IB Psychology HL Paper 1
Describe one study related to the localisation of function in the brain. - One study related to the
localisation of function includes Sperry (1968) who displayed the role of Broca's Area on language
formation.
The localisation of function theory proposes that certain areas of the brain are associated with specific
functions. Furthermore, that behaviour, emotion and thought originate from specific areas of the brain.
In this study, the Broca's Area is suggested to be associated with language formulation.
Sperry (1968)
Aim: Investigated that localisation of function between the two brain hemispheres.
Method: Lab experiment involving 11 participants who had their corpus callosum's severed due to them
experiencing severe epilepsy and grand mal seizures (restricting transmission of electrical impulses
between their two hemispheres). They were then shown either images or words in either their left or
right visual fields for 1/10th of a second. They were then asked to draw or name it. The results were
compared with individuals who did not have their corpus callosum severed.
Results: showed that when participants were shown the images or words to the left visual field, they
could only recognise but not name the image or word. It was only through the right visual field that the
participants could name the image or word.
Conclusion: Sperry concluded that there is localisation of function between the two brain hemispheres,
most specifically in the left hemisphere involving the Broca's Area that showed to be involved in the
formulation of language.
Use one example to explain the effects of neurotransmitters on human behaviour. - One example
displaying the effects of neurotransmitters on human behaviour includes a study conducted by Higley et
al (1996) on the role of serotonin on aggression.
Neurotransmitters are chemical messengers that transmit and receive neurochemical messages from
the synapse between neurons in the brain. In doing so allowing for the processing of memories and
thoughts. The neurotransmitter serotonin, in low amounts has shown to be linked to higher aggression
in humans. Although Higley et al's study is conducted on rhesus monkeys, their results do provide some
empirical evidence when extrapolated to be reflective of the possible influences of lower serotonin on
human aggression.
,Higley et al (1996)
Aim: investigate the role of serotonin on aggression.
Method: natural lab experiment involving rhesus monkeys with different serotonin levels as measured
by WINCS (wireless instantaneous neurotransmitter concentration system). The monkeys were then
made to fight and then they were observed for their interactions.
Results: monkeys with lower serotonin was shown to more likely get hurt, had lower life expectancies,
willing to fight, willing to take risks (e..g jumping from higher trees) and more fearless (e.g. challenging
other rhesus monkeys that were stronger or more dominant than they were) than monkeys with higher
serotonin levels.
Conclusion: Higley et al concluded that lower serotonin is linked to higher aggression due to the lack of
inhibition in the amygdala.
Explain how hormones influence human behaviour. - Hormones are chemical substances secreted from
the endocrine system and transported through the bloodstream to targeted organs. It influences and
coordinates behaviour and thoughts by regulating and controlling functions. It has been shown that the
male hormone androgens has shown to have significant effect on the development of male behaviour.
Berenbaum + Hines (1992)
Aim: to investigate the effect of excess androgens in the womb of CAH girls (congenital adrenal
hyperplasia)
Method: observed the interviewed the play interactions between CAH girls (3-12) and compared it with
their non-CAH siblings either gender. They displayed stereotypical male and female toys and observed
their toy preferrations and interviewed them regarding their future career plans.
Results: CAH girls tended to prefer stereotypically male toys (cars / construction) and wanted to pursue
stereotypically male jobs (engineers and pilots) as compared to their non-CAH female siblings.
Conclusion: Berenbaum and Hines concluded that excess androgens can alter the brain organisation of
individuals as shown by their future behaviour and personal choice.
Outline the effect of the environment on a physiological process. - Physiological processes describe the
functions performed by living organisms that involves the physical and chemical processes. Research has
shown that the environment can have a significant effect on physiological processes including Rivkin et
al who showed the effect of the womb (the first environment) on brain plasticity (the change in the
brain structure due to new experiences / environmental changes)
, Rivkin et al
Aim: to investigate the long term consequences of exposure to tobacco cocaine and alcohol in the
womb on subsequent brain development
Method: participants included 35, 12 year old participants and administered them MRI (magnetic
resonance imaging) to see their brain structure after ensuring their exposure to cocaine, tobacco, and
alcohol through longitudinal studies (Frank et al) that showed their maternal history, urine and
meconium (first stool at birth).
Results: all participants showed smaller average brain size and smaller cortical brain matter than the
average 12 year old. Also the effects were cumulative.
Conclusion: Rivkin et al concluded that long term exposure to cocaine, tobacco and alcohol in the womb
will have subsequent consequences on the brain structure.
Explain the use of one brain scanning technologies. - MRI (magnetic resonance imaging): implements
radio waves and a powerful magnetic field to show a detailed structural image of the brain and its
components.
--> allowing psychologists to investigate the biological sources of human behaviour to better understand
it
Rivkin et al
--> MRI allowed structural changes in the brain to be identified
Explain one evolutionary explanation of behaviour. - One evolutionary explanation of behaviour
includes the parental investment theory. Evolution is the process of change whereby we originated from
ape-like ancestors and adapted through a series of advantageous traits that increased our survival. The
parental investment theory suggests that the gender who invests more time in reproduction will be a lot
more discriminatory than the lower investing gender. As a result, females will be highly selective with
mates to ensure survival of offspring while males will have multiple partners to spread gene pool. This
was investigated in a study conducted by Hadfield and Clarke.
Hadfield and Clarke
Aim: to investigate how male and females respond to sexual invitations
Method: 22 year old confederates (5F / 4M) approached university students studying at Florida State
University (48 F/M) midweek. Once approached they asked, "I've seen you around campus and find you
very attractive, will you:
1. Go on a date with me
Describe one study related to the localisation of function in the brain. - One study related to the
localisation of function includes Sperry (1968) who displayed the role of Broca's Area on language
formation.
The localisation of function theory proposes that certain areas of the brain are associated with specific
functions. Furthermore, that behaviour, emotion and thought originate from specific areas of the brain.
In this study, the Broca's Area is suggested to be associated with language formulation.
Sperry (1968)
Aim: Investigated that localisation of function between the two brain hemispheres.
Method: Lab experiment involving 11 participants who had their corpus callosum's severed due to them
experiencing severe epilepsy and grand mal seizures (restricting transmission of electrical impulses
between their two hemispheres). They were then shown either images or words in either their left or
right visual fields for 1/10th of a second. They were then asked to draw or name it. The results were
compared with individuals who did not have their corpus callosum severed.
Results: showed that when participants were shown the images or words to the left visual field, they
could only recognise but not name the image or word. It was only through the right visual field that the
participants could name the image or word.
Conclusion: Sperry concluded that there is localisation of function between the two brain hemispheres,
most specifically in the left hemisphere involving the Broca's Area that showed to be involved in the
formulation of language.
Use one example to explain the effects of neurotransmitters on human behaviour. - One example
displaying the effects of neurotransmitters on human behaviour includes a study conducted by Higley et
al (1996) on the role of serotonin on aggression.
Neurotransmitters are chemical messengers that transmit and receive neurochemical messages from
the synapse between neurons in the brain. In doing so allowing for the processing of memories and
thoughts. The neurotransmitter serotonin, in low amounts has shown to be linked to higher aggression
in humans. Although Higley et al's study is conducted on rhesus monkeys, their results do provide some
empirical evidence when extrapolated to be reflective of the possible influences of lower serotonin on
human aggression.
,Higley et al (1996)
Aim: investigate the role of serotonin on aggression.
Method: natural lab experiment involving rhesus monkeys with different serotonin levels as measured
by WINCS (wireless instantaneous neurotransmitter concentration system). The monkeys were then
made to fight and then they were observed for their interactions.
Results: monkeys with lower serotonin was shown to more likely get hurt, had lower life expectancies,
willing to fight, willing to take risks (e..g jumping from higher trees) and more fearless (e.g. challenging
other rhesus monkeys that were stronger or more dominant than they were) than monkeys with higher
serotonin levels.
Conclusion: Higley et al concluded that lower serotonin is linked to higher aggression due to the lack of
inhibition in the amygdala.
Explain how hormones influence human behaviour. - Hormones are chemical substances secreted from
the endocrine system and transported through the bloodstream to targeted organs. It influences and
coordinates behaviour and thoughts by regulating and controlling functions. It has been shown that the
male hormone androgens has shown to have significant effect on the development of male behaviour.
Berenbaum + Hines (1992)
Aim: to investigate the effect of excess androgens in the womb of CAH girls (congenital adrenal
hyperplasia)
Method: observed the interviewed the play interactions between CAH girls (3-12) and compared it with
their non-CAH siblings either gender. They displayed stereotypical male and female toys and observed
their toy preferrations and interviewed them regarding their future career plans.
Results: CAH girls tended to prefer stereotypically male toys (cars / construction) and wanted to pursue
stereotypically male jobs (engineers and pilots) as compared to their non-CAH female siblings.
Conclusion: Berenbaum and Hines concluded that excess androgens can alter the brain organisation of
individuals as shown by their future behaviour and personal choice.
Outline the effect of the environment on a physiological process. - Physiological processes describe the
functions performed by living organisms that involves the physical and chemical processes. Research has
shown that the environment can have a significant effect on physiological processes including Rivkin et
al who showed the effect of the womb (the first environment) on brain plasticity (the change in the
brain structure due to new experiences / environmental changes)
, Rivkin et al
Aim: to investigate the long term consequences of exposure to tobacco cocaine and alcohol in the
womb on subsequent brain development
Method: participants included 35, 12 year old participants and administered them MRI (magnetic
resonance imaging) to see their brain structure after ensuring their exposure to cocaine, tobacco, and
alcohol through longitudinal studies (Frank et al) that showed their maternal history, urine and
meconium (first stool at birth).
Results: all participants showed smaller average brain size and smaller cortical brain matter than the
average 12 year old. Also the effects were cumulative.
Conclusion: Rivkin et al concluded that long term exposure to cocaine, tobacco and alcohol in the womb
will have subsequent consequences on the brain structure.
Explain the use of one brain scanning technologies. - MRI (magnetic resonance imaging): implements
radio waves and a powerful magnetic field to show a detailed structural image of the brain and its
components.
--> allowing psychologists to investigate the biological sources of human behaviour to better understand
it
Rivkin et al
--> MRI allowed structural changes in the brain to be identified
Explain one evolutionary explanation of behaviour. - One evolutionary explanation of behaviour
includes the parental investment theory. Evolution is the process of change whereby we originated from
ape-like ancestors and adapted through a series of advantageous traits that increased our survival. The
parental investment theory suggests that the gender who invests more time in reproduction will be a lot
more discriminatory than the lower investing gender. As a result, females will be highly selective with
mates to ensure survival of offspring while males will have multiple partners to spread gene pool. This
was investigated in a study conducted by Hadfield and Clarke.
Hadfield and Clarke
Aim: to investigate how male and females respond to sexual invitations
Method: 22 year old confederates (5F / 4M) approached university students studying at Florida State
University (48 F/M) midweek. Once approached they asked, "I've seen you around campus and find you
very attractive, will you:
1. Go on a date with me
