August 13, 2013
The Neuroanatomy of Hitting
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Stuart Wallace is a contributor at Beyond the Box Score and Camden Depot. A former pitcher turned neuroscientist, he currently lives in Baltimore, Maryland. You can follow him on Twitter at @TClippardsSpecs.
It's been said that the toughest task to accomplish in sports is hitting a baseball. When you consider that your average MLB fastball (roughly 90 miles per hour) goes from the pitcher's hand to the point of contact just in front of home plate in roughly 400 milliseconds, the abilities and performances of the game's best hitters are awe-inspiring. With the vast majority of baseball analysis and discussion being dedicated to what transpires after those 400 milliseconds, let's switch gears a bit and focus on that half second (or so) before the outcome of a pitch thrown is known. What is done in this time from a neurological perspective that determines the end result of a swing? What transpires that gives hitting a baseball the reputation it has as one of the most mentally taxing tasks to perform in sports?
With the help of the research of neurophysiologist Benjamin Libet, we have a good idea of how those 400 or so milliseconds break down. Libet, whose research interests were in the field of conscious awareness, conducted a number of experiments throughout the 1970s and 1980s looking at the relationship between neuronal activity and conscious intention to carry out an act. He found that it takes the brain 350 milliseconds to shift from unconscious activities to engaging the conscious mind, thus making the person aware that an action is being taken. Applying this fact to baseball and doing some quick math, we find that a hitter has 50 milliseconds to react and decide to swing or not swing once his conscious mind is fully aware of the situation, with the ball having already left the pitcher's hand.
To put it in a different perspective, a hitter's conscious mind kicks in when the ball is roughly seven feet away from the plate, again considering the average MLB fastball is 90 or so miles per hour. It takes a batter roughly 270 milliseconds to identify and track the pitch, decide whether he will swing at said pitch, and then start his swing into the hitting zone. With this additional piece of information, we find ourselves with a disparity in timing of 220 milliseconds with respect to conscious awareness and control of hitting; we come to the reality that much of what a hitter does to prepare and execute a swing is controlled by the unconscious (frequently called “subconscious”) mind.
The Libet experiments and the resulting knowledge of the timing disparity between neurological functions and the action of hitting all bring to light the fact that many processes arising from the unconscious mind are the ones responsible for hitting, with further inputs coming from higher cortical functions—the conscious mind—as the event progresses, in the waning milliseconds before contact is (or isn't) made. Libet came to these conclusions with some very basic (at least now) tools of the neuroscience trade: electromyography (EMG) and electroencephalography (EEG).
EMG records and evaluates the electrical activity produced by muscles in response to a neural input, while EEG records and evaluates the electrical activity of the neurons of the brain. While these tools still provide crucial information about the structure and processes of the nervous system, they have been replaced, or at least bolstered, by more technologically advanced equipment and techniques, in particular, magnetic resonance imaging (MRI) and functional MRI.
Briefly, MRI uses radio waves and a powerful magnetic field to create highly detailed images of the body, while fMRI is a special form of MRI that detects changes in blood flow, with the assumption made that blood flow changes correlate with changes in neuronal activity. With an increase in blood flow to a certain part of the brain, an associated increase in neuronal activation for that part of the brain is assumed. The technology has created a boom in neuroscience research, in particular with the investigation of neural networks and the neural correlates of a number of processes, both in disease and in health.
Much of successfully hitting a baseball depends on a harmonious and exacting relationship between the mental and physical aspects of a player's performance; at the root of this is the ability for a hitter to correctly identify and classify pitches. With the help of the latest technology and the lessons of Libet fresh in our minds, we can now delve deeper and begin to find the areas of the brain and the relationships between the unconscious and conscious that allow for the successful recognition of a pitch and the ensuing execution of a swing.
One group of researchers at Columbia University are paving the way toward a better knowledge and understanding of the brain anatomy responsible for pitch recognition and classification and has performed research using fMRI to measure these neural correlates and networks. Let's get a closer look into the hitter's mind with the help of these studies and discuss which parts of the brain are at work when a hitter is up to bat.
We’ll start with the areas that have functions associated with the unconscious mind, which Libet has taught us plays a large role in the ultimate success of a hitter. Composed of a number of structures that lie under the cortex of the brain and function collectively to automate voluntary functions, the basal ganglia is an integral part of the unconscious.
The basal ganglia, including the globus pallidus and putamen. (Courtesy of brainmind.com.)
The structures of the basal ganglia shown to have implications in pitch recognition and classification are the globus pallidus (GP) and the putamen. The GP assists in the regulation of voluntary movement on a subconscious level, as previously mentioned, and it does so by working in concert with the cerebellum, allowing smooth, controlled movements to occur. The cerebellum is responsible for the completion of fine motor movements. The effect of the GP on hitting remains even when the conscious mind is activated and begins to take over—even with conscious processes engaged, the GP helps to regulate voluntary movements and does so by making them as smooth and appropriate as possible. Another function of the GP that shines through during the hitting process is its regulation of subtle movements which allow multiple tasks to be performed smoothly at the same time; in essence, the proverbial ability to both walk and chew gum is highly regulated by the GP.
From the GP, we go to the putamen. Also part of the basal ganglia, the putamen is connected to the GP through a variety of pathways that are beyond the scope of this piece; however, it too is a critical piece of anatomy with respect to subconscious movement regulation. In many respects, the putamen functions as sort of a catch-all; while it does appear to be dedicated to one specific function, it supplies input to a number of processes. However, its influence is particularly seen in specific types of learning, including reinforcement and category (also called “concept”) learning. In reinforcement, the putamen oversees actions in response to particular environmental cues and responses. With regard to concept learning, the putamen provides neural architecture that facilitates the comparing and contrasting of groups or categories in the environment in an effort to group them into a relevant and binding category or to dismiss them if they do not share a common thread.
From these subcortical structures, let's move up the ladder, so to speak, and into the cortical structures and the beginnings of the conscious aspects of hitting. An important aspect of hitting is vision—to hit the ball, you have to see it—so it shouldn't be a huge surprise that the largest portions of the cortex implicated in pitch recognition are those related to vision. The actual cortical structures responsible for vision are located toward the back of your head, in the occipital lobe. Here there are a vast number of anatomical structures and neuronal connections devoted to allowing a person to see the world around them.
The structures that appeared to be the most active in fMRI studies of baseball players are also numerous, but can be broken down and categorized with the help of yet another trailblazing neuroscientist, Korbinian Brodmann. Brodmann's contributions to neuroscience came years before Libet's and are still in use. Brodmann was particularly interested in cytoarchitectonics, the process of mapping the brain's different types of microstructures to different functions. His many years of studying the brain live on in the form of Brodmann areas (BA), which are 52 brain regions organized by their cellular structure and organization. Through these cytoarchitectonic similarities comes a similarity in function; while there still lies a vast amount of variability in the structure and function of certain brain areas, between these Brodmann areas and actual mapping of functions through fMRI studies, we do have a reasonable understanding and grouping of these structures into cohesive functional units.
The 52 Brodmann areas of the brain. (Coutesy of brodmannarea.info.)
Which Brodmann areas and their underlying cortical structures contribute to pitch recognition and classification?
Let's start with the occipital areas of the cortex—BA18 and BA19. The largest region of the occipital cortex by volume, BA18, is comprised of structures including the cuneus, the lateral occipital gyrus, and the lingual gyrus. Functionally, it is responsible for image interpretation, but it also plays an important role in other functions. It receives and organizes information related to light intensity, object motion, and underlying order within visual patterns, while also assisting in the processing of visuospatial and visuoemotional information.
BA19 has many similar functions, including pattern recognition, motion detection and interpretation, and receiving light intensity information. However, its functions diverge a bit from BA18’s with its ability to organize visual memories and monitor and extract features of changes in shape and color, while also participating in the organization of spatial memories and inferential memories. Anatomically, BA19 comprises some of the same structures as BA18, including the cuneus, the lateral occipital gyrus, the lingual gyrus, and the superior occipital gyrus. Due to their shared anatomy and cytoarchitectonic composition, BA18 and 19 have also been collectively labeled the extrastriate cortex.
From the visual cortex, information leading to a successful at-bat moves forward to the frontal lobes of the brain and Brodmann area 10 (BA10). The largest piece of Brodmann cytoarchitectonic real estate, but also the least understood, BA10 is made up of the superior frontal gyrus and middle frontal gyrus. This area of the forebrain performs strategic processes of memory retrieval and executive function. It is postulated that the neural elements of BA10 enable a person to multitask by allowing a task to be maintained in a pending state for subsequent retrieval and execution upon completion of the ongoing one. This part of the brain is what allows one to have many proverbial plates spinning, allowing the bandwidth to add additional plates without a loss of the others.
While the technology discussed in this article has been available for many years, it has not been heavily applied toward sport or baseball-specific functions as an aid in player evaluation, or as a training tool in order to improve a player's performance. With teams already utilizing biometric and biomechanical data to evaluate and monitor player performance and health, it wouldn't be too far-fetched to say that the development, calibration, and implementation of a neural profile that would help in the measurement and projection of a player's performance is on the horizon, and could possibly form part of the foundation of the new wave of tools used to evaluate and enhance player performance.