Biological approaches to behaviour Flashcards
Localization
A concept of the association of psychological functions with particular structures in the brain
What year is Broca’s study?
1961
Broca’s aim?
To investigate the concept of localization of function in a patient “Tan”
Broca’s sample?
Tan: a person who had aphasia + a distinct lesion in posterior inferior frontal gyrus on left frontal lobe (responsible for speech production)
Broca’s method + procedure
Case study + fMRI and autopsy on Tan’s brain
Broca’s findings
Tan was unable to communicate, instead, he was only able to pronounce “Tan” however he was able to understand everything said to him
Broca’s evaluation
+ non-invasive procedures (fMRI scan)
+ given consent form “Tan’s” family
- Lack of applicability as it’s a case study
- No causation relationship, only correlational
- Lack generalization
- Low ecological validity
Broca’s use
o Ethics (got consent from their family) o Research method (case studies) o Localization
H.M Milner’s year
1966
Milner’s aim
to better understand the effects that the surgery had had on patient HM
Milner’s sample
H.M (suffered from severe seizures => medial temporal lobe + hippocampus region got removed
Milner’s findings
o H.M was unable to acquire new episodic memory of events and semantic knowledge about the world.
o Unable to transfer knowledge from STM to LTM
o Hippocampus area is responsible of the formation of memories
o H.M still retained procedural memories (i.e how to ride a bike)
Milner’s evaluation
+ provided detailed qualitative information and insight
+ permitting research on unethical situation
+ high ecological validity (no variables were manipulated and HM was observed in his natural environment)
- unable to generalize the results
- difficult to replicate the procedures
- researcher bias
- time-consuming
Milner’s use
o Ethics (consent, confidentiality, and protection from harm) o Research method (longitudinal case studies) o Localization o Multi-store memory model
Neuroplasticity
the brain’s ability to adapt by forming new connections as a result of experience, learning, or following an injury
Maguire et al year
2000
Maguire et al’s aim
to investigate the difference in brain structure between black cab London taxi drivers and normal people who had no prior experience of driving taxi
Maguire et al’s sample
16 right-handed male drivers (avg. exp of 14.3 years) + 50 right-handed male drivers
Maguire et al’s method + procedure
Correlational study with quais-experiment; double-blind.
Used MRI scans and had one person/ researcher analyze them using two methods; pixel counting and voxel-based morphometry (VBM)
Maguire et al’s findings
o there’s a positive correlation between driving experience and the volume of the grey matter of the hippocampus
o grey matter distributed from anterior (learning new spacial information) to posterior (using information) as driving experience increased
Maguire et al’s evaluation
\+ No research bias (double blind design) \+ Consistency with person counting and analysing the scans (inter-rater reliability) \+ High ecological validity - Bidirectional ambiguity - No before and after (no causation) - Only male samples, ungeneralisable - Small sample size - Culturally specific sample
Neurotransmitters
chemical messengers that transmit a signal from a neuron across the synapse to a target cell, which can be a different neuron, muscle cell, or gland cell.
Crockett el at’s year
2010
Crockett el at’s aim
to investigate the effects of serotonin on promoting prosocial behaviours
Crockett el at’s sample
30 volunteers
Crockett el at’s method + procedure
Experiment w/ repeated measures
- split the sample into two groups (SSRI or placebo)
- Gave participants moral dilemmas which were either impersonal (pulling a lever) or personal (pushing a person). All involved killing 1 person or letting 5 people die.
Crockett el at’s findings
o Responses for impersonal situations did not differ
o Those with SSRI were less likely to interfere in personal dilemmas when compared to the control group
o SSRI increases the serotonin which increases the ability for an individual to establish personal connections with others. Hence, leading to them being less capable of inflicting harm onto others.
Crockett el at’s evaluation
+ counterbalanced
- low ecological validity
- participant bias (citalopram may cause nausea)
Caspi et al’s year
2003
Caspi et al’s aim
investigate the role of 5-HTT gene on developing depression as a result of stressful environmental variables
Caspi et al’s sample
850 New Zealanders (aged 3 to 26)
Caspi et al’s method + procedure
Genetic mapping & questionnaires + life calendars
- Used genetic mapping to separate sample into 3 conditions; 2 long-alleles, 2 short alleles and 1 long + 1 short allele
- Asked participants to record stressful life events on a calendar and had periodic interviews assessing MDD symptoms exhibited by the sample using DSM-iV criteria
Caspi et al’s findings
o Short alleles were more prone to depressive response to stressful events (3+ events at 21 –> MDD at 26)
o No difference in the amount of stressful life events the sample experienced
Caspi et al’s evaluation
\+ large sample size \+ more holistic - self-reported answers - replications don't show the same results - correlational - low reliability
Hormones
chemical messengers that affects behavior and is secreted by the endocrine system of glands into the bloodstream
e.g oxytocin: released by the pituitary gland, leads to an increase in social bond and intimacy
Guastella et al’s year
2008
Guastella et al’s aim
investigate the role of oxytocin in encoding positive social information
Guastella et al’s sample
69 males
Guastella et al’s method + procedures
Experiment
- Split sample into two conditions, one had oxytocin the other had placebo intranasally sprayed into the individual
- Then viewed 36 happy, angry or neutral faces
- One day later, they returned to assess memory of previously seen faces in 72 new + old faces. Asked whether they remembered which faces they had previously seen the day before
Guastella et al’s findings
o Those with oxytocin only recalled previously seen happy faces
o Oxytocin enhanced encoding + stengthened positive social information, intimacy and bonds they felt when viewing the positive happy faces
o The increased concentration of oxytocin cause the participants to feel an increase of intimacy and bond towards the happy faces, which caused them to strengthen the process of encoding the memory into their brains, hence being able to recall whether or not they saw the photo in the previous day.
Pheromones
An airborne chemical messengers released by the body (for instance, through sweat and urine). It has a have physical or emotional effects on other members of the same species.
Lundstrom & Olsson’s year
2005
Lundstrom & Olsson’s aim
investigating the effects of AND (phenomone secreted by males) on women’s mood in the presence of men
Lundstrom & Olsson’s sample
women
Lundstrom & Olsson’s method + procedure
Experiment
- women were swabbed with AND or control solution on their upper lip
- Interacted with male or female researchers in two identical sessions which involved rating male faces, measures of mood, sustained attention, and psychological arousal
* order of researcher was counterbalanced*
Lundstrom & Olsson’s findings
o No effect on their interactions with females
o AND increased the mood and psychological arousal when interacting with males but didn’t affect their attention and attractiveness to males
Evolution
the gradual accumulative change within heritable characteristics of a population
Curtis et al’s year
2004
Curtis et al’s aim
to investigate how the feeling of disgust is an evolutionary response that plays a role in preventing humans from catching diseases
Curtis et al’s sample
<40000 people from 165 countries
Curtis et al’s method + procedure
Correlational study + survey/ questionnaire
- Asked demographic questions (age, gender, ethnicity, etc)
- Asked to rate 20 photos on a scale of 1 to 5 for disgust (photos were in pairs of disease salient and less salient)
Curtis et al’s findings
o Higher ratings for disease-salient photos
o More pronounced in females
o Rating of disgust declined with age
o All of these results were consistent across countries and cultures