Autism Oxytocin Brain Project

BOLD activity level was assessed via fMRI during completion of the face perception task (FPT) of emotional and neutral faces. BOLD scores are reported on a z-scale, with the mean, standard deviation and the minimum and the maximum. This refers to the non-thresholded z-scores that are obtained for each dose before conducting small volume correction analysis.

Time frame: Post Intervention (Up to 70 minutes) at Study Visits 1, 2, 3, and 4

Population: This analysis includes participants with high quality images that were able to be examined. Some participants moved during the MRI resulting in distorted images.

Plasma concentration of oxytocin prior to administration of study intervention and after administration of study intervention will be compared between the different dose levels and placebo. Plasma concentration of oxytocin is expected to increase following administration of intranasal oxytocin.

Time frame: Visits 1, 2, 3 and 4 (before spray and 5 minutes after spray)

Population: Only participants with ASD had blood drawn for plasma oxytocin concentrations. This analysis includes participants who provided a blood sample (one refused to give a sample).

BOLD activity in social-emotional brain regions during the perception of emotional facial videos were measured during the ball-game task. Mean percent change in contrast of parameter estimates in anatomical regions of interest are presented here. A positive value indicates increased BOLD activity while a negative value indicates decreased BOLD activity.

Time frame: Post Intervention (up to 70 minutes) at Study Visits 1, 2, 3, and 4

Population: This analysis includes participants with high quality images that were able to be examined. Some participants moved during the MRI resulting in distorted images.

Investigators will study the effects of intranasal oxytocin (IN-OT) on the resting state functional connectivity between key socio-emotional and social salience brain regions using functional magnetic resonance imaging (fMRI). Resting state functional connectivity is a task-independent metric of brain activity that is based on correlations between low-frequency fluctuations of the blood oxygen level-dependent signal between several brain regions. It reflects the strength of a functional connection that is in good agreement with the underlying neuroanatomy and provides a system-level understanding of brain function. Z-scores represent the number of standard deviations from the mean of 0 and range from -3 to +3, and z-scores greater than 0 indicate greater than average resting state functional connectivity.

Time frame: Post Intervention (Up to 40 minutes after receiving spray) at Study Visits 1, 2, 3 and 4

Population: This analysis includes participants with complete data for all visits. Two participants withdrew and data from another participant were not able to be analyzed due to technical problems during the MRI.

Eye gaze will be recorded via an eye tracker inside the MRI scanner during the face perception task (FPT). Visual fixation between different treatment conditions will be assessed in ASD participants.

Time frame: Post Intervention (Up to 50 minutes) at Study Visits 1, 2, 3 and 4

Population: This analysis includes participants with ASD who had usable data for this outcome. There were difficulties with the eye tracking technology inside the MRI scanner and tracking of the pupil was not successful at all times. Healthy controls did not participate in the eye tracker portion of the study.

Clinical improvements will be rated by a clinician as based on a videotaped interview conducted after the MRI scanning session. Values between the different treatment conditions will be assessed to study the effect of intranasal oxytocin on ASD at the clinical level. The improvement will be assessed based on the quality of social interaction between the experimenter and the participant, specifically as the amount of smiling behavior displayed by participants. Larger values indicate that participants are smiling more frequently.

Time frame: Post Intervention (Up to 180 minutes after receiving spray) at Study Visits 1, 2, 3 and 4

Population: This analysis includes participants with ASD who completed the videotaped interview. One participant declined to be videotaped and is not included in this analysis.

During the SLT, participants complete an implicit association test using faces and words. The faces that are presented in this task are partners' faces with whom participants played during the ball-game inside the MRI scanner. In this task, there are congruent blocks where neutral faces of positive partners are presented with friendly words and neutral faces of negative partners are presented with unfriendly words. During incongruent blocks, neutral faces of positive partners are presented with unfriendly words and neutral faces of negative partners are presented with friendly words. Participants match the face or the word to one of two categories. Longer reaction time indicates difficulty with selecting a category. Longer reaction time in incongruent trials signifies implicit biases were formed for the positive and negative players such that positive partners from the ball-game are now perceived as friendly and negative partners are now perceived as unfriendly.

Time frame: Post Intervention (Up to 130 minutes) at Study Visits 1, 2, 3 and 4

Population: Among participants with autism who completed the study, two participants had outlying data and were removed from this analysis.Two healthy controls did not complete the SLT due to time constraints.