PTSD - Post Traumatic Stress Disorder
Conditions
Keywords
PTSD, butterfly tapping, emotional reactivity, EEG, late positive potential, ERP, emotion regulation
Brief summary
This study aimed to investigate the effects of a single session of Butterfly Tapping (BT), a self-administered form of alternating bilateral stimulation, on emotional reactivity and its neurophysiological correlates. 46 participants will be randomly assigned to an experimental (Exp) or control (Con) group. The Exp group performed a 15-minute session of BT. Emotional reactivity was assessed before and after the stimulation using a detection task with emotional visual stimuli, presented during electroencephalographic (EEG) recording. EEG analyses were conducted using the event-related potential (ERP) method, specifically focusing on the differential amplitude (negative minus neutral) of the Late Positive Potential (LPP), a centro-parietal component associated with sustained processing of emotionally salient stimuli. Results revealed a significant LPP reduction in the Exp group at T1 compared to T0, whereas no change emerged in the Con group. The topographical distribution of the modulation was predominantly central, consistent with models implicating the LPP in higher-order integrative and evaluative processes. These findings provide preliminary neurophysiological evidence that BT may reduce cortical reactivity to negative emotional stimuli in young clinical populations, supporting its potential as a simple and accessible strategy capable of modulating affective responsiveness.
Interventions
BEHAVIORALButterfly Tapping (BT)
Participants adopted the traditional butterfly hug posture: arms crossed over the chest, fingertips placed below the clavicles. They delivered alternating left-right rhythmic taps (\~1 Hz) on their shoulders. Eyes remained closed, and participants were instructed to keep the emotional content active by mentally recalling previously viewed negative images, ensuring sustained affective engagement. Duration: 15 minutes, structured in four blocks of 3 minutes with short pauses. No auditory pacing was provided to preserve spontaneous rhythmicity. Targeted Mechanism Bilateral tactile stimulation aiming to modulate cortico-limbic processing, interhemispheric communication, and sustained emotional reactivity, as indexed by LPP amplitude during ta emotional simple response task
BEHAVIORALNo intervention control
Participants will adopt the same butterfly-hug position, with arms crossed and hands placed on the chest. No rhythmic tapping or movements will be performed. Eyes are closed for the entire session, as in the experimental arm. Participants will held the emotional images in mind just as in the experimental arm. Duration: 15 minutes, identical block structure and timing as the BT condition. Targeted Mechanism Serves as a posture-matched and expectancy-matched control, ruling out effects of: simple stillness, emotional recall, attentional focus, physical posture, general relaxation effects.
Sponsors
University of Rome Foro Italico
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* normal or corrected-to-normal vision; full right-handedness
Exclusion criteria
* neurological or other psychiatric disorders tha PTSD; current use of psychoactive medications.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| LPP | Baseline, End of Treatment (8-12 weeks), and Follow-up (8 weeks after treatment completion) | Late Positive Potential (LPP) Differential Amplitude (Negative - Neutral) The primary neurophysiological outcome will be the modulation of the centro-parietal Late Positive Potential (LPP), extracted from EEG recordings during the Emotional Simple Response Task (E-SRT). The LPP is a well-established marker of sustained attentional and evaluative processing of emotional stimuli. For each participant and time point (T0, T1, T2), ERP waveforms willbe computed separately for negative and neutral images, and difference waves (negative minus neutral) were used to isolate emotion-specific neural reactivity. Primary analyses focused on mean amplitudes in the experimentally defined cLPP time window (456-552 ms) over the centro-parietal electrode cluster (Cz, C1, C2, CP1, CPz, CP2). The primary contrast of interest was the Group × Time interaction, assessing whether a single session of Butterfly Tapping selectively reduced the LPP differential amplitude relative to the static control condition. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Frontal positivity | Baseline, End of Treatment (8-12 weeks), and Follow-up (8 weeks after treatment completion) | Frontal Positivity (188-228 ms). Is sn exploratory secondary marker, indexing early evaluative or response-related processing, quantified over the frontal region (F1, Fz, F2, FC1, FCz, FC2). |
| Behavior | Baseline, End of Treatment (8-12 weeks), and Follow-up (8 weeks after treatment completion) | Behavioral Performance: Response Time (RT) to emotional images Omission Rate (OM) Both extracted from the E-SRT before and after stimulation. |
| Self-report | Baseline, End of Treatment (8-12 weeks), and Follow-up (8 weeks after treatment completion) | Self-Reported Emotional State: State Anxiety (STAI-Y1) Emotional Discomfort (VAS) Collected immediately after each task block to assess subjective affective changes. |
Countries
Italy
Outcome results
None listed