Fear Conditioning Paradigm in Obesity

Study Overview
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Brief Summary
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Fear processing in obesity and specifically the ability to i) learn and remember threatening stimuli, and ii) implicitly (i.e., unconsciously) and explicitly (consciously) discriminate them from neutral ones, will be investigated in affected individuals through the fear-conditioning paradigm.

Official Title
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Implicit Reactions to Threats in Individuals With Obesity: Primary Evidence From Fear Conditioning Paradigm

Conditions
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Obesity

Intervention / Treatment
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* Behavioral: Fear Conditioning


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Right-handed diagnosis of obesity (the level of body mass index - BMI - higher or equal to 30). Exclusion criteria: • concurrent neurological, neurodevelopmental (e.g., autism), motor, somatosensory and/or psychiatric disorders.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cases<br>Participants affected by obesity (the level of body mass index (BMI) higher or equal to 30). | Behavioral: Fear Conditioning<br>* It is a 2-day paradigm. Participants will undergo an auditory fear conditioning task in 3 phases: (1) pre-conditioning habituation, (2) unconditioned stimulus (US) calibration, where USs will be delivered to set the individual stimulation intensity threshold, and (3) fear conditioning, in which participants will be exposed to the conditioned stimulus (CS) associated with the US with an 80% pairing rate. 24 hours later, the (1) implicit recognition of the CS and novel stimuli (NSs), and the (2) explicit recognition, through an alternative forced-choice task will be assessed. Also, (3) the perceptual discrimination (among the CS and NSs) will be tested. Event-related skin conductance responses (SCRs) will be collected as an implicit index of defensive fear responses, while the accuracy in detecting and discriminating the CS from NSs as the explicit index. Psychological questionnaires about anxiety symptoms will be also administered.<br>|
| Controls<br>Not-hospitalized participants with a healthy weight | Behavioral: Fear Conditioning<br>* It is a 2-day paradigm. Participants will undergo an auditory fear conditioning task in 3 phases: (1) pre-conditioning habituation, (2) unconditioned stimulus (US) calibration, where USs will be delivered to set the individual stimulation intensity threshold, and (3) fear conditioning, in which participants will be exposed to the conditioned stimulus (CS) associated with the US with an 80% pairing rate. 24 hours later, the (1) implicit recognition of the CS and novel stimuli (NSs), and the (2) explicit recognition, through an alternative forced-choice task will be assessed. Also, (3) the perceptual discrimination (among the CS and NSs) will be tested. Event-related skin conductance responses (SCRs) will be collected as an implicit index of defensive fear responses, while the accuracy in detecting and discriminating the CS from NSs as the explicit index. Psychological questionnaires about anxiety symptoms will be also administered.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SCRs) | The event-related skin conductance responses (SCRs) in the case of the CS will be measured. This will represent the implicit index. | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recognition % | Level of accuracy (in %) in recognizing and discriminating the CS from NS will be computed. This will represent the explicit index. | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fear conditioning, fear processing, anxiety