week 11

Evolution & brain imaging formative ERQ

30 November 2015
11.01 Evolution and Evolutionary Psychology
be able to examine one evolutionary explanation of behaviour and discuss ethical considerations in
research into the genetic influences on behaviour.

Weekly Reading
Read pp. 57-60 from your Course Companion eText.
Read pp. 29-32 of the Pamoja Supplementary eText, The Biological
Level of Analysis: Section 3. Genetics and Behaviour. B. Evolutionary
explanations of behaviour and C. Ethics and genetic research.

Evolution
Charles Darwins theory of evolution: those who adapt best to the environment will have
a greater chance of surviving, having children, and passing on their genes to their offspring
study by Professor Tetsuro Matsuzawa (2007), of Kyoto University in Japan, was to
examine spatial memory in young chimps
memory skills of both chimpanzees and humans have adapted to
become most suitable for the respective environments in which they each live
Evolutionary psychology
attempt to explain how certain human behaviours are testimony to the development of
our species over time
natural selection select for mechanisms that produce behaviour
Dan Fessler of the University of California at Los Angeles has carried out research on
disgust
view of disgust as a form of protection against disease.
Curtis et al. (2004) carried out research on the Internet to test whether there were
patterns in peoples disgust responses
disgust reaction was most strongly elicited for those images which
threaten ones immune system
www.bbc.co.uk/science/ humanbody/mind/surveys/disgust
confirmation bias that is, they see what they expect to see
statements about how humans used to be are hypothetical
underestimate the role of cultural influences in shaping behaviour
Ethical considerations in research into genetic influences of behaviour

 Research in human genetics aims to identify particular genes involved in hereditary

diseases
undue stress as the participant then fears the potential onset of the disorder
history of the eugenics movement

B. Evolutionary explanations of behaviour

such responses are adaptive
biological reductionism reducing everything to a genetic level, and ignoring human will
and the complexity of human behaviour
circular argument
Wedekind (1995) conducted a study into pheromones
women preferred the pheromones of men dissimilar to themselves
Roberts et al. (2008) followed up on Wedekinds findings, and tested directly whether
taking a contraceptive pill altered odour preferences
C. Ethics and genetic research

genetic testing
babies tested for PKU
determining if there are any genetic abnormalities with the foetus
severe abnormalities, the woman is given the choice of a termination
As we discover more and more about the links between genetic influences on behaviour,
ethical issues continue to arise
have data anonymously coded and conduct a double-blind study
it is this inherited trait that can predict a persons social and economic status in adult life
Plomin, R. (1999) has conducted many studies into the heritability of intelligence

11.02 Evolutionary Explanations of Behaviour

Examine one evolutionary explanation of behaviour.

Review Curtis et al. (2004) and read key sections of the study here. (Links to an external site.)

Over 40 000 individuals completed a web-based survey using photo stimuli.

Images of objects holding a potential disease threat were reported as significantly more
disgusting than similar images with little or no disease relevance

 aim
type of study
participants
procedures
findings: Females reported higher disgust sensitivity than males; there was a
constant decline in disgust sensitivity over the life course; and the bodily fluids of
strangers were found more disgusting than those of close relatives
conclusions: human disgust emotion may be an evolved response to objects in
the environment that represent threats of infectious disease
After undertaking the activities associated with the Curtis et al. (2004) study, write a post here about how
plausible you find this evolutionary explanation of disgust?
I find the evolutionary explanation of disgust to be quite plausible, after reviewing the study by researcher,
Curtis, in 2004. This study proved that natural selection and survival of the fittest have helped to evolve
the behavior of response to a disgusting situation, relating to choosing a mate and a successful
reproduction. Humans have evolved to make connections between certain circumstances and danger. For
example, a something that is threatening to our immune system is automatically going to be disgusting
than something similar, yet non-infectious. Disgust has evolved to be a natural defence mechanism all
around the world. By avoiding things that can make us sick, the more intelligent, or strongest, have
survived in order to reproduce and pass of their behavioral traits. However, as weve learned, the
environment also plays a factor on behavior.
Reply to Magnus: I completely agree with you. Disgust may have evolved from something our ancestors
did use for survival and, therefore, successful reproduction. However, nowadays, everyone has a different
perception of disgust, which may not necessarily relate to survival.
11.03 http://www.ncbi.nlm.nih.gov/pubmed/10840167

11.04 Formative ERQ: Brain Imaging, Biological Factors, and

Behaviour
https://webcontent.pamojaeducation.com/Content/sso/course-companion/psychologyeText/course%20companion/381-387_IBCC_PSYCHOL_11.pdf
http://screencast.com/t/l41Y0GMgsTV
Maguire: http://holah.co.uk/summary/maguire/

MRIs
Maguires Study of Localization of the Brain
Natalie Cassello

27 October 2015
Psychology
Helen Loughran
In 2000, Maguire conducted a modern, natural experiment of taxi drivers in London. He had a MRI for 16
healthy right-handed male taxi drivers between the ages of 32 and 62 and compared those to the MRI of
50 right-handed healthy men who were not taxi drivers. Each of the taxi drivers had been employed for
more than a year and a half after two years of training. Correlation analysis was used in order to compare
the brain scans and the length of time that the taxi driver had been licensed. The amount of gray matter
found in the hippocampus was analyzed with the 3D image from the MRI. It was found that the posterior
hippocampi of the taxi drivers were much larger than those of the control participants. Also, the volume of
the hippocampal correlated to the length of time that the taxi driver had been licensed.
This experiment was completely ethical, as it was a natural experiment and the researcher had no effect
on the natural experiences. Maguire simply was observing and taking MRIs for the 66 participants. His
methodology included collecting samples and then choosing the independent events, being healthy male
taxi drivers between the ages of 32 and 62. Data collection used structural magnetic resonance imaging
in order to create pictures of the brain that could be converted into a 3D image. Gray matter of the
hippocampus was calculated with voxel-based morphemetry (VBM) and pixel counting. The data was
then compared between a taxi driver and non-taxi driver participant of the same age to investigate the
functions of the hippocampus in spatial memory.
Maguires investigation is a good study to show localization of function because it is directly relating
spatial memory, from being a taxi driver, to the size of the hippocampus. The conclusions show that taxi
drivers have larger hippocampus than the control participants, who tend not to use spatial memory as
often as the London taxi drivers, and that the taxi drivers who have spent more time driving have
hippocampi with more volume than those who havent been licensed as long. The direct correspondence
of the job and brain plasticity, or the brains ability to remake itself as it adapts to the environment, is
evidently shown through Maguires study of 2000.

Write an essay of approx 800-1000 words on the following topic:

Discuss the use of brain-imaging

technologies in investigating the relationship between
biological factors and behaviour.

intro: state technologies and studies

technology 1
technology 2
conclusion
focus on brain imaging
http://blogs.pamojaeducation.com/psychology/2013/03/15/model-erq-on-the-bloa/
Nowadays, in the twenty first century, there are many different technologies that assist researchers in
investigating behavior at the biological level of analysis. Two brain imaging technologies used in
investigating the relationship between biological factors and behavior are MRIs, such as in Maguires
study of 2000, and fMRIs, used by Iacoboni during a study in 2005. These studies will be discussed in
more detail to support why these specific brain-imaging technologies are used in science to find
correlations between the brain and behavior.
MRIs, or magnetic resonance imaging, are used to create a 3D digital image of the brain. By scanning the
body with a magnetic field and pulses of radio wave energy, static images of organs and structures inside
the body can be produced. Doctors most often use MRIs to locate tumors, injuries, bleeding, infections,
blood vessel diseases, and brain abnormalities. However, brain functions can be exaggerated with
contrast materials, or dyes, as well. Yet, one limitation of MRIs is that patients do have the possibility of
having an allergic reaction to the foreign chemical. In addition, people with metal implants, such as
pacemakers and metal plates or screws, cannot be scanned because a magnetic field is used instead of
a computer and X-ray technology. When detecting tumors, MRIs are also more sensitive than CT scans.
As used in Maguires natural study in London of 2000 to investigate plasticity and localization of the brain,
MRI scans of 60 males were observed. First, the participants included 16 healthy, taxi drivers, who had
been licensed for at least 2 years, and 50 men who did not drive taxis for a living, who took the role of the
controls. All members were male, right handed, and between the ages of 32 and 62 years old. Data of the
anatomy of the brain was collected with MRI scans and then were analyzed to calculate the amount of
grey matter in the hippocampus of the brains of taxi and non-taxi drivers with voxel-based morphometry

and pixel counting. It was proven that the hippocampus does play a role in spatial memory due to the high
dependence on navigational skills of the London taxi drivers. The correlation analysis also supported the
hypothesis that theres a relationship between brain scans and length of time drivers had been licensed.
The grey matter was calculated with VBM, which provides a 3D measurement of volume of the area. It
was found that the posterior hippocampi were significantly larger and the anterior hippocampi were
smaller of taxi drivers and there was more grey matter in the right posterior hippocampus due to plasticity
and the environmental demands of drivers to use spatial memory. This procedure was only possible due
to the images created by the MRI scan. As this study was a natural experiment, the strengths of this study
include following all guidelines of ethics and a strong methodology. However, because it was not a crosscultural study and only included middle aged men, the limitations include not being able to generalize the
results for all genders in all countries. Other factors also may have had an effect of the spatial memory of
the participants.
fMRIs, or functional magnetic resonance imaging, are used to map changes in the brains metabolism to
show active regions of the brain during certain activities. This newer advanced technology allows for
scientists to investigate localization of the brain and correlations between the brain and behavior, when
engaged in an action. These images also assess effects of trauma to the brain on its function. fMRIs are
easy to carry out and give a higher resolution than PET scans, however there are the same limitations as
MRIs, which include possible allergic reactions to the dye and precaution with metal implants. This
technology is continually improving in the medical field.
Physiologist, Iacoboni, used fMRIs in his study of 2005, which investigated localization of brain
mechanisms responsible for understanding the intentions of others when watching them perform an
action. Twenty three subjects observed a stimuli of something being grasped with and without context. It
was found that premotor mirror neurons are active in the understanding of others actions, as well as the
action recognition. Once the action was in context, the participant was able to better understand the future
action. fMRI scans were helpful in this methodology because they allowed the researched to track the
brain patterns while the participant observed the different scenarios. Iacoboni could see the activated
parts of the brain at all times to come to this conclusion on the regions responsible for understanding
intentions. This microscopic brain imaging technology gave the scientist an opportunity to learn more
about premotor mirror neurons and their correlation with the behavior of understanding future actions and
identifying with present actions. Advantages of this study are that it seemed to follow all rules of ethics.
Participants gave informed consent, were debriefed, were given the ability to withdraw, no mental and
physical harm occurred, and the researcher kept all data collected confidential. It may be argued that
slight deception was used, but was explained at the end. This cross-cultural study also makes it reliable
for making generalizations about the function of mirror neurons. Possible limitations of the method of this
study include participants being in a lab, which may have had an effect on their reaction to the stimulus
because of the participant bias and wanting to give the experiment the expected results.
In conclusion, brain imaging technologies, including MRIs and fMRIs have given scientists the ability to
actually study psychology and other medicine practices at the biological level of analysis. As you can see,
it is crucial that these two brain-imaging technologies be used in order to investigate the relationship
between biological factors and behavior. Maguire decided to use MRIs because they provided him with
clear, microscopic brain images for his study to find the which region controls spatial memory, while
Iacoboni used fMRIs which allowed him to watch the movement and function of the brain while the
participants were stimulated in understanding the intentions of anothers actions. In both cases, these
brain-imaging technologies were necessary in making a connection between the behavior being observed
and the function of the brain at a biological level.

Nowadays, in the twenty-first century, there are many different technologies that assist researchers
in investigating behavior at the biological level of analysis. Two brain imaging technologies used in
investigating the relationship between biological factors and behavior are MRIs, such as in Maguires
study of 2000, and fMRIs, used by Iacoboni during a study in 2005. These studies will be discussed
in detail to support why these specific brain-imaging technologies are used in science to find
correlations between the brain and behavior.
MRIs, or magnetic resonance imaging, are used to create a 3D digital image of the brain. By
scanning the body with a magnetic field and pulses of radio wave energy, static images of organs
and structures inside the body can be produced. Doctors most often use MRIs to locate tumors,
injuries, bleeding, infections, blood vessel diseases, and brain abnormalities. However, brain
functions can be exaggerated with contrast materials as well. One limitation of MRIs is that patients
have the possibility of having an allergic reaction to the foreign chemical. In addition, people with
metal implants, such as pacemakers and metal plates or screws, cannot be scanned because a
magnetic field is used instead of a computer and X-ray technology. When detecting tumors, MRIs
are also more sensitive than CT scans.
As used in Maguires natural study in London of 2000 to investigate plasticity and localization of the
brain, MRI scans of 60 males were observed. The participants included 16 healthy, taxi drivers, who
had been licensed for at least 2 years, and 50 men who did not drive taxis for a living, who took the
role of the controls. All members were male, right handed, and between the ages of 32 and 62 years
old. Data of the anatomy of the brain was collected with MRI scans and then were analyzed to
calculate the amount of gray matter in the hippocampus of the brains of taxi and non-taxi drivers with
voxel-based morphometry and pixel counting. It was proven that the hippocampus does play a role
in spatial memory due to the high dependence on navigational skills of the London taxi drivers. The
correlation analysis also supported the hypothesis that theres a relationship between brain scans
and length of time drivers had been licensed. The gray matter was calculated with VBM, which
provides a 3D measurement of the volume of the area. It was found that the posterior hippocampi
were significantly larger and the anterior hippocampi were smaller of taxi drivers and there was more
gray matter in the right posterior hippocampus due to plasticity and the environmental demands of
drivers to use spatial memory. This procedure was only possible due to the images created by the
MRI scan. As this study was a natural experiment, the strengths of this study include following all
guidelines of ethics and a strong methodology. However, because it was not a cross-cultural study
and only included middle-aged men, the limitations include not being able to generalize the results
for all genders in all countries. Other factors also may have had an effect of the spatial memory of
the participants.

fMRIs, or functional magnetic resonance imaging, are used to map changes in the brains
metabolism by showing active regions of neurons during certain activities. This newer advanced
technology allows for scientists to investigate localization of the brain and correlations between the
brain and behavior when engaged in an action. These images also assess effects of trauma to the
brain on its function. fMRIs are easy to carry out and give a higher resolution than PET scans,
however, there are the same limitations as MRIs, which include possible allergic reactions to the dye
and precaution with metal implants. This technology is continually improving in the medical field.
Physiologist, Iacoboni, used fMRIs in his study of 2005, which investigated localization of brain
mechanisms responsible for understanding the intentions of others when watching them perform an
action. Twenty-three subjects observed a stimulus of something being grasped with and without
context. It was found that premotor mirror neurons are active in the understanding of others actions,
as well as the action recognition. Once the action was in context, the participant was able to better
understand the future action. fMRI scans were helpful in this methodology because they allowed the
researcher to track the brain patterns while the participant observed the different scenarios. Iacoboni
could see the activated parts of the brain at all times to come to this conclusion on the regions
responsible for understanding intentions. This microscopic brain imaging technology gave the
scientist an opportunity to learn more about premotor mirror neurons and their correlation with the
behavior of understanding future actions and identifying with present actions. Advantages of this
study are that it seemed to follow all rules of ethics. Participants gave informed consent, were
debriefed, were given the ability to withdraw, no mental and physical harm occurred, and the
researcher kept all data that was collected confidential. It may be argued that slight deception was
used, but was explained at the end. This cross-cultural study also makes it reliable for making
generalizations about the function of mirror neurons. Possible limitations of the method of this study
include participants being in a lab, which may have had an effect on their reaction to the stimulus
because of the participant bias and wanting to give the experiment the expected results.
In conclusion, brain imaging technologies, including MRIs and fMRIs have given scientists the ability
to actually study psychology and other medicine practices at the biological level of analysis. Maguire
decided to use MRIs because they provided him with clear, microscopic brain images for his study to
find the which region controls spatial memory while Iacoboni used fMRIs which allowed him to watch
the movement and function of the brain while the participants were stimulated in understanding the
intentions of anothers actions. As you can see from these cases, its crucial that these two brainimaging technologies be used in order to investigate the relationship between biological factors and
behavior.