235 research outputs found
Temporal context cues in human fear conditioning: Unreinforced conditional stimuli can segment learning into distinct temporal contexts and drive fear responding
In associative learning, if stimulus A is presented in the same temporal context as the conditional stimulus (CS) - outcome association (but not in a way that allows an A–CS association to form) it becomes a temporal context cue, acquiring the ability to activate this context and retrieve the CS-outcome association. We examined whether a CS- presented during acquisition or extinction that predicted the absence of the unconditional stimulus (US) could act as a temporal context cue, reducing or enhancing responding, in differential fear conditioning. Two groups received acquisition (CSx–US, CSa–noUS) in phase 1 and extinction (CSx–noUS; CSe–noUS) in phase 2 (AE groups), and two groups received extinction in phase 1 and acquisition in phase 2 (EA groups). After a delay, participants were presented with either CSa (AEa and EAa groups) or CSe (AEe and EAe groups). Responding to CSx was enhanced after presentation of CSa but reduced after presentation of CSe, suggesting that training was segmented into two learning episodes and that the unreinforced CS present during an episode retrieved the CSx–US or CSx–noUS association. These findings suggest that temporal context cues may enhance or reduce fear responding, providing an exciting new avenue for relapse prevention research
Multiple fear-related stimuli enhance physiological arousal during extinction and reduce physiological arousal to novel stimuli and the threat conditioned stimulus
Highlights•Involved Pavlovian conditioning, extinction, extinction generalization test, and extinction retest.•Compared extinction with CS+ and CS− and generalization stimuli and ‘extinction-as-usual’.•Multiple stimuli increased physiological arousal to both CSs during, and negative CS evaluations, after extinction.•Multiple stimuli reduced physiological arousal to novel stimuli and CS+ after extinction but did not alter negative CS evaluations.•No group differences were observed in subjective anxiety ratings
To remove or not to remove? Removal of the unconditional stimulus electrode does not mediate instructed extinction effects
Following differential fear conditioning, the instruction that the unconditional stimulus will no longer be presented (instructed extinction) reduces differential electrodermal responding to CS+ and CS-, but does not affect differential conditional stimulus valence evaluations. Reductions in differential electrodermal responding have been attributed to the provision of verbal instructions; however, during instructed extinction the unconditional stimulus electrode is often removed as well. This removal could reduce the participants' general arousal levels rendering the detection of differential electrodermal responding difficult. The current study examined this alternative interpretation by comparing the electrodermal responses and conditional stimulus valence evaluations of an instruction/electrode-on group, an instruction/electrode-off group, and a control group who were not instructed. Following instructed extinction, differential electrodermal responding was eliminated in both instruction groups, an effect that was not influenced by the attachment/removal of the electrode. Replicating previous findings, conditional stimulus valence was not affected by instructed extinction. The results suggest that verbal instructions, not unconditional stimulus electrode removal, reduce differential electrodermal responding during instructed extinction manipulations
Enhanced sensitization to animal, interpersonal, and intergroup fear-relevant stimuli (but no evidence for selective one-trial fear learning)
Selective sensitization has been proposed as an alternative explanation for enhanced responding to animal fear-relevant stimuli—snakes and spiders—during extinction of Pavlovian fear conditioning. The current study sought to replicate the phenomenon using a shock workup procedure as the sensitizing manipulation and to extend it to interpersonal and intergroup fear-relevant stimuli—angry faces and other-race faces. Assessment of selective sensitization was followed by a one-trial fear learning procedure. Selective sensitization, larger electrodermal responses to fear-relevant than to control stimuli after sensitization, or a larger increase in electrodermal responding to fear-relevant than to control stimuli after sensitization was observed across stimulus domains. However, the one-trial fear learning procedure failed to provide evidence for enhanced fear conditioning to fear-relevant stimuli. One-trial fear learning was either absent or present for fear-relevant and nonfear-relevant stimuli. The current study confirms that electrodermal responses to fear-relevant stimuli across stimulus domains are subject to selective sensitization
Using Insights from Cognitive Neuroscience to Investigate the Effects of Event-Driven Process Chains on Process Model Comprehension
Business process models have been adopted by enterprises for more than a decade. Especially for domain experts, the comprehension of process models constitutes a challenging task that needs to be mastered when creating or reading these models. This paper presents the results we obtained from an eye tracking experiment on process model comprehension. In detail, individuals with either no or advanced expertise in process modeling were confronted with models expressed in terms of Event-driven Process Chains (EPCs), reflecting different levels of difficulty. The first results of this experiment confirm recent findings from one of our previous experiments on the reading and comprehension of process models. On one hand, independent from their level of exper-tise, all individuals face similar patterns, when being confronted with process models exceeding a certain level of difficulty. On the other, it appears that process models expressed in terms of EPCs are perceived differently compared to process models specified in the Business Process Model and Notation (BPMN). In the end, their generalization needs to be confirmed by additional empirical experiments. The presented expe-riment continues a series of experiments that aim to unravel the factors fostering the comprehension of business process models by using methods and theories stemming from the field of cognitive neuroscience and psychology
Learning to Learn: Theta Oscillations Predict New Learning, which Enhances Related Learning and Neurogenesis
Animals in the natural world continuously encounter learning experiences of varying degrees of novelty. New neurons in the hippocampus are especially responsive to learning associations between novel events and more cells survive if a novel and challenging task is learned. One might wonder whether new neurons would be rescued from death upon each new learning experience or whether there is an internal control system that limits the number of cells that are retained as a function of learning. In this experiment, it was hypothesized that learning a task that was similar in content to one already learned previously would not increase cell survival. We further hypothesized that in situations in which the cells are rescued hippocampal theta oscillations (3–12 Hz) would be involved and perhaps necessary for increasing cell survival. Both hypotheses were disproved. Adult male Sprague-Dawley rats were trained on two similar hippocampus-dependent tasks, trace and very-long delay eyeblink conditioning, while recording hippocampal local-field potentials. Cells that were generated after training on the first task were labeled with bromodeoxyuridine and quantified after training on both tasks had ceased. Spontaneous theta activity predicted performance on the first task and the conditioned stimulus induced a theta-band response early in learning the first task. As expected, performance on the first task correlated with performance on the second task. However, theta activity did not increase during training on the second task, even though more cells were present in animals that had learned. Therefore, as long as learning occurs, relatively small changes in the environment are sufficient to increase the number of surviving neurons in the adult hippocampus and they can do so in the absence of an increase in theta activity. In conclusion, these data argue against an upper limit on the number of neurons that can be rescued from death by learning
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