Search results for "Classical conditioning"
showing 10 items of 52 documents
Differential Classical Conditioning of the Nocebo Effect: Increasing Heat-Pain Perception without Verbal Suggestions
2017
Background: Nocebo effects, including nocebo hyperalgesia, are a common phenomenon in clinical routine with manifold negative consequences. Both explicit expectations and learning by conditioning are known to induce nocebo effects, but the specific role of conditioning remains unclear, because conditioning is rarely implemented independent of verbal suggestions. Further, although pain is a multidimensional phenomenon, nocebo effects are usually assessed in subjective ratings only, neglecting, e.g., behavioral aspects. The aim of this study was to test whether nocebo hyperalgesia can be learned by conditioning without explicit expectations, to assess nocebo effects in different response chan…
Hippocampal electrical stimulation disrupts associative learning when targeted at dentate spikes
2017
KEY POINTS Dentate spikes are fast fluctuations of hilar local-field potentials that take place during rest and are thought to reflect input arriving from the entorhinal cortex to the hippocampus. During dentate spikes, neuronal firing in hippocampal input (dentate gyrus) and output (CA1/CA3) regions is uncoupled. To date, the behavioural significance of dentate spikes is unknown. Here, we provide evidence that disrupting the dentate spike-related uncoupling of the dentate gyrus and the CA1/CA3 subregions for 1 h after training retards associative learning. We suggest dentate spikes play a significant role in memory consolidation. ABSTRACT Hippocampal electrophysiological oscillations, name…
Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning
2017
Hippocampal theta oscillations (3-12Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at t…
Learning by heart : cardiac cycle reveals an effective time window for learning
2018
Cardiac cycle phase is known to modulate processing of simple sensory information. This effect of the heartbeat on brain function is likely exerted via baroreceptors, the neurons sensitive for changes in blood pressure. From baroreceptors, the signal is conveyed all the way to the forebrain and the medial prefrontal cortex. In the two experiments reported, we examined whether learning, as a more complex form of cognition, can be modulated by the cardiac cycle phase. Human participants ( experiment 1) and rabbits ( experiment 2) were trained in trace eyeblink conditioning while neural activity was recorded. The conditioned stimulus was presented contingently with either the systolic or dias…
Breathe out and learn: Expiration-contingent stimulus presentation facilitates associative learning in trace eyeblink conditioning.
2019
Rhythmic variation in heart rate and respiratory pattern are coupled in a way that optimizes the level of oxygen in the blood stream of the lungs and the body as well as saves energy in pulmonary gas exchange. It has been suggested that the cardiac cycle and respiratory pattern are coupled to neural oscillations of the brain. Yet, studies on how this rhythmic coupling is related to behavior are scarce. There is some evidence that, for example, the phase of respiration affects memory retrieval and the electrophysiological oscillatory state of the limbic system. It is also known that the phase of the cardiac cycle and hippocampal electrophysiological oscillations alone affect learning. Here, …
Social exclusion influences conditioned fear acquisition and generalization: A mediating effect from the medial prefrontal cortex
2020
Abstract Fear acquisition and generalization play key roles in promoting the survival of mammals and contribute to anxiety disorders. While previous research has provided much evidence for the repercussions of social exclusion on mental health, how social exclusion affects fear acquisition and generalization has received scant attention. In our study, participants were divided into two groups according to two Cyberball paradigm conditions (exclusion/inclusion). Both groups underwent a Pavlovian conditioning paradigm, functional near-infrared spectroscopy (fNIRS), and skin conductance response (SCR) assessments. We aimed to determine the effects of social exclusion on fear acquisition and ge…
Fear expression and return of fear following threat instruction with or without direct contingency experience
2016
Prior research showed that mere instructions about the contingency between a conditioned stimulus (CS) and an unconditioned stimulus (US) can generate fear reactions to the CS. Little is known, however, about the extent to which actual CS-US contingency experience adds anything beyond the effect of contingency instructions. Our results extend previous studies on this topic in that it included fear potentiated startle as an additional dependent variable and examined return of fear (ROF) following reinstatement. We observed that CS-US pairings can enhance fear reactions beyond the effect of contingency instructions. Moreover, for all measures of fear, instructions elicited immediate fear reac…
Effects of instruction on acquisition and extinction of electrodermal responses to fear-relevant stimuli.
1977
In the present study we examined the hypothesis that electrodermal responses conditioned to fear-relevant stimuli are insensitive to verbal instructions. In the first experiment, different groups of subjects were conditioned to fear-relevant and fear-irrelevant control stimuli in a long interstimulus interval differential paradigm with shock as the unconditioned stimulus. Then half of the subjects were informed that no more shocks would be presented, and a number of extinction trials followed. The instruction completely abolished responding to fear-irrelevant stimuli, while leaving responses to the fear-relevant stimuli unaffected. In the second experiment, subjects were "conditioned" to fe…
Inside the Thompson laboratory during the “cerebellar years” and the continuing cerebellar story
2011
This paper is based on the talk by one of the authors (DL) given at the symposium for the retirement of RF Thompson (RF Thompson: A bridge between 20th and 21st century neuroscience). We first make some informal observations of the historical times and research conditions in the Thompson laboratory when the cerebellum was found to play a critical role in eye lid classical conditioning, the "cerebellar years". These conditions influenced our collaborative international program on the phenomenon known as "transfer of training" or "savings". Our research shows that the appearance of "savings" is an artifact of the order of testing, and depends upon the functioning of the contralateral interpos…
Towards reactive navigation and attention skills for 3D intelligent characters
2003
This paper presents a neural design which is able to provide the necessary reactive navigation and attention skills for 3D embodied agents (virtual humanoids or characters). Based on Grossberg's neural model of conditioning [6], as recently implemented by Chang and Gaudiando [7], and according to the Adaptative Resonance Theory (ART) and the neuroscientific concepts associated, the neural design introduced has been divided in two main phases. Firstly, an environmentcategorization phase, where an on-line pattern recognition and categorization of the current agent sensory input data is carried out by a self organizing neural network, which will finally provide the agent's short term memory la…