17
Using ST to Improve Skill Acquisition and Prevent Choking Under Pressure
Ericsson (1993) theorized that deliberate practice, rather than genetics, plays the most important role in the acquisition of expertise. His research supports the assertion that experts differ from non-experts in the quantity of deliberate practice they engage in, and suggests that the quality of deliberate practice also plays an important role. Given the high value society places on sports expertise (reflected in the endorsement deals, television rights, and multimillion-dollar contracts that play an integral role in professional sports), research aimed at improving the quality of deliberate practice could have a profound influence on a large proportion of the population. Indeed, research that provides insight into the development and acquisition of expertise, as well as the maintenance of expert performance levels through a variety of conditions, is of the utmost importance to those involved in sports pedagogy.
Before people become experts, they first must acquire the appropriate skills. Psychological research has examined a number of pedagogical tools that have been thought to assist in skill acquisition, one of the most successful being self-talk (ST) (e.g., Ziegler, 1987). Landin (1994) defined ST as a set of verbal cues taught to the student that are "…concise phrases, often just one or two words, that either direct a student's attention to relevant task stimuli or prompt key movement pattern elements of a motor skill" (p.299). Previous research has differentiated ST into positive and negative ST (Van Raalte, 1994), and more recently, into instructional and motivational ST (Theodorakis, Weinberg, Natsis, Douma, & Kazakas, 2000). Instructional ST best fits Landin's definition, and is of central concern in this paper.
Instructional ST always serves to direct the learner's attention, either externally ("to relevant task stimuli"), or internally (to "key movement patterns") (Landin, 1994). The direction of attention is itself an important factor in skill acquisition, retention, and choking under pressure (Baumeister, 1984; Baumeister & Showers, 1986; Beilock & Carr, 2001; Castaneda & Gray, 2007; Gray, 2004; Jackson, 2006; Koedijker, Oudejans, & Beek, 2007; Lewis & Linder, 1996; Wulf, Lauterbach, & Toole, 1999; Wulf, McNevin, Fuchs, Ritter, & Toole, 2000). Although ST and direction of attention are well-studied concepts, to my knowledge the interaction between the two has not yet been explicitly examined.
Skill Acquisition
In a classic study by Ziegler (1987), ST improved acquisition of forehand and backhand ground strokes in beginning tennis players. The tennis players used four stimulus cues designed to appropriately focus their attention at various points in the task. The players were instructed to say "ball" when they saw the tennis ball projected from the machine, thus focusing their attention on the stimulus. To focus the players on the direction of the ball, Ziegler instructed them to say, "bounce" when the ball struck the court. Focus on contact was directed by verbalizing the word "hit" as soon as the players saw the ball hit their racquet. Finally, the players prepared for the next ball by saying "ready" and directing their attention to the ball machine (Ziegler, 1987).
The most striking finding in Ziegler's (1987) work was that the players improved very slowly using traditional instruction and practice methods, while they showed dramatic improvements in movement pattern and outcome scores as soon as the ST intervention was introduced. These findings suggest that the use of ST could have a profound impact on the skill acquisition process.
While Ziegler's (1987) research required both proper movement patterns and a positive outcome for trials to be considered successful, subsequent research has examined the effect of ST on movement patterns and performance outcomes independent of each other. In a study conducted by Perkos, Theodorakis, and Chroni (2002), novice basketball players were taught shooting, passing, and dribbling basketball skills with and without ST. The players who were taught with ST performed significantly better at the dribbling and passing skills. Recently Cutton and Landin (2007) examined the effect of using ST with and without knowledge of performance (KP) augmented feedback to teach the tennis forehand to novice players. While the performance outcomes did not differ significantly between groups, ST was shown to significantly improve movement patterns with and without KP in comparison to a group receiving KP alone. The results of these three studies indicate that ST can be useful to novices both in acquiring correct technique and in performing the newly learned skill effectively. Earlier work by Landin and Hebert (1999) also suggests that ST can be useful to experts in acquiring and perfecting advanced skills as well. Collegiate tennis players were taught to use ST to improve their volleying skill; differences in their movement patterns and performance outcomes were evaluated using a multiple-baseline design (Landin & Hebert, 1999). While their performance outcomes showed a small but significant improvement, their movement patterns displayed dramatic improvement over the course of 10 practice sessions.
The seemingly differential effect of ST on movement patterns and performance outcomes may be attributable to a variety of factors, one such factor being the type of ST used and the type of activity being performed (Theodorakis et al., 2000). In a set of four experiments, Theodorakis et al. (2000) examined the effect of instructional (pertaining to focus on stimuli or movement patterns) versus motivational (positive encouragement) ST over a variety of skills. While instructional ST was shown to improve performance on any skill that motivational ST improved, motivational ST was shown to improve performance only on a gross motor task rather than on complex motor skills. These findings were replicated by Hatzigeorgiadis, Theodorakis, and Zourbanos (2004) in water polo skills, with the exception that instructional ST was not found to improve performance on the gross motor skill as it was in the previous study. These somewhat equivocal findings point to another aspect of ST- aside from being instructional or motivational- that affects its impact on performance.
One study examined the perceived usefulness of instructional and motivational ST across a variety of basketball skills (Chroni, Perkos, & Theodorakis, 2007). Young players instructed to use various types of ST indicated a strong preference for motivational ST instead of instructional ST in most skills, a finding that flies in the face of research evaluating the actual efficacy of each form of ST (Chroni et al, 2007). Although perceptions often have a strong impact, other research has demonstrated that an athlete's belief in the efficacy of ST has no effect on their performance (Araki, Mintah, Mack, Huddleston, Larson, & Jacobs, 2006), which seems to reconcile the findings of Chroni et al (2007) with the rest of the ST literature.
If individual perceptions do not account for the discrepancy in the findings then what does? It is my assertion that differences in the direction that ST focuses attention may have a major effect on the efficacy of ST in various studies.
Studies by Wulf and colleagues (1999, 2000) have provided evidence that an external locus of attention is beneficial to learning and performing a skill. Novice golfers were taught to chip a golf ball with either externally directed instructions (focus on the weight of the club head), or internally directed instructions (focus on the swinging of the arms), and the results indicated that both learning and retention were much better with an external locus of attention (Wulf et al, 1999). Further work by Wulf et al (2000) narrowed down the most appropriate external focal point to the implement being used in the activity. Indeed, Wulf et al (2000) proceeded with a great deal of rigor in attempting to determine the most appropriate focal point. They first determined that external was favourable to internal, then they found evidence that the effect of the action is a better focal point than its antecedent, and finally they demonstrated that it is not merely because focusing on the effect of an action includes the goal of the action that makes it preferable (Wulf et al, 2000). Under the theoretical framework provided by Prinz (1997), the findings of Wulf et al (2000) can be easily understood. Prinz (1997) asserts that actions are planned based on their effect because coding for actions and coding for perceptions are one and the same. Therefore, rather than actions being coded according to particular bodily movements (which would be necessary if an internal locus of attention were to be optimal), actions are coded in accordance to our perceptions of the world in which those movements take place. Thus, externally directed attention provides for superior performance since it is more consistent with how the brain actually codes actions.
Although, theoretically, one should have an external locus of attention when performing physical actions, research has revealed some instances where other variables interact with locus of attention to provide confounding results. In studies of golf chipping (Perkins-Ceccato, Passmore, & Lee, 2003) and baseball hitting (Castaneda & Gray, 2007), skill level has been found to interact with direction of attention such that experts perform best with an external locus while novices perform better with internally focused attention. These findings do not contradict the earlier cited studies that used novice participants because these studies only evaluated a one-time performance, not a process of learning and skill acquisition. Apparently it is the case that the very limited time offered to learn new skills in most of the skill acquisition studies is sufficient to eliminate the interaction between skill and locus of attention; once participants have practiced with an external locus of attention for a short period of time it becomes beneficial, regardless of the participant's skill.
Given the potential effects of direction of attention on skill acquisition and performance, it seems prudent to review the specific cues used in the ST literature to determine if indeed direction of attention confounded the results. In Ziegler's (1987) classic study all ST cues were external and the results were positive for both movement and performance outcomes. The work of Cutton and Landin (2007) with novice tennis players was based on Ziegler's work, but it did not produce the same results. The key difference between the studies were the cues chosen by Cutton and Landin, which were, although similar to the cues employed by Ziegler, vastly different in terms of direction of attention. Right before the groundstroke, Cutton and Landin's (2007) players vocalized the word "turn" and focused on stepping and turning their shoulder correctly, and immediately following contact the players said the words "head down" and concentrated on keeping their eyes down on the contact point. Both of these cues served to direct the players' attention inward to their own movements, and in light of the research on direction of attention and performance, likely decreased the players' performance levels from what they could have been. Thus, perhaps the main reason Cutton and Landin (2007) found significant differences only in movement patterns and not in performance outcomes (as Ziegler did) was that the ST cues they employed served to direct players' attention inward.
Likewise, in Landin and Hebert's (1999) work with highly skilled tennis players, the ST cues were "split" and "turn," both internal, movement-focused cues. Although Landin and Hebert (1999) did find a significant improvement in performance outcomes, the improvement was very small- not nearly as dramatic as the improvement in movement pattern. The lack of improvement in performance one would normally associate with a dramatic improvement in movement pattern seems to be quite likely a function of internally directed attention caused by movement focused ST cues.
Ziegler's (1987) is not the only study to find improved performance outcomes with the use of ST; in fact all studies that I have reviewed that have used externally focused cues have produced the same results. For example, in Theodorakis et al's (2000) examination of motivational versus instructional ST across a variety of skills, performance outcomes were improved in soccer passing by using the cue "I see the target" and in badminton serving by using the cue "I see the net, I see the target;" both externally focused cues. In Hatzigeorgiadis et al's (2004) study on motivational versus instructional ST and water polo skills, performance outcomes were improved in a target hitting task with the external cues "ball, target." However, performance was not improved in a distance-throwing task when the internal cues "elbow, hand" were used.
Upon review of the ST literature, it seems clear that the direction of attention is a major factor in the efficacy of ST cues. In any case, ST appears to improve the acquisition of movement patterns, which should eventually lead to improved performance, and in the cases where cues are optimally chosen, ST appears to improve the acquisition of movement patterns and performance outcomes. However, to my knowledge, there has been no research comparing internally versus externally directed ST.
ST's utility in improving skill acquisition may indeed be dependent on the direction it focuses attention. Direction-of-attention may also be important in another potential use of ST- preventing "choking" under pressure.
Choking Under Pressure
The phenomenon of underperforming in situations that call for one's best effort is colloquially referred to as "choking" under pressure. Two complementary but separate mechanisms for choking have been posited by theorists: (a) explicit monitoring and (b) reinvestment of conscious control (Baumeister, 1984; Beilock & Carr, 2001; Masters, 1992).