Stephen F. Austin State University
Over the past decade different approaches have been developed for noninvasively studying brain activity. For example, positron emission tomography (PET), single photon emission computer tomography (SPECT), and magnetic resonance imaging (MRI) have been more frequently used in research. PET, SPECT, and MRI brain scans were not able to give researchers many of the advantages that a functional MRI (fMRI) can provide (Moonen, 1995). The advantages of the functional MRI include little discomfort, no radiation, clearer spatial and temporal images, and the ability of the examiner to observe detailed anatomical data about the brain (Moonen, 1995). Therefore, the fMRI can allow researchers to examine the activity of a human brain with more detail and precision than ever before.
fMRI allows researchers to examine the pathways and neural connections in the brain. Within the visual system of the brain, there are two distinct pathways that help humans process information. These are the "what" (ventral) and "where" (dorsal) pathways. Both of these pathways are important in the processing of object identification as well as where in the visual space the object is located. These pathways use cues such as depth, texture, and space (Kraunt, Hart, Soher, & Gordon, 1997). Previous fMRI studies have found that as a stimulus becomes more familiar to the participant, there is an enhancement of neural responses in the prefrontal cortex. Their study demonstrated that the object was identified and maintained in the working memory of the participant. Simultaneously to identification, there is a reduction of neural response in the parietal and ventral temporal cortices when the object is repeated (Jiang, Haxby, Martin, Ungerleider, & Parasuraman, 2000). Object identification is one of the first steps in processing a moving object.
Other studies have identified additional ways to process moving objects in the visual field. According to Schubotz and Cramon (2001), when a person is confronted with a moving object, information must be processed in three ways. First is object information; the object must be perceived as a whole unit. Second is spatial information; the direction and distance must be referenced relative to the body and head. Third is timing information; the observer must precisely determine the speed of the object to adapt the observerís own movement. As shown during fMRIs, object information produces a response in the ventrolateral premotor cortex (vPMC) (Schubotz & Cramon, 2001). Spatial information is processed in the dorsolateral premotor region. Finally, the processing of the timing information takes place in the frontal opercular cortex (Schubotz & Cramon, 2001).
Once a particular object is identified, the person can attend to a greater amount of detail on the object. For example, when a person is asked to attend to a specific property of an object, such as motion, top-down processing occurs. Top-down processing can cause an enhanced neural response to other properties of the same object such as depth (OíCraven, Downing, and Kanwisher, 1999). When attention is paid to a particular moving object, an increase in neural response is noticed in V1 and the MT area of the brain (Watanabe, et al., 1998). While attending to the movement of an object, the brain must also track motion. The visual system can track important targets in the following ways. Eye movements can continually track a specific target, or the eye movements can focus on the target by saccades, or slight jumps to different targets (Culham, et al., 1998).
Previous research has found that there is an increase in neural activity in the right hemisphere of the brain when a participant is attempting to process the motion of an object (Dieterich, Bucher, Seelos, & Brandt, 1998). According to Perry and Zeki (2000), when processing spatial attention in the visual system, the work is distributed unequally across the two hemispheres. They found that if a person has a lesion in the left hemisphere of the brain, the participant fails to explore the left side of their environment. In one study participants were given tasks to perform which examined the part of the brain that processes information each hand performs. For the left-handed tasks, there was an increase in activity in the right primary motor cortex and the left cerebellar hemisphere. Right-handed tasks produced an increase in activity in the left primary motor cortex and the right cerebellar hemisphere (Fink, et al., 2000). This research suggests that if an athlete is right or left handed, a ball coming toward them, which they must hit with a bat, racket, or foot, will be processed in different areas of the brain, according to their dominant hand.
Along with processing the movement of the ball in space, the brain must also process the bodyís reaction to the ball coming toward them. Downing, Jiang, Shuman and Kanwisher (2001), have located an area in the brain they have labeled the extrastriate body area, or the EBA. This area, which is located in the lateral occipitotemporal cortex, is believed to process the appearance of the human body, including the position of oneís own body. This could be particularly useful in team sports where a player must be aware of the position of their body in order to connect with a ball.
Over the last few years, there has been a lot of research examining the brain using fMRIs. However, there has been no research studying the processing of information of an athleteís processing of a ball that is used in his/her sport, or other balls they are less familiar with, as well as speed and accuracy. Furthermore, no research has been done to examine the different ways athletes process this information relative to non-athletes or athletes from different sports, viewing sport appropriate and nonappropriate ball. The purpose of the present research is to examine if an athlete processes a ballís motion in the same areas of the brain that a non-athlete would use to process the same ball, also, if an athlete is as accurate in determining when the ball would strike them at varying speeds as a non-athlete. It was hypothesized that athletes will use the parietal cortex of the brain to process the motion of their sports ball, but their processing will be different from non-athletes processing of the same sports balls. It was also hypothesized that an athlete will be more accurate in determining when their respective ball would hit them than non-athletes or other athletes of different sports.
Participants
Participants will consist of 60 college students ranging in age from 18 to 24. There will be 30 athletes, (10 soccer players, 10 tennis players, and 10 baseball players), as well as 30 non-athletes. All athletic participants will be recruited from sign up sheets in the designated sports locker rooms, which will ask for athletes of certain sports; all athletes play their respective sport at Stephen F. Austin State University. Non-athlete participants will be recruited from sign up sheets located in the psychology department at Stephen F. Austin State University. Based on the ethnic composition of Stephen F. Austin Sate University, the ethnic majority will be Caucasian followed by African American along with a small sample of other ethnicityies. Participants will not be compensated in any way; their participation will be completely voluntary.
Materials
A functional magnetic resonance imaging (fMRI) machine will be utilized in this experiment. The stimuli used in this experiment will be three computer-generated 3-D pictures of sports balls, (tennis ball, soccer ball, and a baseball), shown at varying speeds, and in the appropriate context. A questionnaire will be used to obtain participantsí age, ethnicity, and gender as well as what sports they play or do not play.
Procedures
Before beginning participants will read an informed consent form. The participants will participate in the study one at a time. They will then be given a questionnaire to obtain demographics information and the sport they play or a confirmation that the participant does not play a sport. Participants will then be scanned using the fMRI and given a response button to push when they think the ball will hit them. The participants will then be shown a movie of the three sports balls (soccer, tennis, and baseball). The ball will appear to start 100 feet away from them and come closer. Each participant will receive 10 computer-generated random trials, the order and speed of the balls will be varied.
Design
This study utilized a 4 (tennis player, soccer player, baseball player, non-athlete) X 3 (the type of sports ball) X 2 (speed of ball) mixed subjects design. The dependent variables were as follows: location of neural activation and strength of neural activation, and accuracy of estimated contact time.
The analysis, to be performed, would be an examination of the pictures of the brain produced by the fMRI. Also, a mixed ANOVA would be performed to determine the effect on accuracy. The athletes in each sport will perform better on accuracy no matter what the speed is in comparision to non-athletes or the athletes of different sports. This study will not have a main effect between the athlete and type of ball, all athletes scored higher on accuracy then non-athletes and athletes of different sports. There will be a main effect between the non-athletes and the sports. The non-athletes performed worse in all sports than did athletes, even if the sport was not theirs. The results of this study should be in support of the hypothesis. All of the athletes process their respective sports ball in the parietal cortex of the brain and non-athletes processed all balls differently. The non-athletes process the balls in the posterier region of the brain. This is believed to be what would happen based on previous research. Jiang et al. (2000), found that there are two areas in the brain that contribute to the processing of familiar stimuli. One area signals the object to be identified and the other signals whether the stimulus has (or has not) previously been seen. Therefore, when the participant is shown the sport ball that is not their sport, or the non-athlete is shown any of the balls, the brain is signaled that the previous stimuli were not necessary to process. Then, when the participant is shown their respective sports ball, the brain observes it as highly familiar and processes it differently than an unfamiliar object. The processing of highly familiar objects occurs in the frontal cortex (Jiang, et al., 2000). The non-athlete or the athlete who was attempting to process the non-familiar ball will show an increase in neural activity in the parietal cortex of the brain (Jiang, et al., 2000).
Also, it is believed that the speed of the ball and the accuracy to hit the ball would be processed differently when the participant was attempting to judge their sports ball. The non-athletes and the atheletes when judging balls of other sports would have poorer judgment of the speed and accuracy of when the ball would strike them. The ability to track the ball is due to the amount of attention the participant paid to the ball, as well as top-down processing due to experience. These results are based on the research done by Culham et al. (1998). They found that when an object was attended to the participant showed an increase in neural activity in the parietal cortex. Furthermore, Culham et al. (1998), determined that most of the activity in the parietal cortex happened on an arc, which ran within the parietoccipital junction to the PostCS.
The results of this study indicate that athletes and non-athletes do process information about a familiar object differently. The fMRI has shown that athletes process information about familiar objects such as their sports ball in the parietal cortex, which also suggests that the processing which occurs in the parietal cortex is involved in high-level processes. The results of this study would further support the evidence that the dorsal and ventral pathways play an important role in identifying and processing familiar and non-familiar objects (Kraunt, et al., 1997).
Further research could be done in several areas. For example, more athletes involved in different sports may yield different results. Sports such as pool or hockey may use different areas of the brain since these sports utilize different skills. Another area of research could examine if the level of ability affects the area of the brain. Other experimenters could also examine if the athlete needs to pay more attention to the object if the athlete does not play the sport frequently. A third area of research may examine the processing of the ball in the participantís periphery of vision. Some athletes do not need to pay attention to the object to strike the ball, and only glance at the ball in their peripheral vision, for example soccer players.
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