Monday, June 24, 2013
Researchers have studied the brain for years to find the exact role of the brain in cognitive functions. Phineas P Gage, a railway construction worker received a traumatic brain injury, which provides insight into exactly how a traumatic brain injury (TBI) affects cognitive functions. Phineas Gage’s accident uncovered important information about how the brain areas support cognitive function and what happens when a traumatic brain injury (TBI) occurs.
The Role of the Brain in Cognitive Functions
Several structures compose the brain, which play a key role in several cognitive functions. Four structures or lobes that divide the cerebral cortex and play a role in cognitive functions are the frontal lobe, the parietal lobe, the temporal lobe, and the occipital lobe. The frontal lobe’s functions include decision-making, problem solving, and planning. The parietal lobe functions as a processor of the body’s sensory information and controls the ability for understand language (Bailey, 2013). The temporal lobe’s functions include speech, memory, emotional response, and auditory perception. The occipital lobe’s functions include visual perception and color recognition. Other structures of the brain that play a key role in cognitive functions include the subcortical (located beneath the cortex) structures, which include the thalamus, amygdala, caudate, putamen, hippocampus, and cerebellum.
The thalamus functions as a relay station for motor and sensory information, which includes visual, somatosensory, and auditory sensory signals. The amygdala functions as a processor of emotion (strikingly the emotion of fear) and information regarding social functions (Willingham, 2007). The caudate and putamen are separate but related structures important in movement and some barely understood cognitive functions (Willingham, 2007). The hippocampus plays a crucial role in memory. The cerebellum plays a role crucial in motor control and likely in certain higher level cognitive functions, although the exact role is still unknown. Another structure is the spinal cord; along with the brain they compose the central nervous system. The central nervous system collects somatosensory information about matters, such as temperature, pressure, and pain, and sends motor information to the body’s muscles (Willingham, 2007).
Phineas Gage’s Accident
Phineas Gage’s accident is an account of an incident involving Phineas P Gage, born July 9, 1823, in Lebanon, New Hampshire (Grieve, 2010). In 1848 on September 13, Gage a railway construction workman suffered a traumatic penetrating head injury. Gage was working outside Cavendish, Vermont, at the Rutland and Burlington Railroad project, when a tamping iron measuring three feet-seven inches long was accidentally fired through his skull (Grieve, 2010). Reports initially suggested that damage occurred to both of Gage’s lobes in the accident; however, by using modern computerized tomography (CT) scanning on Gage’s skull, there was evidence showing that there was mainly left frontal lobe damage that occurred when the tamping iron passed through his skull. Although a traumatic accident, Gage physically made a good recovery and lived 12 years after the accident but died in San Francisco on May 21, 1860, from epilepsy complications (Grieve, 2010).
What Was Revealed About How Brain Areas Support Cognitive Function
The cognitive abilities of an individual predict functional outcomes after a traumatic brain injury (TBI) (Spitz, Ponsford, Rudzki, & Maller, 2012). Although what is unknown is to what extent concurrent cognitive abilities affect the rate or magnitude of functional recovery (Spitz, Ponsford, Rudzki, & Maller, 2012). A traumatic brain injury (TBI) can precipitate numerous changes to an individual’s emotional, social, and behavioral functioning. Individuals also commonly experience problems with executive functions, information-processing speed, and memory. Before his accident, Gage was a hard worker and responsible individual however after his accident he became irreverent, fitful, impatient of advice or restraint when conflicts occurred with his desires, at times he was pertinaciously obstinate, but vacillating, and capricious (Spitz, Ponsford, Rudzki, & Maller, 2012).
The specific changes that Gage went through pointed to emerging theories concerning localization of brain function, or an idea that specific functions are associated with certain areas of the brain (Cherry, 2013). However, today there is a better understand of the role of the frontal cortex and how it plays a key role in higher order functions, which include social cognition, language, and reasoning.
The role of the brain plays a key role in brain cognitive functions. Phineas Gage, a railroad worker remembered for surviving an accident involving a tamping iron rod passing completely through his skull, which mainly damaged his left frontal lobe. Phineas Gage’s accident enabled neurologists to retrace the emotional and cognition findings of what goes on in an individual’s brain when injuries occur to the frontal lobe areas. Through studying Phineas Gage’s accident relevant information revealed how brain areas support cognitive functioning.
Grieve, A. W. (2010). Phineas P gage - 'the man with the iron bar'. Trauma, 12(3), 171-174. doi:http://dx.doi.org/10.1177/1460408610375648
Willingham, D. T. (2007). Cognition: The thinking animal (3rd ed.). Upper Saddle River, NJ: Pearson/Prentice Hall.
Bailey, R. (2013). About.com: Biology. Retrieved from http://biology.about.com/od/humananatomybiology/a/anatomybrain.htm
Spitz, G., Ponsford, J. L., Rudzki, D., & Maller, J. J. (2012). Association between cognitive performance and functional outcome following traumatic brain injury: A longitudinal multilevel examination. Neuropsychology, 26(5), 604-612. doi:http://dx.doi.org/10.1037/a0029239Cherry, K. (2013). About.com: Psychology. Retrieved from http://psychology.about.com/od/historyofpsychology/a/phineas-gage.htm