Functional Magnetic Resonance Imaging
Introduction
Functional magnetic resonance imaging is a type of technology that uses magnetic resonance to aid in viewing/ imaging of objects found inside the body. It is a specialized type of magnetic resonance imaging, used to measure animal and human spinal cord or brain neural activity through changes in blood flow (hemodynamics). (Raichl and Mintun, 2006). This type of magnetic resonance is one among the many examples of this technology which include magnetic resonance spectroscopy, interventional MRI, diffusion MRI, multinuclear imaging etc. The functional magnetic resonance imaging has been seen to gain popularity in brain mapping due to the relatively low risk involved while using it and also its efficiency. This relatively low risks are; lack of radiation exposure, non-invasiveness and also high availability of the technology.
According to Raichl et al., (2006), it is known that neural activities can be closely linked to changes in blood flow and level of blood oxygen in the brain. This is because active nerve cells have been known to experience increased oxygen consumption preempting them to switch to anaerobic processes glycolysis. This is turn triggers a mechanism that cause changes in the oxyhemoglobin and deoxyhemoglobin concentration and also the blood volume and flow in the cerebral region. (Van et al, 2009).
In the year 1990 some discoveries concerning MRI were made by Dr. Seiji Ogawa, (Gusnard and Raichle, 2001) he introduced the first basic blood deoxyhemoglobin contrast and also an important tool in brain imaging. He introduced the use of the MRI technology known as Blood-oxygen-level dependent (BOLD). The Blood-oxygen-level dependent indicates the T2* weighted contrast dependence on the quantity of deoxygenation blood that is a result of various magnetic characteristics of oxygenated and deoxygenated hemoglobin. This technology was absorbed by many especially Dr. Kenneth Kwong who applied the technology with MRI on human brain to image the brains activity. Presently BOLD has been seen to gain fame in the diagnostic medical field to establish the exact locations in which the brain activities occur, however it has been faced with challenges of its validity since its indicators are not quantitative hence cannot be easily measured (van et al, 2009).
The fMRI technology has been known to be associated with other various fields of study. Some of these disciplines in which this technology has been known to incorporated knowledge include; physics, psychology in that almost all the studies are psychophysical experiments, neuroanatomy, statistics and electrophysiology (Raichle et al., 2006). These disciplines have contributed to the fMRI to be used as aid to further analysis and diagnostic I the field of science and medicine.
Cognitive psychology
Psychology is a broad field that involves the scientific study of the human/animal mental functions and behaviors. It has been known to have many inputs in understanding human behavior. It takes a closer look into interpersonal relationships, cognition, perception attention, personality, emotion, motivation, and behavior and under it. Cognitive psychology is a discipline within psychology that investigates the internal mental processes of thought such as visual processing, memory, problem solving, and language. This type of psychology is interdisciplinary cross cutting even to human–computer interaction, computational neuroscience and logicians which are tools for studying the minds functional organization and brain activity (Schunk, 2008).
Cognitive psychology has given rise to a study known as cognitivism which specifically bases in how information processing is represented by people mentally. It had its foundations in the work of, who provided a theory of stages/phases that describe children's cognitive development. The works of cognitive psychology are based on the works of other psychologists, Wolfgang Köhler, Max Wertheimer, Jean Piaget, Wilhelm Wundt, and Kurt Koffka, who provided the theory of stages of development/ children cognitive development.
Advantages of fMRI in Object recognition
Object recognition has in the past been study that has demanded a lot of research in to help develop the understanding of the working of the body. To many scientists object recognition using artificial mechanisms has been a challenge especially in recognizing an object that is variant in its appearance. This is because; the variations sometimes can be too complex and minute to be distinguished as different. However, it is known that humans have the ability to recognize an object despite the variation in a fraction of a second with least of effort (Biederman, 1987).
This therefore, has prompted researchers to dedicating their time to understand the mechanisms that have been employed by the biological system in solving this similar problem (Biederman, 1987). These studies have however bore fruits since the clues found have helped develop replicate artificial programs for recognition. Strong recognition systems have been built from this kind of understanding using the few pointers that have been given. Different theories have also been coined in order to come up with an appropriate reason why and how the biological system works. Some of the theories include; Theories of pattern recognition, Template matching theories, feature theories and Problems with template theories.
Due to the longer time scale of the fMRI recognition process, this technology has been found more adequate in measuring object representation than the temporal sequence of computations. However, this technology has been used to find some pointers on virtual processing in combination with psychophysics. Initial studies of object recognition involving fMRI in human beings, identified the regions in the brain that respond specifically to objects and faces (Malach et al. 1995; Kanwisher et al., 1997). After researchers conducted other studies, it was indicated that there is a correlation between the activation in face and object selective regions in the brain and success of recognizing each of them respectively. This therefore, provided conclusive evidence that these regions were involved in object recognition. Further it has been asserted that combination of psychophysics and fMRI could result to derivation of pointers/indicators on the type of visual processing that is employed in specific cortical regions.
. Many studies have indicated the uses of fMRI to study human behaviors and reactions. A study by Moll et al., (2002), on peoples response to different moral claims showed change in the brain activity when the people in the study were subjected to the tests. In this the brain was found to have greater activity in the left medial OFC when subjected to the moral conditions and more in the left amygdale when subjected to the non-moral questions.
Another study by Greene et al., (2001), also took advantage of the technology to study conclusively the moral characteristics and distinction between personal and impersonal moral judgments. This was done through use of fMRI scanning of the test subjects while they were being subjected to tailored circumstances of personal and impersonal moral dilemmas and non-moral dilemmas. In this they found out that response of the two different dilemmas led to different forms of activity in some areas of the brain (Greene, et al., 2001). For instance, impersonal and non-moral dilemmas produced increased activity in areas associated with working memory as compared with personal dilemmas. Little difference was however found between the impersonal-moral and non-moral conditions. Others have also used fMRI to asses the neuromechanisms associated with romantic love.
Aron et al., (2005), reported in his study that there is activation in the rightventral tegnum area of the brain and right caudate nucleus areas rich with dopamine when one reacts towards a loved one. In this the study also concluded that these areas with dopamine pathways, contributed to arousal rather than emotions. The fMRI has been used to bring out the psychological understanding of peoples reaction to different circumstances and views of different moral illustrations. This has become an eye opener that has triggered more research to be done.
In other aspects, functional magnetic resonance imaging (fMRI) has been found instrumental in providing researchers with a means to use to determine the neural activity patterns associated with stereotyping, prejudice and discrimination. Using the fMRI parameters on the fact that the degree of neuronal activity determines blood flow to a particular region of the brain, the prejudice researchers have been able to study the human behavior. These researchers have used the technology to examine the brains activities to asses the Lippmans “pictures in our head”. These studies using the fMRI were first conducted on subject’s whose brain activity was measured while passively involved in viewing individuals from different races e.g. white and black individuals. An example was by assessing the subjects while they viewed unfamiliar faces, in this the reaction of a subject when confronted by Black and a White individuals. This showed significance difference in the quantity of amygdale a component that was discovered in rodents responsible for conditioning (Bechara et al., 1995).
On the other hand, fMRI has not just been used to study the human response and behavior to environmental and social situations but has also been used a a psychological diagnostic tool. Individuals with object recognition problems have been subjected to fMRI studies in order for the physicians to diagnose the underlying problems. An example, Bechara et al., (1995) carried out a determining study on patients with bilateral amygdala damage to assess their capacity to learn in a classical conditioning model. This was done using color shapes with some paired with adverse noise. This was to measure their implicit and explicit learning, this showed changes in nervous activity with different situations of he study.
It has also been used to study individuals who have a problem in identifying closely identical objects and faces. In this individuals subjected to the study, were exposed to faces and objects in different instances for quickly. It was then found out that some of the individuals could not process the information necessary to identify two or more objects as distinct and separate. Imaging scans, indicated little or limited activity in some regions of their brains that are supposed to help in recognition. Men with reproductive problems and schizophrenic patients have been seen to be subjected to the fMRI in order to determine their brain activity in various regions that are responsible for normal function. These neuroscientific methods have been deemed necessary in order for one to relate the functions of the brain and the normal portrayed behavior by an individual (Bechara et al., 1995). It be seen then that introduction of the Functional Magnetic Resonance Imaging, has opened up further the understanding of individual behavior in object recognition in relation to the brains activity.
Functional magnetic resonance imaging is a type of technology that uses magnetic resonance to aid in viewing/ imaging of objects found inside the body. It is a specialized type of magnetic resonance imaging, used to measure animal and human spinal cord or brain neural activity through changes in blood flow (hemodynamics). (Raichl and Mintun, 2006). This type of magnetic resonance is one among the many examples of this technology which include magnetic resonance spectroscopy, interventional MRI, diffusion MRI, multinuclear imaging etc. The functional magnetic resonance imaging has been seen to gain popularity in brain mapping due to the relatively low risk involved while using it and also its efficiency. This relatively low risks are; lack of radiation exposure, non-invasiveness and also high availability of the technology.
According to Raichl et al., (2006), it is known that neural activities can be closely linked to changes in blood flow and level of blood oxygen in the brain. This is because active nerve cells have been known to experience increased oxygen consumption preempting them to switch to anaerobic processes glycolysis. This is turn triggers a mechanism that cause changes in the oxyhemoglobin and deoxyhemoglobin concentration and also the blood volume and flow in the cerebral region. (Van et al, 2009).
In the year 1990 some discoveries concerning MRI were made by Dr. Seiji Ogawa, (Gusnard and Raichle, 2001) he introduced the first basic blood deoxyhemoglobin contrast and also an important tool in brain imaging. He introduced the use of the MRI technology known as Blood-oxygen-level dependent (BOLD). The Blood-oxygen-level dependent indicates the T2* weighted contrast dependence on the quantity of deoxygenation blood that is a result of various magnetic characteristics of oxygenated and deoxygenated hemoglobin. This technology was absorbed by many especially Dr. Kenneth Kwong who applied the technology with MRI on human brain to image the brains activity. Presently BOLD has been seen to gain fame in the diagnostic medical field to establish the exact locations in which the brain activities occur, however it has been faced with challenges of its validity since its indicators are not quantitative hence cannot be easily measured (van et al, 2009).
The fMRI technology has been known to be associated with other various fields of study. Some of these disciplines in which this technology has been known to incorporated knowledge include; physics, psychology in that almost all the studies are psychophysical experiments, neuroanatomy, statistics and electrophysiology (Raichle et al., 2006). These disciplines have contributed to the fMRI to be used as aid to further analysis and diagnostic I the field of science and medicine.
Cognitive psychology
Psychology is a broad field that involves the scientific study of the human/animal mental functions and behaviors. It has been known to have many inputs in understanding human behavior. It takes a closer look into interpersonal relationships, cognition, perception attention, personality, emotion, motivation, and behavior and under it. Cognitive psychology is a discipline within psychology that investigates the internal mental processes of thought such as visual processing, memory, problem solving, and language. This type of psychology is interdisciplinary cross cutting even to human–computer interaction, computational neuroscience and logicians which are tools for studying the minds functional organization and brain activity (Schunk, 2008).
Cognitive psychology has given rise to a study known as cognitivism which specifically bases in how information processing is represented by people mentally. It had its foundations in the work of, who provided a theory of stages/phases that describe children's cognitive development. The works of cognitive psychology are based on the works of other psychologists, Wolfgang Köhler, Max Wertheimer, Jean Piaget, Wilhelm Wundt, and Kurt Koffka, who provided the theory of stages of development/ children cognitive development.
Advantages of fMRI in Object recognition
Object recognition has in the past been study that has demanded a lot of research in to help develop the understanding of the working of the body. To many scientists object recognition using artificial mechanisms has been a challenge especially in recognizing an object that is variant in its appearance. This is because; the variations sometimes can be too complex and minute to be distinguished as different. However, it is known that humans have the ability to recognize an object despite the variation in a fraction of a second with least of effort (Biederman, 1987).
This therefore, has prompted researchers to dedicating their time to understand the mechanisms that have been employed by the biological system in solving this similar problem (Biederman, 1987). These studies have however bore fruits since the clues found have helped develop replicate artificial programs for recognition. Strong recognition systems have been built from this kind of understanding using the few pointers that have been given. Different theories have also been coined in order to come up with an appropriate reason why and how the biological system works. Some of the theories include; Theories of pattern recognition, Template matching theories, feature theories and Problems with template theories.
Due to the longer time scale of the fMRI recognition process, this technology has been found more adequate in measuring object representation than the temporal sequence of computations. However, this technology has been used to find some pointers on virtual processing in combination with psychophysics. Initial studies of object recognition involving fMRI in human beings, identified the regions in the brain that respond specifically to objects and faces (Malach et al. 1995; Kanwisher et al., 1997). After researchers conducted other studies, it was indicated that there is a correlation between the activation in face and object selective regions in the brain and success of recognizing each of them respectively. This therefore, provided conclusive evidence that these regions were involved in object recognition. Further it has been asserted that combination of psychophysics and fMRI could result to derivation of pointers/indicators on the type of visual processing that is employed in specific cortical regions.
. Many studies have indicated the uses of fMRI to study human behaviors and reactions. A study by Moll et al., (2002), on peoples response to different moral claims showed change in the brain activity when the people in the study were subjected to the tests. In this the brain was found to have greater activity in the left medial OFC when subjected to the moral conditions and more in the left amygdale when subjected to the non-moral questions.
Another study by Greene et al., (2001), also took advantage of the technology to study conclusively the moral characteristics and distinction between personal and impersonal moral judgments. This was done through use of fMRI scanning of the test subjects while they were being subjected to tailored circumstances of personal and impersonal moral dilemmas and non-moral dilemmas. In this they found out that response of the two different dilemmas led to different forms of activity in some areas of the brain (Greene, et al., 2001). For instance, impersonal and non-moral dilemmas produced increased activity in areas associated with working memory as compared with personal dilemmas. Little difference was however found between the impersonal-moral and non-moral conditions. Others have also used fMRI to asses the neuromechanisms associated with romantic love.
Aron et al., (2005), reported in his study that there is activation in the rightventral tegnum area of the brain and right caudate nucleus areas rich with dopamine when one reacts towards a loved one. In this the study also concluded that these areas with dopamine pathways, contributed to arousal rather than emotions. The fMRI has been used to bring out the psychological understanding of peoples reaction to different circumstances and views of different moral illustrations. This has become an eye opener that has triggered more research to be done.
In other aspects, functional magnetic resonance imaging (fMRI) has been found instrumental in providing researchers with a means to use to determine the neural activity patterns associated with stereotyping, prejudice and discrimination. Using the fMRI parameters on the fact that the degree of neuronal activity determines blood flow to a particular region of the brain, the prejudice researchers have been able to study the human behavior. These researchers have used the technology to examine the brains activities to asses the Lippmans “pictures in our head”. These studies using the fMRI were first conducted on subject’s whose brain activity was measured while passively involved in viewing individuals from different races e.g. white and black individuals. An example was by assessing the subjects while they viewed unfamiliar faces, in this the reaction of a subject when confronted by Black and a White individuals. This showed significance difference in the quantity of amygdale a component that was discovered in rodents responsible for conditioning (Bechara et al., 1995).
On the other hand, fMRI has not just been used to study the human response and behavior to environmental and social situations but has also been used a a psychological diagnostic tool. Individuals with object recognition problems have been subjected to fMRI studies in order for the physicians to diagnose the underlying problems. An example, Bechara et al., (1995) carried out a determining study on patients with bilateral amygdala damage to assess their capacity to learn in a classical conditioning model. This was done using color shapes with some paired with adverse noise. This was to measure their implicit and explicit learning, this showed changes in nervous activity with different situations of he study.
It has also been used to study individuals who have a problem in identifying closely identical objects and faces. In this individuals subjected to the study, were exposed to faces and objects in different instances for quickly. It was then found out that some of the individuals could not process the information necessary to identify two or more objects as distinct and separate. Imaging scans, indicated little or limited activity in some regions of their brains that are supposed to help in recognition. Men with reproductive problems and schizophrenic patients have been seen to be subjected to the fMRI in order to determine their brain activity in various regions that are responsible for normal function. These neuroscientific methods have been deemed necessary in order for one to relate the functions of the brain and the normal portrayed behavior by an individual (Bechara et al., 1995). It be seen then that introduction of the Functional Magnetic Resonance Imaging, has opened up further the understanding of individual behavior in object recognition in relation to the brains activity.
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Functional Magnetic Resonance Imaging
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