Mobile Brain/Body Imaging · Experimental Brain Research

A Portable Solution for Simultaneous Human Movement and Mobile EEG Acquisition: Readiness Potentials for Basketball Free-throw Shooting

Miguel A. Contreras-Altamirano1*, Melanie Klapprott1, Nadine S. Jacobsen1, Paul Maanen1,2, Julius Welzel3, Stefan Debener1,2,4

1 Neuropsychology Lab, Dept. of Psychology, School of Medicine and Health Sciences, Carl von Ossietzky Universität Oldenburg, Germany  ·  2 Cluster of Excellence "Hearing4All", Universität Oldenburg  ·  3 Kiel University, Germany  ·  4 Fraunhofer IDMT, Oldenburg Branch for Hearing

* Corresponding author  |  Experimental Brain Research · Manuscript in review

⚠️ Manuscript in review. This page accompanies a research article currently under peer review at Experimental Brain Research. The underlying EEG/motion dataset is not publicly available.

Synchronized mobile brain/body imaging (MoBI): smartphone-based pose tracking alongside wireless EEG during a basketball free-throw. Brain activity and whole-body movement are captured together, outside the laboratory.

Abstract

Advances in wireless electroencephalography (EEG) technology promise to record brain-electrical activity in everyday situations. To better understand the relationship between brain activity and natural behavior, it is necessary to monitor human movement patterns. Here, we present a pocketable setup consisting of two smartphones to simultaneously capture human posture and EEG signals.

We asked 26 basketball players to shoot 120 free throws each. First, we investigated whether our setup allows us to capture the readiness potential (RP) that precedes voluntary actions. Second, we investigated whether the RP differs between successful and unsuccessful free-throw attempts. The results confirmed the presence of the RP, but the amplitude of the RP was not related to shooting success. However, offline analysis of real-time human pose signals derived from a smartphone camera revealed pose differences between successful and unsuccessful shots for some individuals.

We conclude that a highly portable, low-cost and lightweight acquisition setup — two smartphones and a head-mounted wireless EEG amplifier — is sufficient to monitor complex human movement patterns and associated brain dynamics outside the laboratory.

mobile EEG human pose readiness potential MoBI basketball

The pocketable setup

Everything needed to record synchronized brain activity and movement fits in a backpack.

Two-smartphone pocketable setup for simultaneous EEG and motion capture during basketball free-throw shooting.
Figure 1. Pocketable setup for basketball free-throw shooting. Two tripods hold two Android smartphones in fixed positions. One smartphone wirelessly receives EEG data and records video (Smarting Pro app); the second captures human motion in real time (MediaPipe Pose Landmark Detection). A single Movella DOT sensor at the right wrist streams IMU signals. LSL SENDA and RECORDA apps manage time-synchronous acquisition of all streams.

Two smartphones, one synchronized stream

Instead of a dedicated lab, the recording relies on consumer hardware and open tooling, time-aligned through the Lab Streaming Layer.

  • Wireless EEG from a head-mounted amplifier (Smarting Pro), received and recorded on a smartphone.
  • Markerless pose tracking via a second smartphone running MediaPipe Pose Landmark Detection.
  • Wrist IMU (Movella DOT) providing acceleration to pinpoint movement onset.
  • Time-synchronous acquisition of all sensor streams using LSL SENDA/RECORDA — sharing a common clock.

Synchronized acquisition with LSL

Three sensor streams — EEG, body pose and wrist IMU — captured across two phones and the NeuropsyOL apps, consolidated into one synchronized recording.

🧠
Wireless EEG Phone 1 Smarting Pro app (mBrainTrain) → EEG & video → LSL
🤸
Body pose Phone 2 MediaPipe Pose Landmark Detection app → pose landmarks → LSL · 15 Hz
⌚
Wrist IMU SENDA Movella DOT → SENDA app streams to the LAN → LSL · 60 Hz
⏺
RECORDA app Records EEG, pose & IMU streams → single XDF file

Streaming is distributed across two smartphones (EEG and pose) plus the wrist IMU, while recording is consolidated by RECORDA over a shared local network. All streams carry a common LSL clock — synchronized timestamps, no post-hoc alignment needed. Acquisition uses the open-source RECORDA & SENDA Android apps from the Neuropsychology Lab Oldenburg.

Grand-average readiness potential

A clear pre-movement negativity emerges over central electrodes — captured entirely with a portable, smartphone-based setup.

Grand average of joint human motion capture and ERP: motion postures, ERP topographies, Cz readiness potential waveform, and significance maps.
Figure 4. Grand average of joint human motion capture and ERP. Mobile EEG, motion patterns, and IMU signals combined to analyze the readiness potential (RP) and motor activity during task execution. (A) Motion tracking of body postures at key intervals relative to movement onset. (B) Grand-average ERP topographies show the spatiotemporal evolution of the RP, with increasing negativity over (fronto-)central sites leading up to movement onset. (C) The RP (blue, channel Cz) shows a gradual negative deflection preceding movement onset (red dotted line); onset is determined from wrist acceleration (black line). (D) Mean ERP amplitudes in 100 ms bins tested against zero — topographies display significance.
Grand-average ERP at Cz comparing hits and misses across participants.
Figure 5. Grand-average ERP comparison between conditions. Grand-average Cz amplitude comparing successful (hits, blue) and unsuccessful (misses, red) free throws across all participants, in 100 ms bins from −1500 ms to movement onset. Error bars show the SEM. RP amplitude was not reliably related to shooting success.

Videos

Raw smartphone footage and the synchronized MoBI reconstruction.

Smartphone recording. A single phone on a tripod captures the free-throw attempt while wirelessly logging EEG via the Smarting Pro app.

MoBI reconstruction. Real-time pose landmarks and the wireless EEG signal shown together, illustrating the synchronized brain–body data that the two-smartphone setup yields outside the lab.

BibTeX

@article{contrerasaltamirano2025portable,
  title   = {A Portable Solution for Simultaneous Human Movement and Mobile
             EEG Acquisition: Readiness Potentials for Basketball Free-throw Shooting},
  author  = {Contreras-Altamirano, Miguel A. and Klapprott, Melanie and
             Jacobsen, Nadine S. and Maanen, Paul and Welzel, Julius and Debener, Stefan},
  journal = {Experimental Brain Research},
  year    = {2025},
  note    = {Manuscript in review}
}

Acknowledgements

Software-tool development was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy — EXC 2177/1, Project ID 390895285 — with additional internal funds of the Neuropsychology Lab Oldenburg. We thank the professional basketball club EWE Baskets Oldenburg for their cooperation, the Institute of Sports Science at the University of Oldenburg for enabling data collection, and Reiner Emkes for technical support.