IB Psych Bio Approach

What is localization of function?

The idea that particular brain regions perform specialized functions. Example: hippocampal damage can impair formation of new long-term memories.

What is neuroplasticity?

The brain's capacity to change structurally or functionally through experience, learning or environmental influences. Example: learning a skill can alter neural connections.

What is a neurotransmitter?

A chemical messenger released by neurons that influences communication between cells. Example: serotonin is involved in mood regulation and has been investigated in aggression.

What is a hormone?

A chemical messenger released by endocrine glands into the bloodstream, influencing target tissues and behaviour. Example: testosterone has been studied in relation to aggression.

What is a pheromone?

A chemical signal released by an organism that may influence behaviour or physiological responses in another member of the same species. Human pheromone effects remain debated.

What is genetic similarity?

The degree to which individuals share genetic material. Twin and kinship studies examine whether greater relatedness is associated with similarities in behaviour.

What is an evolutionary explanation of behaviour?

Explains behaviour through natural selection: characteristics that improve reproductive success may become more common across generations. Example: proposed adaptive functions of fear.

What is gene–environment interaction?

The effect of genetic differences on behaviour may depend on environmental exposure, and environmental effects may vary with genetic characteristics. Example: MAOA variation and childhood maltreatment.

What is epigenetics?

Changes in gene expression that do not require changes to the underlying DNA sequence. Environmental experiences can influence whether particular genes are expressed.

How does fMRI investigate brain–behaviour relationships?

It measures blood-oxygen-level-dependent signals as an indirect indicator of neural activity. It can identify activity associated with a task but cannot, alone, prove causation.

What does an MRI measure?

Magnetic resonance imaging produces structural images of the brain. Researchers can compare anatomy, such as hippocampal volume, between individuals or groups.

What is reductionism in biological psychology?

Explaining complex behaviour primarily through biological mechanisms. Strength: generates testable explanations; limitation: may understate cognitive, social and cultural influences.

What is biological determinism?

The claim that behaviour is determined by biological factors. A strong deterministic interpretation can overlook agency, learning and environmental influences.

What is the main limitation of correlational brain research?

Brain activity and behaviour may be associated without one causing the other. Confounding variables and reverse causation may offer alternative explanations.

How does animal research help biological psychology?

It permits controlled investigation of mechanisms that may be difficult to study in humans. However, species differences limit generalization and animal welfare must be protected.

What are the key ethical concerns in animal research?

Minimize pain and distress, justify scientific value, use alternatives where possible, and apply replacement, reduction and refinement. Potential human benefits do not automatically justify suffering.

What was Bechara et al. (2000) investigating?

Aim: investigate decision-making deficits associated with ventromedial prefrontal cortex (vmPFC) damage. Method: human lesion research using a gambling task. Findings linked vmPFC damage with impaired advantageous decision-making. Supports localization, but lesion studies cannot isolate every contributing mechanism. Exact sample details: [verify].

How does Bechara et al. (2000) support localization?

The decision-making difficulties associated with vmPFC damage support a role for this region in decision-making. However, damage may affect connected networks, so the evidence does not establish that one region alone controls decisions.

What did Urry et al. (2006) investigate?

Aim: examine prefrontal regulation of the amygdala and its relationship with cortisol in older adults. Method: correlational neuroimaging and cortisol measurements. Findings linked greater ventromedial prefrontal activity with lower amygdala activity and lower cortisol. Supports emotion regulation, but correlation cannot establish causation. Sample and exact statistics: [verify].

How does Urry et al. (2006) complement localization research?

It links vmPFC activity to amygdala regulation and cortisol, extending localization beyond decision-making to emotion regulation. Together with Bechara et al., it suggests that brain regions contribute to different functions within interacting neural systems.

What did Feinstein et al. (2011) investigate?

Aim: examine fear in a person with bilateral amygdala damage. Method: detailed case study of patient SM using real-life and laboratory fear-provoking situations. Findings showed unusually limited fear responses in several situations. Supports an amygdala role in fear, but one unusual case limits generalizability. Exact procedural details: [verify].

What is a limitation of Feinstein et al. (2011)?

SM was a single, unusual case, so findings may not generalize to everyone. Amygdala damage may also affect connected systems. The study supports a role in fear but does not show that all fear depends exclusively on the amygdala.

What did Scoville and Milner (1957) investigate?

Aim: examine memory following medial temporal lobe surgery. Method: case study of patient H.M. after bilateral medial temporal lobe removal. Findings: severe anterograde amnesia with some preserved abilities. Supports a role for medial temporal structures in forming new declarative memories; one case limits generalization. Exact clinical details: [verify].

How does Scoville and Milner (1957) support localization?

H.M.'s inability to form many new long-term memories after surgery linked medial temporal structures to memory formation. Preserved abilities showed that memory is not a single process located in one structure.

What did Luby et al. (2013) investigate?

Aim: investigate associations between childhood poverty and brain development. Method: longitudinal research with children, assessing socioeconomic circumstances and brain structure. Findings linked poverty with differences in brain development, partly associated with caregiving and stressful experiences. Supports environmental influences on neurodevelopment, but observational evidence cannot prove poverty directly caused the differences. Exact sample/statistics: [verify].

How does Luby et al. (2013) illustrate neuroplasticity?

Associations between childhood socioeconomic adversity and brain development suggest that environmental experiences relate to neural development. However, the study does not establish that every observed difference reflects plasticity or that poverty alone caused it.

What did Passamonti et al. (2012) investigate?

Aim: investigate serotonin and neural responses related to aggression. Method: experimental manipulation of serotonin availability with fMRI during emotional processing. Findings linked reduced serotonin availability with altered neural responses to angry faces. Supports a neurochemical contribution to aggression-related processing, but neural responses are not equivalent to actual aggressive behaviour. Sample/statistics: [verify].

What is a limitation of Passamonti et al. (2012)?

An experimental manipulation strengthens causal inference about serotonin availability and measured responses. However, laboratory responses to emotional faces may not predict real-world aggression, and the effects of a temporary manipulation may not represent chronic differences.

What did Radke et al. (2015) investigate?

The relationship between testosterone and aggression-related behaviour. The uploaded study list identifies it as evidence for hormones and aggression. Use the exact procedure, sample, results and statistics only after checking the original paper: [verify].

What did Caspi et al. (2002) investigate?

Aim: test whether MAOA genotype moderated the relationship between childhood maltreatment and later antisocial behaviour. Method: longitudinal research involving 442 male members of a birth cohort. Findings: maltreatment was more strongly associated with antisocial outcomes among males with low-MAOA activity. Supports gene–environment interaction, not genetic inevitability.

How does Caspi et al. (2002) challenge genetic determinism?

The findings suggest that the association between maltreatment and antisocial outcomes varied by MAOA activity. Neither genotype nor maltreatment alone fully explained the pattern, supporting interaction rather than a single predetermined cause.

What did Gilbertson et al. (2002) investigate?

Aim: investigate genetic vulnerability to PTSD using twins. Method: twin comparisons involving Vietnam-era combat veterans and their co-twins. Findings linked smaller hippocampal volume with PTSD vulnerability, including in some unexposed co-twins. This supports a possible pre-existing vulnerability, but does not establish that hippocampal volume alone causes PTSD. Exact sample/statistics: [verify].

How does Gilbertson et al. (2002) complement Caspi et al. (2002)?

Both investigate biological vulnerability in interaction with life experience. Caspi examines genetic moderation of maltreatment effects; Gilbertson examines hippocampal volume and PTSD vulnerability. Together they challenge explanations based exclusively on genes or environment.

Evaluate the use of fMRI in biological psychology.

Strengths: non-invasive, provides spatial information and measures activity during tasks. Limitations: activity is an indirect signal; reverse inference and correlational designs weaken causal claims. Application: helps researchers investigate brain systems involved in emotion, memory and decision-making.

Describe one study of localization of function. (PEEL)

Point: brain regions have specialized roles. Evidence: Scoville and Milner (1957) studied H.M. after medial temporal lobe surgery. Explain: his severe anterograde amnesia implicated these structures in forming new memories. Link: this supports localization while showing memory involves distinguishable processes.

Explain neuroplasticity using one study. (PEEL)

Point: experience and environmental conditions relate to brain development. Evidence: Luby et al. (2013) linked childhood poverty with differences in brain development. Explain: stress and caregiving may help account for these associations. Link: the findings are consistent with environmental influences on neural development, but do not prove causation.

Discuss the role of neurotransmitters in behaviour. (SEEL)

Statement: neurotransmitters can influence behaviour-related processes. Evidence: Passamonti et al. (2012) investigated serotonin availability and neural responses to angry faces. Explain: this supports a neurochemical contribution to aggression-related processing. Evaluation: laboratory neural responses are not equivalent to real aggression. Link: neurotransmitters contribute to, but do not wholly explain, behaviour.

Evaluate the biological approach to behaviour. (PEEL)

Point: biological explanations are testable and supported by physiological evidence. Evidence: Bechara et al. linked vmPFC damage with decision-making deficits. Explain: lesion and neuroimaging evidence can identify brain–behaviour relationships. Evaluation: reductionism, confounding variables and limited generalizability restrict conclusions. Link: integrate biological findings with cognitive and sociocultural explanations.

To what extent does genetics explain behaviour? (SEEL)

Statement: genetic factors can contribute to behavioural differences, but do not determine every outcome. Evidence: Caspi et al. (2002) found that MAOA activity moderated the association between maltreatment and antisocial outcomes. Explain: this supports gene–environment interaction. Evaluation: one cohort and one gene–environment relationship cannot explain all behaviour. Link: biological vulnerability must be considered alongside experience.

What is a neural network?

A network of interconnected neurons that communicates through electrical and chemical signals. Repeated experience can strengthen or reorganize connections.

What is neural pruning?

The elimination of some neural connections during development and learning. It helps refine neural networks; development reflects both biological processes and experience.

What is a synapse?

The junction between neurons where signals are transmitted, commonly through neurotransmitters crossing the synaptic cleft.

What is an agonist?

A substance that increases a neurotransmitter's effect, for example by mimicking it or increasing its availability at receptors.

What is an antagonist?

A substance that reduces a neurotransmitter's effect, often by blocking its receptor. Its behavioural consequences depend on the system involved.

What is an excitatory neurotransmitter?

A neurotransmitter that increases the likelihood that a receiving neuron will fire an action potential. The effect depends on the receptor and neural context.

What is an inhibitory neurotransmitter?

A neurotransmitter that decreases the likelihood that a receiving neuron will fire an action potential. Neural behaviour reflects interacting excitatory and inhibitory signals.

How can serotonin be linked to aggression?

Serotonin is involved in regulating neural processes relevant to impulse control and emotional processing. Some research associates altered serotonin function with aggression-related responses, but it does not explain all aggression.

How can testosterone be linked to aggression?

Testosterone has been investigated as a biological influence on aggression. Its effects are context-dependent; an association between testosterone and aggression does not establish that testosterone alone causes aggressive behaviour.

How can cortisol affect memory?

Cortisol is involved in the stress response. Its effects on memory can depend on timing, intensity and the type of memory being tested; it should not be described as uniformly improving or impairing memory.

What is an evolutionary explanation of fear?

Fear responses may have been selected because they helped ancestors detect and avoid threats. This proposes an adaptive function, but present-day behaviour also depends on learning and context.

What is an evolutionary explanation of attraction?

Some attraction preferences may reflect adaptations that historically affected reproductive success. Such explanations are hypotheses requiring evidence and should not be treated as universal rules for all individuals or cultures.

What did Buchanan and Lovallo (2001) investigate?

The studies list cites Buchanan and Lovallo (2000) for cortisol and memory. Their experiment examined whether stress-hormone exposure before learning influenced later memory. Verify the exact publication year, procedure and statistics against the original paper: [verify].

What did Sapolsky's research contribute to the study of stress?

Sapolsky's research examined stress physiology, including glucocorticoids and hippocampal function. The studies list cites Sapolsky (1995) for stress and the brain. Exact paper, sample and findings for the intended syllabus example: [verify].

What did Cornwell et al. (2004) investigate?

The studies list identifies Cornwell et al. (2004) as an example concerning androstadienone and attraction. Verify the exact hypothesis, participant sample, procedure and results before using detailed claims in an examination: [verify].

What did Saxton et al. (2008) investigate?

The studies list includes Saxton et al. (2008) under pheromones and attraction. The exact experimental procedure and findings are not established by the supplied list alone: [verify].

What did Wedekind (1995) investigate?

Wedekind's study investigated whether women preferred the odours of men whose MHC genes differed from their own. Participants rated T-shirt odours; the findings suggested a possible role for genetic compatibility in odour preference. Sample and numerical details: [verify].

How should human pheromone research be evaluated?

Some studies report effects of candidate chemical signals on attraction or responses. However, identifying a human pheromone conclusively is difficult, and findings may depend on context, methods and replication. Avoid claiming human pheromone effects are settled science.

What is a twin study?

A design comparing twins to investigate the contribution of genetic and environmental similarity to a trait. Monozygotic twins share nearly all segregating genetic variation; dizygotic twins share about half on average.

What is a limitation of twin studies?

Twins may share environments as well as genes. Equal-environment assumptions, sampling and gene–environment correlation can complicate interpretation. Similarity between twins therefore does not prove that a behaviour is genetically determined.

What did Meyer-Lindenberg et al. (2006/2008) investigate?

The studies list cites Meyer-Lindenberg (2008) for MAOA and aggression. The intended paper and exact year should be checked before memorizing a specific procedure or result: [verify].

What does MAOA do?

MAOA is a gene involved in producing monoamine oxidase A, an enzyme that metabolizes neurotransmitters including serotonin, dopamine and noradrenaline. Variants have been investigated in relation to behaviour, often alongside environmental exposure.

What is selective breeding in animal research?

Researchers breed animals with particular traits to examine whether those traits have a heritable component. It can support genetic explanations, but animal results may not generalize directly to humans.

What is a gene knockout?

A method that disables or removes the function of a selected gene in an organism. Researchers examine resulting changes, but compensatory mechanisms and species differences complicate interpretation.

What did Rosenzweig and Bennett (1961) investigate?

They investigated the effects of enriched versus impoverished environments on rat brain development. Rats in enriched environments showed differences in cortical development compared with rats in impoverished conditions. Exact sample and quantitative findings: [verify].

How does Rosenzweig and Bennett (1961) support neuroplasticity?

Differences in rat brains following different environmental conditions suggest that experience can affect brain development. Controlled animal research strengthens causal inference, but translating the size and nature of effects to humans requires caution.

What did Weiskrantz (1956) contribute to localization research?

The HL studies list includes Weiskrantz (1956) as an animal-research example related to localization. Verify the exact lesion, task, species and findings from the original study before using it as detailed evidence: [verify].

What is the value of animal models in biological psychology?

Animal models allow controlled manipulation of biological variables and investigation of mechanisms that may be difficult to test in humans. Their value depends on how closely the mechanism and behaviour translate across species.

Why is generalizing animal findings to humans difficult?

Species differ in brain organization, physiology, social behaviour and evolutionary history. A mechanism observed in animals may suggest a human hypothesis, but it does not automatically establish the same effect in humans.

What are the 3Rs in animal research?

Replacement: use non-animal alternatives where possible. Reduction: use the minimum number of animals needed for valid research. Refinement: minimize pain, distress and lasting harm.

Evaluate animal research using Rosenzweig and Bennett (1961).

Strength: controlled environmental conditions support a causal interpretation of environmental effects on rat brains. Limitation: rats are not humans, so generalization is uncertain. Ethical evaluation must consider animal distress, scientific value and whether alternatives could answer the question.

Describe one hormone and its effect on behaviour.

Example: testosterone has been investigated in relation to aggression. A biological explanation proposes that hormonal activity can influence behaviour, but context and other variables matter. Use a verified study such as Radke et al. (2015) for specific evidence.

Explain the role of genetic similarity in behaviour.

Genetic similarity can be investigated by comparing relatives, including twins. If more genetically similar relatives show greater similarity in a behaviour, this may support a genetic contribution. Shared environments and gene–environment interactions remain alternative explanations.

Discuss evolutionary explanations of behaviour.

Evolutionary explanations propose that some behaviours reflect adaptations shaped by natural selection. Evidence about fear or attraction may be consistent with adaptive functions. However, adaptive explanations can be difficult to test and risk just-so stories; learning and culture also shape behaviour.

Evaluate the use of animal research to understand human behaviour.

Animal studies allow control and biological manipulation; Rosenzweig and Bennett (1961) illustrate environmental effects on rat brains. However, species differences limit generalization, and animal suffering raises ethical concerns. Evaluate scientific value, alternatives and the 3Rs before concluding whether a study is justified.

To what extent is behaviour biologically determined?

Biological factors such as neural activity, hormones and genes contribute to behaviour. Caspi et al. (2002) supports gene–environment interaction, while Rosenzweig and Bennett (1961) suggests environmental influence on brain development. These findings challenge strict biological determinism; behaviour is best explained through interacting influences.

What is a true experiment?

A design that manipulates an independent variable, measures a dependent variable and controls confounding variables, ideally using random allocation to conditions.

What is a correlational study?

A study measuring the relationship between variables without manipulating them. Correlation can identify associations but cannot establish causation.

Why is informed consent important in biological research?

Participants should understand relevant procedures, risks and their rights before agreeing to participate. Consent supports autonomy, especially when studies involve biological manipulation or sensitive measurements.

Why is anonymity important in biological research?

It prevents participants' identities from being linked to their data. This is particularly important for sensitive genetic, hormonal or behavioural information.

What is the difference between anonymity and confidentiality?

Anonymity means identities cannot be linked to responses; confidentiality means identifiable information is protected from unauthorized disclosure. Researchers must not promise anonymity if identities remain identifiable.

What is the right to withdraw?

Participants may stop participating without pressure or penalty. The conditions for withdrawing already-collected data should also be explained clearly.

Why is debriefing important?

It explains the study's purpose and procedures after participation, addresses reasonable deception, and gives participants an opportunity to ask questions and withdraw their data where applicable.

What is animal-welfare refinement?

Modifying procedures to reduce pain, distress and lasting harm while preserving scientific value. It is one of the 3Rs of animal research.

How does random allocation strengthen an experiment?

It helps distribute participant differences across conditions, reducing systematic confounding. It does not guarantee perfectly equivalent groups, especially with small samples.

Why can an experiment support causal inference?

Researchers manipulate the independent variable and control alternative explanations. Causal conclusions are strongest when confounding variables are controlled and the design is valid.

Why can a correlational study not establish causation?

Directionality is unclear, and a third variable may explain the association. For example, stress and brain differences may influence one another or share other causes.

How can fMRI findings be affected by reverse inference?

Researchers may infer a particular mental process from activity in a brain region. Because regions participate in multiple processes, that activity alone does not uniquely identify the process.

How does Scoville and Milner (1957) illustrate the value of case studies?

H.M.'s detailed clinical history linked medial temporal lobe surgery with severe memory impairment. The case provides rich evidence, but a single individual cannot represent all people or memory systems.

How do Bechara et al. and Scoville and Milner complement each other?

Both use evidence from brain damage to investigate localization. Bechara et al. examined decision-making following vmPFC damage; Scoville and Milner investigated memory following medial temporal surgery. Both suggest specialized functions within interacting brain systems.

How does Luby et al. complement Rosenzweig and Bennett?

Luby et al. examined childhood poverty and brain development in humans; Rosenzweig and Bennett manipulated environmental conditions in rats. Together they suggest environmental conditions relate to brain development, but their methods support different levels of causal inference.

How do Caspi et al. and Gilbertson et al. complement each other?

Caspi et al. investigated MAOA and childhood maltreatment in antisocial outcomes; Gilbertson et al. investigated hippocampal volume and PTSD vulnerability. Both examine biological vulnerability alongside environmental experience.

What is a key limitation of lesion studies?

Brain damage can affect connected regions and neural networks, not just one structure. Lesions may also differ between patients, complicating conclusions about the function of a particular region.

What is a key strength of longitudinal research?

It tracks variables over time, helping researchers establish temporal order and examine developmental patterns. Attrition, confounding variables and cost can still limit conclusions.

How can biological findings be applied to treatment?

Research on neurotransmitters and brain systems can inform medication and intervention development. However, findings from laboratory tasks or neural measures do not automatically demonstrate clinical effectiveness.

How can biological research inform prevention?

Research into vulnerability and environmental influences can identify potential risk factors and inform early support. Associations must be interpreted carefully before they are used to predict individuals' outcomes.

Describe one research method used to study brain and behaviour.

PEEL: fMRI measures blood-oxygen-level-dependent signals during tasks. It allows researchers to compare brain activity across conditions. However, the signal is indirect and usually correlational. Therefore, fMRI helps identify brain–behaviour associations but cannot alone prove causation.

Explain one ethical consideration in biological research.

PEEL: informed consent protects participants' autonomy. Researchers should explain procedures and risks before participation. This matters when manipulating biological variables or collecting sensitive data. Proper consent improves ethical validity, although it does not eliminate every possible risk.

Discuss the use of correlational research in biological psychology.

SEEL: correlational studies identify relationships between biological measures and behaviour. For example, researchers can examine brain structure alongside symptoms. They can study variables that cannot ethically be manipulated. However, directionality and third variables limit causal claims. Correlation is informative but not proof of causation.

Evaluate fMRI as a technique for studying behaviour.

PEEL: fMRI provides non-invasive evidence about activity associated with tasks. Its spatial information can help investigate neural systems. However, its signal is indirect, and reverse inference may mislead. Stronger conclusions require converging evidence from different methods and appropriate behavioural measures.