulted in changes in nitrate or nitrite concentrations in the brain and altered the brain metabolome. Fish were exposed to sodium nitrate (606.9 mg/L), sodium nitrite (19.5 mg/L), or control water for 2–4 weeks and free swim, startle response, and shuttle box assays were performed. Nitrate and nitrite treatment did not change fish weight, length, predator avoidance, or distance and velocity traveled in an unstressed environment. Nitrate- and nitrite-treated fish initially experienced more negative reinforcement and increased time to decision in the shuttle box assay, which is consistent with a decrease in associative learning or executive function however, over multiple trials, all treatment groups demonstrated behaviors associated with learning. Nitrate and nitrite treatment was associated with mild anxiogenic-like behavior but did not alter epinephrine, norepinephrine or dopamine levels. Targeted metabolomics analysis revealed no significant increase in brain nitrate or nitrite concentrations with treatment. Untargeted metabolomics analysis found 47 metabolites whose abundance was significantly altered in the brain with nitrate and nitrite treatment. Overall, the depletion in brain metabolites is plausibly associated with the regulation of neuronal activity including statistically significant reductions in the inhibitory neurotransmitter γ-aminobutyric acid (GABA; 18–19%), and its precursor, glutamine (17–22%). Nitrate treatment caused significant depletion in the brain concentration of fatty acids including linoleic acid (LA) by 50% and arachidonic acid (ARA) by 80%; nitrite treatment caused depletion of LA by ~90% and ARA by 60%, change which could alter the function of dopaminergic neurons and affect behavior. Nitrate and nitrite treatment did not adversely affect multiple parameters of zebrafish health. It is plausible that indirect NO-mediated mechanisms may be responsible for the nitrate and nitrite-mediated effects on the brain metabolome and behavior in zebrafish.

scholarly journals COMPETITION BETWEEN POSITIVE AND NEGATIVE REINFORCEMENT IN THE TREATMENT OF ESCAPE BEHAVIOR

1999 ◽  
Vol 32 (3) ◽  
pp. 285-296 ◽  
Author(s):  
Joseph S. Lalli ◽  
Timothy R. Vollmer ◽  
Patrick R. Progar ◽  
Carrie Wright ◽  
John Borrero ◽  
...  
Keyword(s):  
Negative Reinforcement ◽  
Escape Behavior

Approach-escape interactions in rat brain

1962 ◽  
Vol 203 (5) ◽  
pp. 803-810 ◽  
Author(s):  
M. E. Olds ◽  
J. Olds
Keyword(s):  
Rat Brain ◽  
Lateral Hypothalamus ◽  
Escape Response ◽  
Positive Reinforcement ◽  
Negative Reinforcement ◽  
Escape Behavior ◽  
Lever Response

Animals with electrodes implanted at tegmental escape points and at hypothalamic approach points were tested for positive reinforcement during simultaneous negative stimulation, and for escape behavior during simultaneous positive stimulation. The test of positive reinforcement was made by presenting a correlated hypothalamic stimulus after each lever response, during a 2-min period, while a constant train of stimulation was being applied to a negative reinforcing point in tegmentum. The test of negative reinforcement was made by presenting repeated 1/2-sec trains of tegmental stimulation at a rate of 1/sec and interrupting this sequence for 4 sec after each lever response, during a 2-min period, while a constant train of stimulation was being applied to the positive reinforcing point in lateral hypothalamus. The constant negative train impeded and sometimes inhibited completely the positively reinforced behavior. The constant positive train, however, far from impeding the escape response, regularly facilitated the negatively reinforced behavior. The data were interpreted on the theory of a one-way inhibition from tegmental escape points to the hypothalamic approach one.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

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