Biological Approach Flashcards
Brain Imaging Techniques (Def & Ex.)
Used to examine brain activity, structure, and function non-invasively (MRI, fMRI, EEG, MEG, PET)
MRI (func.); What study that uses MRI?
Used to show BRAIN STRUCTURE and to STUDY ABNORMALITIES; Maguire et al. (2000) - Taxi Driver Study
Cortical Remapping
Definition: A type of neuroplasticity where brain areas take over functions of damaged or unused regions, reorganizing neural pathways.
Mechanisms: When a brain region is damaged or deprived of sensory input, neighboring areas may adapt by forming new connections, allowing recovery or compensation for lost functions.
Role in Behavior: Supports recovery from brain injuries, stroke, or limb amputation (e.g., phantom limb sensations). Demonstrates the brain’s adaptability to environmental changes and experiences.
Supporting Study: Merzenich et al. (1984) – After amputating fingers in monkeys, the cortical areas representing the missing fingers were taken over by adjacent fingers, showing cortical remapping.
Critical thinking: Strengths (biological evidence of brain adaptability, supports neuroplasticity), Limitations (individual differences in plasticity, ethical concerns in animal studies).
Lesion Studies (Def & Ex.)
Examining brain damage to understand function (Ex. Phineas Gage Cast Study)
PET Scan (Def.)
Detects BRAIN ACTIVITY and NEUROTRANSMITTER FUNCTION using radioactive tracers. Used in researches on DISORDERS like ALZHEIMER.
FMRI (Def.); What study uses fMRI?
Shows BRAIN ACTIVITY by detecting BLOOD FLOW. It is used in COGNITIVE and EMOTION studies like Fisher et al. (2005) on Romantic Love.
What are two different scales of Neuroplasticity?
Synaptic plasticity and Cortical remapping
What are the different techniques used to study the brain in relation to BEHAVIOR?
Brain Imaging Techniques and Experimental Techniques
Synaptic Plasticity
Definition: The ability of synapses to strengthen or weaken over time in response to activity levels, shaping learning and memory.
Mechanisms: Long-term potentiation (LTP) increases synaptic strength through repeated activation, while long-term depression (LTD) weakens unused connections. Synaptic pruning removes inefficient connections, refining neural networks.
Role in Behavior: Synaptic plasticity underlies learning, memory formation, and adaptation to experiences. It supports neuroplasticity, allowing the brain to reorganize after injury or environmental changes.
Supporting Study: Maguire et al. (2000) – London taxi drivers had strengthened neural connections in the posterior hippocampus due to spatial navigation, showing experience-dependent synaptic changes.
Critical thinking: Strengths (biological basis for learning and memory, supported by neuroimaging studies), Limitations (correlational research, complex interactions not fully understood).
Post-mortem Studies (Def. & Ex.)
Examining brain of deceased individuals with known behavioral conditions (Ex. Broca’s work on speech production)
What are more DIRECT ways of studying the brain’s role in behavior?
Experimental Techniques (Lesion Studies, Animal Studies, Post-mortem Studies)
What are three studies that support neuroplasticity as mechanisms of learning?
Draganski et al (2004), Draganski et al (2006), Maguire (2000)
What is one example of neuroplasticity?
Learning
Animal Studies (Def. & Ex.)
Conducting controlled experiments on animal brains (Ex. Rosenzweig et al. 1972 on neuroplasticity in rats)
EEG (Def.)
Measures ELECTRICAL ACTIVITY in the brain and I useful for studying SLEEP, EPILEPSY, and COGNITIVE PROCESSES
MEG (Def.)
Measures ELECTRICAL ACTIVITY in the brain by detecting magnetic fields generated by NEURAL IMPULSES
Neuroplasticity
The brain’s ability to change and adapt by making and breaking synaptic connections between neurons in response to learning, experiences, or injury
What are the 3 Principles of the Biological Levels of Analysis?
1: Emotions and behavior are products of anatomy and physiology of the nervous and endocrine system, #2: Patterns and behavior can be inherited, #3: Animal research may inform our understanding of behavior
Studies that demonstrates Principle #1
Remapping of the sensory cortex: Merzenich et al. (1984)
Neuroplasticity as mechanisms of learning: Draganski et al. (2004 & 2006) and Maguire et al. (2000)
Studies that demonstrates Principle #3:
Brain Plasticity in Rats: Rosenzweig et al. (1972)
Acetylcholine and Memory in Rats: Rogers & Kesner (2003)
Studies that demonstrates Principle #2:
Minnesota Twin Study: Bouchard et al. (1990)
5-HTT Gene and Depression: Caspi et al. (2003)
Twin Study on Depression: Kendler et al. (2006)
What, how, and why are particular research methods used at the Biological Level of Analysis?
- Case Studies: In-depth study of rare cases that are chosen to be used because EXPERIMENTING on brain damage is UNETHICAL. (Ex. Phineas Gage [1848] - frontal lobe damage & personality change)
- Experiments: Establishes cause & effect by manipulating variables and is used because it CONTROLS VARIABLES to test neurotransmitter effects. (Ex. Rogers & Kesner [2003] - Acetylcholine & memory in rats)
- Correlational Studies - Examines genetic influences without manipulation and is used because genes can’t be EXPERIMENTALLY CONTROLLED, only compared. (Ex. Bouchard et al. [1990] - Twin study on IQ)
Ethical Considerations related to studies at the Biological level of analysis:
1 Protection from Harm: Rogers & Kesner (2003) - Rats were injected with scopolamine that could potentially affect brain function. Not able to be done for human studies BUT raises concerns about animal welfare and necessity of suffering.
ONE study related to localization of function in the brain
Study #1: Phineas Gage Case Study (Dimasio et al. [1994])
- Aim: determine what areas of Phineas Gage’s brain was damaged in the accident
- Method: MRI technology
- Findings: The frontal lobe was only damaged and he became impulsive, aggressive, and irresponsible
- Conclusion: Frontal lobe is involved in self-regulation, emotional control, and social behavior. Supports the idea of localization.
- Critical thinking: Due to brain plasticity Gage recovered some social function over time, meaning that brain damage can adapt after damage. (Contradicts localization, supports neuroplasicity) There was a lack of pre-accident data, meaning that there was no record of Gage’s personality before the accident and most accounts of his behavior came from second-hand sources years after the accident so they could be over exaggerated or inaccurate. It was a unique incident so there are no other instances that exactly support the data that Gage got.
ONE MORE study that is related to localization of function in the brain
Study #2: HM (Corkin et al. [1997])
- Aim: To determine the exact extent of damage to HM’s brain.
- Method: MRI
- Findings: HM’s hippocampus and amygdala were removed.
- Conclusions: the hippocampus is crucial for forming new explicit memories, while procedural memory relies on different brain regions
-Critical thinking: While the study supports localization of function, HM’s ability to learn new motor skills suggest other brain areas can adapt, challenging strict localization theories
Neuron
A nerve cell that transmits information
Synapse
The gap between neurons where signals are sent
Neurotransmitter
A chemical messenger that carries signals across the synapse
Reuptake
The process where neurotransmitters are reabsorbed by the neuron after transmission
Effects of Seratonin on Human Behavior
Serotonin & Depression: Low serotonin (regulates mood, sleep, and emotions) levels are linked to depression, causing symptoms like sadness, fatigue, and low motivation. (Ex. SSRIs & Depression Treatment [Selective Serotonin Reuptake Inhibitors]: Prozac, for example, blocks reuptake, meaning that serotonin stays longer in the synapse which can improve mood and reduce depressive symptoms.
Effects of Acetylcholine on Human Behavior (Def. & Ex.)
Function: deals with memory, learning, muscle movement, and attention.
Study: Martinez and Kesner (1991)
Aim: To investigate the role of ACh in the formation of memories.
Method: Trained 3 groups of rats to run a maze (G1 was injected w chemicals to block ACh receptor sites [less ACh] , G2 was injected with a chemical to block ACh eating enzymes [More ACh], G3 was Controlled)
Conclusion: ACh is essential for memory formation. Less ACh led to learning difficulties, while more ACh improved memory and maze performance.
Critical Thinking: Strengths (Controlled variables & Reliable results), Limitations (Limited generalizability to humans)
Fisher et al (2003)
Aim: Investigate the role of dopamine in romantic love.
Method: 17 participants in 7mon+ relationships “in love”; fMRI scans while viewing a loved one vs. a neutral acquaintance
Findings: Viewing a loved one activated the dopaminergic reward system; Similar to brain activity in addiction
Conclusion: Love is a motivational system, not just an emotion.
Critical Thinking: Strengths (Biological evidence, controlled fMRI scans), Limitations (Small sample, cultural bias, correlational [no cause-effect])
Explain two hormones in human behavior
Cortisol: a stress hormone that affects memory and cognitive function. (Newcomer et al [1999] & Bremner et al [2003])
Oxytocin: a hormone linked to social bonding, trust, and emotional attachment. (Baumgartner et al [2008])
Newcomer et al. (1999)
Aim: Investigate cortisol’s effect on memory
Method: Double-blind study, 3 groups took different cortisol levels for 4 days. High Cortisol (160 mg/day) stimulated major stress, Low Cortisol (40 mg/day) stimulated minor stress, Placebo has no active ingredient.
Findings: High cortisol group performed worse on verbal memory test while low cortisol group had no significant memory decline compared to placebo.
Critical thinking: Strengths (controlled, double-blind, reliable results), Limitations (Short-term study, cortisol effects may vary long-term)
Baumgartner et al (2008)
Aim: Investigate oxytocin’s role in trust during social interactions
Method: Participants plays a trust game involving financial risk. They were told their trust has been broken multiple times. Oxytocin group received oxytocin via nasal spray. Placebo group received a placebo spray.
Findings: O group continues to trust despite betrayal while placebo group became more cautious and reduced trust.
Conclusion: Oxytocin increases trust, even after betrayal, show its role in social bonding and relationships.
Critical thinking: Strengths (Controlled experiment, biological evidence for trust), Limitations (Lab setting, trust in real-life situations may be different.
Discuss two effects of the environment on the physiological processes
Stress:
- Stress affects brain structure and function, particularly impact the hippocampus and prefrontal cortex
- Rosenzweig (1972)
Intelligence:
- Genetic vs. environmental influences on intelligence
- Kendler et al. (2015)
Rosenzweign (1972)
Aim: Investigate the effects of an enriched vs. impoverished environment on brain development in rats
Method:
- Enriched environment: rats housed in complex cages with other rats, toys, and stimulating activities.
- Impoverished Environment: Rats housed in solitary, simple cages.
-Brain structure analysis: After 30-60 days, rats’ brains were analyzed for structural changes.
Findings: Rats in the enriched environment had thicker cerebral cortex and larger hippocampus, linked to learning and memory. Rats in impoverished environment showed thinner cortex and smaller brain regions associated with memory.
Conclusion: Environmental stress or stimulation can significantly impact brain development, particularly affect areas involved in learning and memory.
Critical thinking: Strengths (well constructed experiment, clear cause-effect relationship), Limitations: Animal study, hard to generalize to humans.
Kendler et al. (2015)
Aim: Investigate how adoptive environments influence intelligence.
Method: Adopted children raised in higher SES families. Biological siblings raised by biological parents (lower-SES)
Findings: Adopted children had an average of IQ 5 points higher than their non adopted-biological siblings. Higher-SES adoptive families provided better education, stimulations, and resources, contributing to cognitive development.
Conclusion: Environmental factors, such as education, SES, and parental support, significantly shape intelligence, showing that intelligence is not solely genetic.
Critical thinking: Strengths (Large sample size, real-world application, strong environmental evidence), Limitations (Correlational, adoption policies may influence results)
Examine one interaction between cognition and physiological processes.
Memory and Brain Structure (HM [Scoville & Milner] [1957])
Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behavior (What is shows, How it works, Strengths & Limitations)
MRI & fMRI
What it shows:
- MRI: structural images of the brain to study brain damage, abnormalities, and volume differences in brain regions
- fMRI: Real-time brain activity by measuring changes in blood flow, which shows which areas are active during specific tasks
How it works:
- MRI: magnetic field and radio waves to create the images by measuring hydrogen atom alignment
- fMRI: detects oxygenated vs. deoxygenated blood levels; more oxygen = more blood flow
Strengths:
- MRI: images provide clear structural details, non-invasive, useful for detecting brain damage and neuroplasticity
- fMRI: shows both structure and activity, non-invasive, can study real-time cognitive processes like memory, emotions, and decision making
Limitations:
- MRI: Shows only structure not activity, expensive and time consuming, not suitable for patients with metal impacts or claustrophobia
- fMRI: Lower image resolution, expensive, interpretation issues (motion affects accuracy and brain activity does not always indicate causation)
Studies:
- MRI: Maguire et al. (2000) & HM Case study (1997)
- fMRI: Fisher et al. (2003) & Sharot et al. (2007)
Sharot et al. (2007)
Aim: Investigate the role of the amygdala in emotional (flashbulb) memories
Method: get 24 participants who were in NYC during 9/11 and use fMRI scans while recalling the attack (emotionally significant) and summer vacation (neutral event)
Findings: High amygdala activation when recalling 9/11 (especially for those closer to the attack), and no significant amygdala activation for neutral memories.
Conclusion: The amygdala plays a key role in emotional memory, supporting flashbulb memory theory—emotionally charged events are remembered more vividly.
Critical thinking: Strengths (uses fMRi for biological evidence), Limitations (Correlational, and self-reported memories may be inaccurate)
With reference to relevant research studies, to what extent does genetic inheritance influence behavior?
Gene 5-HTT: Responsible for creating proteins that influence the reuptake of serotonin, which regulates mood. [Caspi et al. (2003) & Levenson et al. (2013)]
Twin studies: Twin studies compare the behaviors of monozygotic (MZ) and dizygotic (DZ) twins to assess the influence of genetics vs. environment on behavior. MZ twins share 100% of their genes, while DZ twins share 50%. Higher similarity in MZ twins suggests a genetic influence. (Bouchard et al. (1990)
Caspi et al. (2003)
Aim: Investigate how the 5-HTT gene (serotonin transporter) influences depression after stressful life events.
Method: Longitudinal study of 847 participants. Divided into three groups based on their 5-HTT gene variant (Short/Short, Short/Long, Long/Long). Assessed for life stressors and depression.
Findings: Participants with at least one short allele were more likely to develop depression after stress. Long/Long allele had a protective effect.
Conclusion: Supports the diathesis-stress model—genes interact with environment to influence mental health.
Critical thinking: Strengths (large sample, real-life application). Limitations (correlational, self-reported stress and depression).
Levenson et al. (2013)
Aim: To determine the role of the 5-HTT gene in marital satisfaction.
Method: Followed couples since 1989, surveying them on marital satisfaction.
Findings: Individuals with a short 5-HTT allele were more likely to be unhappy in an unhealthy relationship or happy in a healthy relationship.
Conclusion: The 5-HTT gene influences emotional regulation, which may affect marital satisfaction, especially in stressful relationships.
Critical thinking: Strengths (longitudinal study provides insights into how genetic factors influence behavior over time), Limitations (correlational, does not establish a direct cause-effect relationship).
Bouchard et al. (1990)
Aim: Investigate the relative contributions of genetics and environment on intelligence and personality.
Method: Compared IQ scores and personality traits of MZ and DZ twins, both raised together and apart.
Findings: MZ twins raised together had higher IQ similarities compared to DZ twins, suggesting that genetics account for about 70% of intelligence.
Conclusion: Both genetics and environment contribute to behavior, but genetics plays a large role in IQ and personality.
Critical thinking: Strengths (large sample size, controlled conditions), Limitations (difficult to separate environmental influences completely).
Examine one evolutionary explanation of behavior (Romantic Love)
Buss’ Evolutionary Theory of Love
- Evolutionary Explanation: Romantic love evolved to increase pair-bonding and ensure long-term commitment for child-rearing and genetic survival. It helps keep partners together to care for offspring and maximize reproductive success.
- Strengths of Theory: Supports long-term pair bonding as essential for offspring survival and shows cross-cultural consistency in love-related behaviors.
- Limitations of Theory: Focuses mainly on heterosexual relationships and may not fully account for the diversity of love experiences across sexual orientations. Testing evolutionary hypotheses in modern societies is difficult.
Examine one evolutionary explanation for behavior (Homosexuality)
Kin Selection Theory
- Evolutionary Explanation: Homosexuality may persist through kin selection, where individuals invest in the survival of their relatives’ offspring, thus ensuring the continuation of shared genetic material. Same-sex attraction may also promote cooperation and altruism in close-knit communities.
- Strengths of Theory: Explains the persistence of homosexuality despite no direct reproductive benefit and is supported by observations of similar behavior in animals.
- Limitations of Theory: Hard to measure genetic relatedness in humans and may not fully isolate biological factors from cultural and social influences.
Discuss ethical considerations in research into genetic influences on behavior.
Caspi et al. (2003) – 5-HTT Gene and Depression:
- Concerns about privacy and confidentiality of genetic testing.
- Potential psychological harm from discovering genetic susceptibility to depression.
- Informed consent was crucial to ensure participants understood the implications of genetic testing.
Bouchard et al. (1990) – Minnesota Twin Study
- Concerns about the psychological impact of separating twins for research purposes.
- Informed consent was needed to explain the use of personal data and genetic testing.
- Potential emotional impact on participants learning about their genetic connections.
Command term: Define
Give the precise meaning of a term or concept
Command term: Describe
Give a detailed account of something, explaining key features or characteristics.
Command term: Explain
Provide a clear account of how or why something happens, with a focus on cause and effect
Command term: Outline
Give a brief summary of the main points
Command term: Discuss
Present a balanced argument, including strengths, weaknesses, and relevant research
Command term: Evaluate
Assess the strengths and limitations by providing reasoned judgement
Command term: Compare
Identify similarities and differences between two or more concepts or studies
Command term: Contrast
Highlight differences between two or more concepts or studies
Command term: To what extent
Assess the degree to which as statement or argument is true, often considering both sides
Command term: Analyze
Break down a topic into its component parts and explain how they relate to each other
Maguire et al. (2000)
Aim: Investigate whether the hippocampus changes in response to spatial navigation experience.
Method: Quasi-experiment, MRI scans compared 16 male London taxi drivers to 50 matched controls.
Results: Taxi drivers had larger posterior hippocampi and smaller anterior hippocampi than controls. Time spent as a taxi driver correlated with posterior hippocampal volume.
Conclusion: The hippocampus adapts to spatial navigation demands, demonstrating neuroplasticity.
Critical thinking: Strengths (objective MRI scans, supports neuroplasticity), Limitations (correlational, only male taxi drivers studied).
Phineas Gage (1848)
Aim: Investigate the effects of brain damage on personality and behavior.
Method: Case study of a railroad worker who survived an iron rod passing through his skull, damaging his frontal lobe. Observations and reports analyzed his behavior.
Results: Gage’s personality changed—he became impulsive, aggressive, and had poor decision-making skills.
Conclusion: The frontal lobe plays a key role in personality, impulse control, and decision-making.
Critical thinking: Strengths (early evidence of brain localization, natural experiment), Limitations (lacks replicability, retrospective accounts may be exaggerated).
Neural Networks
Definition: A system of interconnected neurons that process and transmit information. Neural networks are formed and strengthened through learning and experience.
Formation: Neural networks develop through synaptic plasticity, where repeated activation of neural pathways strengthens synaptic connections (long-term potentiation) and weakens unused connections (synaptic pruning).
Role in Behavior: Neural networks underlie cognitive functions like memory, learning, and emotions. They support neuroplasticity, allowing the brain to adapt to experiences and recover from injury.
Supporting Study: Maguire et al. (2000) – London taxi drivers had increased posterior hippocampal volume due to repeated spatial navigation, demonstrating experience-based neural network development.
Critical thinking: Strengths (supported by biological evidence, explains learning and memory formation), Limitations (correlational studies, complexity of neural networks not fully understood).
Neural Pruning
Definition: The process of eliminating weak or unused synaptic connections, improving the efficiency of neural networks.
Mechanisms: Synapses that are frequently used are strengthened (long-term potentiation), while those rarely activated are pruned. This occurs heavily during childhood and adolescence but continues throughout life.
Role in Behavior: Essential for cognitive development, learning, and memory. Helps refine neural pathways for more efficient processing. Dysregulation of pruning has been linked to neurodevelopmental disorders (e.g., schizophrenia).
Supporting Study: Draganski et al. (2006) – Found structural brain changes in medical students before and after exams, suggesting neural pruning and strengthening in response to learning.
Critical thinking: Strengths (biological evidence for learning and brain efficiency, explains cognitive development), Limitations (difficult to directly observe pruning in humans, correlational studies).
