May 24, 2021 BMS lab

Penalty Kicks and Brain Activity – fNIRS Study

FIFA reported that 3.572 billion viewers watched the soccer matches from June 14 to July 15 in 2018 (Reuters 2018). With about half of the world’s population interested in the sport, many were left wondering why do the players miss the penalty kicks so often. One BMS Lab study by Max Slutter, Nattapong Thammasan, and Mannes Poel exploring the missing penalty kicks has garnered media attention.

Figure 1. The experimental setting: (A) pictures of the experiment from the front (top), back (middle), and side (bottom) angle; (B) experimental protocol; (C) placement of the equipment. The laptop close to the chair was used by the participants to fill in the questionnaires. The GoPro camera that was closest to the goal was aiming at the player and the other camera was aiming at the goal. (Slutter et al., 2021)

Research and Experiment

A vital part of professional soccer matches is the penalty kicks. However, it is not uncommon for them to be missed. Inspired by this, Max Slutter, Nattapong Thammasan, and Mannes Poel conducted a study with the BMS Lab on the topic. Their goal was to investigate brain activity during the real situation of penalty kicking using fNIRS. More precisely, they investigated the performance and performance under pressure, experienced and inexperienced players, anxiety and experienced and inexperienced players.

To accomplish their goal, they set up an experiment, consisting of three rounds: one without a goal kipper, one with an amiable goalkeeper and one with a competitive goalkeeper. In the experiment, 22 volunteers participated, taking 15 shots under the three conditions. 

Table 1. Mean accuracy, standard deviation (in brackets), and area under the ROC (in italic style) of SVM-based classification from five runs using a different type of features.
(Slutter et al., 2021)

Findings

They found that supportive evidence that activating the correct regions of the brain leads to successful performance under pressure.  

In terms of performance, they found that task-irrelevant PFC was related to missing the penalties, stating that the activation of the PFC can infer a distraction. The authors reveal that the cause is the long-term thinking ability of the PFC, since the players may be concerned about the result of their penalty kick. 

However, when it comes to the connectivity of motor cortex and the DLPFC under the higher pressure round, they found no significant results about performing under high levels of pressure. Additionally, there was no significant difference between the experienced and inexperienced players when kicking a penalty. 

On the other hand, they found that the experienced players when anxious showed higher left temporal cortex activation. They state that that would indicate that the experienced players overthink the situation while neglecting their skills. Nevertheless, when it comes to the inexperienced players being anxious, they observed no significant results. 

Yet, when removing the experience from the picture, the averaged PFC was related to the anxiety of the players. Additionally, the increased right PFC showed to be related to anxious players. Meanwhile, the motor cortex tends to have power activation when anxious, notwithstanding the experience level. 

Figure 2. Correlation coefficients between each behavioral resultant scores in all players, experienced players, and inexperienced players. Significant correlations at p < 0.05 (corrected by Bonferroni correction) are with red borders (Slutter et al., 2021).

Conclusion

To sum up, the players who were successful when under pressure had the most activity in the motor cortex. Meanwhile, the unsuccessful players had more activity in the pre-frontal cortex and the left temporal cortex. The authors state that the players are likely missing due to overthinking the outcome of the kick or overthinking the kick itself. Interested in finding out more details about the study? You can read the full article here.