Free explainer5 min read
Executive function
Understand the model, recognise it in a stem, separate the look-alikes, then apply it.
Start with the mental model
**Executive function is the brain's own project manager — not any one skill, but the system that decides which skill to use, when to switch, and when to stop**. A person can have every individual skill intact — memory, language, even a high IQ — and still fail at life the moment nobody else is holding the plan for them.
Visual explanationUse the diagram to rebuild the concept from memory.
01Core model
• Executive function is a family of higher-order CONTROL processes, not a single skill: planning, response inhibition, cognitive flexibility/set-shifting, initiation, and self-monitoring.
• It is coordinated chiefly by the dorsolateral prefrontal cortexThe front part of the brain responsible for planning, judgement and controlling impulses.Read more → (the 'cold', abstractly-tested network), with a related but separable orbitofrontal/ventromedial network handling the 'hot', socially-oriented side (impulse control, social judgement).
• It draws on working memory (holding and manipulating information, Baddeley's central executive) as a resource, but is not the same as working memory itself — a normal digit span does not guarantee intact planning.
• It is formally probed by tasks built to expose failure of CONTROL rather than failure of stored knowledge. For example, the Wisconsin Card Sorting Test scores set-shifting by counting perseverationPersistently repeating a word, phrase, or action after it is no longer relevant or has already been asked for.Read more → on the old rule, Trail Making Test B measures alternating attention between two sequences, the Stroop test measures inhibiting an automatic response, and the Tower of London measures forward planning.
• It is dissociable from general intelligence (IQ): the classic post-frontal-injury patient tests with a normal or even high IQ yet cannot plan a day, hold a job, or inhibit socially inappropriate behaviour — first demonstrated by the historical case of Phineas Gage.
• It is impaired in frontal lobeThe front part of the brain, involved in planning, personality and impulse control.Read more → lesions of any cause, fronto-striatal disease (Parkinson's disease, vascular/subcortical dementia), attention-deficit hyperactivity disorder (ADHDAttention-deficit hyperactivity disorder, a condition of inattention, impulsivity and sometimes hyperactivity.Read more →), schizophreniaA long-term mental illness involving episodes of psychosis such as hallucinations and delusions.Read more →, and can be secondarily impaired in depression (mimicking dementia — 'pseudodementia').
• Frontal damage classically also impairs INSIGHTA person's awareness and understanding that they are unwell and need help.Read more → — the patient denies any problem despite obvious disorganisation — which is itself a marker of the same underlying deficit, not a separate diagnosis. In practice, this is why families, not patients, usually raise the concern first.
02Recognise it in an SBA
• A vignette describing perseverationPersistently repeating a word, phrase, or action after it is no longer relevant or has already been asked for.Read more → — repeating a previously correct but now-wrong response despite feedback — on a sorting or switching task is describing executive dysfunction (set-shifting failure).
• A vignette describing a patient with a NORMAL IQ or intact formal knowledge who nonetheless cannot plan, organise, or complete real-world tasks is describing executive dysfunction, not a normal-cognition reassurance.
• A vignette describing accurate digit span (forwards or backwards) alongside a genuine planning or switching failure is showing that working memory and executive function have DISSOCIATED — name the control deficit, not the memory span.
• A vignette describing disinhibited, tactless or impulsive social behaviour with PRESERVED formal set-shifting test performance is describing an orbitofrontal/'hot' pattern, not the dorsolateral/'cold' pattern the umbrella term usually implies.
• A vignette describing poor free recall that improves markedly with multiple-choice cueing is describing a frontal retrieval-strategy problem, not a hippocampal episodic-memory disorder.
03Separate the look-alikes
Executive function (the higher-order control system) vs working memory (a resource it draws on) — a normal backward digit span does not rule out perseverationPersistently repeating a word, phrase, or action after it is no longer relevant or has already been asked for.Read more → on a set-shifting task; they dissociate. | |
Executive function vs sustained attention — sustained attention is maintaining focus on one UNCHANGING task; executive function specifically requires shifting strategy or inhibiting a competing response, which sustained attention tasks never demand. | |
Executive function vs processing speed — a person can be executively intact but simply slow (bradyphrenia), or fast but executively impaired; timed test performance alone does not distinguish the two. | |
Executive function vs episodic memory — frontal damage can impair free recall through a poor retrieval STRATEGY that normalises with cueing, which looks like 'forgetfulness' but is not a hippocampal memory-storage problem. | |
Executive function vs general intelligence (IQ) — the single most examined dissociationA disconnection between a person's thoughts, feelings, memories, or sense of identity, often as a response to stress.Read more →: a preserved or normal IQ score does NOT rule out severe executive dysfunction, and the reverse claim is the classic trap. | |
Executive function (dorsolateral, 'cold') vs social cognition/theory of mind (orbitofrontal, 'hot') — both are frontal, but orbitofrontal damage classically SPARES card-sorting performance while producing disinhibited, tactless behaviour instead. | |
Executive function vs global cognitive impairment/dementia — a selective, isolated executive deficit with everything else intact has real localising value; calling it 'dementia' or 'global impairment' loses that specificityThe proportion of people who truly do not have a condition that a test correctly identifies as negative.Read more →. |
How the exam thinksRead the question the way the examiner wrote it.
What people get wrong here
• ⚠️ Assuming a normal or high IQ rules out significant cognitive impairment — it specifically does not for executive function; this is the textbook Phineas-Gage-style dissociationA disconnection between a person's thoughts, feelings, memories, or sense of identity, often as a response to stress.Read more → and the single highest-yield trap in this topic.
• Treating 'working memory' and 'executive function' as interchangeable because both involve the word 'executive' (Baddeley's central executive) — working memory is a component resource, not the whole control system.
• Attributing slowed performance on a timed executive test (Trail Making Test B) automatically to processing speed rather than to the set-shifting/attention-alternation the test is actually designed to isolate.
• Calling poor free recall in a frontal patient a 'memory problem' when recognition/cueing is intact — that pattern is a retrieval-strategy deficit, not hippocampal memory loss.
• Assuming all frontal lobeThe front part of the brain, involved in planning, personality and impulse control.Read more → damage produces the same picture — dorsolateral damage classically produces perseverationPersistently repeating a word, phrase, or action after it is no longer relevant or has already been asked for.Read more → and poor planning with social behaviour relatively preserved; orbitofrontal damage classically produces disinhibition and poor social judgement with card-sorting performance relatively preserved.
• Forgetting that impaired INSIGHTA person's awareness and understanding that they are unwell and need help.Read more → is part of the executive dysfunction picture itself, not evidence the patient is being deliberately unco-operative or malingeringDeliberately faking or exaggerating symptoms for an obvious external gain, such as money or avoiding work.Read more →.