Search results for "ehdollistuminen"
showing 10 items of 20 documents
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…
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…
Common and separable behavioral and neural mechanisms underlie the generalization of fear and disgust
2021
Generalization represents the transfer of a conditioned responses to stimuli that resemble the conditioned stimulus (CS). Previous studies on generalization of defensive avoidance responses have primarily focused on fear and have neglected disgust generalization, which represents a key pathological mechanism in some anxiety disorders. In the present study we examined common and distinct mechanisms of fear and disgust generalization by means of a fear or disgust multi-CS conditioning and generalization paradigm with concomitant event-related potential (ERPs) acquisition in n = 62 subjects. We demonstrate that compared to fear, disgust-relevant generalized stimuli (GS) elicited larger expecta…
Effect of emotional picture viewing on classical eyeblink conditioning
2004
Conditioned generalisation in generalised anxiety disorder : the role of concurrent perceptual and conceptual cues
2021
Previous research in extinction indicates no difference in US expectancies for aversive and non-aversive unconditioned stimuli (USs). In this study, we bridged these topics by examining how concurrent perceptual and conceptual cues influence conditioned generalisation of generalised anxiety disorder (GAD) patients by using non-aversive USs. The study included two consecutive phases: acquisition and generalisation. In the acquisition phase, we used blue and purple images as the perceptually conditioned stimuli, images of animals and household items as the conceptually conditioned stimuli, and non-aversive images as unconditioned stimuli (US). In the generalisation phase, we used images conta…
Intranasal oxytocin decreases fear generalization in males, but does not modulate discrimination threshold
2021
Background: A previously acquired fear response often spreads to perceptually or conceptually close stimuli or contexts. This process, known as fear generalization, facilitates the avoidance of danger, and dysregulations in this process play an important role in anxiety disorders. Oxytocin (OT) has been shown to modulate fear learning, yet effects on fear generalization remain unknown. Methods: We employed a randomized, placebo-controlled, double-blind, between-subject design during which healthy male participants received either intranasal OT or placebo (PLC) following fear acquisition and before fear generalization with concomitant acquisition of skin conductance responses (SCRs). Twenty-…
Diffuse and discrete associations in aversive classical conditioning
2002
The aim of the present study was to assess the role of the cerebellar interpositus nucleus (IPN) in different types of associations during classical eyeblink conditioning in rabbits.
EEG correlates of learning in classical eyeblink conditioning in humans
2010
Ihmisten välillä on suurta vaihtelua oppimissuorituksessa klassisen ehdollistumisen tehtävissä laboratoriokokeissa. Erot kognitiivisissa kyvyissä voivat selittää osan vaihtelusta, mutta luultavampaa kuitenkin on että vaihtelu ihmisen sisäisessä vireystilassa aiheuttaa hajontaa oppimiskyvyssä. Tutkimuksessamme opetimme ihmisiä silmäniskuehdollistamisessa ja mittasimme ihmisten spontaania jatkuvaa aivosähkökäyrää silmät auki/kiinni –tilanteissa opettamisjaksojen välissä. Tarkkailimme erityisesti theta- (3 – 8 Hz) ja alfa- (9 – 13 Hz) taajuuksia nähdäksemme, selittääkö toinen näistä ihmisten välisiä suorituseroja. Theta-aktiivisuus liitetään usein oppimis- ja tiedonkäsittelyprosesseihin sinäns…