Effects of an external compared to an internal focus of attention on the excitability of fast and slow(er) motor pathways

Resolving the Centipede's Dilemma: external focus distance and expertise in applied, continuous skills

Research has reliably demonstrated that an external focus of attention during skill production enhances performance, retention, and transfer relative to an internal focus on movement mechanics. The optimisation of external focus points, across a range of contexts and performers, is important for effective skill production. Two studies were conducted evaluating the impact of external focus distance in an applied, continuous sports skill (kayak sprinting) with participants of two different expertise levels. In Study 1, using a within-participants design, recreational kayakers (n = 20) were timed sprinting 75 m in a surf ski under proximal external focus, distal external focus, and control conditions. The distal focus (on the finish) (29.75 s) was significantly faster than both other trials (ps < 0.001). The control condition (30.95 s) was significantly faster than the proximal focus (on the boat) (32.37 s) (p = 0.003). The effect size was large (ηp2 = 0.55). In Study 2, specifically trained racers in sprint kayaks (K1s) (n = 16) were timed in a 100 m K1 sprint under the same three conditions as in Study 1. The control condition (28.96 s) was significantly faster than the proximal focus trial (29.83 s) (p = 0.02). The effect size was large (ηp2 = 0.23). There was no significant difference between the distal focus trial (29.03 s) and the other conditions. These findings suggest that focus distance can play a pivotal role in continuous skills. Whilst recreational performers may benefit immediately from a distal focus, this might not be the case for specifically trained athletes. Further, a proximal focus on fitted, passive equipment may be detrimental to performance.

Attentional focus differentially modulates the corticospinal and intracortical excitability during dynamic and static exercise

Although attentional focus affects motor performance, whether corticospinal excitability and intracortical modulations differ between focus strategies depending on the exercise patterns remains unclear. In the present study, using single- and paired-pulse transcranial magnetic stimulation and peripheral nerve stimulation, we demonstrated changes in the cortical and spinal excitability under external focus (EF) and internal focus (IF) conditions with dynamic or static exercise. Participants performed the ramp-and-hold contraction task of right index finger abduction against an object (sponge or wood) with both exercises. They were asked to concentrate on the pressure on the sponge/wood induced by finger abduction under the EF condition, and on the index finger itself under the IF condition. Motor-evoked potential (MEP) and F-wave in the premotor, phasic, or tonic phase, and short- and long-interval intracortical inhibition (SICI and LICI, respectively), and intracortical facilitation (ICF) in the premotor phase were examined by recording surface electromyographic activity in the right first dorsal interosseous muscle. Increments in the MEP amplitude were larger under the EF condition than under the IF condition in the dynamic, but not static, exercise. The F-wave, SICI, and LICI did not differ between focus conditions in both exercises. In the dynamic exercise, interestingly, ICF was greater under the EF condition than under the IF condition and positively correlated with the MEP amplitude. These results indicate that corticospinal excitability and intracortical modulations to attentional focus differ depending on exercise patterns, suggesting that attentional focus differentially affects the central nervous system responsible for diverse motor behaviors.NEW & NOTEWORTHY We investigated attentional focus-dependent corticospinal and intracortical modulations in dynamic or static exercise. The corticospinal excitability was modulated differentially depending on the focus of attention during dynamic, but not static exercise. Although the reduction of intracortical GABAergic inhibition was comparable between focus conditions in both exercises, intracortical facilitation was smaller when focusing on the internal environments in the dynamic exercise, resulting in lower activation of the corticospinal tract.

Golf skill learning: An external focus of attention enhances performance and motivation

An external focus of attention has been shown to enhance the performance and learning of motor skills, relative to an internal focus (see Chua, Jimenez-Diaz, Lewthwaite, Kim, & Wulf, 2021). In the present study, we examined possible motivational consequences of learners' experience of greater movement success with an external focus. Participants were asked to learn a golf pitch shot. In addition to measuring learning, we assessed self-efficacy, as well as positive and negative affect in groups that received external versus internal focus instructions. Furthermore, we examined the feasibility of providing several focus instructions in the same practice session as the learning of complex skills typically requires more than one instructional cue. The results showed that skill learning was enhanced by instructions that promoted external foci, as measured by golf shot accuracy on delayed retention and transfer tests. The external focus group also showed higher positive affect and reduced negative affect at the end of practice, and higher self-efficacy before retention testing, compared with the internal focus group. These findings provide support for several assumptions of the OPTIMAL theory (Wulf & Lewthwaite, 2016). From a practical perspective, they highlight the attentional and motivational benefits of an external focus.

Paired corticomotoneuronal stimulation of the preactivated ankle dorsiflexor: an open-label study of magnetic and electrical painless protocols

Paired corticomotoneuronal stimulation (or electrical PCMS: ePCMS) is the repetitive pairing of an electrical stimulus to a nerve with a transcranial magnetic stimulation of the primary motor cortex (TMS-of-M1) to noninvasively influence spinal plasticity. We compared ePCMS with the new painless PCMS protocol pairing a magnetic stimulus to the nerve with TMS-of-M1 (mPCMS) in the preactivated tibial anterior muscle (TA). Sixteen healthy adults participated in two sessions (mPCMS, ePCMS), each with 180 pairs of [low-intensity TMS-of-M1 + nerve stimulation] at 0.2 Hz. TA motor-evoked potentials (MEP) to single-pulse TMS at pre-PCMS, immediately and 30 min after PCMS, were cluster-analyzed to discriminate responders and non-responders. Paired-pulse TMS-of-M1 and F-waves were also tested and BDNF polymorphism influence was explored. Both PCMS protocols significantly increased MEP amplitudes (n = 9 responders each), but the time-course differed with mPCMS inducing larger MEP increase over time. The number of BDNF-methionine carriers tended to be larger than Val66Val in mPCMS and the reverse in ePCMS, thus warranting further investigations. The MEP changes of the preactivated TA likely occurred at the pre-motoneuronal level and larger mPCMS after-effects over time may be related to the afferents recruited. mPCMS seems relevant to be tested in future studies as a painless noninvasive approach to induce sustained pre-motoneuronal plasticity in spinal cord injury.

External and internal focus of attention differentially modulate corticospinal excitability in anticipatory postural adjustments

Whether attentional focus modulates the corticospinal excitability of the lower limb muscles in anticipatory postural adjustments (APAs) when performing a ballistic movement of the upper limb remains unclear. The present study used transcranial magnetic stimulation (TMS) to examine the corticospinal excitability of the lower limb muscles along with the kinematic profiles during dart throwing with different attentional foci, external focus (EF) and internal focus (IF). In 13 healthy participants, TMS was applied immediately before electromyographic onset of the tibialis anterior (TA) muscle, and the motor evoked potential (MEP) was recorded in the TA and soleus (SOL) muscles. The performance accuracy was significantly higher in the EF condition than in the IF condition. In both EF and IF conditions, MEP amplitude in the TA muscle, but not the SOL muscle, was significantly higher immediately before TA muscle onset (- 100, - 50, and 0 ms) compared to the control. In particular, the MEP increment in the TA muscle before TA muscle onset (- 50 and 0 ms) was significantly larger in the EF condition than in the IF condition. Our findings provide the first evidence for the modulation of corticospinal excitability in APA by changing attentional focus.

A Pilot Study on Attentional Focus in Prescribing Physical Exercise in Outpatients with Obesity

This pilot study compared the effects of two attentional focus strategies on fitness parameters and body composition in outpatients with obesity. This was a randomized, controlled study that enrolled 94 obese individuals and allocated them into an internal focus group (IF) or an external focus group (EF) while performing six weeks of a home-based training program. The home-based exercise program was the same for both groups except for the instructions that shifted the attention to an external or an internal condition. At the beginning and after the intervention period, participants were assessed for functional performance using the Functional Movement Screen (FMS), body balance using the Modified Balance Error Scoring System (M-BESS) and muscular strength with the Handgrip Strength Test (HST) and the Five-Repetition Sit-To-Stand (FRSTS) test. Concerning body composition and anthropometric parameters, the body mass index (BMI) and fat mass percentage (FM%) were calculated. Significant improvements, main interactions and effects of time and groups were highlighted in the EF group as compared to the IF group in FMS (35% vs. 21%), M-BESS (42% vs. 18%), HST (13% vs. 7%) and FRSTS (23% vs. 12%) measures, while FM% (5%) and BMI (6% vs. 5%) showed a similar improvement overtime (p < 0.001). In conclusion, our findings provide initial evidence that a 6-week training program performed following external focus instruction is able to promote significant enhancements in movement efficiency, balance and muscular strength as compared to an internal focus cue. Fitness coaches and therapists might consider integrating a specific attentional focus strategy when designing rehabilitation programs in subjects with obesity.

Pay attention! The influence of coach-, content-, and player-related factors on focus of attention statements during tennis training

It is well established that adopting an external focus of attention (EF) enhances motor learning when contrasted to an internal focus (IF) or a neutral condition. Despite consistent evidence for this performance-enhancing effect of an EF, recent studies show that coaches predominantly induce an IF in the communication with athletes. It remains, however, unknown whether and to what degree coach-, content- or player-related factors have an impact on the focus of attention during youth tennis training. Therefore, we recorded all statements from 10 tennis coaches during six training sessions with a total of 87 youth athletes aged 18 years or younger. All statements were categorized according to the focus they induced (IF, EF, neutral, best place to hit the ball, mix, no focus) and the form of communication (instruction, feedback). Of the relevant statements (n=3049), 45.1% promoted an EF, whereas 33.1% induced an IF. Evaluation of coaches-, player- and content-specific features (education, age of coach/player, training content, skill level) showed that more statements with an IF were given when training beginners. The data also show more statements with an EF for instructions (59.0%) compared to feedback (43.0%). Our results contrast with other sports where instructions with an IF predominate. Thus, instrumented sports with external targets (e.g. tennis) might be better suited for inducing an EF. The data also show that coaches are more likely to use IF when communicating with beginners. Consequently, an EF should not be induced in every possible situation, even if this is often communicated so far.