Influence of Oxytocin on Neurophysiological Responses to Live Faces
Condition: Oxytocin
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      Previous research has indicated that direct eye gaze compared to averted gaze, elicits a
      higher skin conductance response (SCR), and a more pronounced left frontal cortex activity
      than right frontal cortex activity (resulting in positive asymmetry scores). On a behavioral
      level, participants tend to look shorter at live faces with a direct gaze as compared to
      averted gaze (Akechi et al., 2013). Further, subjective evaluations showed that a direct gaze
      is rated more arousing and less pleasant than an averted gaze (Akechi et al., 2013; Hietanen,
      Leppänen, Peltola, Linna-aho, & Ruuhiala, 2008).

      Importantly, oxytocin administration increases the number of fixations and to looking time
      towards the eye region during live social interaction. Further, oxytocin has been shown to
      influence SCR and heart rate variability. Therefore, it is conceivable that oxytocin will not
      only influence the gaze duration of the participant, but also the physiological and
      neurological responses elicited by direct eye gaze.

      In this study, the investigators will investigate whether oxytocin modulates the behavioural
      (eye gaze and subjective ratings), neurological (EEG) and physiological (skin conductance,
      heart rate and respiration) responses elicited by direct gaze.
    

Detailed description: 
      Previous research has indicated that direct eye gaze compared to averted gaze, elicits a
      higher skin conductance response (SCR), and a more pronounced left frontal cortex activity
      than right frontal cortex activity (resulting in positive asymmetry scores). On a behavioral
      level, participants tend to look shorter at live faces with a direct gaze as compared to
      averted gaze (Akechi et al., 2013). Further, subjective evaluations showed that a direct gaze
      is rated more arousing and less pleasant than an averted gaze (Akechi et al., 2013; Hietanen,
      Leppänen, Peltola, Linna-aho, & Ruuhiala, 2008).

      Importantly, oxytocin administration increases the number of fixations and to looking time
      towards the eye region during live social interaction. Further, oxytocin has been shown to
      influence SCR and heart rate variability. Therefore, it is conceivable that oxytocin will not
      only influence the gaze duration of the participant, but also the physiological and
      neurological responses elicited by direct eye gaze.

      In this randomized, placebo controlled, double blinded study, the investigators will
      investigate whether oxytocin modulates the behavioral and neurophysiological responses
      elicited by direct gaze. In order to do so, the investigators will measure behavioural (eye
      gaze and subjective feelings), physiological (skin conductance, blood volume pulse, and
      respiration) and neurological (EEG) responses during presentations of a live person's face
      with direct gaze and closed eyes, before and after oxytocin or placebo administration.

      The investigators hypotheses that oxytocin attenuates the heightened SCR and pronounced EEG
      asymmetry during direct gaze. Further, they expect that oxytocin increases the number of
      fixations and duration of those fixations towards the eye region. Exploratory, the
      investigators will also investigate whether oxytocin administration influences respiration
      and the subjective reports on experience of live eye contact. Lastly (and also exploratory),
      they will explore whether certain personality traits (as measured by SAAM (state adult
      attachment measure) and SRS (social responsiveness scale)) influence the modulatory effect of
      oxytocin on neurological and behavioural responses.

      Note that this study is part of a larger study in which the investigators also register
      several neurophysiological responses (blood volume pulse, respiration, heart rate, EEG, skin
      conductance) during rest before and after oxytocin or placebo administration.
    

Intervention name(s): Oxytocin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Syntocinon nasal spray; Placebo nasal spray
Other intervention name(s): syntocinon
Intervention MeSH terms: Oxytocin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: biomedical intervention; oxytocin; EEG; skin conductance response; heart rate; gaze direction; eye contact