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\b[<Aberrant salience> is a useful account of how some psychotic experiences become compelling, but it is a <hypothesis> about a process contributing to symptoms, not a complete explanation of <schizophrenia>.] Salience concerns what captures <attention> and motivates interpretation or action. It is distinct from whether a stimulus is physically intense, pleasurable or objectively informative.
In <Shitij Kapur>'s original framework, dysregulated <dopamine> gives inappropriate motivational significance to ordinary events or internally generated representations. A coincidental glance can consequently feel urgent and personally directed. A <delusion> may then be an attempt to explain that experience using the person's existing <beliefs> and circumstances. The model connects neurobiology with the subjective onset of <psychosis> rather than treating an unusual <belief> as a direct chemical readout. It also predicts that dampening salience can reduce the compelling quality of experiences before their interpretation has been revised. This is a theoretical synthesis, not an experiment proving the entire causal chain.<Psychosis as a state of aberrant salience by Shitij Kapur>[American Journal of Psychiatry 160, 13–23; original framework linking biology, phenomenology and pharmacology]{ref}
The framework makes two separable predictions: inappropriate significance should attach to uninformative cues, and relevant cues may fail to gain appropriate significance. They should be measured independently. In the <Salience Attribution Test> used by <Jonathan P. Roiser> and colleagues, visual cues varied along colour and form dimensions, with only one dimension predicting monetary <reinforcement>. Reaction-time speeding and explicit <probability> ratings indexed responding to relevant versus irrelevant features. Patients showed reduced adaptive salience; importantly, the diagnostic groups did not differ overall in <aberrant salience>. Greater explicit <aberrant salience> occurred in patients with <delusions> relative to patients without them. The small, predominantly medicated sample, subgroup analysis and multiple comparisons prevent presenting this as a universal <schizophrenia> deficit.<Do patients with schizophrenia exhibit aberrant salience? by Jonathan P. Roiser and others>[Psychological Medicine 39, 199–209; Salience Attribution Test, Results and study limitations]{ref}
A useful measurement caution follows directly. If equally uninformative features receive noisy ratings $R_1,R_2$, the absolute difference $|R_1-R_2|$ is generally positive even when both estimates are unbiased. For independent normal errors of <variance> $\sigma^2$, its expectation is $2\sigma/\sqrt\pi$. A high score can therefore reflect rating noise or poor <probability> discrimination as well as genuinely assigned significance. Repeated trials, reliability assessment, explicit task comprehension and measurements of adaptive <learning> are needed to interpret the score.
Biological evidence is compatible with, but does not uniquely identify, the <hypothesis>. <Oliver D. Howes> and colleagues used fluorodopa <PET> to compare people with prodromal symptoms, patients with <schizophrenia> and controls. Elevated synthesis-related uptake in the associative <striatum> in the prodromal group links <dopamine> dysfunction to a stage before established psychotic illness. This was a case-control study; uptake is not a recording of cue-specific phasic <dopamine>, and a high-risk group does not establish that every individual will develop <schizophrenia>. It supplies an upstream biological constraint, not a demonstration that a particular neutral cue caused a <delusion>.<Elevated striatal dopamine function linked to prodromal signs of schizophrenia by Oliver D. Howes and others>[Archives of General Psychiatry 66, 13–20; case-control fluorodopa PET]{ref}
Several explanatory steps remain. An account must specify why significance is assigned to this event, how a persistent interpretation is selected, and why contradictory evidence fails to revise it. <Attention>, <memory retrieval>, prior <beliefs> and the social environment can supply those constraints. <Dopamine> dysfunction need not explain all negative symptoms or cognitive difficulties. <Antipsychotic> effects cannot alone establish the original cause: altering a downstream component can improve symptoms arising through several pathways. Nor should a medication-associated decrease in ordinary <motivation> automatically be taken as recovery of selective salience.
A similar perspective is particularly productive for <substance use disorder>. <Incentive salience> distinguishes cue-triggered wanting from pleasure. <Cindy L. Wyvell> and colleagues separately trained a sucrose-seeking response and a reward-predictive cue. Accumbens amphetamine enhanced cue-triggered responding in a test without <reward> <reinforcement>, without enhancing sucrose liking measured by taste reactivity. A later sensitization experiment found amplified cue-triggered seeking in a drug-free test after prior exposure. The experiments distinguish <motivation> from hedonic impact; they do not themselves demonstrate every feature of human addiction.<Intra-accumbens amphetamine increases the conditioned incentive salience of sucrose reward by Cindy L. Wyvell and others>[Journal of Neuroscience 20, 8122–8130; separate instrumental and cue training, extinction test and taste reactivity]{ref}<Incentive sensitization by previous amphetamine exposure by Cindy L. Wyvell and others>[Journal of Neuroscience 21, 7831–7840; drug-free test ten days after sensitization]{ref}
This suggests how drug cues can capture behaviour even when enjoyment has declined or the person intends abstinence. Unlike <psychosis>, however, these cues were genuinely associated with <reward>. The shared issue is excessive or poorly regulated motivational control, not necessarily significance attached to statistically irrelevant events.
<Anxiety disorders> offer a second, more limited analogy: threat-related cues can monopolise <attention>, avoidance can maintain their significance, and safe cues may be treated as dangerous. In <panic disorder>, catastrophic interpretation can make ordinary bodily sensations feel threatening. Such accounts concern <threat appraisal> and discrimination and do not justify assuming identical <dopamine> abnormalities across diagnoses. \b[<Aberrant salience> is most informative as a testable, transdiagnostic process whose computational meaning, neural implementation and clinical consequences must each be specified.]
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