Mental Imagery And Its Effects On Performance In Tennis
Introduction
It should come as no surprise that physical training can greatly improve a person’s performance in sports. Attributes such as strength and stamina are essential in sports as they tend to be physically demanding. However, what people may not know is that besides physical properties, the cognitive aspect also offers interesting gateways into techniques that can benefit sports performance. Ever since the decline of behaviourism as the primary school of thought in psychology, psychologists have started to accept and consider these kinds of theories involving intangible constructs such as predictions and habits. As a result, many cognitive theories have emerged over the years. One of these for instance, is the effects of mental imagery on performance in sports.
In order to explain this phenomenon and the effectiveness of this technique, the term mental imagery must first be defined in order to establish a difference between mental imagery and physical training. Then, previous research addressing the effects of mental imagery on physical performance will be explored to showcase the usefulness of mental imagery. Next, the relationship between tennis and mental imagery will be presented to demonstrate how the latter can be applied to a specific sport. Finally, the cognitive and biological theories behind mental imagery will be discussed in order to explain how it functions.
Mental Imagery
Before defining mental imagery, it is important to first define the term cognition. Cognition is
defined as “the mental processes involved in the acquisition of knowledge”. It can thus be concluded that the terms “mental” and “cognitive” are synonymous in meaning. It is important to avoid any confusion as these two terms will be used interchangeably in the essay.
The standard definition of mental imagery is “the cognitive rehearsal or mental processing of a physical activity in the absence of any gross physical movements”. Other terms that share the same meaning include imagery practice, symbolic rehearsal, covert rehearsal, and introspective rehearsal. While it was originally believed that mental imagery could have different traits from sensory or perceptual stimulus, it is now accepted that they can appear indistinguishable from their genuine sensory counterparts.
Imagery and Performance
The earliest theory of mental imagery can be found in Washburn (1916). She proposed that when people imagine themselves to be in an activity, their muscles would be stimulated. Moreover, she suggested that the muscular movements produced through mental imagery were identical to the muscular movements produced through the physical activity, albeit at a much smaller magnitude. This however, was just a theory, and it wouldn’t be until Jacobson (1932) for empirical evidence to appear. Through the use of electromyography, Jacobson was able to prove that actual muscular movements occurred in the muscles that were involved in mental imagery. Thus, Jacobson’s study proves that mental imagery can affect physical performance, although it does not show any signs of improving it.
Sackett (1934) was the first to show evidence of mental imagery improving physical performance. By using a maze retention task, Sackett found that although physical practice was superior to mental practice, mental practice was still effective in improving performance. Similarly, Vandall, Davis and Clugston (1943) investigated the role of mental imagery in dart throwing by comparing the accuracy of the throw. They concluded that mental imagery improves performance almost as much as physical practice, which was different from Sackett’s conclusion. Later, Richardson (1967) conducted the first extensive review examining the effects of mental practice on physical performance. He concluded that, overall, mental imagery was effective in improving performance: “the trend of most studies indicate that mental practice procedures are associated with improved performance on a task” (Richardson 1967). In 1972, Corbin also investigated mental imagery and reached the more general conclusion that mental practice was better than no practice at all. In 1982, the statistics showed that the majority of studies in the past have come to the conclusion that mental practice was an effective means of increasing performance. 30 studies showed that mental imagery improves physical performance, and 4 studies showed no improvement (Martens 1982). Even in recent years, studies like Murphy and Martin (2002), Molinaro (2005) and Weinberg (2008) still reach the same conclusions in which mental imagery is beneficial to physical performance.
To conclude, there is a wide variety of studies and empirical evidence that suggests that the practice of mental imagery can positively affect physical performance. This includes the physical performance in sports, ranging from football (Golby, Sheard and Lavallee 2005), diving (Grouios 1992), rugby (McKenzie 1989), and golf (Molinaro 2005). However, due to this essay focusing on tennis instead of sports in general, the following section will be specifically about the relationship between the use of mental imagery on the performance of tennis players.
Imagery Training in Tennis
To understand the relationship between mental imagery and tennis, tennis itself as a sport must first be broken down and analysed. Firstly, tennis is a very fast-paced sport revolving around a combination of precision, reflexes, hand-eye coordination, agility, technique, and judgement. A lack of any of these alone can determine your potential worth as a tennis player. Tennis is so precise in fact, it was stated by Weinberg that in an average tennis match, players have to make approximately one thousand decisions, each of which have to be made in fractions of a second. This would mean that a professional tennis player would not only need to react to the situation at hand, but come up with the appropriate countermeasures and successfully enact them all in a matter of milliseconds. From a psychological perspective, this shows how tennis players need to maximise their cognitive ability in order to succeed in the industry.
Secondly, tennis players need a biomechanical understanding of how the tennis racket hits the ball in order to achieve the intended trajectory. In other words, the point of contact between the tennis racket and the ball requires a sophisticated level of precision, which can only be achieved with dedicated practice in order to form the necessary muscle memory. This is important, as even the tiniest difference in an angle of trajectory can make the difference between a winner (the term for a winning shot in tennis) or a bad shot. This is similar to procedural memory in psychology, and mental imagery may be helpful in improving it.
Lastly, tennis is different from other sports such as basketball and football, in the sense that there are many more intervals of rest between points. In between every point, the server can rest for a maximum of twenty seconds to think of strategies before serving again. Moreover, after every other game in a set, the players are allowed to switch sides of the court and can rest for a maximum of ninety seconds. These intervals may of course have either positive or negative consequences. For example, for an amateur player, distractions or irrelevant thoughts may enter their mind, and hinder their performance. On the other hand, a professional can use this time to form strategies, or refresh their mindset in order to optimize the chances for success. To sum up, depending on how players use these intermissions, it can either positively or negatively affect performance.
In conclusion, due to the very nature of tennis revolving around different psychological aspects, it shows how players have a vulnerability to mental influence. As a result, in order to maximise their performance in the sport, not only do they need to optimize their physical ability, tennis players must also maximise their cognitive ability, which can be done with the help of mental imagery. It is also important to note that tennis is an extremely profiting and popular sport worldwide, which makes it not only one of the most fashionable sports to play, but for research as well.
Due to the relationship between mental imagery and tennis, there have been many pieces of literature dedicated to the various cognitive strategies a tennis player can employ. This literature all share the same consensus that mental ability plays a significant role in the game of tennis. For example, tennis coaching books such as Smart Tennis: How to play and win the mental game (Murray 1999), Serve to Win (Novak Djokovic 2013), and A Champion's Mind: Lessons from a Life in Tennis (Pete Sampras 2008) all emphasize how cognitive ability and mental imagery play a crucial part in the nurturing of tennis skills. Even professional tennis players themselves admit that mental fortitude grants an edge in the sport. Players like Jimmy Conners stated that tennis was 95% mental at the professional level, and Chris Evert stated how mental strategies played a vital role in her winning 21 Grand Slam titles. Researchers Defrancesco and Burke studied the strategies used by a large sample of professional tennis players. Their results showed that higher ranked players attributed more of their good performance to psychological variables than lower ranked players did. For example, 93.8% of the highest ranked players employed the mental strategy of imagery, 100% employed mental preparation, and 93.8% employed relaxation. On the contrary, the lowest ranked players had 85.4%, 95.1% and 82.9% respectively. From this, we can see that even professional tennis players highly value cognitive and mental preparedness.
Besides professional players, studies have shown that mental imagery can boost the performance of junior players too. Atienza, Balaguer and Garcia-Merita gathered a sample of junior tennis players and split them into three groups. These groups were: physical practice only, physical practice plus video modelling, and physical practice, video modelling and imagery training. Results indicated that the physical practice only group did not show any signs of improvement, while the other groups showed significant improvements on tennis performance, with the group having imagery training improving the most. From the results of this study, it can be deduced that the usage of mental imagery is more effective than just physical ability.
As we can see, the relationship between tennis and mental imagery is astounding, due to the very nature of the sport. Also, the majority of tennis players, ranging from professional to amateur, also agree that mental imagery training improves their tennis performance. Furthermore, numerous studies have been conducted that show this trend as well. However despite the empirical and anecdotal support from these studies, there is still much to be researched regarding how mental imagery operates and what alters its effectiveness. As such, the following section will be dedicated to examining the theories behind mental imagery and to examine variables that determine the effectiveness of mental imagery training.
Theories of Mental Imagery
In this section, the four major theories regarding how mental imagery affects performance will be addressed. These theories are the symbolic learning theory, psycho-neuromuscular theory, bio-informational theory and arousal set theory.
Symbolic Learning Theory
The symbolic learning theory suggests that actions are symbolically coded into the central nervous system. This means that according to the theory, the brain takes information and transforms it into an abstract form rather than a mental picture or verbal representation. This is also known as the concept of propositional networks. Due to these propositional networks, information is turned into mental blueprints of the required motor task. The effectiveness of these blueprints is enhanced the more automated the recall of it is. If the symbolic learning theory is true, then the practice of mental imagery would have more effect on cognitive tasks than motor tasks, and a few studies show this. For instance, Hird, Landers, Thomas and Horan conducted a study in which two tasks were performed, one cognitive and one motor. Participants performed both tasks twice, once without mental imagery and once with mental imagery, and improvements were measured. The results showed greater improvement on the cognitive task than the motor task, offering evidence leaning towards symbolic learning theory.
However, the symbolic learning theory fails to explain a handful of queries. While it
is able to show how early skill acquisition is enhanced by the coding of information
through imagery, symbolic learning theory does not explain how performance is
enhanced in people who already have the information well established in their brain. In the case of tennis, it does not explain how experienced tennis players are able to improve performance through mental imagery. Furthermore, while the study above delivers a distinction between cognitive and motor tasks, Janssen and Sheikh also state that nothing is purely cognitive or motor, and all actions share traits of both cognitive and motor tasks.
Psycho-neuromuscular Theory
The psycho-neuromuscular theory is based on Carpenter's (1894) ideomotor principle.
Carpenter suggested that neuromuscular movements of a small magnitude are produced during imagined movement, and that these neuromuscular movements are identical to
those of the actual movement, but just to a lesser degree in magnitude. As previously reviewed, Jacobson's results provided the first firm support for the presence of this effect. Since then, other studies conducted by Suinn and Bird both have results that support this. Suinn made use of electromyography by attaching an EMG to the legs of a skier and recorded the neuromuscular movements when he was skiing down a hill. He then asked the skier to only imagine performing the act and recorded his neuromuscular movements again. The results showed that the muscle movements from both cases were almost identical, although the muscle movements from imagining the task were obviously much smaller in magnitude. Bird conducted a similar study using athletes practicing different sports including basketball, riding, swimming, rowing and water skiing. She also found that the neuromuscular movements recorded during mental imagery were very similar to that obtained during the actual activity.
However, the psycho-neuromuscular theory has its flaws. Psychologists Hecker and Kraczor claim that the psycho-neuromuscular theory only proves that mental imagery affects our neuromuscular movements, and doesn’t explain why it can enhance performance. Moreover, there has yet to be evidence pointing towards mental imagery producing localised neuromuscular activity. All in all, further support for localization of neuromuscular activity is needed for the psycho-neuromuscular theory to continue to develop.
Bio-Informational Theory
Another possible explanation for mental imagery affecting performance is the bio-informational theory. This theory states that each mental image is formed by a set of
organised propositions, which are neural representations of the stimuli and responses associated with an action, and are stored in the long-term memory. These propositions are split into stimulus propositions and response propositions. Stimulus propositions transmit information about the imagined environment, while response propositions transmit information regarding the behavioural activity. For example, imagining a tennis match would involve the stimulus propositions of the feel of holding a tennis racket, the sight of the ball, the net and the opponent. The response propositions for this image might include muscular tension in the racket arm, increased perspiration and anxiety. According to bio-informational theory, for mental imagery to improve performance, response propositions must be activated repeatedly so that they can be modified, improved and strengthened. This is because emotional and physiological responses are prominent in response propositions. If the athlete is able to modify these responses to any given situation, the athlete enhances their control over the game and gains the advantage, hence improving their performance.
The bio-informational theory is bolstered by the finding that experienced athletes benefit more from imagery than amateur athletes. This is because experienced athletes tend to have well-established stimulus and response propositions of muscle movement in their brain. An amateur athlete is more likely to have worse stimulus and response propositions, allowing detrimental response propositions to be processed and rehearsed in mental imagery, which of course would have the effect of decreasing sports performance.
An important implication drawn from the bio-informational theory is that mental imagery training should be as realistic to the actual real life situation as possible. For example, images should contain not only the conditions of the situation, but also the athlete's behavioural, psychological and physiological responses to the situation. By including these responses the image will be more vivid and should thus result in improved performance.
