Placebo Effect

This study examines whether a computerized attention-training intervention called attention bias modification (ABM) can reduce symptoms of social anxiety disorder (SAD) in adults, and whether symptom improvement is specifically related to changes in attentional processing or to nonspecific factors such as expectancy and placebo effects.

The goal of this clinical trial is to learn whether non-invasive brain stimulation, called transcranial temporal interference stimulation (tTIS), can reduce negative affect, and how expectations shaped by care providers influence these effects. The main questions this study aims to answer are: (1)Does active tTIS reduce negative affect more effectively than sham (inactive) tTIS? (2)Do positive treatment expectations enhance the effects compared to negative expectations? Participants will: (1) Receive either active or sham tTIS. (2) Be provided with positive or negative messaging regarding treatment effectiveness. (3) Interact with care providers and complete assessments measuring negative affect and physiological responses.

This study will investigate how different warm-up strategies affect physical performance in female athletes who practice invasion sports (e.g., soccer, handball, and basketball). Participants will complete three different conditions: a standard warm-up only, a warm-up followed by a performance-enhancing activity, and a warm-up followed by a low-intensity activity designed to simulate the same expectations without real physiological effects. After each condition, athletes will perform tests of vertical jump performance and change-of-direction speed. In addition, participants will report their perceived effort, expectations, muscle soreness, and recovery status. The study will include eighteen female athletes and will be conducted under controlled conditions, including standardized hydration, recovery, and environmental factors. The design will allow comparison of the physical and psychological effects of the different warm-up strategies on performance.

In this experiment, the investigators study the brain pathways underlying several promising context interventions that enhance the strength of placebo effects. Specifically, the investigators examine the separate and joint effects of two of the most powerful context interventions: Social modeling-observing someone else being effectively treated-and prior treatment success or failure experiences. Participants will be randomized into 4 groups (Social modeling: observed success vs. observed failure and Conditioning: experienced success vs. experienced failure). The objectives are to investigate the placebo effect on pain relief and aversive image stimuli between and within-subjects. Each group will undergo a behavioral induction phase, fMRI placebo test phase, and an identical 3-month follow up fMRI placebo test phase. Follow-up assessment will provide some of the first evidence on predictors of the durability of placebo and context interventions.

The current study probes the involvement of the opioid system in placebo effects on social pain, using the opioid antagonist naloxone. 60 participants who recently experienced an unwanted breakup will experience rejection-related stimuli and receive painful heat and pressure stimuli during fMRI scanning. Participants will be randomized to receive either a naloxone or saline nasal spray, and be informed that the spray is either saline, or an effective pain and negative emotion reducing agent.

In this experiment,the investigators study the effects of interpersonally induced placebo effects and a mindful awareness induction on negative affect. Specifically, it will be examining the effects of interpersonally induced placebo effects (sham tDCS vs. control) and a mindful awareness induction (mindful state vs. control), as well as their interaction. Each group will undergo fMRI scanning and physiological recording will performing the Multimodal Negative Affect Task (MNAT).

This clinical trial aims to investigate the neurophysiological mechanisms of placebo and nocebo effects on sports performance, using Electroencephalography (EEG) and isometric strength testing of the lower extremities. The primary objective of this trial is to identify temporal mechanisms and cortical regions and networks involved in generating placebo and nocebo effects before (expectation) and at onset of athletic performance (perception). The trial will include four groups, two of them experimental, one an active control and one natural history, meaning participants in this group will receive no intervention and won't be EEG controlled. Data will be collected on two occasions with baseline data for EEG, expectations and performance as well as key participant characteristics being collected on day one. On day two, in a deceptive process, participants in the two experimental groups will take an inert substance presented as either performance enhancing or inhibiting and subsequently experience a reinforcement of beliefs via exposure to explicit adjectives. EEG data will be collected during reinforcement of beliefs. In the active control group, participants will receive no substance, but this group will follow the same procedure as the experimental groups with neutral adjectives. Participants will then perform isometric strength and fatigue resistance tests on an isometric dynamometer. EEG data as well as subjective data on expectations and rating of perceived exhaustion will be collected.

This project aims to examine whether these forms of attention to sensory information can modulate the mind-body interaction. This will be demonstrated through a study focused on the placebo effect with attention manipulation. Specifically, the project will focus on the construct of mindful attention to increase the precision of the likelihood and reduce the effects of priors, and on directed attention to modify the position and precision of the likelihood, hypothetically modulating the placebo effect. The study involves recruiting 128 healthy individuals, who will be asked to cycle on an ergometer for approximately 60 minutes, with alternating phases in which attention will be manipulated. After an initial warm-up phase, they will receive a placebo drink, presented as "highly stimulating." An additional group of 32 participants will not receive either the placebo drink or the attentional stimuli, but will undergo the same training cycles. All participants will receive a pre-intervention assessment, and heart rate, emotions, and perceived fatigue will be monitored.