scholarly journals Context-Specific Habituation: A Review

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1767
Author(s):  
Andrea Dissegna ◽  
Massimo Turatto ◽  
Cinzia Chiandetti
Keyword(s):  
Experimental Data ◽  
Nervous System ◽  
Theoretical Model ◽  
Associative Learning ◽  
Animal Species ◽  
Response Decrement ◽  
Repeated Stimulation ◽  
Widespread Belief ◽  
Context Specific

Habituation consists of the progressive response decrement to a repeated stimulation, a response decline that is not accounted for by sensory or motor fatigue. Together with sensitization, habituation has been traditionally considered to be a prototypical example of non-associative learning, being affected only by the features of the stimulation, as for instance its intensity or frequency. However, despite this widespread belief, evidence exists showing that habituation can be specific to the context of the stimulation, thus suggesting that habituation can have an associative nature. Such an unexpected characteristic of habituation was in fact predicted by a theoretical model of associative learning proposed by Wagner in a series of works that appeared in the late 1970s. Here, we critically review the experimental data that since then have been accumulated in support of this hypothesis. What emerges from the literature is that context-specific habituation is common to several animal species and that the ability to form an association between the habituating stimulus and its context is independent of the complexity of the animal’s nervous system. Finally, context-specific habituation is observed for a variety of organism’s responses, ranging from visceral to motor and mental activities.

Learned Placebo Effects in the Immune System

2014 ◽  
Vol 222 (3) ◽  
pp. 148-153 ◽  
Author(s):  
Sabine Vits ◽  
Manfred Schedlowski
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Associative Learning ◽  
Placebo Response ◽  
Immunosuppressive Drug ◽  
Immune Functions ◽  
Placebo Effects ◽  
New Therapeutic Approaches ◽  
Biological Variables ◽  
Experimental Approaches

Associative learning processes are one of the major neuropsychological mechanisms steering the placebo response in different physiological systems and end organ functions. Learned placebo effects on immune functions are based on the bidirectional communication between the central nervous system (CNS) and the peripheral immune system. Based on this “hardware,” experimental evidence in animals and humans showed that humoral and cellular immune functions can be affected by behavioral conditioning processes. We will first highlight and summarize data documenting the variety of experimental approaches conditioning protocols employed, affecting different immunological functions by associative learning. Taking a well-established paradigm employing a conditioned taste aversion model in rats with the immunosuppressive drug cyclosporine A (CsA) as an unconditioned stimulus (US) as an example, we will then summarize the efferent and afferent communication pathways as well as central processes activated during a learned immunosuppression. In addition, the potential clinical relevance of learned placebo effects on the outcome of immune-related diseases has been demonstrated in a number of different clinical conditions in rodents. More importantly, the learned immunosuppression is not restricted to experimental animals but can be also induced in humans. These data so far show that (i) behavioral conditioned immunosuppression is not limited to a single event but can be reproduced over time, (ii) immunosuppression cannot be induced by mere expectation, (iii) psychological and biological variables can be identified as predictors for this learned immunosuppression. Together with experimental approaches employing a placebo-controlled dose reduction these data provide a basis for new therapeutic approaches to the treatment of diseases where a suppression of immune functions is required via modulation of nervous system-immune system communication by learned placebo effects.

ERP Evidence for Implicit Priming of Top–Down Control of Attention

2016 ◽  
Vol 28 (5) ◽  
pp. 763-772 ◽  
Author(s):  
Chris Blais ◽  
Emily Hubbard ◽  
George R. Mangun
Keyword(s):  
Associative Learning ◽  
Stroop Effect ◽  
Congruency Effect ◽  
Simon Task ◽  
Electrical Signal ◽  
Lower Visual Field ◽  
Specific Effects ◽  
High Conflict ◽  
Contemporary Work ◽  
Context Specific

Proportion congruency effects are the observation that the magnitude of the Stroop effect increases as the proportion of congruent trials in a block increases. Contemporary work shows that proportion effects can be specific to a particular context. For example, in a Simon task in which items appearing above fixation are mostly congruent and items appearing below fixation are mostly incongruent, the Simon effect is larger for the items appearing at the top. There is disagreement as to whether these context-specific effects result from simple associative learning or, instead, a type of conflict-mediated associative learning. Here, we address this question in an ERP study using a Simon task in which the proportion congruency effect was context-specific, manipulating the proportion of congruent trials based on location (upper vs. lower visual field). We found significant behavioral proportion congruency effects that varied with the specific contexts. In addition, we observed that the N2 response of the ERPs to the stimuli was larger in amplitude for the high congruent (high conflict) versus low congruent (low conflict) conditions/contexts. Because the N2 is known to be greater in amplitude also for trials where conflict is high and is believed to be an electrical signal related to conflict detection in the medial frontal cortex, this supports the idea that conflict-mediated associative learning is involved in the proportion congruency effect.

Simulations of Synaptic Transmission Using Lattice Boltzmann Methods

2002 ◽  
Author(s):  
Mehrak Mahmoudi ◽  
Piroz Zamankhan ◽  
William Polashenski
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Theoretical Model ◽  
Lattice Boltzmann ◽  
Chemical Substance ◽  
Human Central Nervous System ◽  
Lattice Boltzmann Methods ◽  
Nerve Impulses ◽  
System A ◽  
The Central Nervous System

The nervous system remains one of the least understood biological structures due in large part to the enormous complexity of this organ. A theoretical model for the transfer of nerve impulses would be valuable for the analysis of various phenomena in the nervous system, which are difficult to study by experiments. The central nervous system is composed of more than 100 billion neurons, through which information is transmitted via nerve impulses. Nerve impulses are not immediately apparent since each impulse may be blocked during transmission, changed from a single impulse into repetitive impulse, or integrated with impulses from other neurons to form highly intricate patterns. In the human central nervous system, a neuron secretes a chemical substance called a neurotransmitter at the synapse, and this transmitter in turn acts on another neuron to cause excitation, inhibition, or some other modification of its sensitivity.

The structure of the Cincinnati arch as determined by short period Rayleigh waves

1969 ◽  
Vol 59 (1) ◽  
pp. 399-407
Author(s):  
Robert B. Herrmann
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Layer Thickness ◽  
Rayleigh Waves ◽  
Layer Model ◽  
Depth Data ◽  
Short Period ◽  
Best Fitting ◽  
Good Agreement

Abstract The propagation of Rayleigh waves with periods of 0.4 to 2.0 seconds across the Cincinnati arch is investigated. The region of investigation includes southern Indiana and Ohio and northern Kentucky. The experimental data for all paths are fitted by a three-layer model of varying layer thickness but of fixed velocity in each layer. The resulting inferred structural picture is in good agreement with the known basement trends of the region. The velocities of the best fitting theoretical model agree well with velocity-depth data from a well in southern Indiana.

Development of a Methodology for the Evaluation of Motion Sickness Incidence in Railways

2013 ◽  
Author(s):  
Claudio Braccesi ◽  
Filippo Cianetti ◽  
Renzo Scaletta
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Motion Sickness ◽  
Evaluation Method ◽  
Low Frequency ◽  
Comparison With Experimental Data

The present paper illustrates an evaluation method developed by the authors to quantify the index of motion sickness incidence (MSI) in railways motion conditions. This index is formerly defined in literature to quantify diseases coming from low frequency motions (kinetosis). The proposed method, suggested as alternative to the only one existing in reference norm, involves PCT index, well known in railways context, and weighting curves for accelerometric signals, which are also specified in railways regulations. The approach of the method, consistent with the theoretical model, developed by the authors themselves in previous works, allows to obtain MSI index versus time and/or track progressive distance. The model is validated through comparison with experimental data available in literature and with measures recorded and obtained on regular trains during tests performed in Slovenia (EU).

scholarly journals Coordination Numbers of Bivalent Ions in Organic Solvents

2021 ◽  
Vol 95 (10) ◽  
pp. 2059-2064
Author(s):  
M. A. Orekhov
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Molecular Dynamic ◽  
Coordination Number ◽  
Organic Solvents ◽  
Organic Molecule ◽  
Dynamic Models ◽  
Coordination Numbers ◽  
A Value ◽  
Bivalent Ions

Abstract Molecular dynamic models are created for properties of bivalent ions in organic solvents. It is shown that molecules of the considered solvents bound to ions via oxygen atoms. A theoretical model is developed that describes the ion coordination number. The coordination number in this model is determined by the ratio between the sizes of the ion and the atom organic molecule bound to it. It is shown that the coordination number depends weakly on the solvent and strongly on the type of ion. A value of 0.13 nm is obtained for the effective size of an oxygen atom bound to a bivalent ion. The constructed theoretical model agrees with the results from molecular dynamic calculations and the available experimental data.

Radiation-Induced Buoyancy-Driven Flow in Rectangular Enclosures: Experiment and Analysis

1987 ◽  
Vol 109 (2) ◽  
pp. 427-433 ◽  
Author(s):  
B. W. Webb ◽  
R. Viskanta
Keyword(s):  
Experimental Data ◽  
Temperature Field ◽  
Theoretical Model ◽  
Radiation Flux ◽  
Convective Motion ◽  
Radiative Heating ◽  
Working Fluid ◽  
Injection Technique ◽  
Flux Divergence ◽  
Radiation Induced

Experiments have been performed to study the rate of internal radiative heating on the natural convective motion in a vertical rectangular enclosure irradiated from the side. A Mach–Zehnder interferometer has been used to determine the temperature field, and a fluorescing dye injection technique was employed to illustrate the flow structure with water as the working fluid. A theoretical model is developed for predicting the absorption of thermal radiation and the subsequent buoyancy-driven flow. Predictions based on spectral calculations for the radiation flux divergence agree well with the experimental data.

scholarly journals FINAL STATE INTERACTIONS IN B → ππK AND $B\to K\overline{K}K$ DECAYS

2007 ◽  
Vol 22 (02n03) ◽  
pp. 645-648
Author(s):  
L. LEŚNIAK ◽  
R. KAMIŃSKI ◽  
B. EL-BENNICH ◽  
B. LOISEAU ◽  
A. FURMAN
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Unitary Representation ◽  
B Meson ◽  
Final State ◽  
B Meson Decays ◽  
Meson Decays ◽  
Neutral B Meson ◽  
Final State Interactions

Analysis of charged and neutral B meson decays into π+π-K, K+K-K and [Formula: see text] is performed using a unitary representation of the ππ and [Formula: see text] final state interactions. Comparison of the theoretical model with the experimental data of the Belle and BaBar Collaborations indicates that charming penguin contributions are necessary to describe the B → f0(980) K and B → ρ(770)0 K decays.

Focus Within or On Others: The Impact of Reviewers' Attentional Focus on Review Helpfulness

2021 ◽  
Author(s):  
Zhanfei Lei ◽  
Dezhi Yin ◽  
Han Zhang
Keyword(s):  
Boundary Condition ◽  
Theoretical Model ◽  
Positive Impact ◽  
Online Reviews ◽  
Attentional Focus ◽  
Controlled Experiments ◽  
Review Helpfulness ◽  
Context Specific ◽  
The Impact ◽  
Consistent Support

When reviewers write online reviews, they differ in the focus of their attention: some focus on their own experiences, whereas some direct their attention to others—prospective consumers who may read the reviews in the future. This paper explores how, why, and when reviewers’ attentional focus can influence the helpfulness evaluation of reviews beyond the impact of substantive review content. Drawing on the attentional focus and persuasion literatures, we develop a theoretical model proposing that reviewers’ attentional focus may influence consumers’ perception of review helpfulness through opposing processes, and that its overall effect is contingent on the review’s two-sidedness. Results of one archival analysis and five controlled experiments provide consistent support for our hypotheses. This work challenges the predominant view of the positive impact of other-focus (vs. self-focus), explores the interpersonal impact of a reviewer’s attentional focus on prospective consumers who are total strangers, and reveals an important, context-specific boundary condition.

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