Within 2 weeks of the first study visit, the participant will return to the University where they will undergo MRI.

The difference in fMRI signal intensity in the right amygdala between the negative affect and scrambled stimuli during the task.

The change in fMRI signal intensity in the left insula between the emotional and non-emotional stimuli during the task.

The difference in fMRI signal intensity in the left insula between the negative affect and scrambled stimuli during the task.

The change in fMRI signal intensity in the right insula between the emotional and non-emotional stimuli during the task.

The difference in fMRI signal intensity in the right insula between the negative affect and scrambled stimuli during the task.

The change in fMRI signal intensity in the bilateral dorsomedial prefrontal cortex (dmPFC) between the emotional and non-emotional stimuli during the task.

The difference in fMRI signal intensity in the bilateral dorsomedial prefrontal cortex (dmPFC) between the negative affect and scrambled stimuli during the task.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a five-minute recording period. Signal intensity will also be measured using fMRI in the ventromedial prefrontal cortex (vmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-vmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-vmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a ten-minute recording period. Signal intensity will also be measured using fMRI in the ventromedial prefrontal cortex (vmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-vmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-vmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a five-minute recording period. Signal intensity will also be measured using fMRI in the dorsomedial prefrontal cortex (dmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-dmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-dmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a ten-minute recording period. Signal intensity will also be measured using fMRI in the dorsomedial prefrontal cortex (dmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-dmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-dmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

The difference in mean amplitude EDA response between the emotional and non-emotional stimuli during the task.

The difference in mean amplitude EDA response between the negative affect and scrambled stimuli during the task.

EDA response amplitude during rest.

Change in accuracy for stimulus matching between the emotional and non-emotional stimuli during the task.

Change in accuracy of go/no go (press for go trials and no-press for no go trials) between the negative affect and scrambled stimuli during the task.

Participants will be randomly assigned to one of 3 conditions that differ by who is with them in the MRI scanner room: Primary Parent, Close Friend, No Social Partner.

Questionnaires: The participant will complete questionnaires, including ones on pubertal development and quality of relations with parents and friends.

MRI: Within 2 weeks of the first study visit, the participant will return to the University where they will undergo MRI.

Participants will be randomly assigned to one of 3 conditions that differ by who is with them in the MRI scanner room: Primary Parent, Close Friend,No Social Partner.

Questionnaires: The participant will complete questionnaires, including ones on pubertal development and quality of relations with parents and friends.

MRI: Within 2 weeks of the first study visit, the participant will return to the University where they will undergo MRI.

Total of all reporting groups

Participants will be randomly assigned to one of 3 conditions that differ by who is with them in the MRI scanner room: Primary Parent, Close Friend,No Social Partner.

In this case, the close friend was present in the MRI room during the assessment.

Participants will be randomly assigned to one of 3 conditions that differ by who is with them in the MRI scanner room: Primary Parent, Close Friend,No Social Partner.

In this case, no social partner was present in the MRI room during the assessment.

Heart rate will be derived from the pulse-oximeter signal collected during periods of emotional affect and rest during the course of the assessment. The variable, heart rate response, is a numeric output (beats per minute) from validated software (BIOPAC). The outcome measure will be reported (in beats per minute) as the difference between heart rate response during the period of emotional affect and period of rest.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The change in fMRI signal intensity in the left amygdala between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in fMRI signal intensity in the left amygdala between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The change in fMRI signal intensity in the right amygdala between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in fMRI signal intensity in the right amygdala between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The change in fMRI signal intensity in the left insula between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in fMRI signal intensity in the left insula between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The change in fMRI signal intensity in the right insula between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in fMRI signal intensity in the right insula between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The change in fMRI signal intensity in the bilateral dorsomedial prefrontal cortex (dmPFC) between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in fMRI signal intensity in the bilateral dorsomedial prefrontal cortex (dmPFC) between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a five-minute recording period. Signal intensity will also be measured using fMRI in the ventromedial prefrontal cortex (vmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-vmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-vmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a ten-minute recording period. Signal intensity will also be measured using fMRI in the ventromedial prefrontal cortex (vmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-vmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-vmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-vmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a five-minute recording period. Signal intensity will also be measured using fMRI in the dorsomedial prefrontal cortex (dmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-dmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-dmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

For each participant, blood oxygenation level dependent (BOLD) signal intensity (unitless measure) will be measured using fMRI in the bilateral amygdala over a ten-minute recording period. Signal intensity will also be measured using fMRI in the dorsomedial prefrontal cortex (dmPFC) over the same period of time. An interaction analysis will be conducted to measure the effect of task condition on bilateral amygdala-dmPFC functional connectivity, which will be reported as a Z-score. A Z-score of zero indicates no difference in amygdala-dmPFC functional connectivity as a function of task. A more positive Z-score indicates increased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks. A more negative Z-score indicates decreased amygdala-dmPFC functional connectivity during the emotional blocks of the task relative to the control blocks.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in mean amplitude EDA response between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The difference in mean amplitude EDA response between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

EDA response amplitude during rest.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

The Self Report of Stress is an 8-item questionnaire assessing participant level of stress at various time points across the session. Items are rated on a 5 point Likert scale. Total score is the unweighted mean of item scores. Total scores range from 0 to 40, with higher scores indicating greater stress. The assessment will be administered at baseline (no stress) and during a period of stress. The outcome will be reported as the difference between the baseline period and experimental stress period.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

Change in accuracy for stimulus matching between the emotional and non-emotional stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

Change in accuracy of go/no go (press for go trials and no-press for no go trials) between the negative affect and scrambled stimuli during the task.

193 participants were completed, with 63 Alone, 64 Parent, and 66 Friend. For each outcome, all available analyzable data were included in results, sometimes resulting in lower n.

Participants will be randomly assigned to one of 3 conditions that differ by who is with them in the MRI scanner room: Primary Parent, Close Friend,No Social Partner.

In this case, the close friend was present in the MRI room during the assessment.

Participants will be randomly assigned to one of 3 conditions that differ by who is with them in the MRI scanner room: Primary Parent, Close Friend,No Social Partner.

In this case, the no social partner was present in the MRI room during the assessment.