Task 3 - Brainy Methods Flashcards
SIX cellular stages
- Neurogenesis
- Cell migration
- Differentiation
- Syaptogenesis
- Neural cell death
- Synapse rearrangement
Neurogenesis
the mitotic division of nonneuronal cells to produce neurons
Cell migration
the movements of cells to establish distinct nerve cell populations (brain nuclei, layers of the cerebral cortex, and so on)
Differentiation
the transformation of precursor cells into distinctive types of neurons and glial cells
Syaptogenesis
the establishment of synaptic connections, as axons and dendrites grow
Neural cell death
the selective death of many nerve cells
Synapse rearrangement
the loss of some synapses and development of others, to refine synaptic connections
Behavioural approaches
- naturalistic observations
- structured observations
- interviews and questionnaires
- meta-analytic studies
Naturalistic observations
Advantages:
- View operations as they occur
- Adapt to events as they unfold
- Can note antecedents and consequences of behaviors; See real-life behaviours
Disadvantages:
- Participant reactivity and observer bias
- Little control over variables
- Cause-and effect relationships difficult to establish
Structured observations
Advantages:
- More control over conditions that elicit behaviours
Disadvantages:
- Children may not react as they would in real life
Interviews and questionnaires
Advantages:
- Quick way to asses children’s knowledge or reports on behaviour
Disadvantages:
- Children/parents may not respond truthfully or accurately
- Difficult to compare responses
- Researcher bias on questions and interpretation responses
Meta-analytic studies
Advantages:
- Pools large body of research to sort out conflicting findings
- No participants to observe
Disadvantages:
- Requires careful mathematical computation
- Variables may not have been defined identically across studies
Imaging methods
- Structural MRI
- Functional MRI
- EEG/ERP recordings
Research Designs General
- correlational design
- experimental design
- field experiment
- quasi-experiment
- (single) case-study
Correlational design
Strengths:
- Useful when conditions do not permit manipulation
Weaknesses:
- Cannot determine cause-and-effect relationships
Experimental design
Strengths:
- Can isolate cause-and-effect relationships
Weaknesses:
- May not yield information about real-life behaviours
Field experiment
Strengths:
- Can isolate cause-and-effect relationships; behaviours are obeserved in natural settings
Weaknesses:
- Less control over treatment conditions
Quasi-experiment
Strengths:
- Takes advantage of natural separation of children into groups
Weaknesses:
- Factors other than the independent variables may be causing results
(Single) case-study
Strengths:
- Does not require large pool of participants
Weaknesses:
- Can be vulnerable to observer bias; ability to generalize to larger population may be limited
Cross-sectional design (def.)
different groups compared at one time
Longitudinal design (def.)
same group (group A) compared at different times (at ages 10, 12, and 14 years)
Sequential design (def.)
combination of cross-sectional and longitudinal design
Cross-sectional design
Advantages:
- Requires less time; less costly than longitudinal study
Disadvantages:
- Cannot study individual patterns of development or the stability of traits; subject to cohort effects
Longitudinal design
Advantages:
- Can examine the stability of characteristics
Disadvantages:
- Requires a significant investment of time and resources; problems with participant attrition; can have age-history confound.
Learning effects
Sequential design
Advantages:
- Combines the advantages of both longitudinal and cross-sectional approaches; can obtain information about stability of traits in a short period of time
Disadvantages:
- Has same issues as longitudinal studies; but to a lesser degree
The cerebrum consists of four lobes:
- Frontal lobe: motor cortex, “higher order functions”, attention, working memory, planning
- Temporal lobe: audition, language (understanding)
- Parietal lobe: associations, spatial functions
- Occipital lobe: vision, complex object recognition
Stages in prenatal development
- Germinal stage: Zygote
Days 1-14
–> From conception to implantation in uterine wall; cell division - Embryonic period: Embryo
weeks 2-8
–> Differentiation of most organs and body systems; a sensitive period of development - Fetal period: Foetus
week 8-birth
–> Growth in size and genesis of processes to help organs and systems function
Prenatal brain tissue growth
- Neurulation
- Cell proliferation or neurogenesis
- Migration / aggregation
- Neurulation
- CNS arises from neural plate: Neural plate –> neural grove –> neural tube
- withing 3 weeks from conception the first brain tissue is starting to form
- Proliferation / neurogenesis
- differentiation of the neural tube
- production of new nerve cells
- Migration and Aggregation
Migration:
- supported by glial cells
- inside-out-pattern of cortical development
- external influences e.g. alcohol > fetal alcohol syndrome
Aggregation:
- brain structures
External influences on cell migration
e.g. alcohol toxic to the developing brain (fetal alcohol syndrome)
Prenatal structural brain development
- most growth takes place in cerebral cortex
- development of cerebral cortex relatively late, as compared to e.g. midbrain/brain stem
Postnatal development:
Reorganization of the human cortex
- dendritic/axonal growth
- synapse production
- pruning
- myelination
- Dendritic/axonal growth
- axons and dendrites are formed
- at tips of both axons & dendrites are growth cones
- some axons have to bridge long distance of up to 1m (motor neurons)
- Synapse production (synaptogenesis)
but: development processes continue throughout childhood and adolescence
- Synaptic pruning
- elimination of redundant
- development pruning = loss of synapses
- follows synaptogenesis
mechanism:
– competition
– stabalization/strengthening
– elimination
Cognitive development during adolescence
(12 to 18 years)
- ability to think abstract;y
- ability to analyze situations logically
- ability to think realistically about the future/goals
- consider hypothetical situations, use of metaphors
- moral reasoning
Reward/incentive
‘affecting pathway’
- relatively early in adolescence
- linked to changes in the limbic system
Self regulation
‘cognitive pathway’
- relatievely late in adolescence
- linked to changes in the prefrontal cortex
–> lack of synchrony makes adolescents vulnerable
Limbic system
- nucleus accumbans
Limbic system
- nucleus accumbens:
involved in:
risk taking, reward seeking, (impulsivity) - amygdala
involved in:
processing emotional information - prefrontal cortex
involved in:
decision making, inhibition
when limbic system dominates preforntal cortical functions:
- decrease in reasoned thinking
- increase in impulsive behaviour
decision making:
- in LOW emotional conditions: rational (cold)
- in HIGH emotional condition: irrational (hot)
sequential
mixture of longitudinal and cross sectional – observe a group of children over three years f.e. start with three different groups – different age groups for an amount of time
