IB Psychology SL cheat sheet

Localisation of function: Broca's area (left frontal lobe) controls speech production; damage causes Broca's aphasia (telegraphic, effortful speech with intact comprehension). Wernicke's area (left temporal lobe) controls language comprehension; damage causes Wernicke's aphasia (fluent but meaningless speech, poor comprehension).

Neuroplasticity: the brain's ability to reorganise itself by forming new neural connections throughout life. Dendritic branching and synaptic pruning occur in response to experience; Maguire et al. (2000) found larger posterior hippocampi in London taxi drivers, correlating with time on the job.

Neurotransmission: neurons communicate across synapses via neurotransmitters. Excitatory neurotransmitters (e.g., dopamine, glutamate) increase the likelihood of an action potential; inhibitory (e.g., GABA) decrease it. Agonists mimic or enhance; antagonists block receptor sites.

Localisation vs. holism: strict localisation argues specific brain areas control specific behaviours; the holistic view (e.g., Lashley's equipotentiality) argues functions are distributed. Modern evidence supports localisation for basic functions but distributed networks for complex behaviours.

Techniques for studying the brain: fMRI measures blood oxygenation (BOLD signal) to infer activity; EEG records electrical activity with high temporal but low spatial resolution; PET scans use radioactive tracers to measure metabolism; lesions (natural or surgical) link structure to function.

Hormones and behaviour: testosterone is linked to aggression (e.g., higher levels in violent offenders, though correlational); cortisol is released in stress and can impair memory (e.g., chronic stress shrinks the hippocampus). Oxytocin is linked to trust and bonding.

Genetics: twin studies compare monozygotic (100% shared genes) and dizygotic (50%) twins; higher concordance in MZ twins suggests heritability. Adoption studies separate genetic from environmental influences. Candidate genes (e.g., 5-HTTLPR for serotonin) are studied but effects are small and probabilistic.

Evolutionary explanations: behaviours that increased survival and reproductive success are selected. Examples include mate preferences (Buss, 1989: men value youth/fertility, women value resources) and preparedness to learn phobias of ancestral threats (Seligman).

Ethical considerations in biological research: informed consent, protection from harm (e.g., invasive procedures, drug side effects), confidentiality of genetic/neurological data, and careful use of animal models.

Multi-store model (Atkinson & Shiffrin, 1968): sensory register (brief, modality-specific) → short-term memory (capacity ~7±2 items, duration ~18-30 s, acoustic coding) → long-term memory (unlimited capacity, lifetime duration, semantic coding). Rehearsal transfers information to LTM.

Working memory model (Baddeley & Hitch, 1974): central executive (attentional control) + phonological loop (verbal/acoustic) + visuospatial sketchpad (visual/spatial) + episodic buffer (integrates information, added 2000). Explains dual-task performance better than the multi-store model.

Schema theory: mental frameworks that organise knowledge and guide interpretation, encoding, and retrieval. Schemas can cause distortion (Bartlett's 'War of the Ghosts' showed reconstruction based on cultural schemas) and facilitate memory for schema-consistent information.

Reconstructive memory: memory is not a faithful recording; retrieval involves reconstruction using schemas. Loftus & Palmer (1974) showed leading questions (verb 'smashed' vs 'hit') altered speed estimates and later memory for broken glass, demonstrating the misinformation effect.

Thinking and decision-making: dual-process models distinguish System 1 (fast, automatic, intuitive) from System 2 (slow, deliberate, analytical). Heuristics (availability, representativeness, anchoring) are mental shortcuts that can produce biases. Tversky & Kahneman (1974) demonstrated anchoring and availability effects.

Biases in thinking: confirmation bias (seeking confirming evidence), hindsight bias (overestimating predictability of past events), and framing effects (choices depend on how options are presented, e.g., gains vs losses).

Reliability of cognitive processes: flashbulb memories (vivid, detailed memories of shocking events) feel accurate but decay like ordinary memories (e.g., Neisser & Harsch, 1992, Challenger disaster); confidence is not a reliable indicator of accuracy.

Research methods in cognitive psychology: laboratory experiments (high control, low ecological validity), case studies of brain-damaged patients (e.g., HM, Clive Wearing) inform models of memory, and neuroimaging links cognitive processes to brain activity.

Emotion and cognition: emotion can enhance memory for central details but impair peripheral details (weapon focus effect); mood-congruent memory and mood-dependent retrieval show that emotional state influences what is recalled.

Social identity theory (Tajfel & Turner, 1979): individuals derive self-esteem from group membership; categorisation into in-groups and out-groups leads to in-group favouritism and out-group discrimination even in minimal group paradigms (Tajfel, 1970).

Social cognitive theory (Bandura, 1977): behaviour is learned through observation, imitation, and modelling. Attention, retention, reproduction, and motivation determine whether observed behaviour is performed; vicarious reinforcement (seeing others rewarded/punished) shapes behaviour.

Conformity: Asch (1951) found that ~32% of responses conformed to a unanimous incorrect majority (line-judging task); conformity increases with group size (up to ~4), unanimity, and difficulty. Normative and informational social influence explain why.

Obedience: Milgram (1963) found 65% of participants administered the maximum 450V shock when instructed by an authority figure; obedience decreases with proximity to the victim, absence of authority, and presence of disobedient peers.

Bystanderism: Darley & Latané (1968) showed the bystander effect-the more people present, the less likely any one helps. Diffusion of responsibility, pluralistic ignorance, and evaluation apprehension explain it; helping increases when the situation is clearly an emergency and someone else helps.

Cultural dimensions (Hofstede): individualism vs. collectivism (focus on self vs. group), power distance (acceptance of hierarchy), uncertainty avoidance, masculinity vs. femininity, long-term orientation. These dimensions predict differences in behaviour and values across cultures.

Acculturation (Berry): strategies based on maintaining one's heritage culture and participating in the host culture: integration (both), assimilation (host only), separation (heritage only), marginalisation (neither). Integration is generally associated with best adaptation outcomes.

Enculturation: the process by which individuals learn the values and norms of their culture, through parents, peers, school, and media. Cultural norms shape behaviour such as cooperation, competition, and display rules for emotion.

Group dynamics: group polarisation (discussion strengthens initial tendencies), groupthink (Janis: desire for harmony suppresses dissent), and deindividuation (loss of self-awareness in crowds, linked to antisocial behaviour, e.g., Zimbardo's anonymity studies).

Research methods in sociocultural psychology: field experiments (high ecological validity, less control), naturalistic observation, surveys/cross-cultural comparisons (risk of imposed etic-applying one culture's concepts to another), and archival research.