On the Mangrove Simple EMDR controller, amplitude adjusts the strength of the tactile signal delivered through the hand-held tappers. It also affects the duration of each pulse. That makes amplitude an important comfort and perception control—but it should not be confused with the emotional intensity of therapy or the effectiveness of EMDR.
A stronger pulse is not automatically better, and a gentler pulse is not automatically less useful. The practical aim is a clear, tolerable alternating signal that fits the client, the task and the clinician’s trained judgement.
What amplitude changes
Turning the amplitude control changes how strongly each tapper is felt. On the Mangrove system, the red and green tapper LEDs also change brightness, providing a visible indication of when each side is energised and the relative amplitude setting.
The tappers continue to alternate left and right. Amplitude changes the tactile character of each pulse; it does not select the number of cycles, determine the lightbar path or change which side comes next.
Amplitude is not treatment intensity
The word “intensity” can create confusion. In equipment terms, it may refer informally to how strong a vibration feels. In therapy, however, emotional activation, distress and processing are different matters.
The amplitude knob does not measure or prescribe those clinical experiences. It controls a physical output. EMDR remains a structured psychotherapy in which tactile stimulation is one possible form of dual attention bilateral stimulation.
Start with a neutral demonstration
Before using the tappers during clinical work, demonstrate them without suggesting that the client should prefer a particular strength. A simple sequence is:
- Ask the client to hold the tappers in a natural, relaxed position.
- Begin at a clearly perceptible but conservative amplitude.
- Deliver a short demonstration.
- Ask whether both sides feel distinct and reasonably even.
- Invite the client to describe the sensation in their own words.
- Make a small adjustment if needed, then check again.
This process is equipment familiarisation, not a protocol. The clinician remains responsible for readiness, consent, observation and the clinical use of bilateral stimulation.
Check more than whether the client can feel it
A tactile pulse can be perceptible without being comfortable. Useful feedback may include whether it feels too sharp, too strong, too faint, uneven or distracting. Hand position can also change the experience: gripping tightly may feel different from resting the tappers loosely in the palms.
Consider relevant sensory, pain, skin, joint or hand-comfort factors within your scope of practice. If the client does not want tactile stimulation or finds it uncomfortable, another modality may be more appropriate. Equipment choice should not override informed client feedback.
Recheck after changing speed
Amplitude and speed are separate controls, but the experience of a tactile pulse can change when the overall pace changes. A setting that feels clear at a slower rate may feel different when pulses occur more quickly.
On the Mangrove controller, amplitude can also affect the resulting speed relationship, so the operating guidance recommends setting amplitude and lightbar travel length before finalising speed. After adjusting one control, briefly recheck the combined output rather than assuming everything else feels unchanged.
Compare left and right before the session
Perform a short function check with both tappers connected. Confirm that they alternate, that both outputs are perceptible and that the indicator LEDs correspond with the active side. If one tapper seems absent or markedly different, check the connections before increasing amplitude.
Do not use extra strength to compensate for a loose plug, damaged cable or incorrectly connected accessory. Remove damaged equipment from use and follow the manufacturer’s support guidance.
Adjust deliberately, not reactively
During a session, avoid making large unexplained changes. If an adjustment is clinically appropriate, pause or use the controls in accordance with your training, make a modest change and check the client’s response.
Changing one variable at a time makes feedback easier to interpret. If amplitude, speed and phase are all changed together, it may be unclear which difference the client is noticing.
A comfort control—not a promise of outcome
Adjustable amplitude makes tactile bilateral stimulation more flexible. Its purpose is to help the practitioner provide a signal that can be clearly perceived without assuming that every client should use the same setting.
The equipment controls the pulse. Accredited EMDR training, client preference, observation and professional judgement guide its clinical application.
Explore Mangrove’s Simple EMDR and Simple ABS systems, both of which use the same master controller and tactile tappers.