Behavioural Science & Sociocultural Psychiatry · Paper A
Attention
The same complaint, 'poor concentration', can come from several different attentional failures. Someone may focus well in silence but collapse with distraction, or stay focused for two minutes but not twenty. The exam move is to ask what the task demands: filtering, sustaining, switching, or doing two things at once.
Selective attention filters irrelevant stimuli while keeping the target in focus; the Stroop task adds interference because the automatic reading response must be inhibited. Sustained attention, or vigilance, maintains performance over time and may show a vigilance decrement as misses increase. Alternating attention shifts flexibly between tasks with different rules. Divided attention handles two task streams at the same time and is usually more demanding than alternating attention. Focused attention is the simpler ability to respond to a specific stimulus. These attention systems depend heavily on frontal, parietal, and subcortical networks, so bedside errors often overlap with executive dysfunction.
Attention is not one single skill, it is several separate skills that the brain runs in different ways, and each has its own named bedside test. A fresh MBBS graduate who treats 'attention' as one blob will miss the exam's favourite trick: giving a vignette that isolates exactly ONE attention subtype and asking which one it is. Learning to sort attention into its named parts, rather than just noting a patient 'seems distractible', is the single most useful habit for this topic.
Attention is the cognitive process of selectively concentrating mental resources on one part of the environment, or one task, while filtering out or managing everything else. It is tested at the bedside using simple, quick tasks, and in formal psychology using longer computerised tasks, because different tasks stress different sub-skills.
The trap is assuming attention subtypes sit on a single ladder from 'easy' to 'hard', with alternating attention often wrongly assumed to be the hardest or 'highest' level. In fact divided attention, holding two tasks active at once, is generally considered more demanding than alternating attention, which only requires switching between tasks one at a time rather than truly running both together.
Selective attention is the ability to focus on one stimulus while filtering out competing distractors; the classic bedside and research test is the Stroop task, where a person must name the ink colour of a colour-word (like the word 'RED' printed in blue ink) while suppressing the automatic urge to simply read the word. Sustained attention, also called vigilance, is the ability to maintain focus over a longer stretch of time; it is tested with a continuous performance test (CPT), a task lasting many minutes where the person must respond to a rare target among frequent non-targets, and it typically shows a vigilance decrement (a gradual worsening of accuracy as the task goes on and boredom or fatigue sets in). Divided attention is the ability to manage two tasks simultaneously, such as talking while driving, and is more cognitively demanding than alternating attention, where a person instead switches back and forth between two tasks one at a time, never truly doing both together. All four subtypes can be impaired independently, which is exactly why the exam tests them as separate named entities rather than one global concept.
Suppose a patient in clinic answers questions normally when spoken to alone, but the moment a second person joins the conversation and starts talking at the same time, the patient loses the thread entirely and cannot follow either speaker. This pattern points specifically to a divided-attention deficit, not a general concentration problem, because the patient managed a single-stream task (one speaker) without difficulty. Now imagine a different patient who performs a 20-minute continuous performance test: the first five minutes are essentially perfect, but performance steadily worsens minute by minute for the rest of the task. That specific worsening-over-time pattern is the vigilance decrement, and it localises the problem to sustained attention rather than to selective or divided attention, because the deficit only appears once time and boredom accumulate.
Selective attention and sustained attention are easily confused because both can be described loosely as 'concentration', but selective attention is about filtering competing stimuli at a single moment, whereas sustained attention is about holding that focus across time. Divided and alternating attention are also often confused: divided attention runs two tasks in true parallel, while alternating attention only ever attends to one task at a time and simply switches the target of that attention back and forth.
There is no single diagnostic label called 'attention deficit' in an adult psychiatric assessment; instead, clinicians use targeted bedside tests, digit span, serial sevens, the Stroop task, and where needed formal continuous performance testing, matched to the specific subtype under suspicion, and interpret results against the patient's baseline educational level and any sedating medication.
When an attention deficit is identified, management depends entirely on the underlying cause rather than the attention finding alone: NICE guidance directs assessment toward causes such as delirium, depression, or attention-deficit hyperactivity disorder (), each of which has its own distinct management pathway; treating the attention symptom in isolation without identifying its cause is considered poor practice.
When a vignette names a specific test, Stroop, continuous performance test, dual-task or task-switching, work backwards from the test to the attention subtype it measures, rather than trying to guess the subtype directly from a vague description of 'poor concentration'.
Attention splits into selective, sustained, divided and alternating subtypes, each with its own named bedside test, and the exam rewards matching the precise term to the precise task rather than treating attention as one uniform skill.