Insula

Anatomy

• Deep in the lateral sulcus, covered by the frontal, parietal and temporal opercula; surrounded by the circular sulcus.
• Short (anterior) and long (posterior) insular gyri.
• The anterior insula contains von Economo neurons.
• Blood supply: M2 segments of the MCA.

Functions

• Interoception: sensing internal body states such as heartbeat, breathing, hunger and bladder fullness.
• Subjective emotional experience and body awareness.
• Disgust processing; primary gustatory cortex (anterior insula/frontal operculum).
• Pain and temperature (posterior insula), autonomic regulation.
• Salience network (with the ACC): switching between the DMN and the executive network.
• Empathy, evaluation of uncertainty and risk, craving.

Connections and chemistry

• ACC (salience network)
• Amygdala
• OFC and vmPFC
• Thalamus VMpo/VMb (interoceptive input)
• Hypothalamus and brainstem autonomic centers

Development

Developmental course through childhood and adolescence.

• Interoceptive awareness develops in adolescence.
• Connections of the anterior insula–ACC salience network strengthen in adolescence.
• Adolescents show a marked insula response to social exclusion (Cyberball).

Clinical

• Anxiety disorders: anterior insula hyperactivity, intolerance of uncertainty.
• Anorexia nervosa: disturbed interoceptive processing and body perception.
• ASD: differences in interoception, alexithymia, salience network differences.
• Substance use: smokers with insula damage quit easily and without urges (the “craving” disappears) (Naqvi et al., 2007). The insula turns the bodily feeling of craving into a conscious urge. B
• Tourette syndrome: insula activation during the premonitory urge.
• A shared transdiagnostic finding: the most consistent sites of gray matter loss across psychiatric disorders are the bilateral anterior insula and the dorsal ACC (193 studies; Goodkind et al., 2015). Weakening of the salience network relates to executive difficulties regardless of diagnosis. A

Treatment

This region from the perspective of medication, psychotherapy and neuromodulation. Letter badges are evidence levels.

• Deep TMS (H4 coil): FDA-cleared in adults as a short-term aid to smoking cessation (August 2020; sham-controlled trial of 262 people, 18 sessions over 6 weeks). The first TMS clearance in addiction. A
• Interoception-focused approaches (body awareness, breath and heartbeat awareness) are being studied in anxiety, eating disorders and ASD; the insula is their theoretical target. C

Assessment

Neuropsychological tasks and measures that probe this region's function.

• Heartbeat detection/counting tasks
• Interoceptive awareness scales
• Recognition of disgusted facial expressions, empathy paradigms

Lesions and damage

Clinical findings expected with damage or dysfunction.

• Taste disturbance, autonomic dysregulation (right insula — arrhythmia).
• Impaired recognition of disgust, anosognosia (right posterior).
• Left anterior insula: apraxia of speech.

In the model

How this structure is defined in the 3D model, and the data source.

As in real anatomy it lies beneath the opercula; when selected, its surroundings turn transparent and it becomes visible.

References

Full citations for the card; links go to the paper (DOI) or a PubMed search.

1. Goodkind M et al. JAMA Psychiatry 2015. Search PubMed
2. Naqvi NH et al. Damage to the insula disrupts addiction to cigarette smoking. Science 2007 (kartta zaten vardı). Search PubMed
3. BrainsWay Deep TMS H4, FDA 510(k), sigara bırakma, Ağustos 2020. Search PubMed