What is aberrant salience?

Aberrant Salience: Definition and Clinical Significance

Aberrant salience is the incorrect assignment of significance or importance to neutral stimuli that would normally be considered irrelevant or innocuous, and is considered a central mechanism in the development of psychosis and schizophrenia spectrum disorders.

Understanding Aberrant Salience

Aberrant salience represents a fundamental disturbance in how the brain processes and attributes meaning to stimuli in the environment. This concept helps explain several key aspects of psychotic disorders:

Core Components of Aberrant Salience

• Inappropriate significance attribution: The brain incorrectly flags neutral or irrelevant stimuli as being highly significant or meaningful 1
• Disrupted filtering: Normal filtering mechanisms that help distinguish relevant from irrelevant information become dysfunctional
• Neurobiological basis: Believed to arise from excess dopamine activity that leads to inappropriate signaling of salience 2

Dimensions of Aberrant Salience

Research using the Aberrant Salience Inventory (ASI) has identified several key domains 3:

1. Increase in meaning: Assigning excessive significance to mundane events
2. Sharpening of senses: Heightened sensory experiences
3. Heightened emotionality: Exaggerated emotional responses to stimuli
4. Heightened cognition: Excessive focus on particular thoughts or ideas
5. Impending understanding: Feeling that a revelation or special understanding is imminent

Clinical Relevance and Manifestations

Aberrant salience has significant implications for understanding and treating psychotic disorders:

Relationship to Psychotic Symptoms

• Positive symptoms: Strong correlations exist between aberrant salience and delusions, conceptual disorganization, and hallucinatory behavior 3
• Emotion processing: Aberrant salience is linked to impaired recognition of positive emotions, with patients often misclassifying emotional expressions 1
• Daily life experiences: Higher aberrant salience scores predict psychotic-like experiences in everyday situations 4

Neural Processing Abnormalities

• Brain network dysfunction: Patients with schizophrenia show abnormal beta oscillations in response to relevant versus irrelevant stimuli—specifically, greater synchronization to irrelevant stimuli than to relevant ones 2
• Prefrontal cortex abnormalities: Multiple studies have identified decreased activity in the dorsolateral prefrontal cortex, dorsal anterior cingulate cortex, and other regions of the salience network during emotional salience processing 5

Clinical Applications

Understanding aberrant salience has important implications for clinical practice:

• Early identification: Aberrant salience may serve as an early marker for psychosis risk, potentially allowing earlier intervention
• Symptom monitoring: Tracking changes in aberrant salience could help monitor disease progression or treatment response
• Treatment targets: Therapies that normalize salience attribution might help reduce psychotic symptoms

Pitfalls and Considerations

• Heterogeneity: Aberrant salience manifests differently across individuals and may relate differently to various symptom dimensions
• State vs. trait: While aberrant salience appears elevated in both acute psychosis and remission phases, it is more pronounced during active psychotic episodes 3
• Assessment challenges: Self-report measures like the ASI may be limited by insight deficits in severely psychotic patients

Understanding aberrant salience provides a valuable framework for conceptualizing the subjective experience of psychosis and may offer new avenues for early detection and intervention in schizophrenia spectrum disorders.