Everyone gossips. It is an inherent social trait of human beings, despite tending to have negative meaning to most. In fact, two thirds of conversations are devoted to social topics (Dunbar 2004). It is one of the most common uses for language, and it may even be that language evolved primarily for this purpose. Because of its prominence in human function, it is essential to learn how gossip and spending two thirds of our time talking about others was selected for evolutionarily.
In order for a trait to be passed on and integrate itself into a genetic legacy, it must give its members an advantage of some kind. It is easy to see the selective advantage of claws for hunting, broader leaves for greater light absorption, or opposable thumbs for skilled tool use, but the advantages of language and gossip are less obvious. The answers to why we spend our lunch breaks chatting with Phil about his love life may lie with our primate ancestors and chimpanzee cousins.
Modern chimpanzees maintain close social groups of around 55. The group interactions are complex, and rivalries, wars, group splits, and high drama is common in the wild. Underlying the group actions of chimpanzees are the individual social actions, especially grooming. Chimpanzees spend as much as 20% of their time grooming one another. This time could be spent hunting or reproducing, but the complex social structure of primate groups demands that individual relationships be maintained through social grooming (Gazzaniga 2008).
As hominids evolved and grew bigger brains, specifically bigger neocortical size, their capacity for maintaining larger social groups also grew. But, the more members of the social group, the more people you need to groom to keep social order and the less time spent hunting and reproducing. Eventually, grooming became less selective because of the detriment to other survival needs, and this is where language began to take hold (MacLeod 2005). When maintaining relationships with 150-200 people (the maximum social group size of most humans), language becomes a much more efficient way to keep social order and still perform other survival tasks. Gazzaniga (2008) writes,
“If language began to substitute for grooming, one could “groom”, that is to say, gossip, while doing other things, such as foraging, traveling, and eating.”
The emergence of language as our method of grooming creates other problems, however. Language allows cheating or lying, as well as deception, interpretation/misinterpretation of meaning, and the need to understand others’ viewpoint. For the first time in evolutionary history, hominids have needed to “put themselves in the other’s shoes”. This may have led to modern homo sapiens’ theory of mind, the ability to ascribe mental states and other attributes to other people. It has also led to our ability to identify cheaters, deceive ourselves, and use language as a means to reproduce (flirting).
Works cited:
Dunbar, R.I.M. (2004).Gossip in evolutionary perspective. Review of General Psychology. 8(2), 100-110.
Gazzaniga, M.S. (2008). Human. New York, New York: HarperCollins.
MacLeod, M., & Graham-Rowe, D. (2005). Every primate's guide to schmoozing. New Scientist. 187, 10.
Monday, February 23, 2009
Brain lateralization and Interpreting Intentions
M.A. Goodale and A.D. Milner discuss the possibility of separate neurological processing streams for visual sensory information in A neurological dissociation between perceiving objects and grasping them. They present the case of a woman, D.F., who has brain damage ventrally in the lateral occipital region and parasagittal occipitoparietal region. They tested separate processing streams by using D.F. as a subject.
D.F. was asked to perform a series of trials that showed the remarkable difference in her ability to perceive object orientation and her ability to direct accurate movements with objects in differing orientations. Her results were compared to control subjects. In one instance, D.F. was asked to report the orientation of lines corresponding with orientation slots, as well as the orientation of blocks on a table. She had huge errors in verbally reporting these orientations, even confusing horizontal for vertical. In sharp contrast, when asked to physically place cards in slots, she performed with excellence, and showed behavioral signs of comprehending the object’s orientation and correct placement from the moment her hand began moving. In addition to simply orientation, object size and form were tested with D.F. In these tests, she had difficulty reporting whether white plaques of differing dimensions were different or alike (52% accuracy), but when asked to pick up the plaques, she showed strong behavioral evidence of knowing the object’s dimension, and did not differ from control subjects.
These results suggest “separate processing systems not for different subsets of visual information, but for the different uses to which vision can be put.” This means that there must be an area that processes conscious perceptual judgments separate from one that operates our automatic visuomotor processes that mediate skilled movements. This necessitates serious study not just of the visual/sensory inputs but also the patterns of output connections, processed internally within the brain and determined independent of visual information type. In other words, we need to look at what people mean to do with what they see, and not just study what they are seeing.
This undercuts those who believe visual information is interpreted and responded to only by the visual cortex and then sent to other brain functions as either spatial localization or object identification. There is clear evidence in this research of multiple, distinct brain areas that correspond with specific systems for processing different intentions associated with the visual information. This may even suggest that our brain has evolved to process our intentions as carefully as it processes our senses.
Further research since 1991 has been performed by a number of scientists. As one example, Clavagnier et al. (2000) assert further evidence for “functional subdivisions”. Their research focused primarily on the posterior parietal cortex. The numerous studies in this realm all point to the great degree of lateralization in the human brain. Gazzaniga (2008) discusses the lateralization of the human brain’s language centers: Broca’s and Wernicke’s areas, and suggests that this lateralization may be what makes humans truly unique from our primate ancestors. We not only need to process the phonemes of speech and how to recreate those sounds, but also their function and meaning. It is the toil of processing the semantics and pragmatics of language that has led to some of the unique lateralizations in the human brain.
Works Cited:
Clavignier, S., et al. (2000).Two systems of spatial representation: evidence from parietal lesions in humans. European Journal of Neuroscience. 12, 2.
Gazzaniga, M.S. (2008). Human. New York, New York: HarperCollins.
Goodale, M.A., & Milner, A.D. (1991). A neurological dissociation between perceiving objects and grasping them. Nature. 349, 154-156.
D.F. was asked to perform a series of trials that showed the remarkable difference in her ability to perceive object orientation and her ability to direct accurate movements with objects in differing orientations. Her results were compared to control subjects. In one instance, D.F. was asked to report the orientation of lines corresponding with orientation slots, as well as the orientation of blocks on a table. She had huge errors in verbally reporting these orientations, even confusing horizontal for vertical. In sharp contrast, when asked to physically place cards in slots, she performed with excellence, and showed behavioral signs of comprehending the object’s orientation and correct placement from the moment her hand began moving. In addition to simply orientation, object size and form were tested with D.F. In these tests, she had difficulty reporting whether white plaques of differing dimensions were different or alike (52% accuracy), but when asked to pick up the plaques, she showed strong behavioral evidence of knowing the object’s dimension, and did not differ from control subjects.
These results suggest “separate processing systems not for different subsets of visual information, but for the different uses to which vision can be put.” This means that there must be an area that processes conscious perceptual judgments separate from one that operates our automatic visuomotor processes that mediate skilled movements. This necessitates serious study not just of the visual/sensory inputs but also the patterns of output connections, processed internally within the brain and determined independent of visual information type. In other words, we need to look at what people mean to do with what they see, and not just study what they are seeing.
This undercuts those who believe visual information is interpreted and responded to only by the visual cortex and then sent to other brain functions as either spatial localization or object identification. There is clear evidence in this research of multiple, distinct brain areas that correspond with specific systems for processing different intentions associated with the visual information. This may even suggest that our brain has evolved to process our intentions as carefully as it processes our senses.
Further research since 1991 has been performed by a number of scientists. As one example, Clavagnier et al. (2000) assert further evidence for “functional subdivisions”. Their research focused primarily on the posterior parietal cortex. The numerous studies in this realm all point to the great degree of lateralization in the human brain. Gazzaniga (2008) discusses the lateralization of the human brain’s language centers: Broca’s and Wernicke’s areas, and suggests that this lateralization may be what makes humans truly unique from our primate ancestors. We not only need to process the phonemes of speech and how to recreate those sounds, but also their function and meaning. It is the toil of processing the semantics and pragmatics of language that has led to some of the unique lateralizations in the human brain.
Works Cited:
Clavignier, S., et al. (2000).Two systems of spatial representation: evidence from parietal lesions in humans. European Journal of Neuroscience. 12, 2.
Gazzaniga, M.S. (2008). Human. New York, New York: HarperCollins.
Goodale, M.A., & Milner, A.D. (1991). A neurological dissociation between perceiving objects and grasping them. Nature. 349, 154-156.
Wednesday, February 11, 2009
Dead Dualism
Scientists have long understood reverence for the dead as being a behavior unique to humans. According to Gazzaniga, this behavior may be due in part to our dualistic tendencies. We unreflectively perceive that a particular human is more than just a body; there is something about each human that transcends the body—an essence. Common expressions like “beauty is on the inside” attest to our implicit beliefs that the abstract “person” has worth, and all corporeal qualities are accidental and irrelevant. At death even, the dead and dysfunctional state of the body does not take away from our hopes that the particular person will live on. In sum, dualistic beliefs in regards to the dead end up being quite religious.
When did this sort of dualistic reverence for the dead begin to happen? Ina Wunn argues that interpretation has become a problem when it comes to archaeological excavations, and archaeologists too quickly attribute significance to early burials. For example, many believe that in the Middle Paleolithic (150,000 to 35,000 years ago) Neanderthals and Homo sapiens participated in complex religious rituals. Because Neanderthals buried their dead in sleeping positions, and surrounded them by goat horns, stone tools, and skins, archaeologists speculate that Neanderthals may have had the notion that, because they are hunters in this life, they will still be hunters after they die in the next life (Joseph 2001). But Wunn explains that the Neanderthal man must have felt rage, mourning, and confusion at the loss of a beloved person, which could have induced the Neanderthal to affectionately handle the corpse. At most a hesitation to leave a loved-one, the Neanderthal burials by no means implicate a dualistic perspective or belief in the afterlife.
Another big research question has been about whether other species have elaborate reactions to dead con-specifics, which may mean we are not the only dualists. Of course, other animals would not have the symbol system to be able to hold intellectual beliefs about the afterlife, but they surely may have a type of categorizing that remembers and has feelings for the dead individual, despite the dead body. Elephants in particular have been observed to pay great attention to carcasses of con-specifics. In a study by McComb and Baker (2006) the team performed three experiments to see whether this claim is true. In the first experiment they observed the reactions to and time spent with an elephant skull, a piece of ivory, and a piece of wood. In the second, the elephants had the choice of an elephant skull, a rhino skull, or a buffalo skull. In the final, they placed three skulls of recent matriarchs in front of the elephants, only one of which was a relative. The results indicated very significant preferences for elephant skulls or ivory over other objects, and no significant difference between the matriarchs.
The researchers conclude that the elephants do have strong preferences for the dead among their species, recognizable through the ivory material. Does this study, however, automatically cancel out any chance of elephants being dualistic, as Gazzaniga claims it does? Not exactly. First of all, it may be significant that the skull of the relative is taken out of its scene-of-death context. The elephant-that-never-forgets may remember the location of a dead relative, but its actual skull (especially cleaned of any scent or body rot) may be very unrecognizable to an elephant. Humans certainly would not easily remember the skull of a loved one, but might become reverent at the sight of any human remains. Either way, there is no ruling out of a general respect for the dead among elephants that is found in very few species besides humans. And there is certainly no saying that an elephant may not be thinking “this skull once belonged to a living elephant.” It may be interesting, if anything is known about elephant brains, and whether it is actually possible or practical to give elephants brain scans, to see what parts of the brain are activated during their investigations of the dead. Particularly it would be interesting if their emotional centers were at work.
Works Cited
Gazzaniga, M.S. 2008. Human: The Science Behind What Makes Us Unique. Harper Collins:
Joseph, R. 2001. The limbic system and the soul: Evolution and the neuroanatomy of religious experience. Zygon. 36:;105-136.
McComb, K., L. Baker, C. Moss. 2006. African elephants show high levels of interest in the skulls and ivory of their own species. Biology Letters. 2:26-28.
Wunn,
Swearing Study
We have two groups. One watches a movie during which the characters swear profusely (like The Boondock Saints), the others watch a children's movie (like The Jungle Book). Then all the participants are given an extensive survey which asks amongst other questions how often the given participants swear or use profanity. Then after the lengthy survey is completed and handed in the experimenter will accidently spill coffee all over and inform the participants that they need to re-do new surveys. We will listen for who is more likely to swear.
Emotional Suppression
James Gross and his colleagues were very interested in simulation and the emotional effect it could have on people. According to Michael Gazzaniga, they “thought that since reappraisal isn’t so cognitively taxing, it should have more positive social consequences” (Gazzaniga 186). The experiment they designed was quite simple, but it was their ability to monitor physiological reactions that proved most insightful. Groups of women who did not know each other watched a movie that would normally cause a negative reaction, and then met to discuss the film. A percentage of the women were given instructions for how to behave during their interaction. Some were told to suppress how they felt so that their responses were undetectable, others to reappraise why they felt that way so that it would not bother them, others to interact as they normally would, and all of their partners had no idea (Gazzaniga 186).
The results of this experiment were very distinct. When the woman with whom another participant was interacting was suppressing her emotional response, and only in that condition, the uninstructed woman’s blood pressure would increase noticeably (Gazzaniga 186).
Quite directly inferred by the experimenters was the fact that, “interacting with people who express little positive emotion and who are unresponsive to emotional cues actually increases the cardiovascular activity in their social partners” (Gazzaniga 186). This confirmed what Gross suspected when he hypothesized that having to focus on oneself limited one’s ability to respond to the person with which one interacts. The conscious attention that is being paid to someone not only affects the response of the person he or she is conversing with, but also similarly affects the suppresser’s physiological state. This shows how important simulation is in social interaction, because of the negative results which appear when people provide and/or receive no feedback (Gazzaniga 186).
While there is not much to dispute within the interpretation of the results of this experiment, it would be most interesting to have had the brain activity of the participants monitored during the discussions. The only concrete evidence that is provided comes from the increased cardiovascular activity. Observing the behavior of the brain as it tried to suppress emotion, or as it dealt with an unresponsive partner could provide more insights as to what areas have to do with simulation, perception, self-monitoring, and self-control.
Perhaps the most interesting thing which can be discussed with this information is the ability of people to detect and respond, even subconsciously, when the attention of others is devoted. It only serves to highlight the difficulty in successfully lying, and create a larger gap between truly listening to someone and focusing on what you are going to say next. Especially in situations where one is in emotional need of support, such as Gross’ experiment, it can be especially detrimental to refuse responding to someone.
Also very significant, for a broader outlook, is the effect of emotions and cognitive activity upon the rest of the body. This is almost a slap in the face to the mind-body discussion. If we can consciously manipulate what we reveal about our emotional state to others and manipulation (or perception of it in others) affects important physical systems in our bodies, there is an undeniable connection between emotional interactions and physical well-being. It would be interesting to evaluate children who came from unstable or emotionally depraved living situations on a variety of health standards compared with their peers from more affectionate and emotionally responsive homes.
Gazzaniga, Michael S. Human: The Science Behind What Makes Us Unique. New York: Harper Collins, 2008. pp. 184-186.
Gross, J.J. (2002). Emotion regulation: Affective, cognitive, and social consequences. Psychophysiology 39: 281-91.
Gross, J.J., et al. (2003). The social consequences of expressive suppression. Emotion 3: 48-67.
The results of this experiment were very distinct. When the woman with whom another participant was interacting was suppressing her emotional response, and only in that condition, the uninstructed woman’s blood pressure would increase noticeably (Gazzaniga 186).
Quite directly inferred by the experimenters was the fact that, “interacting with people who express little positive emotion and who are unresponsive to emotional cues actually increases the cardiovascular activity in their social partners” (Gazzaniga 186). This confirmed what Gross suspected when he hypothesized that having to focus on oneself limited one’s ability to respond to the person with which one interacts. The conscious attention that is being paid to someone not only affects the response of the person he or she is conversing with, but also similarly affects the suppresser’s physiological state. This shows how important simulation is in social interaction, because of the negative results which appear when people provide and/or receive no feedback (Gazzaniga 186).
While there is not much to dispute within the interpretation of the results of this experiment, it would be most interesting to have had the brain activity of the participants monitored during the discussions. The only concrete evidence that is provided comes from the increased cardiovascular activity. Observing the behavior of the brain as it tried to suppress emotion, or as it dealt with an unresponsive partner could provide more insights as to what areas have to do with simulation, perception, self-monitoring, and self-control.
Perhaps the most interesting thing which can be discussed with this information is the ability of people to detect and respond, even subconsciously, when the attention of others is devoted. It only serves to highlight the difficulty in successfully lying, and create a larger gap between truly listening to someone and focusing on what you are going to say next. Especially in situations where one is in emotional need of support, such as Gross’ experiment, it can be especially detrimental to refuse responding to someone.
Also very significant, for a broader outlook, is the effect of emotions and cognitive activity upon the rest of the body. This is almost a slap in the face to the mind-body discussion. If we can consciously manipulate what we reveal about our emotional state to others and manipulation (or perception of it in others) affects important physical systems in our bodies, there is an undeniable connection between emotional interactions and physical well-being. It would be interesting to evaluate children who came from unstable or emotionally depraved living situations on a variety of health standards compared with their peers from more affectionate and emotionally responsive homes.
Gazzaniga, Michael S. Human: The Science Behind What Makes Us Unique. New York: Harper Collins, 2008. pp. 184-186.
Gross, J.J. (2002). Emotion regulation: Affective, cognitive, and social consequences. Psychophysiology 39: 281-91.
Gross, J.J., et al. (2003). The social consequences of expressive suppression. Emotion 3: 48-67.
Sally, Ann, and Asch
Advanced Theory of Mind is often cited as one of the key characteristics which make humans unique. Other primates can be shown to have a lesser developed Theory of Mind, as showed by scientists at Tomasello’s lab (Gazzaniga 51) in the false-belief Sally and Ann task. The apes are at about the same level as a child before he reaches the age of four or five. In order to pass this task, the subject needs to be able to realize that one of the other participants has a false belief about the location of an object (one that the subject saw moved while the other was out of the room). This has long been a type of standard in evaluating Theory of Mind. Taking these results as precedent, it is a little disconcerting to examine Solomon Asch’s line test, which has become a classic example in social psychology. The set-up for his experiment was to plant the subject in a room with seven confederates. Essentially, the process was to show the participants series of lines, asking which one was the longest. Going down the row, one by one, each participant would answer with his or her opinion as to which was the longest, the true subject being asked last, after hearing everyone else’s answer. Asch was sure to make all of the lengths distinct, so that it would be relatively obvious which line was the longest (Gazzaniga 144).
After a series in which all of the participants were correct, Asch had his planted participants answer incorrectly, stating that the lines were of equal length, or even the opposite of their true relation. The real subject, being last in the line, would hear all of these answers and more often than not, would agree with the incorrect response (Gazzaniga 144). Psychologists tell us that the percentage who agreed changed if there was even one other person present who stated the correct answer (Aronson 242).
After discussing their performance with the experimenters, it seemed that people had different reasons for going along with the group, such as avoiding embarrassment or thinking there was something wrong with their own perception (Aronson 242). This experiment is usually interpreted in light of the field of social psychology. So the results are credited to the effect of social pressure on a person’s behavior.
There is nothing unfounded in the interpretation of these results, and since it has become a classic experiment in social psychology, it obviously has provided huge insights. It might be important though, to examine the similarity the set up of this procedure has to that of the Sally and Ann task. Some of the participants claimed to think that they themselves had false beliefs about the length of the line. However, these opinions seemed based off of their Theory of Mind which said that the others in the group had had correct opinions in the past, so perhaps the majority was right. This occurred even though the subjects thought they had seen something contradictory. Isn’t this what happens in the false-belief test? A participant who has provided consistently correct answers provides a guess which is in opposition to what the subject has seen, but those with underdeveloped Theory of Mind still say that the other is correct. Although it is not likely that apes responded incorrectly because they were embarrassed to contradict the other, they were assuming the other to be right, which seems to be a relatively simple form of what the subjects in Asch’s experiment based their answers upon. Perhaps a new indicator of Theory of Mind is in demand.
Aronson, Elliot, et al. Social Psychology. Prentice Hall: New Jersey, 2007. pp. 240-245.
Asch, S. (1956). Studies of independence and conformity: A minority of one against a unanimous majority. Psychological Monographs 70: 1-70.
Call, J., and Tomasello, M. (1999). A nonverbal false belief task: The performance of children and great apes. Child Development 70: 381-95.
Gazzaniga, Michael S. Human: The Science Behind What Makes Us Unique. New York: Harper Collins, 2008. pp. 51, 144.
After a series in which all of the participants were correct, Asch had his planted participants answer incorrectly, stating that the lines were of equal length, or even the opposite of their true relation. The real subject, being last in the line, would hear all of these answers and more often than not, would agree with the incorrect response (Gazzaniga 144). Psychologists tell us that the percentage who agreed changed if there was even one other person present who stated the correct answer (Aronson 242).
After discussing their performance with the experimenters, it seemed that people had different reasons for going along with the group, such as avoiding embarrassment or thinking there was something wrong with their own perception (Aronson 242). This experiment is usually interpreted in light of the field of social psychology. So the results are credited to the effect of social pressure on a person’s behavior.
There is nothing unfounded in the interpretation of these results, and since it has become a classic experiment in social psychology, it obviously has provided huge insights. It might be important though, to examine the similarity the set up of this procedure has to that of the Sally and Ann task. Some of the participants claimed to think that they themselves had false beliefs about the length of the line. However, these opinions seemed based off of their Theory of Mind which said that the others in the group had had correct opinions in the past, so perhaps the majority was right. This occurred even though the subjects thought they had seen something contradictory. Isn’t this what happens in the false-belief test? A participant who has provided consistently correct answers provides a guess which is in opposition to what the subject has seen, but those with underdeveloped Theory of Mind still say that the other is correct. Although it is not likely that apes responded incorrectly because they were embarrassed to contradict the other, they were assuming the other to be right, which seems to be a relatively simple form of what the subjects in Asch’s experiment based their answers upon. Perhaps a new indicator of Theory of Mind is in demand.
Aronson, Elliot, et al. Social Psychology. Prentice Hall: New Jersey, 2007. pp. 240-245.
Asch, S. (1956). Studies of independence and conformity: A minority of one against a unanimous majority. Psychological Monographs 70: 1-70.
Call, J., and Tomasello, M. (1999). A nonverbal false belief task: The performance of children and great apes. Child Development 70: 381-95.
Gazzaniga, Michael S. Human: The Science Behind What Makes Us Unique. New York: Harper Collins, 2008. pp. 51, 144.
Comparitive Frontal Lobe Size
In 1997, Katerina Semendeferi and her colleagues published their study on comparative frontal lobe sizes in the Journal of Human Evolution. The subjects whose frontal lobe sizes were determined were ten humans, six chimpanzees, three bonobos, two gorillas, four orangutans, four gibbons, and five monkeys. The number of primates exceeded the sample numbers of all previous studies of primate neuroanatomy (Gazzaniga 19).
There was not much surprise felt by the smug Homo sapiens when the results showed that their frontal lobe volumes were the largest in the group. However, it was previously supposed that the proportional size in humans would also exceed expectations, which it did not. In fact, the frontal lobe, compared to the rest of the brain, was quite similar amongst all of the test subjects (Gazzaniga 19).
The factual conclusion of what Semendeferi’s study found was that the human frontal lobe is the size that would be predicted for a brain that size among primates. Since the frontal lobe is significant to language and thought, the researchers offered a few explanations for these higher functions. The first is that the region could have been reorganized with selective cortical area enlargement. Another option is the development of increased intra and interconnectedness of neural circuits in brain sectors. There is the also the possibility for the modification of local circuitry within subsectors of the frontal lobe. Finally, subsectors could have been added or dropped as deemed most beneficial. Upon hearing these results, Todd Preuss noted that it is important to differentiate between the frontal and the prefrontal cortex (the prefrontal is further towards the front and has an extra later of neurons). He suggests that there might be a percentage difference between these two sectors, allowing the more sophisticated prefrontal cortex to comprise more of the area. Semendeferi confirms the potential in this hypothesis by mentioning that area 10, which is in the prefrontal cortex, is close to two times larger in humans than in apes (Gazzaniga 20).
At first, the results of Semendeferi’s study turn the world of common opinion on its head. When many are discovering things, such as higher intelligence and mental capabilities, which point towards the uniqueness of humanity, it is unsettling to hear that there is nothing great about the area of the human brain so involved in higher functioning. Preuss’ explanation and the final suggestion of the researchers make a lot of sense from an evolutionary standpoint – an organism minimizing or even eliminating less beneficial parts in order to maximize space available for new advantageous areas. It also maintains a closer link with apes. It is for that same reason that the lack of difference becomes a bit disconcerting. The uniqueness of Homo sapiens is in danger, if the ability for higher functioning could be realized in other apes as their prefrontal and frontal cortexes became more efficient. If the natural course of evolution produces apes with advanced language, memory, and moral abilities, it will be more difficult to classify humanity as distinct. It is more comforting to presume that the conditions which led to the development of those abilities are unique to Homo sapiens, and the possibility for them to present themselves to another species is past. Essentially, what is most adaptive for humanity is advanced intelligence, but even the “perfect” orangutan would never develop a sophisticated theory of mind. This then begs the question of what would determine that humans should be the lucky ones; which enforces the uniqueness. Yet who is to say that the intelligence developed in Homo sapiens is superior to the songs of whales? However, uniqueness has never required superiority.
Gazzaniga, Michael S. Human: The Science Behind What Makes Us Unique. New York: Harper Collins, 2008. pp. 19-20.
Preuss, T.M. (2001). The dsicovery of cerebral diversity: An unwelcome scientific revolution. In Falk, D., and Gibson, K. (eds.), Evolutionary Anatomy of the Primate Cerebral Cortex (pp. 138-64). Cambridge: Cambridge University Press.
Semendeferi, K., et al. (1997). The evolution of the frontal lobes: A volumetric analysis based on three-dimensional reconstructions of magnetic resonance scans of human and ape brains. Journal of Human Evolution 32: 375-88.
Semendeferi, K., et al. (2001). Prefrontal cortex in humans and apes: A comparitive study of area 10. American Journal of Physical Anthropology 114: 224-41.
There was not much surprise felt by the smug Homo sapiens when the results showed that their frontal lobe volumes were the largest in the group. However, it was previously supposed that the proportional size in humans would also exceed expectations, which it did not. In fact, the frontal lobe, compared to the rest of the brain, was quite similar amongst all of the test subjects (Gazzaniga 19).
The factual conclusion of what Semendeferi’s study found was that the human frontal lobe is the size that would be predicted for a brain that size among primates. Since the frontal lobe is significant to language and thought, the researchers offered a few explanations for these higher functions. The first is that the region could have been reorganized with selective cortical area enlargement. Another option is the development of increased intra and interconnectedness of neural circuits in brain sectors. There is the also the possibility for the modification of local circuitry within subsectors of the frontal lobe. Finally, subsectors could have been added or dropped as deemed most beneficial. Upon hearing these results, Todd Preuss noted that it is important to differentiate between the frontal and the prefrontal cortex (the prefrontal is further towards the front and has an extra later of neurons). He suggests that there might be a percentage difference between these two sectors, allowing the more sophisticated prefrontal cortex to comprise more of the area. Semendeferi confirms the potential in this hypothesis by mentioning that area 10, which is in the prefrontal cortex, is close to two times larger in humans than in apes (Gazzaniga 20).
At first, the results of Semendeferi’s study turn the world of common opinion on its head. When many are discovering things, such as higher intelligence and mental capabilities, which point towards the uniqueness of humanity, it is unsettling to hear that there is nothing great about the area of the human brain so involved in higher functioning. Preuss’ explanation and the final suggestion of the researchers make a lot of sense from an evolutionary standpoint – an organism minimizing or even eliminating less beneficial parts in order to maximize space available for new advantageous areas. It also maintains a closer link with apes. It is for that same reason that the lack of difference becomes a bit disconcerting. The uniqueness of Homo sapiens is in danger, if the ability for higher functioning could be realized in other apes as their prefrontal and frontal cortexes became more efficient. If the natural course of evolution produces apes with advanced language, memory, and moral abilities, it will be more difficult to classify humanity as distinct. It is more comforting to presume that the conditions which led to the development of those abilities are unique to Homo sapiens, and the possibility for them to present themselves to another species is past. Essentially, what is most adaptive for humanity is advanced intelligence, but even the “perfect” orangutan would never develop a sophisticated theory of mind. This then begs the question of what would determine that humans should be the lucky ones; which enforces the uniqueness. Yet who is to say that the intelligence developed in Homo sapiens is superior to the songs of whales? However, uniqueness has never required superiority.
Gazzaniga, Michael S. Human: The Science Behind What Makes Us Unique. New York: Harper Collins, 2008. pp. 19-20.
Preuss, T.M. (2001). The dsicovery of cerebral diversity: An unwelcome scientific revolution. In Falk, D., and Gibson, K. (eds.), Evolutionary Anatomy of the Primate Cerebral Cortex (pp. 138-64). Cambridge: Cambridge University Press.
Semendeferi, K., et al. (1997). The evolution of the frontal lobes: A volumetric analysis based on three-dimensional reconstructions of magnetic resonance scans of human and ape brains. Journal of Human Evolution 32: 375-88.
Semendeferi, K., et al. (2001). Prefrontal cortex in humans and apes: A comparitive study of area 10. American Journal of Physical Anthropology 114: 224-41.
Wednesday, February 4, 2009
Human Simulation as Basis for Advertising?
Simulation may be the reason why some kinds of advertising work well. Advertising often involves people with a product. Those people, of course, are usually very happy to have that product! They are also usually young, attractive, worthy of respect and admiration, etc.
If people are very influenced by such advertisements, it may be because they are wired for simulation. The person, whether unconsciously or to some degree consciously, is possibly able to see themselves as being that happy person with the product. Thus, the person may, without realizing it, simulate the person in the commercial and buy the product.
Of course, this kind of advertisement may implicate more than just simulation. Perhaps the information in the commercial, or just the repeated emphasis on the product, is what makes the person go for the product. There would have to be an experiment that compared reactions to commercials about a product with people in them and without people.
Our particular experiment goes like this: A person is sitting at a computer screen. 75 images of mannequins wearing certain outfits will be flashed before her, for 4 seconds each. During this time period she must indicate by pressing a key whether she likes the outfit or dislikes the outfit (meaning she would or would not buy the outfit). Of course, numerous styles will be exhibited to account for the various tastes of the women!
Afterwards, she will watch 5 short commercials which show very happy and attractive women wearing 5 of the outfits she had seen. A few hours later she will be reshown the 75 images of mannequins again, but she is only given 2.5 seconds to respond with her preference this time.
Will she have changed her mind about those 5 particular outfits significantly more than the other 70?
In a follow-up survey, would she think that she had changed her mind or had been influenced by the commercials?
There may be too many variables in this experiment, and the results consequently may not implicate simulation. In addition, there may need to be a blind. Any ideas to improve this?
--Jenn & Hannah
If people are very influenced by such advertisements, it may be because they are wired for simulation. The person, whether unconsciously or to some degree consciously, is possibly able to see themselves as being that happy person with the product. Thus, the person may, without realizing it, simulate the person in the commercial and buy the product.
Of course, this kind of advertisement may implicate more than just simulation. Perhaps the information in the commercial, or just the repeated emphasis on the product, is what makes the person go for the product. There would have to be an experiment that compared reactions to commercials about a product with people in them and without people.
Our particular experiment goes like this: A person is sitting at a computer screen. 75 images of mannequins wearing certain outfits will be flashed before her, for 4 seconds each. During this time period she must indicate by pressing a key whether she likes the outfit or dislikes the outfit (meaning she would or would not buy the outfit). Of course, numerous styles will be exhibited to account for the various tastes of the women!
Afterwards, she will watch 5 short commercials which show very happy and attractive women wearing 5 of the outfits she had seen. A few hours later she will be reshown the 75 images of mannequins again, but she is only given 2.5 seconds to respond with her preference this time.
Will she have changed her mind about those 5 particular outfits significantly more than the other 70?
In a follow-up survey, would she think that she had changed her mind or had been influenced by the commercials?
There may be too many variables in this experiment, and the results consequently may not implicate simulation. In addition, there may need to be a blind. Any ideas to improve this?
--Jenn & Hannah
Thursday, January 29, 2009
Yawning as Empathy?
Empathic behavior has always been somewhat of a paradox to scientists: why would an organism which is bent on individual survival want to understand the emotions that another is feeling? The answer, of course, is complex, revolving around the idea that empathic behaviors contribute both to society and personal health—the former of which may also, in some way, contribute to individual fitness. To gain more insight on this answer, scientists are interested in what other kinds of behavior and parts of the brain empathic behavior is associated with, and whether humans are the only ones that exhibit it.
Platek et al. (2003) hypothesized that contagious yawning is an empathic behavior. To test this idea, they had subjects watch tapes of people laughing, yawning, or with neutral expressions. Laughing was the control, as it is also understood as a contagious behavior. Subjects were observed during the process, to see how much they yawned. All the subjects had to fill out a Schizotypal Personality Questionnaire, for those with schizophrenic personality treats are less empathic, and for that reason the researchers hypothesized that those with more schizophrenic personality traits would exhibit less contagious yawning. In addition, one group of the subjects had to do some theory of mind tasks, reading stories in which a successful task would mean they recognized first and second-order false beliefs in others. Another group did some self-recognition tasks, in which the speed in which they recognized their own faces among ‘ faces was recorded. Recognition involved pressing a key, and researchers tested the speed of both the left and right hand.
The results fit the hypothesis well. People who had less schizotypal personality traits exhibited significantly more contagious yawning, and these people also scored significantly better on the theory of mind tasks and self-recognition tasks using the left hand (which implicates the right brain, which functions in empathy). Theory of mind, of course, is understood as a kind of empathic behavior, and many researchers hypothesize that self-recognition precedes and is necessary for empathic behavior. A later study by Platek et al. (2005) located brain activation for contagious yawning which supported their empathic modeling hypothesis. There was significant activation in the bilateral precuneus and posterior cingulate, which have also been shown to be involved with recognizing self-referent information, and the second of which may show structural asymmetries and disorders in schizophrenic patients. They conclude contagious yawning is a primitive and unconscious form of empathic modeling that “…is subserved by substrates that are precursors to a more sophisticated and distributed system involved in conscious self-processing.”
Platek et al. (2003) hypothesized that contagious yawning is an empathic behavior. To test this idea, they had subjects watch tapes of people laughing, yawning, or with neutral expressions. Laughing was the control, as it is also understood as a contagious behavior. Subjects were observed during the process, to see how much they yawned. All the subjects had to fill out a Schizotypal Personality Questionnaire, for those with schizophrenic personality treats are less empathic, and for that reason the researchers hypothesized that those with more schizophrenic personality traits would exhibit less contagious yawning. In addition, one group of the subjects had to do some theory of mind tasks, reading stories in which a successful task would mean they recognized first and second-order false beliefs in others. Another group did some self-recognition tasks, in which the speed in which they recognized their own faces among ‘ faces was recorded. Recognition involved pressing a key, and researchers tested the speed of both the left and right hand.
The results fit the hypothesis well. People who had less schizotypal personality traits exhibited significantly more contagious yawning, and these people also scored significantly better on the theory of mind tasks and self-recognition tasks using the left hand (which implicates the right brain, which functions in empathy). Theory of mind, of course, is understood as a kind of empathic behavior, and many researchers hypothesize that self-recognition precedes and is necessary for empathic behavior. A later study by Platek et al. (2005) located brain activation for contagious yawning which supported their empathic modeling hypothesis. There was significant activation in the bilateral precuneus and posterior cingulate, which have also been shown to be involved with recognizing self-referent information, and the second of which may show structural asymmetries and disorders in schizophrenic patients. They conclude contagious yawning is a primitive and unconscious form of empathic modeling that “…is subserved by substrates that are precursors to a more sophisticated and distributed system involved in conscious self-processing.”
If contagious yawning is primitive, then perhaps it is found in other animals. Anderson et al. (2004) found that 33% of their subject group of female chimpanzees exhibited contagious yawning (for humans it is between 40 and 60%). Like human infants, chimpanzee infants did not show contagious yawning. The fact that chimpanzees have contagious yawning, can perform some theory of mind tasks, and can recognize themselves in the mirror may mean that chimpanzees have some empathic abilities.
This is all very interesting evidence, linking yawning with a primitive empathy, but it may be that researchers are jumping the gun. Yawning has always been an enigma, so perhaps researchers are too eager about this new hypothesis. They may be making the mistake of simplifying the brain, by localizing similar functions into one area. The failure of “limbic system” terminology testifies to this type of error. Certain parts of the brain may house a variety of seemingly unrelated functions.
In addition, chimpanzees, surely, exhibit some empathy, but it is not because they have contagious yawning; their empathy is manifested in theory of mind and self-awareness. Yawning seems to be tacked on to the mix. There are definitely other possible reasons for contagious yawning. For example, yawning might contribute to fitness in a more proximate way (e.g. cooling the brain), and the tendency to mimic another that yawns could be an important adaptation for survival in evolutionary history. Certainly the necessity of classifying yawning as a primitive empathic behavior is questionable.
Platek, S.M., Critton, S.R., Myers, T.E., and
Platek, S., Mohamed, F., and
Wednesday, January 21, 2009
Do Apes have Theory of Mind?
Much effort has been made in cognitive science to understand the extent to which apes have theory of mind. Theory of mind, Gazzaniga describes, was first put forward by Premack and Woodruff, and is “the ability to observe behavior and then infer the unobservable mental state that is causing it” (2008). Humans develop it in full by the age of four.
The false-belief task, some researchers believe, is important in demonstrating theory of mind, so Call & Tomasello (1999) put 4-5 year old children, chimpanzees, and orangutans to the test. In this task, the subject is not allowed to watch as adult A hides a reward (a sticker for children, and food for apes) underneath one of two containers, while adult B watches. The subject is allowed to watch as adult B marks the container he or she believes to contain the reward. In this case, the subject would always choose the marked container to uncover the reward. However, in the false belief trial, Adult B watches the hiding, but then leaves for a period of time, during which the subject watches Adult A switch the containers. After Adult B comes back in the room, marking the container which he or she believes to hold the reward (the wrong one, of course), the subject must choose which container has the reward. The results of this study are that the 4 and 5 year old children recognized that Adult B has a false belief, and picked the correct container that Adult B had not marked. The apes, however, picked the container Adult B had marked. They did not recognize that Adult B had a false belief.
This experiment is an especially good measure of false belief, because 1) it is nonverbal, so apes can participate in it, and 2) it involves tasks that the apes have already mastered. Some past studies on false belief had produced ambiguous results because it was not certain whether the apes were so focused on trying to perform the task that they could not even begin to attempt to understand the mind of another.
The researchers ultimately concluded from this study that apes do not have much of a theory of mind, at least in the sense of understanding that others may hold false beliefs. Though, Gazzaniga brings up the point that theory of mind is certainly more than just being aware of false belief.
A crucial problem with the experiment is that it leaves out the possibility that apes do have theory of mind, but with conspecifics, not with humans. Humans, certainly, cannot accurately infer the mental state of another animal; our epistemology is staunchly anthropocentric. Just the same, it may be very difficult for an ape to infer something about the state of a human mind. Thus, this study does not really prove that apes have no theory of mind in regards to their peers. Call & Tomasello try to buttress the validity of human theory of mind, and thus its reliability as a standard for all, by pointing out how humans so readily attribute mental states not only to animals but to inanimate objects. However, their argument collapses: there is a good chance that humans are attributing wrong mental states to animals and inanimate objects. Therefore, the apes may also be attributing a wrong mental state to Adult B, not due to deficit theory of mind, but due to inaccurate theory of mind.
Whether apes do have some degree of theory of mind or not, and whether or not humans even have the ability to detect it and describe it, are not the only important issues broached by this experiment. The other is what it really means for our understanding of the human mind to be able to compare human and ape cognition. It is especially notable that, as Gazzaniga points out, younger children (at least below the age of 2), autistic children, and apes all perform similarly (that is, badly) on the false-belief task. It is definitely an interesting notion that ontogeny recapitulates phylogeny, that at one point in the womb humans have gills like a fish, and by the age of 2 they have similar cognition to that of an ape. The continuum between humans and animals is evident: humans are surely animals that are higher-functioning. In addition, however, the idea that autistic children and apes are on a similar social level is consequential. How a human person can be defined is called into question, as the autistic child, by the theory of mind classification, loses something distinctive to humanity.
Gazzaniga, M.S. 2008. Human: The Science Behind What Makes Us Unique. Harper Collins:
Call, J., and M. Tomasello. 1999. A nonverbal false belief task: The performance of children and great apes. Child Development 70:381-95.
A Unique Frontal Lobe Size?
For a long time it was assumed that humans engaged in particularly human cognitive activities such as creative thinking, future planning, language, and high-functioning memory because humans, compared to other apes, have a higher frontal lobe to brain ratio. In an important experiment, Semendeferi et al. (1997) found evidence that severely countered this assumption.
The experimenters measured the volumes of frontal lobes and whole brains of living human brains and of post-mortem brains of the chimpanzee, gorilla, orangutan, gibbon, and the macaque. To measure the volumes they took magnetic resonance (MR) scans of the brains and then three-dimensionally reconstructed the scans. Major landmarks common to all species were used to distinguish the boundaries of the frontal lobe. In addition, they measured the volumes of the 3 frontal lobe sectors (dorsal, mesial, orbital) across the species. In order to account for any possible differences between living and dead brains, like shrinkage, they compared the living human frontal lobe to a post-mortem human frontal lobe.
The results of the experiment indicated that humans do have the largest absolute volume of both the brain and the frontal lobe; however, all of the hominoids have a similar frontal lobe to brain ratio. In other words, humans do not have a larger frontal lobe than a human-sized primate brain would be expected to have. In addition, the relative size of the three sectors were similar across the primate species.
Semendeferi et al. would, however, call attention to some qualifications. First of all, the relative human and chimpanzee frontal lobes values are most similar, while there is a slight, but steady decrease in relative frontal lobe size as the species are located further up the human phylogenetic tree. For example, the relative values for the orangutan brain are at the low end of the human range, as are the gorilla values. The researchers suggest that the data may indicate that frontal lobes becoming relatively larger is a trend of hominoid evolution, but not specifically of hominid evolution. After the split of chimpanzees from the common African hominoids, there was apparently no further increase in relative frontal lobe size all the way to modern humans.
There is, of course, plenty of scientific critique to this study, and the researchers know it. Their sample size is small, and they admit their samples may include outliers (especially the gorilla!). In this 1997 study, however, they intended merely to begin a database of brain volume measurements, using repeatable techniques, to which future studies may contribute. A humble and meager start, which can only produce tentative conclusions.
The study, nevertheless, debunks a classically held assumption, and leaves scientists really wondering what it is about the human brain that is unique. If the human and the chimpanzee have equal relative frontal lobe sizes, and yet only one can speak and write and create grand oeuvres d’art, what accounts for this great difference? Certainly, the study did not address other aspects of the frontal lobe besides overall relative size: perhaps organization of the frontal lobe changed during hominid evolution. Gazzaniga (2008) lists four hypotheses regarding how the human frontal lobes can account for high functioning: reorganization and enlargement of some cortical areas, richer connections between frontal sectors, modification of circuitry in frontal subsectors, and other micro- or macroscopic subsectors added or removed. In addition, the relative prefrontal cortex was not measured in this study, and perhaps the prefrontal cortex to frontal lobe ratio may be important in distinguishing between human functioning and ape functioning. The role of the prefrontal cortex in high functioning is especially implicated in a study by Baare et al (1999), which found that in schizophrenic patients, problems with verbal and visual memory and semantic fluency may be related to a decrease in volume of frontal lobe (especially prefrontal) structure.
This study, especially, delivers a slight blow to a philosophical understanding of human personality as being very distinct from that of an animal’s. Here, we do not see relative frontal lobe enlargement as being a unique derived character during hominid evolution, but it is a shared character among all hominoids. The clearest line this study draws is not between humans and the rest of apes, but divides humans and chimps from the rest of the apes. This is further evidence that humans are not qualitatively distinct from other apes, but that brain changes amongst species can be pinpointed on a rather blurred continuum. A win for reductionism of the human mind? Not necessarily. Much more work needs to be done to show how high-functioning human brains materially evolved over time from lower-functioning ape brains.
References:
Semendeferi, K., H. Damasio, R. Frank, G.W. Van Hoesen. 1997. The evolution of the frontal lobes: A volumetric analysis based on three-dmensional reconstructions of magnetic resonance scans of human and ape brains. Journal of Human Evolution 32:375-88.
Gazzaniga, M.S. 2008. Human: The Science Behind What Makes Us Unique. Harper Collins:
Baare, W.F.C, H.E. Hulshoff, R. Hijman, W.P.T. Mali, M.A. Viergever, R.S. Kahn. 1999. Volumetric analysis of frontal lobe regions in schizophrenia: relation to cognitive function and symptomatology. Biological Psychiatry. 45:1597-1605
Tuesday, January 20, 2009
Kirk Vanacore1: Evolution and Infanticide
Kirk Vanacore
Evolution and Infanticide
Evolution is link directly to reproductive success. If a trait enhances one’s chances of reproducing, the trait is more likely to become prominent. One question rises: are we mentally prone to act in this way? Michael S. Gazzaniga is certain this is so: “To be sure, the human brain is a bizarre device, set in place through natural selection for one main purpose – to make decisions that enhance reproductive success.”[1] A prominent biologist, Edward O. Wilson, agrees: “The human mind is a device for survival and reproduction.”[2] But it seems rather narrow minded to reduce all of humanities actions to these two ends. After all it seems that humans don’t spend most of their time gathering essential resources and having sex. There is also one major contradiction Gazzaniga brings up himself: infanticide. Many animals, including our closest relatives the primates, will kill babies – sometimes with the purpose of simply mating again with the mother. So, if the human brain’s goal were reproduction, why would one kill the products of reproduction – infants?
Gazzaniga states “infanticide is a typical behavior in many species within every group of animals – birds, fish, insects, rodents, and primates.”[3] The reason, he explains is economic:
What makes it possible for these species to kill, just as it is possible for some to indulge in infanticide, is once again economic. It is cheap to kill. The cost-to-benefit ration is good. When you kill and infant, you don’t really risk being injured yourself, so the cost is low. You gain either a food source or increased change of mating with the female because when her infant is dead, she will stop lactating and ovulate again.[4]
Infanticide is done because it will benefit the killer; the animal will gain something whether it is simply more food or a chance to reproduce. Studies have even shown that infanticide is an evolutionary adaptation meant to increase the killer’s chance in mating. One German study of langur monkeys showed that the monkeys who committed infanticide, often mated with the mothers of the dead infants.[5]
While this may explain part of the brain’s instinct toward infanticide, there is another side to the tendency. A study by Doctor Susan Levitzky found that some human mothers had thoughts of infanticide. The children of the mothers had infant colic syndrome, a condition where the infant may scream perpetually for long periods of time due to stomach pain. The study revealed that 70% of the mothers considered aggressive actions against their children and 26% considered infanticide.[6] This raises a major question about the human brain: if the brain’s two main goals are survival and reproduction, why would mothers consider killing their offspring when they do not threaten their mother’s survival? This case suggests that are other considerations, like comfort or peace, that may even trump reproduction when the human brain makes decisions.
[1] Gazzaniga; “Human: The Science Behind What Makes Us Unique;” Harper Collins, New York (2008), p29.
[2] Wilson; “On Human Nature;” Harvard University Press (1978).
[3] “Human” p68.
[4] “Human” p 72.
[5] Borries, Launhardt, Epplen, Epplen, Winkler; “DNA analyses support the hypothesis that infanticide is adaptive in langur monkeys,“ The Royal Society; Proc. R. Soc. London; B (1999) 266.
[6] Levitzky, MD; “Infant Colic Syndrome—Maternal Fantasies of Aggression and Infanticide” Clinical Pediatrics, Vol. 39, No. 7, 395-400 (2000).
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