Influence of Oxytocin on Approach-avoidance Tendencies to Social and Non-social Stimuli

Study Overview
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Brief Summary
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In this study, a randomized, placebo-controlled between-subject design is adopted to investigate the effect of a single-dose of intranasally administered OT on approach-avoidance related motivational tendencies during the processing of a series of social and non-social, positively and negatively valenced stimuli. To obtain a behavioral measure of approach-avoidance tendencies, participants will be able to control the viewing time of the presented stimuli, by pressing 'up' or 'down' on a keyboard. During stimulus presentation neurophysiological recordings will be performed to obtain a neural measure of approach-avoidance motivational tendencies, based on electroencephalographic recordings (EEG: frontal alpha asymmetry). Also assessments of autonomic arousal, based on skin conductance recordings will be collected.

Detailed Description
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The neuropeptide oxytocin (OT) plays an important role in a wide-range of complex social behaviors. Recently however, the 'social' specificity of OT's action has been challenged, considering several observations of non-social effects of OT showing for example that OT reliably reduces stress also in non-social tasks. To account for these non-social effects of OT, the General Approach-Avoidance Hypothesis of OT (GAAO) has been put forward, positing that OT primarily modulates approach/ avoidance motivational tendencies and behaviors by impacting on the mesocorticolimbic circuitry linked to reward (approach) as well as cortico-amygdala circuits linked to threat (avoidance) (Harari-Dahan and Bernstein, 2014). Since the neural substrates underlying 'social' approach and avoidance are not distinct from those underlying 'non-social' approach and avoidance, the GAAO posits that the modulatory effects of OT should not be limited to social behaviors. In this view, the GAAO puts forward that OT may indeed enhance the attentional salience of many social cues, but not because they are social per se; but because many social stimuli are emotionally-evocative and personally-relevant. In this study, a randomized, placebo-controlled between-subject design is adopted to investigate the effect of a single-dose of intranasally administered OT on approach-avoidance related motivational tendencies during the processing of a series of social and non-social, positively and negatively valenced stimuli. To obtain a behavioral measure of approach-avoidance tendencies, participants will be able to control the viewing time of the presented stimuli, by pressing 'up' or 'down' on a keyboard. During stimulus presentation neurophysiological recordings will be performed to obtain a neural measure of approach-avoidance motivational tendencies, based on electroencephalographic recordings (EEG: frontal alpha asymmetry). Also electrodermal recordings (skin conductance) will be collected to obtain assessments of sympathetically-driven autonomic arousal. In accordance to the GAAO account, it is hypothesized that OT will reduce avoidance-related motivational tendencies (assessed behaviorally and using EEG), irrespective of sociality (i.e. similar effect towards social and non-social stimuli). In accordance to prior research, skin conductance responses are hypothesized to reduce after OT, indicating reduced sympathetically-driven autonomic arousal. On the other hand, considering the implicated role of sympathetic arousal in orienting responses, OT might also facilitate an enhancement of skin conductance responses, i.e., being reflective of OT's role in enhancing salience toward emotionally-evocative stimuli.

Official Title
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Influence of Oxytocin on Approach-avoidance Tendencies to Social and Non-social Stimuli

Conditions
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Basic Science

Intervention / Treatment
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* Drug: Oxytocin
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: right-handed male age between 18 and 35 Normal or adjusted-to-normal vision (with lenses only) Dutch as mother tongue Exclusion Criteria: female age below 18 or above 35 neurological or psychiatric condition (e.g. epilepsy, stroke, concussion), (e.g. anxiety disorder, depression) use of psychotropic medication (e.g. anxiolytics, antidepressants)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

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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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Oxytocin<br>Syntocinon nasal spray (40 IU/ml; oxytocin, product code RVG 03716); single intranasal dose of 24 international units (IU; 3 puffs of 4 IU per nostril) | Drug: Oxytocin<br>* Syntocinon nasal spray<br>|
| Placebo Comparator: Placebo<br>Saline natriumchloride solution nasal spray; single intranasal dose (3 puffs per nostril) | Drug: Placebo<br>* Placebo nasal spray<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in EEG frontal alpha asymmetry after nasal spray administration | The influence of oxytocin administration on EEG frontal alpha asymmetry | Average over trials, baseline and approximately 30 minutes after nasal spray administration | 
| Change in behavioral approach-avoidance (number of up or down key presses, prolonging or shortening the viewing time towards presented stimuli) | During the presentation of a series of stimuli, participants will be able to prolong or shorten the viewing time towards the presented stimuli, by pressing an 'up' or 'down' key on a keyboard. The number of up versus down key-presses will be taken as a measure of behavioral approach-avoidance. The influence of oxytocin administration on the number of up or down key presses will be assessed. | Average over trials, baseline and approximately 30 minutes after nasal spray administration | 
| Change in skin conductance (type of electrodermal recording) after nasal spray administration | The influence of oxytocin adminstration on skin conductance | Average over trials, baseline and approximately 30 minutes after nasal spray administration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oxytocin, sociality, approach-avoidance motivational tendencies, EEG frontal assymmetry, skin conductance, autonomic arousal