Brain Imaging Techniques or Technocolor Phrenologyby Vini Samy | April 1, 2006
Brain imaging techniques are increasingly being utilized to investigate cognition. This branch of research is referred to as cognitive neuroscience. Some have suggested that these techniques run the danger of simply emerging as “techno-color phrenology”, where no insights are actually gained about the cognitive processes themselves. It is dubious whether these techniques have contributed to our understanding of the cognitive process under investigation beyond simply locating brain areas.
Cognitive Psychology is a relatively new, nevertheless one of the most well-known and applied branches in psychology. It examines the internal mental state of the person in order to understand the external behavioral condition. Cognition, the mental processes of an individual, are central to this field of psychology. It values the existence of beliefs, desires and motivations and the meaning they hold. These mental states arise and form due to the incoming sensory information, which are then integrated and processed in various ways. The processing of this information is believed to provide an insight to the comprehension of human thinking. There are many domains within cognitive psychology which deals with memory, perception, thinking, problem solving, language and decision-making. Unlike other areas of psychology, Cognitive psychology does not reject scientific investigations as a convincing way of learning. Therefore there exists an aspect of psychology which is widely associated with both cognitive psychology and neuroscience and is known as cognitive neuroscience.
The brain functions underlying mental activity can be mapped out. Brain imaging techniques, such as Functional Magnetic Resonance Imaging (fMRI), Positron emission tomography (PET) and electroencephalogram (EEG) are ways of investigating these cognitive processes. Monitoring brain activity during behavioral or cognitive operations helps localize the regions of the brain involved in that specific task. That is, it provides a brain-behavior relationship. Another advantage of these brain imaging techniques are that it allows us to observe the changes in brain activation according to the activity performed in a living, conscious individual.
fMRI explains the use of MRI to measure the hemodynamic response related to neural activity in the central nervous system. fMRI is a non-invasive technique that is used to scan a particular location in the brain to understand its role. It has a good spatial resolution, but poor temporal resolution. PET is a “nuclear medicine medical imaging” system that creates a 3-D map of the functional processes in the body. That is, PET is used to measure the blood flow to different parts of the brain, as this imaging is based on the supposition that areas of high radioactivity are linked with brain activity. PET is a valuable technique for detection of certain disorders, as it targets the radio-chemicals used for specific bodily functions (Sarter et al., 1996). Electrical activity of the brain can be measured by placing electrodes on the scalp. Recordings can be made from these electrodes and the resulting traces are known as EEG. Although this technique is used for various purposes, in cognitive neuroscience, it is used to study the function of the brain by recording EEGs while manipulating the behaviors of the subject. All these types of brain imaging techniques are used in conjunction with each other. For example, fMRI are used together with EEG, which has a much higher recording frequency.
As impressive as these techniques are, they have received just as much criticism as they have been praised. Questions have been raised about its reliability and more so of how much ‘science’ it comprises. fMRI and PET scans published in articles show colorful images of the brain, which makes it seem less scientific and more decorative and fancy. Science and scientists prefer raw data that are open to interpretation and improvement. However, the results from these scans show a flawless photo displaying the exact brain regions involved in specific activities. The ideas and findings these imaging techniques reveal seem to be too rigid and structured. A notorious criticism has been that neuroimaging techniques are nothing more than “Technicolor phrenology” (Faux, 2002). It raises questions of the authenticity of the data as to how much it has been manipulated using techniques such as Photoshop. Also, brain imaging can portray and yield pictures that are far too removed from the truth. With the manipulation of colors and editing of the raw graphics, these images may imply much more precision than actually exists.
Since the invention of these techniques, much research has provided us with a greater understanding of the cognitive processes that exist. The consistency and the validity of these techniques can be explored from the many articles that have been written on this subject. Even though most cognitive functions have been correlated with a brain region, cognitive neuroscience strives to travel farther and discover other existing, but undiscovered, regions that might aid in certain cognitive processes.
If we only look at the enormous research that has been done with the help of these procedures, it is apparent that imaging techniques such as the fMRI and PET do more than just confirm cognition happens in the brain. They map out brain areas that are associated with their respective behavior or cognition patterns. They provide us with a deeper understanding about the functions themselves. Each study provides a further piece in helping complete the bigger puzzle.
The idea of linking each and every human ability with particular areas in the brain seems all too unrealistic and impractical. An argument put forth by R. Grant Steen, says that fMRI and such techniques are nothing but a tool for the psychologists and the neuroscientists alike to visualize and understand something that is not directly seen through human eyes. That is, just as the biologists use microscopes to understand about the DNA and the genes, so do the psychologists, to understand cognitive processes such as decision-making. On the other hand, the accuracy and the legitimacy of these techniques need to be scrutinized. By just indirectly measuring blood flows, fMRI scans cannot provide us with definite area and the cognitive function it governs. This is also due to the lack of erudition this technique seems to have about the brain being a series of networks. Much work has proved that most mental tasks require a combination of structures in their brain working in sync. Then again, behavioral psychologists, argue that it is not necessary to have brain maps to understand cognitions and behaviors. According to them, biological factors are only a small factor in the way humans behave and think (Dobbs, 2005). It is the environment and its re-enforcers that we need to consider in order to obtaining an extensive knowledge of how and why we behave or think in certain ways.
Regardless of its flaws, brain imaging has undoubtedly become the fundamental step to facilitate the understanding of the structure-function correlation. These techniques need to be valued, at the same time improved, as we learn more about the brain and its functions. Just because these techniques are imperfect, it seems asinine to discard their uses or what it discovers. As Marcus Raichle, a Washington University neurologist pointed out, throwing away the findings of imaging techniques would be similar to that of questioning the existence of stars due to a faulty telescope.
Regard it as a valuable tool, or as “the new phrenology”, no one can deny the numerous amounts of information and insight that these techniques have bestowed us with. These techniques are largely used to try and pin down some very complex behaviors of a very complex organ. Taking this into consideration, one has to be pleased about how far we have come in understanding the complexity of the brain through the capacity of such techniques. It is not to say that further upgrades and enhancement of these techniques based on the current concepts and theories will move us further from contemplating whether these techniques have done more than simply confirm that cognition happens in the brain.
Sarter, M., Berntson, G. G., & Cacioppo, J. T. (1996). Brain Imaging and Cognitive Neuroscience. American Psychologist , 51(1),13-21.
Faux, S. “Cognitive neuroscience from a behavioral perspective: A critique of chasing ghosts with Geiger counters.” The Behavior Analyst, 25:161-173, 2002
Dobbs, D. (2005, April). “Hard Science or Technicolor Phrenology?”
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