A. D. Craig's influential model of the insula proposes a functional gradient from posterior to anterior. How does this gradient run?

A: Posterior insula handles language and speech; anterior insula handles motor coordination

B: Posterior insula receives raw homeostatic/interoceptive signals from the body; anterior insula integrates these with emotional and cognitive context to produce subjective feelings

C: Posterior insula is involved in pain suppression; anterior insula is involved in pain amplification

D: Posterior insula processes auditory information; anterior insula processes visual information

Craig (2002, 2009) proposed a hierarchical model: the posterior insula receives ascending interoceptive signals from the body — temperature, pain, itch, visceral sensations, heartbeat — via the spinothalamic tract and thalamus. As information flows anteriorly, successive integrations with emotional valence, cognitive context, and salience representations occur. The anterior insula — particularly its anterior-most portion — is where Craig locates the substrate of "how I feel right now": a moment-to-moment representation of the body's physiological state that underlies subjective feelings, sense of self, and conscious awareness of bodily states. This architecture explains why the anterior insula activates across a wide range of emotional and social conditions.

The insula was identified as the primary cortical representation for which taste-related function by early stimulation and lesion studies, including Penfield's cortical mapping?

A: The gustatory cortex — the primary cortical processing area for taste

B: The primary auditory cortex relay for phonological processing during speech

C: The cortical representation of olfactory imagery during recall

D: The relay for visual information to the prefrontal cortex

Early electrical stimulation studies by Penfield and Faulk (1955) produced gustatory sensations when the insular cortex was stimulated. Subsequent anatomical and physiological work confirmed the insula — particularly its posterior, granular portion — as primary gustatory cortex in primates, receiving input from the thalamic ventral posteromedial nucleus (VPMpc). Taste signals travel from the taste buds via the solitary nucleus, to the thalamus, and then to the posterior insula. This gustatory function is now understood as one component of the insula's broader interoceptive role: taste is itself a form of chemosensory interoception that informs the organism about ingested substances.

Neuroimaging studies consistently show anterior insula activation during experiences of physical pain, and the same anterior insula region is activated when viewing a loved one in pain — providing a neural basis for empathy.

Svar: Sant

Tania Singer and colleagues (2004) conducted a landmark fMRI study in which participants received painful stimulation and then observed their partner receiving the same stimulation. The affective component of pain — processed in the anterior insula and anterior cingulate cortex — was activated both by first-hand pain and by observing a partner's pain. The sensory-discriminative component (somatosensory cortex) was activated only for first-person pain. This suggested that the anterior insula provides a shared neural representation that underpins empathy: feeling another person's pain exploits the same circuits used for one's own. Individual differences in insula activation during empathy correlate with self-reported empathic concern.

Which emotion has been most consistently linked to insular cortex activation, with lesions to the insula sometimes producing specific impairments in recognising this emotion in others?

A: Fear

B: Anger

C: Disgust

D: Sadness

Disgust — an emotion associated with the rejection of contaminated food, moral violations, and socially threatening stimuli — reliably activates the insula and basal ganglia. Lesions of the insula (often from Huntington's disease, which affects both the insula and basal ganglia) produce specific deficits in recognising disgust expressions in others while leaving recognition of fear or anger relatively intact. Calder et al. (2000) documented this pattern in a patient with insula/basal ganglia damage. The link is thought to reflect the insula's role in interoception: disgust evolved as a visceral response to potentially dangerous substances, and the insula's representation of "gut feelings" underpins both the experience and recognition of this emotion.

Naqvi et al. (2007) published a striking finding about smokers with insular cortex damage. What did they find?

A: Smokers with insula damage smoked more heavily because they lost the aversive interoceptive signals (e.g., throat irritation) that normally moderate consumption

B: Smokers with insula damage showed dramatically higher rates of quitting, often immediately and without craving or relapse, suggesting the insula mediates smoking urges

C: Smokers with insula damage developed a specific inability to form new associations between smell cues and smoking urges, while general craving was unaffected

D: Smokers with insula damage lost the ability to experience pleasure from smoking but continued to smoke because habit circuits remained intact

Naqvi et al. (2007) studied smokers who had sustained brain damage and found a striking dissociation: smokers with insula damage were far more likely to have quit smoking easily (89%) — typically immediately and without significant cravings or relapse — compared to smokers with damage elsewhere. This finding implicated the insula in the interoceptive dimension of drug craving: the bodily "urge" to smoke, the anticipatory visceral sensations that drive seeking behaviour. The insula appeared to link the pharmacological effects of nicotine to the bodily state that constitutes craving. Subsequent work has implicated the insula in craving across multiple substances (alcohol, cocaine, opioids), suggesting it as a potential target for addiction treatment.

Antonio Damasio's somatic marker hypothesis proposes that the anterior insula is part of the neural system that tags decision options with bodily (somatic) signals representing their anticipated emotional consequences, biasing choices toward advantageous outcomes.

Svar: Sant

Damasio's somatic marker hypothesis (1994, 1996) proposes that decision-making is guided by bodily states — somatic markers — that tag different options with emotional signals representing past consequences. The anterior insula, in its role as a cortical representation of bodily states, is a key node in this system. Damage to the ventromedial prefrontal cortex (vmPFC) — which interacts with the insula — produces the "somatic marker" deficit: patients make disadvantageous decisions on the Iowa Gambling Task (choosing high-immediate-reward but high-long-term-punishment decks) despite apparently intact reasoning. Insula activity to bodily signals, particularly in uncertain or risky contexts, provides the "gut feeling" that normally guides adaptive choice.

Interoceptive accuracy — the ability to accurately perceive internal bodily states such as one's own heartbeat — is associated with which psychological outcomes?

A: Interoceptive accuracy is negatively correlated with emotional awareness and intensity; people with poor interoception feel emotions more intensely

B: Higher interoceptive accuracy is associated with stronger emotional responses, better decision-making in emotional contexts, and is impaired in conditions such as alexithymia and depersonalisation

C: Interoceptive accuracy is unrelated to emotional experience and reflects only cardiovascular health

D: High interoceptive accuracy reliably predicts greater cognitive empathy but reduced affective empathy

Experimental measures of interoceptive accuracy — most often heartbeat detection tasks — predict individual differences in emotional awareness and intensity. Craig and Critchley have shown that anterior insula grey matter volume and activity correlates with interoceptive accuracy; individuals higher in interoceptive accuracy report more intense emotional experiences. Disruptions to interoception are clinically significant: alexithymia (difficulty identifying and describing one's own emotions) is associated with poor interoceptive accuracy and reduced anterior insula activation. Depersonalisation disorder, in which people feel detached from their own body and emotions, involves reduced insula and somatosensory activation to bodily stimuli.

The insula is a key node in which large-scale brain network, which is activated by salient, attention-capturing stimuli and coordinates switching between other brain networks?

A: The default mode network (DMN)

B: The dorsal attention network (DAN)

C: The salience network (SN)

D: The executive control network (ECN)

Menon and Uddin (2010) proposed that the anterior insula and anterior cingulate cortex form the core of the salience network — a large-scale network activated by emotionally or biologically relevant stimuli. The salience network's proposed function is to identify the most relevant events in internal and external environments and signal other brain networks to respond. Specifically, the salience network is thought to orchestrate the switch between the default mode network (active during rest and self-referential thought) and the central executive network (active during demanding cognitive tasks). Disruption of the salience network — particularly insula dysfunction — has been implicated in schizophrenia, autism spectrum disorder, and frontotemporal dementia.