Introduction
Many studies have been conducted to determine the relationship that exists between biological components of the body of organisms, the brains, and behavior. These studies have brought about interesting results that became the basis of the theories and concepts that we currently apply in psychology. Furthermore, these studies have shown that human behavior is a direct manifestation of the activity of the brain. To determine this fact, scientists conducted empirical and practical studies to state the mechanisms behind various systems in the body of a human, including the nervous system, to determine how they influence human behavior.
From the studies that have been conducted, it is clear that the mind is actually the organ that plays a significant role in determining, shaping, and manipulating human behavior (Hock, 2002). At this point, it is essential to state that many scholars in the field of psychology believe that the mind is a phenomenon that develops from the nervous system (Hock, 2002). This fact, therefore, explains why many researchers in this field of study mainly focus on the various aspects of the nervous system in a bid to explain what exactly makes people behave in the way they do.
This paper will focus on the relationship that exists between physiology and psychology. To define its objectives, this paper will critically analyze the concept of psychobiology. Furthermore, this paper will expound on the various works that have been written by renowned researchers in the field of psychobiology. Particularly, this paper will expound on Karl S. Lashley and focus on his efforts to find the engram. In addition, this paper will examine the study by Donald O. Hebb and his efforts in exploring cell assemblies and phase sequences. It this research, we will use various theories and concepts in psychology to support the findings and arguments that will be presented.
Psychobiology
As it has been previously asserted in this paper, many researchers in the field of psychology have been trying to determine the relationship between psychological phenomena and biological foundations in animals. In this respect, researchers try to determine the relationship that exists between psychology and physiology. According to Broudas (2010), this relationship is critical for any individual since it determines the behavior that will be displayed. Since the early days of psychology, individuals such as Aristotle, Hippocrates, and Pavlov conducted a number of studies to find these relationships. These studies laid the foundation for the current knowledge that is present in psychobiology.
By the turn of the 18th century, the man had learned a lot about the physical world. During this era, however, the world had seen a scientific revolution. This revolution played a significant role in how the man gained an understanding of living organisms and their relationship with their environment (Broudas, 2010). Using the scientific method in psychological studies, researchers from then on have been involved in studies that aimed at determining the means through which empirical events are usually presented in the consciousness of animals (Broudas, 2010). This quest has thus resulted in immense and rigorous studies that expounded knowledge on sense perception to motor reactions in living beings, particularly in animals. Based on these findings, it is thus evident that a relationship exists between the psychology of an individual (the neural system) and his/her physiology (biological system).
Early studies that were conducted on the nervous system of organisms revealed that there were two different types of nerves; sensory nerves and motor nerves (Hergenhahn, 2013). From the studies by Charles Bell and François Magendie during the 19th century, it was found that sensory nerves conveyed impulses from sensory receptors in the body to the brain. At the same time, motor nerves passed the brain’s interpretation of these impulses to tissues and muscles all around the body. This explains the responses that animals have to various stimuli within their environment. This phenomenon is referred to as the Bell-Magendie law that forms the basis of psychobiology.
The works by Johannes Muller further developed Bell-Madendie’s law. In his works, Muller asserted that different receptors are sensitive to different stimuli. Given the five basic senses that a human has, the body has developed different receptors that respond only to specific stimuli. For instance, the eye is sensitive to light energy, while the ears perceive sound waves. According to work by Muller, different sensory organs have a different degree of response to different stimuli (Hock, 2002).
Thus, while the eye is highly tender to light energy, it can respond to changes in pressure. However, its reaction to changes in pressure will not be as effective as its response to light energy. Therefore, the responses that we get from the various sensory organs result in the development of the physical picture of the environment that surrounds us. Based on this concept, Muller went ahead by asserting that individuals are not conscious of the physical environment that surrounds them, but the sensations that arise from this environment (Hothersall, 2003). As such, the nervous system plays a significant role in determining the nature of responses in individuals and not the overall nature of the environment. Therefore, an individual will only perceive and understand the nature of his/her environment based on the sensory receptors that he/she possesses.
The Relationship between Physiology and Psychology
By the 20th century, a lot of advancements had been done in the various fields of psychology. In the field of psychobiology, for instance, a number of researches were actively involved in studies, which aim was to determine the relationship between psychology and behavior. Karl Lashely, for instance, was greatly involved in the field of psychobiology during the 20th century. Unlike many researchers in the field of psychology, Lashley’s educational background was not in psychology but in biology. He possessed a Master’s degree in bacteriology and a PhD in Genetics. However, Lashley gained interest in psychology and collaborated with John Watson in a number of psychological studies.
The early works of Lashley were based on Watsonian behaviorism. However, Lashley and Watson developed different interests in research and hence their studies focused on different aspects of psychology. In particular, Lashley’s early works mainly focused on conditioned reflexes (Hergenhahn, 2013). To further develop his work, Lashley studies tried to prove that the brain operates as a switchboard that interprets information from sensory nerves by transforming them into motor reactions (Hergenhahn, 2013).
However, the results of his studies were different from what he expected. According to his behavioral beliefs, the brain operates likes a switchboard, however, the results of his studies revealed that specific responses to stimuli do not originate from specific parts of the brain. Furthermore, the findings showed that the loss of sensory response highly depended on the damage of the cortex of the brain. This result therefore supported the notion that the cortex of the brain operates as a unified entity as postulated by Gestalists (Hergenhahn, 2013). This phenomenon was thus referred to as the concept of mass action.
Furthermore, Lashen works proved that the brain response to a given stimuli will only be lost if the entire brain area that is involved in the interpretation of this stimuli is completely destroyed. In this respect, therefore, an individual will continue to perceive a given stimuli as long as a proportion if not all the cells of a given area of the brain that is responsible for the interpretation of this stimuli at hand are present (Hock, 2002). Based on this concept, an individual will only lose a specific sense if the entire part of the brain that is associated with interpretation of this stimulus is lost. This phenomenon is referred to as equipotentiality and postulates that the brain operates as an integrated organ and not as a switchboard.
Much of Lashley’s later works were mainly focused on the search for the engram. In psychology, the engram is considered to be a point in the brain that supports memory and learning. While Lashley had discovered that the brain operates as an integrated organ and not as a switchboard, he wanted to determine where learning and memory occur in the brain. As Hothersall (2003) asserted, past experience sensation that originates from raw elements of conscious experiences that an individual has been involved in results into perception. However, for an individual to relate a perceived sensation to a current reception, he/she needs to have memory of the sensation and the resultant response. This is a result of the fact that each physical experience that an individual is involved in usually results in a specific activity in the brain (Hothersall, 2003). Despite his failure to identify the locus of the engram in the brain, Lashley’s work has been influential in cognitive psychology.
Lashley’s works influenced other researchers in the field of psychobiology. Donald O. Hebb, is an example of an individual who worked with Lashley during the 1930s. As a result of their interaction, later works by Hebb followed Lashley’s basic principles, especially with regards to the concepts of mass action and equipotentiality. In addition to this, Hebb’s concepts in psychobiology were mainly influenced by Pavlovian psychology.
As discussed earlier, part of Lashen’s early works were based on the concept of reflexes, which basic concepts are based on pavlovian psychology. This is because it is believed that a response in an organism occurs due to the response of a specific stimulus (Broudas, 2010). However, while reflexes do not require prior learning, Pavlov discovered that conditioning could result in the pairing of stimuli with the behavior of an organism. Through conditioning therefore, an unconditioned stimulus and an unconditional response could be paired to result into a conditioned stimulus and responses (Hock, 2002).
During the 1930s, Hebb also worked together with Wilder Penfield. His main work was to evaluate patients who were recovering from brain surgery. Of the many observations that he made, Hebb discovered that most patients did not lose much of their intelligence even after losing significant tissues of their frontal lobes of their brains. As a result of these findings, he concluded that intelligence develops from infancy. It is during this period of development that an individual acquires concepts as well as way of thought that influences his/her overall intelligence. Therefore, if an individual suffers from brain injury during the infancy stage of development, there is a high possibility that his/her overall level of intelligence will be affected. However, if an individual suffers brain injury after maturity, it will be difficult for his/her level of intelligence to be altered (Hothersall, 2003).
To support this idea, Hebb came up with the concept of cell assemblies and phase sequences. According to this concept, Hebb believes that the nervous system of a newborn is characterized by random interactions. However, through experience and exposure to various stimuli, these interactions are linked together. For instance, when we look at a claw hammer, our attention shifts from its head, to its handle, and then its claws. The visualization of the different parts of this object results into the firing of complex neurons associated to their function. Hebb referred to this phenomenon as “cell assembly” (Hothersall, 2003).
However, since these different cell assemblies arise as a result of the presence of a claw hammer, the brain will package them in response to the presence of a hammer. It results in the association of neurons that were once separated that can be triggered by either an internal or an external stimulation (Broudas, 2010). Furthermore, Hebb asserted that the integration of various cell assembles results in a phenomenon referred to as “phase sequences” which overall result is the development of one stream of thought as a result of several stimuli. Therefore, during the infant stages of development, an individual tends to develop cell assemblies and phase sequences based on the stimuli he/she receives from the environment. In later stages of development, however, learning involves the rearrangement of the cell assemblies and phase sequences that have already been acquired based on creativity and insight. (Gibbons, 2006).
These days, there are quite a number of studies having been carried out in the field of psychobiology. However, it is essential to note that the basis of these studies highly relies on the information that had been been acquired in earlier studies by pioneers such as Pavlov, Gestalists, Lashen, and Hebb. For instance, through his efforts, Lashen managed to identify that the operation of the brain is not as a switchboard as he had earlier anticipated, but as a unified entity. From this information, Lashen concluded that the process of learning is stored in distinctive parts of the brain. Therefore, in an event of injury, the level of memory loss will be determined by the extent to which the brain tissue has been damaged and not the location of the injury within the brain. This is because the brain stores information in the most simple but yet concise manner (Broudas, 2010).
However, it is essential to note that the information stored in the brain exclusively relies on sensory experiences. Therefore, a given memory will only be associated with a given stimulus and response, because each event that individuals are engaged in usually results in a specific activity of the brain. However, when this event ceases, the brain activity also comes to an end. Despite this fact, the brain usually stores the memory trace of the environmental event and the resultant brain activity.
This phenomenon is similar to Hebb’s concept of cell assembly. According to Hebb’s arguments, different neurons can be stimulated by a given activity hence resulting in cell assemblies. This stimulation can trigger various neurons together or in close successions to form phase sequences. This process can be considered as a learning process that will be stored in the brain of an individual as memory. As such, given cell assembly will only be triggered by a given stimulus in response to an environmental cue. Thus, the processes of cell assemblies and phase sequences give various environmental neurological representations. In the event where a cell assembly or phase sequence is stimulated in an individual, the environmental events and cues that were responsible for their manifestations usually come up in a form of thoughts or memory traces. These concepts therefore play a significant role in the perception of events such as fear, arousal, happiness, and so on (Broudas, 2010).
In the contemporary world, many researchers use Hebb’s cell assembly and phase sequence concepts to support the process of learning. The concept of artificial learning, for instance, comprises of Hebb’s concepts as its core foundations. However, unlike Hebb’s concepts, the latter are based on artificial neurons of input, hidden, and output units (Hergenhahn, 2013). Just like the operations of the brain, the interaction between these artificial neurons exclusively relies on the stimulus that originates from the environment. The concept of artificial intelligence has been widely applied in the contemporary world.
For instance, this concept is widely applied in the process of teaching English as a second or as a foreign language. Students find it difficult to learn English since their first languages act as a barrier. The process of learning a language is usually a progressive progress and hence requires a comprehensible input, processing, and output. According to Krashen’s monitor model, it has been argued that the process of learning can be enhanced using a comprehensible input since speaking is considered as an outcome of learning (Gibbons, 2006).
It is as a result of this fact that many teachers use scaffolding, facilitation, facial expressions, and other teaching strategies to ensure that the learners comprehend the message that is being conveyed to them. This forms the hidden segment of learning where a student internalizes the information received into a comprehensible form. The students’ level of output also plays a critical role in attaining a learning rich environment (Swain, 1995). After the student has learnt the fundamentals of the new language and has acquired the basics, he/she needs to put into practice the acquired knowledge (in this case, the target language). This concept has been explained by a several theories on output. These theories state that the practicing of the learned language increased the accuracy and fluency of the learner (Lightbrown and Spada, 2006). This is because students will have the ability to notice the various aspects of the target language and develop metalinguistic awareness.
Conclusion
Psychobiology has played a critical role in explaining the concepts that link physiology and psychology. The works of researchers such as Pavlov, Aristotle, Lashen, and Hebb have provided us with information that has enabled us to understand the relationship that exists between our physical environment and our bodies. It is through these responses that all animals are able to respond appropriately to different environmental cues. As such, individuals have been able to manipulate their environments in order to meet their physiological needs and hence sustain life.
References
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Hothersall, D. (2003). History of Psychology. California: McGraw-Hill. Web.
Hock, R.R. (2002). Forty studies that changed psychology: Explorations into the history of psychological research. (4th ed.). New Jersey: Pearson Education. Web.
Lightbrown, P. and Spada, N. (2006). How languages are learned. New York: Oxford University Press. Web.
Swain, M. (1995). Principle & practice in applied linguistics : Studies in honour of h. G. Widdowson. London: Sage. Web.