Pharmacological and Behavioral Interventions for Focus: The Comparison of Reversal Learning Under the Influence of Lysergic Acid Diethylmide (LSD), Methylphenidate (MPH) and Mindfulness Based Cognitive Therapy
Keywords
No Thumbnail Available
Authors
Issue Date
2017-08-28
Language
en
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The ability to learn and flexibly adapt behavior in response to salient changes in the surrounding environment is a fundamental skill for survival. Cognitive rigidity is characteristic of many mental disorders such as attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), depression and drug addiction. Psychoactive medications and cognitive therapies have attempted to treat cognitive rigidity by altering learning and feedback processing.
The aim of this study is to assess if pharmacological and behavioral interventions differently alter the ability to learn and unlearn stimulus-outcome contingencies and feedback sensitivity. Specifically, we will assess how small doses of methylphenidate (MPH) (n=102), lysergic acid diethylmide (LSD) (n=19) and mindfulness based cognitive therapy (MBCT) (n=110) affect reversal learning. All participants completed a Probabilistic Reversal Learning (PRL) task which requires them to learn the different probabilities of receiving rewards and punishment for each of the three cues. Midway through the task, the probabilities are reversed and participants must now update the values associated with these cues. The PRL tasks provide a window on adaptive behavior, as it allows us to assess two crucial components: (1) the (in)ability to reverse well-learnt responses (‘perseverative behavior’), and (2) immediate behavioral adaptation following motivational outcomes (‘feedback sensitivity’).
A single dose of catecholamine transporter blocker MPH (20 mg) improved acquisition learning and reduced sensitivity to negative feedback in healthy controls as a function baseline individual variability and trait impulsivity, respectively. In contrast, a single dose of LSD (75 µg), a predominantly serotonergic receptor partial agonist, did not affect reversal learning but significantly reduced outcome sensitivity in healthy controls. The difference between the MPH and LSD highlights the dissociable effects of dopaminergic and serotonergic interventions on learning stimulus-outcome contingencies and feedback sensitivity. The PRL task was an effective diagnostic tool for assessing perseverative behavior but not abnormal feedback sensitivity in an adult ADHD population. MBCT did not differ from the wait-list control group in terms of reversal learning or feedback sensitivity. Further, baseline cognitive flexibility did not affect the change in ADHD symptom severity. These findings suggest that pharmacological interventions target differential aspects of reversal learning, however, MBCT was not more effective than alternative ADHD treatments for shifting learning or feedback sensitivity.
Description
Citation
Supervisor
Faculty
Faculteit der Sociale Wetenschappen