REVIEW 2 major objections 5 minor 26 references
A portable solution for simultaneous human movement and mobile EEG acquisition: readiness potential for basketball free-throw shooting
T0 review · 2 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash
Pith's one-line read Two off-the-shelf smartphones plus a wireless EEG cap can record the readiness potential during real basketball free throws.
desk verdict A credible mobile-EEG feasibility study with a load-bearing but fixable movement-onset validation gap. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The load-bearing tool is the synchronized recording chain. One smartphone receives 32-channel EEG at 250 Hz from a head-mounted wireless amplifier along with the amplifier's inertial sensors; a second smartphone runs MediaPipe Pose Landmark Detection at 15 Hz to track 33 body landmarks; and a wrist-worn IMU streams acceleration at 60 Hz. Lab Streaming Layer binds the streams into a single file. To time-lock brain activity, the analysis first detects a set-point when the right wrist crosses eye level on the pose stream, then walks backward through the wrist acceleration signal to find movement onset as the last sample below a threshold of baseline mean plus one standard deviation. EEG epochs from -2.5 s to movement onset are cleaned with ICA-based artifact removal and averaged to produce the readiness potential. The synchronization of EEG, pose, and IMU timestamps to that movement onset is what makes a comparison between neural preparation and subsequent movement outcome possible.
What would settle it
Take the same two-phone recordings and redefine movement onset using a high-speed camera or the first detectable motion of the right throwing hand rather than the wrist-accelerometer threshold; if the significant negative deflection at Cz disappears or shifts outside the -400 to 0 ms window, the claim that the portable setup captures the readiness potential is not established.
Extended reading notes
Core claim
The discovery this paper argues for is that a minimally invasive, low-cost two-smartphone system can simultaneously capture human pose and EEG well enough to observe a canonical brain signature of action preparation in a natural skilled task. Averaged across participants, the EEG shows a readiness potential over fronto-central channels, with a significant negative deflection at Cz from -400 to 0 ms before movement onset (mean -6.54 to -13.52 µV; z = -2.53 to -3.92; FDR-corrected p = 0.049 to 0.003; r = 0.50 to 0.77). However, the amplitude of the RP was not related to shooting outcome at the group or single-trial level (largest mean R² = 0.047, i.e., 4.7% explained variance), and only a minority of participants showed pose differences between successful and unsuccessful attempts. The authors present this as evidence that the setup is sufficient for monitoring movement and brain dynamics outside the laboratory, not that the RP forecasts performance.
Load-bearing premise
The load-bearing premise is that the wrist-worn accelerometer's threshold, baseline mean plus one standard deviation, marks the true onset of the shot, because EEG epochs, pose epochs, and every performance correlation are aligned to that time zero; the paper's own validation found the most consistent motion at that instant in the left hand and hips, not the right throwing hand.
Editorial extensions
If this is right
- Readiness potentials can be elicited and recorded during whole-body, goal-directed motor skills outside the laboratory, extending the RP beyond finger presses and isolated movements.
- RP amplitude before a free throw does not predict make versus miss in this population; performance is better linked, for some individuals, to body posture during execution.
- A two-smartphone rig with a wireless EEG cap is enough to align neural, inertial, and pose data streams in a natural setting, reducing cost and mobility barriers.
- Pose-based set-point detection plus reverse thresholding provides a practical event marker for natural movements that lack a discrete button-press onset.
- This supports further mobile brain-body imaging studies and possibly portable neurofeedback applications in real environments.
Reading between the lines
- The null RP-performance relationship may be a timing artifact of the onset marker: if the wrist IMU threshold captures a preparatory crouch or ball hand-over rather than throw initiation, single-trial RP estimates would be systematically jittered, biasing point-biserial correlations toward zero; re-epoching around a video-verified release frame would test this.
- The pose differences, lower wrist before the shot, higher wrist at set-point, and stable head, suggest a compact marker set for automated coaching feedback, but the small explained variance and individual specificity mean such feedback would need to be personalized rather than generic.
- Because the setup is cheap and untethered, a natural extension would be to run the same rig with elite versus novice shooters; expertise differences in RP amplitude found in earlier work might reappear in between-subject designs even though within-subject trial outcome did not correlate.
Signed reviews
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper reports a portable, low-cost mobile brain/body imaging setup consisting of two Android smartphones, a wireless 32-channel EEG amplifier, and a wrist-worn IMU, used to record brain activity and full-body pose while 26 basketball players performed 120 free throws each. The authors analyze (i) the readiness potential (RP) preceding the throwing movement, (ii) whether RP amplitude differs between successful and unsuccessful shots, and (iii) whether pose landmarks differ between hits and misses. They report a significant negative deflection at Cz and adjacent fronto-central channels from -400 to 0 ms before their accelerometer-derived movement onset, no significant relationship between RP amplitude and shooting success, and exploratory pose differences in 10 of 26 participants with small explained variance. The paper concludes that the setup is sufficient to monitor complex human movement and associated brain dynamics outside the laboratory.
Significance. If the movement-onset alignment is valid, this is a useful methodological contribution to mobile EEG and MoBI research. The setup is genuinely portable, low-cost, and lightweight; the authors provide open code and data availability; and the statistical reporting is largely transparent, including FDR corrections, effect sizes, and an honest presentation of null results for the RP-performance relationship. The pose analysis is explicitly exploratory, and the small effect sizes are not overstated. The central risk is the validity of the accelerometer-derived movement onset, which the paper's own validation does not confirm. Because every EEG epoch, pose window, set-point latency, and performance correlation is time-locked to that event, this issue is load-bearing for the main feasibility claim. The paper would be strengthened substantially by independent validation of the onset marker, for example via video annotation, EMG, or a second motion sensor on the ball.
major comments (2)
- [Results, 'Movement onset validation'; Figure 3] The validation of the movement-onset marker does not confirm that the right-wrist accelerometer threshold identifies the onset of the throwing movement. The binomial tests across participants show significant motion at the accelerometer-defined t=0 in the left index finger, left pinky, left thumb, left wrist, and both hips, but not in the right throwing wrist. Since the right-wrist IMU defines t=0 for all subsequent analyses, this result suggests that the threshold may be capturing a preparatory postural adjustment, a ball-handover movement, or a cross-device synchronization artifact rather than the initiation of the free-throw. The RP-like morphology could still arise if the same non-throwing movement consistently precedes each shot by a roughly constant interval, but in that case the paper's central claim of capturing the readiness potential for the basketball free-throw is not established. The authors should validate the onset against an independent ground-truth marker (e.g., manual video annotation, EMG, or a second sensor on the ball) or, at minimum, quantify and discuss the temporal offset between the detected event and the actual throwing onset.
- [Materials and Methods, 'Onset detection'; Limitations] The threshold-based onset detection procedure is described only qualitatively. No trial-to-trial or participant-level variability of the detected onsets is reported, and the set-point latency is given only as a group mean (544 ms after onset) without a range or standard deviation. In addition, the Limitations section acknowledges 'minimal delays in synchronization' (citing Iwama et al., 2024) but does not quantify the jitter or latency between the EEG, PLD, and IMU streams, despite the fact that all streams were aligned via linear interpolation on EEG timestamps. Because the entire analytic pipeline depends on the temporal alignment of these streams, the authors should provide quantitative synchronization error estimates and assess the stability of the onset detection across trials and participants.
minor comments (5)
- [Materials and Methods, 'Presence of the RP' vs. Results, 'Presence of the RP'] The Methods state that the presence of the RP was evaluated using t-tests, but the Results report Wilcoxon signed-rank tests; please reconcile this discrepancy.
- [Abstract and Results, 'Presence of the RP'] The abstract reports effect sizes as r = 0.50 to 0.77, but the Results do not explain how these are derived from the reported z-values; please specify the computation (e.g., r = z / sqrt(N)).
- [Results, 'Movement onset validation'] The description of the binomial tests is incomplete: it is not stated whether the test is performed on the proportion of participants showing a significant Wilcoxon effect at each body part, and the correction for multiple comparisons across body parts is not explained in enough detail to be reproduced.
- [Discussion, 'Movement onset validation'] The sentence 'Inspection of the PLD signals confirmed that hand/wrist motion was among the first body parts involved in initiating a basketball free-throw motion sequence' appears to contradict the statistical validation reported in the Results, which found the most consistent movement at the left hand and hips; please clarify or qualify this statement.
- [References] The reference list contains an entry for 'Hayes, M.H.S. and Patterson, D.G. (1921)' that is not cited anywhere in the text; please remove it or cite it appropriately.
Circularity Check
No circularity: the central RP and pose results are empirical measurements time-locked to an accelerometer onset, not outputs defined by inputs; self-citations are limited to software tools and are not load-bearing.
full rationale
This is an empirical measurement and feasibility study without a formal derivation chain. The central claim—that a portable smartphone-and-wireless-EEG setup can capture the readiness potential before basketball free throws—is supported by time-locking EEG to an accelerometer-derived movement onset and testing whether the pre-onset EEG amplitude deviates from zero. The EEG signal is independent of the accelerometer threshold, so the observed negative deflection is not imposed by the onset definition; it is a genuine empirical result, albeit one whose accuracy depends on the validity of the onset marker. The null relationship between RP amplitude and shooting outcome and the exploratory pose differences are descriptive correlations, not predictions from fitted parameters. The paper does cite the authors' own software tools (Blum et al. 2021; Maanen et al., in preparation) for LSL-based synchronization and pose streaming, but these citations support the recording infrastructure rather than the empirical conclusion, and the conclusion does not reduce to them. The main weakness identified in the paper—that the PLD validation found the most consistent motion at movement onset in left-hand and hip landmarks rather than the right throwing wrist—is a measurement-validity concern, not a circularity: the onset definition and the EEG outcome are not equivalent by construction. No equation, fitted parameter, or uniqueness claim is defined in terms of its own output. Therefore, no significant circularity is present.
Assumptions & free parameters
free parameters (1)
- Movement onset threshold =
baseline mean + 1 SD of wrist acceleration, applied per participant
assumptions (5)
- domain assumption Self-reported right-handedness and at least 3 years of regular basketball experience are accurate inclusion criteria (Methods, Participants).
- domain assumption The right-wrist IMU acceleration signal, thresholded at baseline mean plus one SD, marks the true onset of the shooting movement (Methods, Onset detection).
- domain assumption Linear interpolation of 15 Hz PLD data and 60 Hz IMU data onto 250 Hz EEG timestamps preserves temporal alignment well enough for 100 ms bins (Methods, EEG data analysis).
- domain assumption ICA plus ICLabel reliably separates movement and physiological artifacts from neural EEG in a throwing task (Methods, EEG preprocessing).
- domain assumption MediaPipe PLD 2D coordinates (with z discarded) are sufficient to characterize whole-body posture for the free-throw task (Methods, Materials; Discussion).
Cite this review
Pith. "Pith review of A portable solution for simultaneous human movement and mobile EEG acquisition: readiness potential for basketball free-throw shooting." pith.science (2026). https://pith.science/paper/6622CDZ5
@misc{pith2026250105378,
author = {Pith},
title = {Pith review of: A portable solution for simultaneous human movement and mobile EEG acquisition: readiness potential for basketball free-throw shooting},
year = {2026},
howpublished = {\url{https://pith.science/paper/6622CDZ5}},
note = {Machine review of arXiv:2501.05378}
}
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 over fronto-central channels, with significant negative deflection at channel Cz, from -400 to 0 ms before movement onset ($M$ $\pm$ $SE$: -6.54 $\pm$ 2.26 to -13.52 $\pm$ 2.42 $\mu$V; $z$ = -2.53 to -3.92; FDR-corrected $p$ = 0.049 to 0.003; $r$ = 0.50 to 0.77). However, the amplitude of the RP was not related to shooting success (all FDR-corrected $p$ > 0.05; maximum mean $R^2$ = 0.047, i.e., 4.7% explained variance). Preliminary exploratory pose analysis conducted offline indicated the presence of participant-specific variations in posture between successful and unsuccessful shots in 38.5% of participants (10/26), with 4.5% explained variance (maximum mean landmark $R^2$ = 0.045). We conclude that a highly portable, low-cost and lightweight acquisition setup, consisting of two smartphones and a head-mounted wireless EEG amplifier, is sufficient to monitor complex human movement patterns and associated brain dynamics outside the laboratory.
Figures
Figures from the paper (5 more)
Reference graph
Works this paper leans on
-
[1]
Alves, Heloisa; Voss, Michelle W.; Boot, Walter R.; Deslandes, Andrea; Cossich, Victor; Salles, Jose Inacio; Kramer, Arthur F. (2013). Perceptual -cognitive expertise in elite volleyball players. In Frontiers in psychology, 4, p
work page 2013
-
[18]
Available online at https://www.frontiersin.org/journals/human - neuroscience/articles/10.3389/fnhum.2024.1466853. Konttinen, N., & Lyytinen, H. (1993). Brain slow waves preceding time -locked visuo - motor performance. Journal of sports sciences , 11(3), 257 –266. DOI: 10.1080/02640419308729993. Konttinen, N., Lyytinen, H., & Konttinen, R. (1995). Brain ...
-
[20]
Robin, Nicolas; Toussaint, Lucette; Charles -Charlery, Cédric; Coudevylle, Guillaume R. (2019). Free throw performance in non -expert basketball players: The effect of dynamic motor imagery combined with action observation. In Learning and Motivation, 68, p. 101595. DOI: 10.1016/j.lmot.2019.101595. Robles, Daniel; Kuziek, Jonathan W. P.; Wlasitz, Nicole A...
-
[23]
Tan, Sok Joo; Kerr, Graham; Sullivan, John P.; Peake, Jonathan M
Available online at https://www.frontiersin.org/journals/human - neuroscience/articles/10.3389/fnhum.2024.1483024. Tan, Sok Joo; Kerr, Graham; Sullivan, John P.; Peake, Jonathan M. (2019). A Brief Review of the Application of Neuroergonomics in Skilled Cognition During Expert Sports Performance. In Frontiers in human neuroscience, 13, p
arXiv 2019
-
[36]
DOI: 10.3389/fpsyg.2013.00036. Bakker, Lisanne B. M.; Nandi, Tulika; Lamoth, Claudine J. C.; Hortobágyi, Tibor (2021): Task specificity and neural adaptations after balance learning in young adults. In Human Movement Science 78, p. 102833. DOI: 10.1016/j.humov.2021.102833. Bertollo, Maurizio; Di Fronso, Selenia; Filho, Edson; Conforto, Silvia; Schmid, Mau...
arXiv 2021
-
[80]
Wolke, Robin; Welzel, Julius; Maetzler, Walter; Deuschl, Günther; Becktepe, Jos (2024)
DOI: 10.2307/3001968. Wolke, Robin; Welzel, Julius; Maetzler, Walter; Deuschl, Günther; Becktepe, Jos (2024). Validity of tremor analysis using smartphone -compatible computer vision frameworks – a comparative study (under revision). Woodman G. F. (2010). A brief introduction to the use of event -related potentials in studies of perception and attention ....
doi:10.2307/3001968 2024
-
[111]
Makeig, S., Gramann, K., Jung, T
DOI: 10.15203/CISS_2016.111. Makeig, S., Gramann, K., Jung, T. P., Sejnowski, T. J., & Poizner, H. (2009). Linking brain, mind, and behavior. International journal of psychophysiology : official journal of the International Organization of Psychophysiology , 73(2), 95 –100. DOI: 10.1016/j.ijpsycho.2008.11.008. Makeig, Scott; Debener, Stefan; Onton, Julie;...
-
[126]
DOI: 10.1249/00005768-199301000-00016. De Vos, Maarten; Gandras, Katharina; Debener, Stefan (2014): Towards a truly mobile auditory brain -computer interface: exploring the P300 to take away. In International journal of psychophysiology : official journal of the International Organization of Psychophysiology 91 (1), pp. 46–53. DOI: 10.1016/j.ijpsycho.2013...
Show all 26 references
-
[166]
Expert -novice differences in SMR activity during dart throwing
Cheng, Ming-Yang; Hung, Chiao-Ling; Huang, Chung-Ju; Chang, Yu-Kai; Lo, Li-Chuan; Shen, Cheng; Hung, Tsung -Min (2015). Expert -novice differences in SMR activity during dart throwing. In Biological psychology, 110, pp. 212–218. DOI: 10.1016/j.biopsycho.2015.08.003. Cheron, G....
2015 doi
-
[246]
Chien‐Ting Wu, Li‐Chuan Lo, Jung‐Huei Lin, Heng‐Shing Shih & Tsung‐Min Hung (2007)
DOI: 10.3389/fpsyg.2016.00246. Chien‐Ting Wu, Li‐Chuan Lo, Jung‐Huei Lin, Heng‐Shing Shih & Tsung‐Min Hung (2007). The relationship between basketball free throw performance and EEG coherence, International Journal of Sport and Exercise Psychology , 5:4, 448 -450. DOI: 10.1080...
2007
-
[247]
Slegers, P
DOI: 10.1108/SBM-10-2021-0119. Slegers, P. M., Lian, C., Zhang, Q., Li, J., & Zhao, Y. (2021). Shooting Prediction Based on Vision Sensors and Trajectory Learning . Applied Sciences, 12(19), 10115. DOI: 10.3390/app121910115. Subramanian, Barathi; Olimov, Bekhzod; Naik, Shraddh...
2021 doi
-
[278]
DOI: 10.3389/fnhum.2019.00278. Tang, W. -T. and Shung, H. -M. (2005): Relationship between isokinetic strength and shooting accuracy at different shooting ranges in Taiwanese elite high school basketball players. In IES 13 (3), pp. 169–174. DOI: 10.3233/IES-2005-0200. Taylor M...
2005
-
[283]
Maglott, Jonathan C.; Shull, Peter B
DOI: 10.1007/s42113-020-00097-5. Maglott, Jonathan C.; Shull, Peter B. (2019). Wearable occlusion device for assessing cognitive basketball shooting performance between males and females. In: Proceedings of the International Conference on Industrial Control Network and System ...
2019 doi
-
[289]
Penner, L
DOI: 10.1038/s41467-019- 13967-9. Penner, L. S. J. (2021). Mechanics of the Jump Shot: The “Dip” Increases the Accuracy of Elite Basketball Shooters. Frontiers in Psychology , 12, 658102. DOI: 10.3389/fpsyg.2021.658102. Pion-Tonachini, L., et al. (2019). ICA -based artifact re...
2021
-
[420]
Figari Tomenotti, Federico; Noceti, Nicoletta; Odone, Francesca (2024): Head pose estimation with uncertainty and an application to dyadic interaction detection
DOI: 10.1186/s40359-023-01317-w. Figari Tomenotti, Federico; Noceti, Nicoletta; Odone, Francesca (2024): Head pose estimation with uncertainty and an application to dyadic interaction detection. In Computer Vision and Image Understanding 243, p. 103999. DOI: 10.1016/j.cviu.202...
2024
-
[458]
F., & Keeping, E
Kenney, J. F., & Keeping, E. S. (1962). Root Mean Square. In Mathematics of Statistics. Pt. 1 (3rd ed., pp. 59-60). Princeton, NJ: Van Nostrand. Keshvari, F., Farsi, A., & Abdoli, B. (2023). Investigating the EEG Profile of Elite and Non- Elite Players in the Basketball Free T...
1962
-
[509]
Cheng, M
DOI: 10.1111/ejn.15595. Cheng, M. Y., Huang, C. J., Chang, Y. K., Koester, D., Schack, T., & Hung, T. M. (2015). Sensorimotor Rhythm Neurofeedback Enhances Golf Putting Performance. Journal of sport & exercise psychology , 37(6), 626 –636. DOI: 10.1123/jsep.2015-
2015 doi
-
[694]
Landers, D
DOI: 10.3389/fnhum.2016.00694. Landers, D. M., Han, M., Salazar, W., Petruzzello, S. J., et al. (1994). Effects of learning on electroencephalographic and electrocardiographic patterns in novice archers. International Journal of Sport Psychology, 25(3), 313–330. Latreche, Ameu...
1994
-
[1495]
Raś, Maciej; Nowik, Agnieszka M.; Klawiter, Andrzej; Króliczak, Grzegorz (2019): When is the brain ready for mental actions? Readiness potential for mental calculations
DOI: 10.3390/app13031495. Raś, Maciej; Nowik, Agnieszka M.; Klawiter, Andrzej; Króliczak, Grzegorz (2019): When is the brain ready for mental actions? Readiness potential for mental calculations. In Acta Neurobiologiae Experimentalis, 79 (4), pp. 386–398. DOI: 10.21307/ane-2019-
2019 doi
-
[1621]
Deecke, L., Boschert, J., Weinberg, H., & Brickett, P
DOI: 10.1111/j.1469-8986.2012.01471.x. Deecke, L., Boschert, J., Weinberg, H., & Brickett, P. (1983). Magnetic fields of the human brain (Bereitschaftsmagnetfeld) preceding voluntary foot and toe movements. Experimental brain research, 52(1), 81–86. DOI: 10.1007/BF00237152. De...
1983
-
[1707]
Hamilton, G
DOI: 10.3389/fpsyg.2019.01707. Hamilton, G. R., & Reinschmidt, C. (1997). Optimal trajectory for the basketball free throw. Journal of Sports Sciences, 15(5), 491–504. DOI: 10.1080/026404197367137. Hatfield, Bradley D. and Kerick, Scott E. (2012). The Psychology of Superior Sp...
1997
-
[2019]
New York, NY, United States: Association for Computing Machinery (ACM Digital Library), pp. 37–41. DOI: 10.1145/3333581.3333599 . Maanen et al. (2024). Enhancing Mobile Brain and Body Imaging: Open -Source Solutions for Real-World Research Applications (updates in revision). M...
2024
-
[2046]
Zink, Rob; Hunyadi, Borbála; van Huffel, Sabine; Vos, Maarten de (2016): Mobile EEG on the bike: disentangling attentional and physical contributions to auditory attention tasks
DOI: 10.3758/APP.72.8.2031. Zink, Rob; Hunyadi, Borbála; van Huffel, Sabine; Vos, Maarten de (2016): Mobile EEG on the bike: disentangling attentional and physical contributions to auditory attention tasks. In Journal of neural engineering 13 (4), p. 46017. DOI: 10.1088/1741-2...
2016 arXiv
-
[2243]
Nastase, Samuel A.; Goldstein, Ariel; Hasson, Uri (2020): Keep it real: rethinking the primacy of experimental control in cognitive neuroscience
DOI: 10.1038/s41598-018-38447-w. Nastase, Samuel A.; Goldstein, Ariel; Hasson, Uri (2020): Keep it real: rethinking the primacy of experimental control in cognitive neuroscience. In Neuroimage 2 22, p. 117254. DOI: 10.1016/j.neuroimage.2020.117254. O'Brien, Jessica; Ottoboni, ...
2020
-
[3228]
Sanchez-Lopez, Javier; Fernandez, Thalia; Silva -Pereyra, Juan; Martinez Mesa, Juan A.; Di Russo, Francesco (2014): Differences in visuo -motor control in skilled vs
DOI: 10.3390/electronics11193228. Sanchez-Lopez, Javier; Fernandez, Thalia; Silva -Pereyra, Juan; Martinez Mesa, Juan A.; Di Russo, Francesco (2014): Differences in visuo -motor control in skilled vs. novice martial arts athletes during sustained and transient attention tasks:...
2014 doi
-
[8012]
Espenhahn, S., van Wijk, B
DOI: 10.1038/s41598-024-58146-z. Espenhahn, S., van Wijk, B. C. M., Rossiter, H. E., Berker, A. O., Redman, N. D., & Rondina, J. et al. (2019). Cortical beta oscillations are associated with motor performance following visuomotor learning. Neuroimage, 195, 340 –353. DOI: 10.10...
2019
Reviewed August 10, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.