Brain and Behavior
___ = SAQ studies
Functioning of the brain can influence our behaviour and vice versa.
1.Techniques used to study the brain in relation to behaviour
With modern brain imaging techniques, psychologists can investigate correlations between the
brain and behavior using a range of new technological techniques that do not involve harming
animals. (can be an alternative to animal research).
When studying the brain, particular techniques are used.
The choice of techniques used to correlate the brain with behaviour is based on a variety of
factors including opportunity, available technology and costs. An awareness of these limitations
as well as the strengths of these different techniques is important when evaluating the
contribution they have made to understanding behaviour.
1.1 Functional magnetic resonance imaging (fMRI) to study biological effects on the brain
Useful for studying modeled behavior in laboratories.
Blood Oxygen Level Dependent (BOLD) signal. fMRIs enable researchers to investigate the
function of the brain. MRI shows a still image, fMRI enables us to see which areas of the brain
are activated when performing certain tasks. When neurons in a particular part of the brain are
firing, more blood is sent to that area of the brain. When oxygenated blood is placed in an
external magnetic field, it emits pulses of energy.
The fMRI detects this change in blood flow, allowing correlations between areas of the brain that
are active and the particular tasks being investigated. Not only that, since we know that the most
active areas of the brain are supplied with the most oxygenated blood, we can also determine
which area of the brain is the most active.
fMRIs can be useful because they can measure functional changes in the brain, whereas MRIs
can only measure structural changes in the brain. Excellent spatial resolution.
Limitation: it is important to discriminate between systematic patterns of activation and random
noise. Some sources of noise include head movements, fidgeting and random thoughts.
Eliminating noise requires a lengthy experimental procedure with many trials. Also, only
relatively long lasting processes can be studied because temporal resolution is 1 second.
, Radke et al. (2015) or Goetz et al. (2016)
Passamonti et al. (2012)
Aim: To investigate the effects of tryptophan depletion on the communication between the
amygdala and frontal lobes while viewing facial signals of aggression,
Method:
IV: Tryptophan content in mixture of amino acid
DV: Communication between amygdala and frontal lobes
Participants: Volunteers
Treatment:
- Experiment: Participants were given a mixture of amino acids that lacked tryptophan
(serotonin-low condition)
- Placebo (control): Participants were given the same mixture of amino acids that contained a
normal amount of tryptophan
Participants were given the experimental and placebo treatment on different days
After each treatment, participants' brains were scanned using functional magnetic resonance
imaging (fMRI) as they were shown pictures of faces with angry, sad and neutral expressions.
fMRI measured how different brain regions communicate with one another and reacted to the
different faces
Participants were given a questionnaire to determine which whether participants had aggressive
tendencies
Findings:
Communication between amygdala and frontal lobes was weaker during the experiment than
placebo days. In individuals with natural aggressive tendencies, the difference was especially
pronounced.
When serotonin levels are low, it may be more difficult for the prefrontal cortex to regulate
emotional responses generated within the amygdala
Evaluation:
Strength:
- Technology
- Clear IV and DV
- True experiment
Limitations:
- Reductionistic
___ = SAQ studies
Functioning of the brain can influence our behaviour and vice versa.
1.Techniques used to study the brain in relation to behaviour
With modern brain imaging techniques, psychologists can investigate correlations between the
brain and behavior using a range of new technological techniques that do not involve harming
animals. (can be an alternative to animal research).
When studying the brain, particular techniques are used.
The choice of techniques used to correlate the brain with behaviour is based on a variety of
factors including opportunity, available technology and costs. An awareness of these limitations
as well as the strengths of these different techniques is important when evaluating the
contribution they have made to understanding behaviour.
1.1 Functional magnetic resonance imaging (fMRI) to study biological effects on the brain
Useful for studying modeled behavior in laboratories.
Blood Oxygen Level Dependent (BOLD) signal. fMRIs enable researchers to investigate the
function of the brain. MRI shows a still image, fMRI enables us to see which areas of the brain
are activated when performing certain tasks. When neurons in a particular part of the brain are
firing, more blood is sent to that area of the brain. When oxygenated blood is placed in an
external magnetic field, it emits pulses of energy.
The fMRI detects this change in blood flow, allowing correlations between areas of the brain that
are active and the particular tasks being investigated. Not only that, since we know that the most
active areas of the brain are supplied with the most oxygenated blood, we can also determine
which area of the brain is the most active.
fMRIs can be useful because they can measure functional changes in the brain, whereas MRIs
can only measure structural changes in the brain. Excellent spatial resolution.
Limitation: it is important to discriminate between systematic patterns of activation and random
noise. Some sources of noise include head movements, fidgeting and random thoughts.
Eliminating noise requires a lengthy experimental procedure with many trials. Also, only
relatively long lasting processes can be studied because temporal resolution is 1 second.
, Radke et al. (2015) or Goetz et al. (2016)
Passamonti et al. (2012)
Aim: To investigate the effects of tryptophan depletion on the communication between the
amygdala and frontal lobes while viewing facial signals of aggression,
Method:
IV: Tryptophan content in mixture of amino acid
DV: Communication between amygdala and frontal lobes
Participants: Volunteers
Treatment:
- Experiment: Participants were given a mixture of amino acids that lacked tryptophan
(serotonin-low condition)
- Placebo (control): Participants were given the same mixture of amino acids that contained a
normal amount of tryptophan
Participants were given the experimental and placebo treatment on different days
After each treatment, participants' brains were scanned using functional magnetic resonance
imaging (fMRI) as they were shown pictures of faces with angry, sad and neutral expressions.
fMRI measured how different brain regions communicate with one another and reacted to the
different faces
Participants were given a questionnaire to determine which whether participants had aggressive
tendencies
Findings:
Communication between amygdala and frontal lobes was weaker during the experiment than
placebo days. In individuals with natural aggressive tendencies, the difference was especially
pronounced.
When serotonin levels are low, it may be more difficult for the prefrontal cortex to regulate
emotional responses generated within the amygdala
Evaluation:
Strength:
- Technology
- Clear IV and DV
- True experiment
Limitations:
- Reductionistic
