Localisation of function
Comprehensive study guide for IB Psychology
Study Notes
Mark Scheme
SECTION A MARK SCHEME (4 marks) Must Include: • Functional specialization: regions have specific functions • Brain damage case studies as evidence • Double dissociation (different lesions → different deficits) • Named case (e.g. H.M.: bilateral medial temporal lobe) • Specific deficit (e.g. anterograde amnesia vs. intact procedural memory) • Inference: region is necessary for that function
Link Formula: "Damage to [region] caused [specific deficit] while [other ability] remained intact, demonstrating [region] is localized to [function]."
Watch Out: Don't use single case deficits (e.g. only anterograde amnesia) without mentioning what was preserved. Double dissociation (X damaged = deficit A intact, Y damaged = deficit B intact) is the gold standard.
SECTION B MARK SCHEME (6 marks) 0 marks: No relevant knowledge. 1–2 marks: Basic definition; minimal application. 3–4 marks: Case study mentioned; partial application to scenario. 5–6 marks: Definition includes key nuance that the brain operates as an integrated system; H.M. case study perfectly chosen and accurately described; anterograde amnesia vs. intact procedural memory distinction is explicit and well-linked; "bilateral medial temporal lobectomy" — excellent use of precise terminology.
Why Full Marks
"Bilateral medial temporal lobectomy" demonstrates precise anatomical knowledge; anterograde amnesia correctly defined and contrasted with intact procedural memory; H.M. case explicitly demonstrates the double dissociation that supports localisation.
Detailed feedback: • Definition includes the key nuance that the brain operates as an integrated system — sophisticated • H.M. case study is perfectly chosen and accurately described • Anterograde amnesia vs. intact procedural memory distinction is explicit and well-linked • "Bilateral medial temporal lobectomy" — excellent use of precise terminology This is a model answer.
Model Answer
Section A Sample Answer
Localization of function is the theory that specific regions of the brain are responsible for specific cognitive functions. While the brain operates as an integrated system, certain areas like the hippocampus or Broca's Area show functional specialization. Evidence for this often comes from case studies of individuals with localized brain damage, where specific behaviors are impaired while other cognitive functions remain intact.
This is illustrated by the case study of H.M., who underwent a bilateral medial temporal lobectomy that removed his hippocampus. Following the surgery, he suffered from profound anterograde amnesia, meaning he could not form new declarative memories, yet his procedural memory (the ability to learn motor skills) remained intact. H.M.'s case demonstrates localization of function by providing evidence that the hippocampus is specifically associated with the formation of declarative memory while leaving other forms of memory unaffected.
Section B Sample Answer
Localisation of function is the theory that specific parts of the brain are responsible for specific behaviors, supported by neuroimaging and lesion studies. In this scenario, problem-solving is associated with the prefrontal cortex, which handles planning and decision-making. The "open" features of the hub, like digital whiteboards, specifically activate this region by requiring novel cognitive strategies. Additionally, it has been suggested that a mirror neuron system in the parietal and frontal lobes may play a role in the collaborative aspect, though this remains debated. This demonstrates localisation because the performance increase suggests the hub's features selectively activate the prefrontal cortex, providing behavioral evidence for the localisation of logical reasoning.