Relationship between dysfunction of the prefrontal cortex

Relationship between dysfunction of the prefrontal cortex The prefrontal cortex (PFC) is an essential aspect of the frontal lobes in the brain. Executive function is carried out by the prefrontal cortex: where abilities to differentiate among conflicting thoughts and to determine what is good or bad operate. The PFC is connected very compactly with the rest of the brain which allows the PFC to be responsible for guiding features such as memory, emotion, decision-making, planning actions, and attention. If the PFC is damaged and the activity in it is minimal then this affects many things. The PFC could be damaged by lesions or even due to the misuse of drugs or alcohol (Rogers et al., 2010). In turn the damage to the PFC can lead the brain to make irrational decisions; have loss of behavioural control or even have a complete personality change: all of which explain why people may perform antisocial behaviour (ASB). Lesions in the prefrontal cortex have massive effects on decision making. (Manes et al., 2001). ASB stems from the fact that a human being has taken the decision as to whether they should act in a way that is not seen as appropriate in society: therefore, the damage to the PFC may have led them to this decision. Manes (2001) carried out a study to examine this theory. Manes found that out of several different groups he had with lesions in different parts of the brain the group with large frontal lesions was the only group to exhibit risky decision making. This contradicts most other studies: including studies by Benjamin Libet and colleagues which showed that brain activity associated with deliberate decisions can be detected shortly before we are conscious of making the decision. (Libet, 1983) Participants were asked to note when they first felt the intention of making a movement by noting the position of a dot on a computer screen. The participants were first aware of their intentions about 200 milliseconds before actually acting. This is much later than the onset of readiness potential: meaning that the decision to act in a particular way in this study was risky. This experiment was heavily criticised for its accuracy. However, recent research has proven that if anything the actual onset of conscious intention is later. (Lau, 2006). The PFC can not only change the way somebody makes decisions -many studies have proven that lesions in the PFC can cause a complete personality change, where a good mannered personality can be changed instantly to an unpleasant one. (Chow, 2000) This was substantially displayed in the accident of Phineas Gage, (Harlow, 1848) where he survived a horrific accident after a large iron rod went completely through his head, destroying much of his brains left frontal lobe. This accident resulted in a vast personality change of Gage, which raised one of the first discussions as to whether damage to the prefrontal cortex can change a persons behaviour. This then led to even more studies into this issue which resulted in one of the largest studies of patients with brain damage. Grafman (1996) found that the patients that showed an increase in aggression were most strongly associated with PFC lesions in a sample of 279 veterans of the Vietnam War. However, the higher scores were mostly associated with verbal aggression rather than physical. This, yet again, supported Harlows observation of Gage. (Grafman, 1996) The PFC is essential for behavioural control; therefore, this is why PFC lesions lead to ASB. Anti-social behaviour can be described as behaviour that is likely to cause harassment, alarm or distress to [others]. (Riley, 2007). Many studies have demonstrated the direct effect that the PFC has on determining ASB. Violent behaviour is connected with structural and functional shortages in the prefrontal cortex according to many brain imaging studies. A meta-analysis of these studies was carried out by Yang et al (2009), where 43 structural and functional imaging studies were looked at. Results showed an 11% reduction in PFC grey matter in patients with anti-social personality disorder (APD). From all of these studies it was concluded that there is reduced prefrontal structure and function in antisocial individuals. Anderson (1999) also investigated this he examined the long term consequences of PFC lesions before 16 months in two adults. It resulted in the two adults having severely impaired social behaviour despite basic cognitive abilities and also insensitivity to consequences of decisions. The two patients suffered from defective social and moral reasoning; showing attainment of complex social and moral rules had been impaired. This study explained that early prefrontal damage syndrome leads to syndrome resembling psychopathy. A great deal of empirical research demonstrates that mental illness is higher in incarcerated populations and estimates that as many as 25% of defendants evaluated for capability are medically and legally incompetent to stand trial. (Golding, 1984). With this fact in mind, many people argue that minds are simply what brains do (Minsky, 1948) If this is the case then people are controlled by their brain, therefore have little personal choice as to how they behave. It is clear that the PFC has a huge effect on behaviour of human beings. It can have such an effect that it changes a persons entire personality from positive to negative. Anything that minimises the activity in the PFC can lead to negative consequences. It can make somebody less effective at decision making; make people violent and entirely change somebody as a person. All of these things in turn lead to antisocial behaviour which raises huge debate as to whether people who are antisocial due to minimal activity in the PFC are criminals or are innocently mentally ill human beings. It is certain how important the PFC is to the brain and the research that has been carried out shows that we should not abuse the PFC (alcohol, drugs) as it is very significant to enable us to behaviour in a responsible manner.

Fences vs. Oedipus Essay

The Importance of Fatherhood Fatherhood is important and is often taken for granted and not treated with the respect it deserves. In the plays Fences and Oedipus the King, Troy and Oedipus are affected by the lack of fatherhood. In Troy’s case, he fails to be a supportive father to his son, Cory, ultimately distancing himself from his family. As for Oedipus, he is cursed by the gods before his birth, due to his father, Laius, raping and kidnapping a young boy (Weineck). Although the situations of each play are different the need for fathers is very similar. This topic may not seem of much importance but fatherhood can truly affect a child or the actual father. Both of these plays seem to be affected by the past which leads to the fathers putting their problems on the shoulders of their child. Fathers play an important role in a child’s life. Not only are they seen as their rock, but also as their protection. This is especially important in a boy’s childhood. This is shown by the relationship of Troy and Cory. Although, Troy is always around in Cory’s youth, he never gives any support for what Cory does. This is proved when Cory has a chance to talk to a college recruiter about football, but Troy claims he has no future in sports and just needs to give it up and go get a job and start making money (Roberts 1046). This incident, along with other questionable actions, lead to the resentment of Troy, not only by Cory, but by the entire family. The other questionable action by Troy was him cheating on his wife with another woman. This event is what totally crushed his relationship with his family, whom now refused to give him any respect. With no respect for Troy, Cory one day makes a comment towards his father, which does not sit well with Troy. This comment soon turns into an argument which, leads to Cory picking up a bat and threatening Troy. Troy then takes the bat from Cory’s hands and knocks him down (Weales). At this point Troy can show his dominance towards Cory but instead tells him to leave (Roberts 1071). This not only shatters the relationship between Troy and Cory but it shows the carelessness of Troy towards his son. Throughout the rest of the play, when Cory is present, the resentment of Troy is shown. Cory even contemplates not attending Troy’s funeral because he was tired of living in the shadow of his father (Roberts 1074). The relationship of a father to his son is essential to not only the son’s maturation process, but also to the father and his livelihood. Troy and Cory make good examples for this, because after Cory left Troy was never the same and in the same light it can be said the Cory learned from his father. He learned how to not be like his father. Before Oedipus the King, we know that King Laius of Thebes commits a crime in which he is punished for raping and kidnapping a child from a different kingdom. For this crime Laius is cursed by the god, Apollo. The curse stated that Laius’s â€Å"first born son would murder his father then marry his mother†. Instead of Laius abstaining from marriage or sex to prevent this curse from occurring, he marries and has a son, Oedipus (Weineck). This stupidity of Laius begins the failure of his fatherhood. Laius has not only compromised his life but he has created a terrible situation for Oedipus when he is grown. This father and son relationship is not direct but the actions and carelessness of Laius ultimately affect Oedipus, which makes his life literally a living hell. Like in Fences Laius is careless about his son, like Troy. Although Oedipus is his father’s murderer, it is unknown if Oedipus intentionally killed Laius. It is actually said that he was defending himself, so it is hard to put any fault on the lack relationship with Laius (Roberts 786). This lack of relationship also can be said to have led to the downfall of Oedipus. This is because when Oedipus find that he has murdered his father and married his mother he exiles himself. It can be said that if Laius had not impregnated Jocasta, or had he killed Oedipus as an infant, this terrible fate would never had happened. Laius could have also raised Oedipus and created a positive relationship between the two which could have prevented this situation. This relationship between Laius and Oedipus was flawed from before the birth of Oedipus resulting in the horrific fate that Oedipus experienced. This flawed relationship can be argued to have had no chance but it can be seen that at the end of the play Oedipus is affected by the knowing of murdering his father. The difference in Oedipus’s relationship with his father compared to normal father/son relationships was that he never really knew he had a relationship with his father, but all along it was his faulty relationship with Laius that cursed Oedipus in the first place. Although these two plays are very different in time periods, the basic buildup of each play is very similar. Father’s and son’s is a way these two plays connected very well. Laius and Troy perform a very careless fatherhood whereas Oedipus and Cory are helpless and cannot defy what their fathers do or have done. Cory, out of respect for his father, cannot do the thing he wanted to do such as, football, and this resulted in the broken relationship between Cory and Troy. This is comparable to Oedipus, in a way, because he was unable to defy the curse of the gods on his father which also leads to a broken relationship with Laius. These plays at first glance have nothing in common but when broken down they truly have a similarity in the importance of a father.

Medieval vs Renaissance Art Essay

There were no notions of real-life techniques and proportion. Figures, which were more prominent, were drawn larger than the others. All figures are motionless, they sit or stand and there are no attempts to depict movement. There is little in the way of nude bodies, erotic scenes and sexual connotations. People were painted with stoic, serious expressions; the lack of emotions was obvious. Pictures were not voluminous; they were flat and stable. The background was painted with one color. Artists used ordinary basic colors. Paintings weren’t very realistic, but the artists did not necessarily want them to be so. The art was treated as the means of connection with God, and the main purpose of it was to foster the spiritual development of the people. The Early Renaissance starts in Italy in fourteenth century AD due to a number of reasons. According to Jim Lane, perhaps the biggest factor contributing to the rise of the Renaissance was money. He states â€Å"when it became economically feasible to enclose an entire city in fortress walls, then those with money could begin to relax and enjoy it, which meant a craving for beauty that meant art. The city of Florence, Italy, is a classic exampleâ€Å"(Lane, 1998). The church was no longer the only institution with the resources to commission works of art. Religion was not able to serve as the only reason for creativity any more. While religious imagery still dominated many works of art during this period, secular and humanistic themes began to emerge as well. People were in the focus of this art period. They were depicted the way they looked in their real life. It was not uncommon for a wealthy merchant to commission a portrait of himself. People were interested in the anatomy of the human body. The knowledge of anatomy was reflected in the new art. Bodies looked not only real, but attractive for viewers. Most of them were depicted in motion, and appeared much more lifelike. This interest in anatomy precipitated the appearance nude images in paintings and sculpture. An emphasis on natural beauty, and the human form began to emerge. All figures were placed on the canvas considering the perspective. Painters paid attention to light; they started using the technique of shadows and lights in their paintings. Artists were interested in the way people express their emotions and did their best to render the emotional expressions on the faces of people on the paintings. The same features occurred in sculpture as well. It is obvious that art develops in relation to the prior art periods. Some periods build upon the tone and style of earlier periods, while others strike out in new ways in reaction to the earlier period. There are clear examples of how Renaissance art continued the traditions of medieval art. However, the combinations of new styles, techniques, subjects, and philosophies leads to the conclusion the Renaissance developed in reaction to the medieval era. The Renaissance served as the transitional period between the medieval art and the new period in human history. The Renaissance brought significant change to the world of art. Artists started creating art for the sake of art, and not necessarily for the sake of god. They created new art forms, and mastered their skills in order to make things look as they are in real life on the canvas. God was not the only point of depiction. The Renaissance Art is much closer to the conception of art which is common now. It uses mixed colors, shades, real sizes, and perspective. Unlike Renaissance art, medieval art is more primitive. The pieces of art were representations of crucial spiritual content. These differences are best explained by examining a few examples. For instance, the medieval Virgin Mary is rather specific (Duccio, 1300). She is depicted only with the upper part of her body. She holds the infant in her arms. Her face is cold and reserved. The background is static. All objects are two-dimensional; there is no volume or change in colors. The picture lacks dynamics. At the same time, it is a classical representation of Virgin Mary. It was created for the purpose of religious worship. The Virgin Mary is the main figure at the picture. In this respect, the infant on her hands is smaller than he should be in reality. Madonna is the representation of Virgin Mary in Renaissance art. Madonna Litta by da Vinci (1490) shows the tendencies of how the art developed. First of all, both Madonna and her child look lifelike. They appear much more human in their facial complexion, proportions and positions. They are not static. The child holds his finger in his mouth. He is playful and alive. Madonna holds him in her hands and looks at him carefully. Viewers can notice the feelings of comfort and pleasure in the way she looks at her baby. This transition from expressionless, some may say emotionless, depictions of humans to lifelike, active characters can be seen throughout Renaissance art. The Renaissance artists wanted to depict realism in their art. They strived to have the images correspond in some way to the real world. In this respect, they tried to learn how to paint the world they have, not only the world which belongs to Saints. This shift in philosophy during this period created the necessity to create art in a different manner. People became interested in themselves. This may be the most obvious reason why these two art periods are so different. At the same time, Renaissance art is the logical continuation of the development of art in human history. People do not stay the same; the world is changing, so the art changes too. It is hard to imagine that the Renaissance period would have developed in the manner that it did without the foundation laid during the medieval period. It’s clear that later periods built extensively off the techniques and philosophies developed during the Renaissance. The Renaissance served as the greatest transitional period from earlier, more primitive styles, and set the stage for modern art as we know it. References Duccio di Buoninsegna. (1300) Madonna and Child [Picture]. Retrieved from: http://www. metmuseum. org/toah/works-of-art/2004. 442 da Vinci, L. (c. 1490) Madonna Litta. [Picture]. Retrieved from: http://www. abcgallery. com/L/leonardo/leonardo13. html Lane, J. (1998). Renaissance (1400 – 1600). Retrieved from: http://www. humanitiesweb. org/spa/gil/ID/35

What Is Correlation in Statistics

Sometimes numerical data comes in pairs. Perhaps a paleontologist measures the lengths of the femur (leg bone) and humerus (arm bone) in five fossils of the same dinosaur species. It might make sense to consider the arm lengths separately from the leg lengths, and calculate things such as the mean, or the standard deviation. But what if the researcher is curious to know if there is a relationship between these two measurements? Its not enough to just look at the arms separately from the legs. Instead, the paleontologist should pair the lengths of the bones for each skeleton and use an area of statistics known as correlation. What is correlation? In the example above suppose that the researcher studied the data and reached the not very surprising result that dinosaur fossils with longer arms also had longer legs, and fossils with shorter arms had shorter legs. A scatterplot of the data showed that the data points were all clustered near a straight line. The researcher would then say that there is a strong straight line relationship, or correlation, between the lengths of arm bones and leg bones of the fossils. It requires some more work to say how strong the correlation is. Correlation and Scatterplots Since each data point represents two numbers, a two-dimensional scatterplot is a great help in visualizing the data. Suppose we actually have our hands on the dinosaur data, and the five fossils have the following measurements: Femur 50 cm, humerus 41 cmFemur 57 cm, humerus 61 cmFemur 61 cm, humerus 71 cmFemur 66 cm, humerus 70 cmFemur 75 cm, humerus 82 cm A scatterplot of the data, with femur measurement in the horizontal direction and humerus measurement in the vertical direction, results in the above graph. Each point represents the measurements of one of the skeletons. For instance, the point at the bottom left corresponds to skeleton #1. The point at the upper right is skeleton #5. It certainly looks like we could draw a straight line that would be very close to all of the points. But how can we tell for certain? Closeness is in the eye of the beholder. How do we know that our definitions of closeness match with someone else? Is there any way that we could quantify this closeness? Correlation Coefficient To objectively measure how close the data is to being along a straight line, the correlation coefficient comes to the rescue. The correlation coefficient, typically denoted r, is a real number between -1 and 1. The value of r measures the strength of a correlation based on a formula, eliminating any subjectivity in the process. There are several guidelines to keep in mind when interpreting the value of r. If r 0 then the points are a complete jumble with absolutely no straight line relationship between the data.If r -1 or r 1 then all of the data points line up perfectly on a line.If r is a value other than these extremes, then the result is a less than perfect fit of a straight line. In real-world data sets, this is the most common result.If r is positive then the line is going up with a positive slope. If r is negative then the line is going down with negative slope. The Calculation of the Correlation Coefficient The formula for the correlation coefficient r is complicated, as can be seen here. The ingredients of the formula are the means and standard deviations of both sets of numerical data, as well as the number of data points. For most practical applications r is tedious to compute by hand. If our data has been entered into a calculator or spreadsheet program with statistical commands, then there is usually a built-in function to calculate r. Limitations of Correlation Although correlation is a powerful tool, there are some limitations in using it: Correlation does not completely tell us everything about the data. Means and standard deviations continue to be important.The data may be described by a curve more complicated than a straight line, but this will not show up in the calculation of r.Outliers strongly influence the correlation coefficient. If we see any outliers in our data, we should be careful about what conclusions we draw from the value of r.Just because two sets of data are correlated, it doesnt mean that one is the cause of the other.