Cognitive Science: An Introduction/Cognitive Science Defined

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Cognitive Science is the interdisciplinary study of minds. It is characterized in two important ways: theoretically and methodologically.

Theoretically, cognitive science differs from some other fields that study minds in that it tends to focus on a particular level of analysis-- that of information processing.

Levels of Analysis[edit]

Many things in the world can be productively studied at many levels of explanation. Take, for example, the weather. We can try to understand and predict the weather at a global level. At this level we would look at large ocean currents, and convection currents in the air. We can find patterns, such as how hurricanes always rotate in a counter-clockwise direction in the Northern Hemisphere due to the Coriolis force.

At this level of explanation, we are using terms such as "hurricane," and "current," which describe objects of such great complexity that it seems strange to even refer to them as objects. However, the reason that these terms are legitimate is because we can make better-than-chance predictions about their behavior. This indicates that we are dealing with a level of aggregation that is a legitimate one to study.

At a lower level, we can look at weather in terms of cold fronts. At an even lower level we can look at individual atoms and how they interact. Each level has a set of terms it uses to describe what exists. This set of terms is called the "ontology." Each level of analysis is useful for investigating certain classes of problems. Questions and their answers are described in terms of this ontology.

Similarly, people can be legitimately studied at multiple levels of analysis. Sociology, economics, and political science look at how groups of people interact. Social Psychology studies how individuals interact with each other, and how social identities affect human behavior. Cognitive psychology looks at how people perceive and use their memories to think and act. Neuroscientists look at how the brain functions, and organic chemistry investigates how molecules in living creatures interact. Although you could study people at an atomic or quantum level, it is so similar to quantum behavior in other objects that it's not worth distinguishing the quantum study of people from the quantum study of other things.

Even the levels described above have sub-levels. There are multiple levels within biology: biologists look at molecules,synapses, neurons, networks, maps, sub-systems, and the whole nervous system.

There is a tendency for scientist to be dismissive of levels of analysis that are higher than one's own. Lower level analysis tends to deal with things that are smaller, simpler, and easy to predict. It is impossible to have a sociology experiment with the kind of control that a physicist enjoys. But do not be a level of explanation bigot! All of these levels are legitimate, and are appropriate for certain kinds of questions. Just as it's (currently) impossible to predict the weather using chemistry, it's impossible to predict the behavior of a person using biology.

The Biological Level of Analysis: Synaptic Changes[edit]

Analysis at the biological level begins at the nervous system. The nervous system is broken up into two main divisions: the central nervous system and the peripheral nervous system. The central nervous system is a center for incoming and outgoing information and is made up of the nerves of the brain and spinal cord. The peripheral nervous system acts as a center to convey messages between the organs in the human body and the central nervous system. It is further subdivided into the somatic nervous system and the automatic nervous system. The somatic nervous system is in control of the muscles, bones and skin. It consists of the sensory somatic nerves, which bring information to the CNS, and the motor somatic nerves which cause a response. The automatic nervous system consists of special motor nerves which are responsible for the internal organs. It is made up of the sympathetic nervous system, which prepares the body for stress and the parasympathetic nervous system, which helps the body recover from stress (Di Giuseppe et al., 2003). This build up of neural circuits allows the body to learn how to properly respond to its environment. Knowing the parts of the nervous system allows for the understanding of how reflexes come about, how pain and fear are learned, how stress is managed and how we are able to learn basic tasks as children.

Biological analysis is based of Hebbian Theory, which simply states that neurons that fire together, wire together. Donald Hebb suggested that neurons act together to influence behavior, linking in networks called call assemblies. Regarding his Hebbian Theory, Hebb stated that, "When an axon of cell A is near enough to excite a cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiently, as one of the cells firing B, is increased". This is how learning occurs and how neural connection are made during the process (Weiten et al., 2013).

A baby is born with all the neurons possible, over time the ones not stimulated will be lost as the stimulated ones are making new connections. This is the same time where children can learn new languages, respond to textures and stimuli in their environment and learn how to protect themselves from their surroundings.

Reflexes are often involuntary and unconscious; occurring with little brain involvement. Babies for instance are born with a set of reflexes that allow them to respond to different situations (Di Giuseppe et al., 2003). One of which is the Rooting reflex, which consists of a baby opening it mouth and searching for a nipple when touched on the cheek (Weiten et al., 2013). This reflex ensures a babies survival by always obtaining nutrients. The framework of this reflex and many others is build prenatal stage where the baby can respond to the sounds it hears. Other reflexes, such as response to pain and discomfort are learned later on when the baby is born. For instance, if a toddler were to place their hand on a burner, they would quickly move it away with little thought. They would not be able to keep their hand on the burner for a long period of time. This is because of the reflex that occurs. The temperature receptors in the skin are triggered by the high heat, which causes a signal to be sent through the sensory nervous system to the interneurons located in the spinal cord. It is here where the signal splits in two directions; one going to the brain to be stored for future reference and one to the motor neurons to signal back. This signaling back causes the effectors neurons to generate a response, thus contracting the muscles to move the hand. The pain that results later is caused by the signal that reached the brain and was stored; this pathway forms a framework of the reflex and is termed, reflex arc. This framework is built by the neurons that were stimulated and would have made new connections via dendrites with each other (Di Giuseppe et al., 2003). The pain induced by the neurons in the brain would have taught the toddler to not touch the burner. If the toddler was to repeat this action, the neurons that make up the framework would fire together in response; making the synaptic space between them even stronger. The child, once more, would learn not to touch the burner or anything similar.

However, this doesn't only have to occur with response to pain and discomfort. Due to having a great amount of neurons, a toddler has the ability to learn many languages. When a child is learning a new language, many neurons are active inside their brain making connections and removing the ones not needed. The ones that form the new connections become better and stronger with practice of the language; making a difficult task second nature (Weiten et al., 2013). We are able to talk fluently with no struggle to form sentences in our native tongue; it is second nature to us. But if you compare the speech of an adult to that of a toddler, then the difference is extraordinary. The toddler takes a longer time to form sentences, talks at a slower speed and uses simple language. Over time, the toddler will get better as their synapses have repeated usage, eventually reaching the level of an adult between the ages of 8-10. The same process is taken for any subject or activity. If a toddler learns and practices math every day, then math problem solving would be easier for them in comparison with someone who lacks mathematical practice. However, neurons don't stop making connections when the toddler grows. The connections between neurons and repeated usages of synapses occurs, but at a lower rate. It is much harder to learn a language at twenty four than at four, but not impossible. With practice and effort, an individual can form new connections that make then able to solve mathematical equations, play the piano, or speak a new language.

This analysis is based of Hebbian Theory, which simply states that neurons that fire together, wire together. Donald Hebb suggested that neurons act together to influence behavior, linking in networks called call assemblies. Regarding his Hebbian Theory, Hebb stated that, "When an axon of cell A is near enough to excite a cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiently, as one of the cells firing B, is increased" (Weiten et al., 2013). This is how learning occurs and how neural connection are made during the process.

The Chemical Level of Analysis: Neurotransmitters[edit]

Analysis at the chemical level observes the biological level at a deeper level of interaction; the interaction between neurotransmitters and neurons. A neurotransmitter is a chemical substance that is contained in a vesicle and released at proper time into the synapses. A synapses consist of two neurons, one forming the axon and the other the dendrite, the space between is the synaptic cleft, which neurotransmitters travel across when an impulse is fired. Each neurotransmitter also has a specific chemical shape, that matches a specific area in the dendrite that it passes to. No other neurotransmitter can fit in this area except the one it is made for (Di Giuseppe et al., 2003).

Depending on the neural pathway that is activated, different neurotransmitters can be released for different situations and cause different reactions. Dopamine is associated with reinforcement and addiction; when a person goes through an experience were they are proud of their accomplishments, such as achieving a A+ on a midterm, dopamine would reinforce the satisfaction of doing well, resulting in the person gaining motivation to do well on all midterms and assignments. If a person if trying to quit an addiction, such as cocaine or smoking, they may feel anxiety on a daily bases due to withdrawal. This is due to the serotonin released to regulate anxiety (Russell et al., 2010).

Children often despise the taste of rich and savory foods, such as coffee and seafood. However, around older ages these foods become somewhat common individuals diets; they become tolerated and enjoyed. This change occurs due to the chemical reactions in the brain during the first experience with the foods.

During development in the womb, babies often swallow amniotic fluid, which differs in taste depending on what is eaten by the mother. This allows the baby to practice swallowing and digestion to prepare for the real world, as well as to have some pre-formed experiences with their future food; the baby would have a tendency to like certain foods that it tasted in utero when its born (Weiten et al., 2013). As a toddler, the child's stomach cannot handle certain foods, due to the child still developing and not being able to digest certain macromolecules available in food. Thus, this results in the child vomiting or having a bad reaction to bitter or rich foods. At the chemical level however, neurotransmitters such as dopamine are released during the first experience to reinforce the concept that bitter or rich foods are bad, forming the concept that coffee is horrible or shrimp is slimy; the body has a time sensitivity to certain things that allow for its safety. This may have also been an evolutionary defense since bitterness is associated with toxicity (Runtz, 2012). As the child starts to reach adulthood, their digestive system matures, as well as their taste buds and nasal receptors, and they are able to handle a verity of foods. Its during this time that their brain chemistry changes; dopamine might reinforce the good experience of bitter and rich foods such as coffee or sea food. Later this might lead to a dependence on coffee which will also lead to a change in brain chemistry.

Addiction is described as a need for substance that entails frequent usage and physical dependence and later abuse. With each usage the brain learns that the drug causes a feel of utopia, thus wanting more. Eventually, with repeated usage, the first dosage becomes tolerated, having no desired effect, thus the dosage increases 10-fold. Most of these drugs mimic the shape of other natural neurotransmitters; therefore being able to bind successfully to the respective receptor; they also affect the uptake of the neurotransmitters (Kolb and Whishaw, 2011). In cocaine addicts, the drug blocks dopamine reuptake, but also stimulates release of it, thus causing the symptoms of euphoria and depression that follow. In smokers, nicotine activates the acetylcholine receptors causing an individual to have a decrease in stress and an increase in alertness. During withdrawal these reactions are changed, causing an individual to "miss" their euphoria emotion or "high" (Russell et al., 2010).

The Psychological Level of Analysis: Eating some fish can make you sick[edit]

Psychology defines learning as change in the behaviour or knowledge of an individual that is due to an experience. Learning can be categorized into different sections, such as classical conditioning, operant conditioning, and observational learning. With classical conditioning, a stimuli is used to create a response, that response is then generated again but with a different stimuli. This was demonstrated using Pavlov's dog; the dog would hear a bell, begin to salivate and would receive food. After many trails, when the dog would hear the bell it would begin to salivate, even when no food was received. This type of learning is said in include the developing phobias (Weiten et al., 2013).

A phobia is having an irrational fear of an environment situation or object that present no realistic danger what so ever. These can develop from a bad experience and can sometime disappear over time or be serious enough to need medical care. If a child was bitten by a dog, they might have a phobia of dogs as an adult. Which would lead them to have anxiety when near dogs due to fearing being bitten again. This can also occur if a toddler is informed from a young age that an object is dangerous. If a parent tells a toddler that getting hurt when falling and falling in general is something to fear, the child may grow up to have a fear of heights due to fear of falling and getting hurt (Weiten et al., 2013).

In operant conditioning, the consequences control the response. This can explain actions such as studying, going to work or asking someone out. These actions are not simple reflexes, they are regulated by their consequences. We study to not fail exams, which will lead to not failing classes. We go to work to have an income so we can pay for necessary things like food, a home, transportation. We ask someone out with the chance that a relationship might occur. If the consequences are positive, then the relationship between them and the response or stimuli increases. If you study for an X amount of hours and get a A+ on an exam, then the relationship between good grades and motivation to study gets stronger. However, if you ask someone out and they reject, you may experience low self-confidence and lack of self assurance. Which will lower the chances of you asking someone out in the future due to the feeling experienced with rejection; relationship between response and consequences is decreased (Weiten et al., 2013).

Observational learning occurs when the behaviour of an individual is affected by others around them. This learning occurs in three stages. The first being attention; we pay attention to others actions and the consequences that follow. We repeat the ones with positive outcomes and avoid the negative. A very controversial example would be out standards for beauty. Young girls observe photo shopped ideals of women in magazines and commercials looking happy and being around others who seem to love them. The girls then get the idea that if they looked like the women then they would also be as happy and as loved as them. The outcome is a unrealistic standard of beauty passed through generations. The second stage is retention; if we observe something that results in a positive outcome and don't have a chance of repeating it, then we store it in out memory in order to repeat it when given a chance. If for instance you arrive at a restaurant and order a dish, but later observe another individual with a dish that they seem to be enjoying greatly, you will store that information in your memory and the next time your are at the restaurant you will order the same dish to have the same enjoyment they felt. The third stage is reproduction; were an individual tries to reproduce the action observed and stored in his/her memory to their best ability. We can watch someone figure-skate, but when trying to repeat the action the task is harder than observed with no background knowledge or practice (Weiten et al., 2013).

The Sociological Level of Analysis: Taboos[edit]

In every society there are rules that are followed to allow it to function properly. These rules regulate the social behavior of individuals and are often derived through generations. Through generations, social change occurs that causes new social rules to come about, this leading to certain taboos or traditions. For instance, in western society, as well as many others, female students are stereotyped as being weaker at mathematics than their male counterparts. These stereotypes are created through generations and often generalized a person based solely on their appearance. In older times, mathematical subjects were seen as masculine, where as females were taught music, arts, and language subjects due to their femininity. As a society we adapted to this stereotype and many others.

Although we think we can avoid the effects of stereotyping, after years some of our behavior gets affected. This is seen with how females are treated differently than males when it comes to academics and life experiences. We often perceive men who have had relations with many women as desirable and more masculine, while women who have had relations with many men are looked down on and shamed; they are perceived as not respecting of themselves. Females learn of this stereotype early on and often fear being judged in relationships due to how many men they had relations with. Whereas, men who have not had relations with many women often fear being judged for their lack of experience. Academically, females are told that they have a lesser ability to solve mathematical problems than their male counterparts, as well as, excelling at STEM subjects makes them less feminine. This stereotype causes some females to avoid STEM subjects or not work as hard in them to succeed due to the generalization. We adapt to these stereotypes and they are passed through generations.

Different societies may also have certain food that they believe cause certain outcomes, like gaining intelligent, being unintelligent, have a certain disorder or have a birth defect. In western society including Europe, eating cat and dog meat is extremely taboo since these animals are considered beloved pets. However, in China and other parts of the world eating these meats are a normal part the diet (Demick, 2008). In Peru, eating guinea pigs is a common part of a diet, however, in western society the thought of eating such an animal is revolting and barbaric (Morales, 1995). Western society does consume a large amount of beef product and dairy products, which is a extremely taboo in many Hindi societies due to the cow being a sacred animal (Sharpes, 2006). Over time western society experienced events that caused social change to occur and make dogs and cats beloved pets, societies like the ones in China did not go through the same social change and see these animals as food items. We adapted to the change that we should love dogs and cat like family members and get defensive as a society if someone shows cruelty to such animals. These adaptations are passed to generations and are learned by individuals at a young age. For instance, a toddler might grow up with a puppy and might describe the dog as his/her best friend when they reach their teenage years.

The Cognitive Level of Analysis: Adjusting parameters on production[edit]

The cognitive level deals with rules called productions, which entails the mind to do what it does with little information. This is supported with the processing of the outcome of an action. This processing usually involves if-then rules, to create a belief or image that will be put in context in other situations. For instance, if you are hungry, and you go to a new restaurant, then eat. Depending on the outcome, the productions used to get to that thought will be either made stronger or weaker for future events. If the outcome was getting horribly sick from going to the new restaurant, then in the future when you are hungry the thought of that particular restaurant wouldn't be pleasant. A link is formed between the unpleasant experience and getting sick, causing the pathway of that thought not to fire as frequently. If the experience was an excellent one, then the action of eating at that restaurant will be repeated in the future. Since the cognitive level deal with how information is processed, this would be different for everyone in all situations. If a student has a midterm, and they study, then get a excellent marks, the pathway that lead to the decision to study will fire more frequently in the future. However, if another student has does the same process, but ends up with a lower mark or a failing one, the pathway to study will fire less frequently due to the negative outcome that resulted.

The Physical Level of Analysis[edit]

Using the subatomic level to try to explain consciousness is often not taken seriously by many cognitive scientists. Trying to use quantum effects and quantum levels to explain how people learn and process information is more absurd to some cognitive scientists. However, Roger Penrose that just like the universe, the mind and brain are far more complex than what we previously thought. The brain doesn't a have strict function of power up and down for one process at a time, but a complex one that works at the same time on many quantum levels. Unlike a computer that can process many items, but has limitations, the brain is are superior due to lack of limitations (Jones, 2014).

Cognitive Science's Level of Explanation: The Functional or Information Level[edit]

Cognitive science tends to focus on a particular level of analysis. As described in the previous chapter, cognitive science tries to understand minds as though they were computer programs. What this means is that cognitive scientists want to understand how information is processed in minds at a very detailed level.

Where another psychologist might be satisfied with a description of, say, how IQ contributes to, say, memory of lists of digits, statistical models like this at too high a level for the cognitive scientist, who want to go one layer deeper. They want to understand cognition at a level of detail such that one could make a computer program that would process information in the same way.

It is a common misconception that cognitive scientists view minds as computers. Perhaps this was the case early on, but today the computer program is the correct metaphor. We know that people do not have things like hard drives and graphics cards. However, computer programs can be written to simulate any system (to varying degrees of accuracy). Cognitive science looks for explanations not that look like traditional computer programs per se, but explanations that are encoded at the computer-program level of detail.

For example, it is not enough to simply say that people remember the occupations of people they meet. To achieve the level of detail necessary for a cognitive science level of description, one would need to specify other things, such as what symbols are used to encode this information, and how it is indexed in memory so that processes can retrieve it, and other properties such as how easily it is retrieved from memory, whether or not it is believed, and how much, whether it is associated with a probability of being true, what other ideas it is connected to, and so on.

Most cognitive science explanations regard cognition as a program that is running on top of the networks of neurons. For the most part, cognitive scientists view the minds of complex animals, such as humans, as software running on neural hardware. Below the information level is the neural level, and cognitive science has started to take an interest in that as well. In terms of levels of explanation, cognitive scientist are finding ways in which activity best described at the neural level leaks up into the information processing level. For example, synesthesia is a disorder in which senses are often mixed up. For example, feeling shapes when tasting things. The most common form of synesthesia is number-color synesthesia. This is because the parts of the brain that process numbers and colors are literally touching each other.

The Scope of Cognitive Science[edit]

We have distinguished cognitive science from general psychology in that cognitive science is interested in a particular level of explanation. However, cognitive psychologists are also interested in that level of explanation. A further distinction from psychology is that cognitive scientists are interested in all minds, even if they are not animal, where psychology focuses on human and animals minds.

What other kinds of minds are there? There are two salient examples. The first is the class of artificial minds. The term "artificial" in this context is the opposite of "natural." It simply means "human-made." When cognitive scientists and artificial intelligence researchers create computer programs that do intelligent tasks, the behavior of those programs are of interest. Cognitive scientists are interested not only in what cognition is, but what it could be. If alien life is ever discovered, cognitive scientists would be interested in its cognition as well.

The second salient example is that of distributed cognition. This topic will be discussed in detail later in the book, but briefly, distributed cognition is cognition that emerges from a group of interacting entities, such as a person with a calculator, a hive of bees, or perhaps the perception that one's immune system carries out when detecting foreign entities.

Cognitive Science's Methodological Definition[edit]

Cognitive science is also frequently defined by its methodology. In particular, it is the interdisciplinary study of minds. As described in the history chapter, cognitive science uses methodologies primarily from cognitive psychology, artificial intelligence, philosophy, linguistics, and neuroscience. Other fields that contribute, but to a lesser degree, are education, anthropology, and behavioral economics.

What does it mean to be an interdiscipline? This is a topic that is actively discussed; this book will present one answer. An interdiscipline is a community of scholars that acknowledge problems, explanations, and methods of the associated disciplines. Papers written for an interdiscipline will, ideally, remark on the ramifications of the findings and contextualize them with the other associated disciplines as much as possible. This is often limited by the knowledge and abilities of individual researchers. We might contrast an interdiciplinarity with multidiciplinarity, which requires no effort of interaction.

Cognitive science is not the only interdiscipline. Women's studies involves history, philosophy, sociology, political science, literary theory, etc. Religious studies is an interdiscipline involving history, anthropology, and philosophy, among others.

Biochemistry and molecular biology were separate fields at one point, attending different conferences and publishing in different journals. It turned into an interdiscipline, and might now be considered a discipline in its own right. Perhaps someday cognitive science will be its own discipline. For now, most studies that are considered cognitive science studies have methods that clearly come from some subset of the associated disciplines.

What is a Cognitive Scientist?[edit]

A cognitive scientist must use scholarly methods to study the mind. Apart from that, opinions vary. We will offer four definitions, in order of increasing exclusivity:

  1. A cognitive scientist is any scholarly practitioner studying minds from one of the associated sub-fields. According to this definition, a philosopher working on philosophy of mind problems would be considered a cognitive scientist even if she never read about work in other fields, published in other fields, or contextualized her findings with the theories and problems in other fields.
  2. A cognitive scientist is any scholarly practitioner studying minds from one of the associated sub-fields who has a working knowledge of some of the other subfields and actively contextualizes her work with the theories and problems of some of the other subfields. She is active in the cognitive science community.
  3. Same as the definition above, except that she actively collaborates with scholars in other disciplines that use different methods. For example, an artificial intelligence researcher who works with a neuroscientist to make computer models of networks that execute some cognitive task.
  4. A cognitive scientist is any scholarly practitioner studying minds who uses methodologies from multiple associated subfields. For example, if a linguist runs experiments on human participants in addition to her traditional linguistic analysis. She also is a member of the community and contexualizes her findings.


Summary[edit]

Cognitive science is the study of minds, but is further defined in two basic ways: in terms of its preferred level of explanation (that is, the level of a computer program), and in terms of its methodology (that is, an interdiscipline, primarily consisting of cognitive psychology, linguistics, artificial intelligence, philosophy, and neuroscience.)


Study Questions Answers
Under what conditions is a level of analysis acceptable in a scientific field? When accurate predictions can be made in terms of that level's ontology.
What is the metaphor cognitive scientists use to understand minds? They view mind as a computer program (not a computer.)
Cognitive scientists prefer cognition described in detail such that ___. One could write a computer program that would process information in the same way.
In the cognitive science metaphor, mind is __ and the brain is __. software, hardware
What are the main contributing fields of cognitive science? 1. ? 1. Cognitive Psychology (mnemonic: CLAPN' in that all fields clappin' for cognitive science)
What are the main contributing fields of cognitive science? 1. Cognitive Psychology, 2. ? 2. Linguistics (mnemonic: CLAPN' in that all fields clappin' for cognitive science)
What are the main contributing fields of cognitive science? 1. Cognitive Psychology, 2. Linguistics, 3. ? 3. Artificial Intelligence (mnemonic: CLAPN' in that all fields clappin' for cognitive science)
What are the main contributing fields of cognitive science? 1. Cognitive Psychology, 2. Linguistics, 3. Artificial Intelligence, 4. ? 4. Philosophy (mnemonic: CLAPN' in that all fields clappin' for cognitive science)
What are the main contributing fields of cognitive science? 1. Cognitive Psychology, 2. Linguistics, 3. Artificial Intelligence, 4. Philosophy, 5. ? 5. Neuroscience (mnemonic: CLAPN' in that all fields clappin' for cognitive science)

References[edit]

Russell, P.J., S.L. Wolfe, P.E. Hertz, C. Starr, M.B. Fenton, H. Addy, D. Maxwell, T. Haffie, & K. Davey. 2010. Biology: Exploring the Diversity of Life, first Canadian edition. Nelson Education Ltd., Toronto, ON. 892-893 pp.

Weiten, W., D. McCann, D.F. Halpern. 2013. Psychology Themes and Variations: Third Edition. Nelson Education Ltd. Toronto, ON. Di Giuseppe. M., A. Vavitsas., B. Ritter, D. Fraser, A. Arora, and B. Lisser. Biology 12. 2003. Nelson Education Ltd. Toronto. 412-424 pp.

Demick, B. 2008. Chinese seek to pull cats from the menu. Los Angeles Times

Sharpes, D.K. 2006. Sacred Bull, Holy Cow: Cultural Study of Civilization's Most Important Animal. Peter Lang Publishing, Inc. New York. 208-222 pp. Morales, E. 1995. The Guinea Pig: Healing, Food, and Ritual in the Andes. University of Arizona Press

Jones, A.Z. 2014. Is Consciousness Related to Quantum Physics?. About.com Education, Physics.

Runtz, M. 2012. Natural History. Kendall Hunt Publications.

Kolb, B. and Whishaw, I.Q. 2011. An Introduction to Brian and Behaviour: Third Edition. Worth Publishers, United States of America. 255-256 pp.