Handout: Insula Cortex Lesions: Behavioral Deficits

	PSY 448 Clinical Neuropsychology	Last revised: Sept. 28, 2021
Insula Cortex Lesions: Behavioral Deficits

Based on Jones et al. (2010) & other references

Interoception, Emotion and Emotional Decision-Making

Interoception is a recognition of internal body states which are then related to how one is feeling (emotion)

Decreased addictive behaviors (lowered gambling, ease of giving up smoking) [why? person may not be able to feel their interior state and cravings, etc. for the addictive focus]

A kind of "emotional blindness" to the value (positive or negative) of risks leading to greater poor judgment in actions

Impairment in recognizing the emotion of "disgust" in facial or vocal cues (especially left insula damage)

Impairment in understanding other people’s pain (posterior insula lesions) and other emotions (anterior insula lesions)

Perceptual Functions

The insula receives taste, smell, and interior bodily sensations and, thus, is central to the perception of flavor/taste. It is also a crucial area of encoding pain. More controversial is the role of the insula in auditory perception

Difficulties in perceiving and recognizing taste on the right side of the tongue (right insula lesions) or in bilateral problems in taste recognition

Difficulties in assigning taste adjectives to smells (e.g., "bitter" or "sweet") in left insula damage]

Heightened pain thresholds or asymbolia, i.e., perceiving pain but it is not felt as aversive or noxious (posterior insula lesions)

Auditory agnosia on the contralateral side of the body after stroke in the insula

Speech & Sensory-Motor Integration

Possible problems of articulation of speech (a form of aphasia) in left anterior lesions

Bodily Awareness

Disturbed sensation of limb & body ownership in damage between the insula and the frontal lobe (especially lesions of the right insula)

Denial of paralysis (= "anosognosia for hemiplegia) or denial of lack of skin sensation (anosognosia for hemianaestheria) in right posterior lesions. Note that denial of paralysis or lack of feeling (on the left side of the body) is seen when the right side of the brain is damaged.

The experience of somatoparaphrenia, i.e., the delusion that the body is being touched by another person's hand and the experience of the upper arm as part of a foreign object

Anxiety Disorders

There is a strong connection between the amygdala and insula cortex. Much research has focused on the amygdala and its association with fear and anxiety disorders. More recent research focusing on the insula (Méndez-Ruette et al. 2019) suggests that heightened levels of insula activity is associated with (1) generalized anxiety disorder, (2) panic disorder, (3) phobias, (4) obsessive-compulsive disorder, and (5) PTSD.

References

Corradi-Dell’Acqua, C., Ronchi, R., Thomasson, M., Bernati, T., Saj, A., & Vuilleumier, P. (2020) Deficits in cognitive and affective theory of mind relate to dissociated lesion patterns in prefrontal and insular cortex. Cortex, 128, 219-233. https://dx.doi.org/10.1016/j.cortex.2020.03.019

Jones, C. L., Ward, J., & Critchley, H. D. (2010). The neuropsychological impact of insular cortex lesions. Journal of Neurology, Neurosurgery and Psychiatry, 81(6). https://10.1136/jnnp.2009.193

Méndez-Ruette, M., Linsambarth, S., Moraga-Amaro, R., … (2019). The role of the rodent insula in anxiety. Frontiers in Physiology. https://doi.org/10.3389/fphys.2019.00330

Moro, V., Pacella, V., Scandola, M., Besharati, S., Rossato, E., Jenkinson, P., & Fotopoulou, A. (2021). A fronto-insular-parietal network for the sense of body ownership (preprint). ResearchSquare. https://dx.doi.org/10.21203/rs.3.rs-428666/v1

Interoception, Emotion and Emotional Decision-Making
Interoception is a recognition of internal body states which are then related to how one is feeling (emotion) Decreased addictive behaviors (lowered gambling, ease of giving up smoking) [why? person may not be able to feel their interior state and cravings, etc. for the addictive focus] A kind of "emotional blindness" to the value (positive or negative) of risks leading to greater poor judgment in actions Impairment in recognizing the emotion of "disgust" in facial or vocal cues (especially left insula damage) Impairment in understanding other people’s pain (posterior insula lesions) and other emotions (anterior insula lesions)
Perceptual Functions
The insula receives taste, smell, and interior bodily sensations and, thus, is central to the perception of flavor/taste. It is also a crucial area of encoding pain. More controversial is the role of the insula in auditory perception Difficulties in perceiving and recognizing taste on the right side of the tongue (right insula lesions) or in bilateral problems in taste recognition Difficulties in assigning taste adjectives to smells (e.g., "bitter" or "sweet") in left insula damage] Heightened pain thresholds or asymbolia, i.e., perceiving pain but it is not felt as aversive or noxious (posterior insula lesions) Auditory agnosia on the contralateral side of the body after stroke in the insula
Speech & Sensory-Motor Integration
Possible problems of articulation of speech (a form of aphasia) in left anterior lesions
Bodily Awareness
Disturbed sensation of limb & body ownership in damage between the insula and the frontal lobe (especially lesions of the right insula) Denial of paralysis (= "anosognosia for hemiplegia) or denial of lack of skin sensation (anosognosia for hemianaestheria) in right posterior lesions. Note that denial of paralysis or lack of feeling (on the left side of the body) is seen when the right side of the brain is damaged. The experience of somatoparaphrenia, i.e., the delusion that the body is being touched by another person's hand and the experience of the upper arm as part of a foreign object
Anxiety Disorders
There is a strong connection between the amygdala and insula cortex. Much research has focused on the amygdala and its association with fear and anxiety disorders. More recent research focusing on the insula (Méndez-Ruette et al. 2019) suggests that *heightened levels* of insula activity is associated with (1) generalized anxiety disorder, (2) panic disorder, (3) phobias, (4) obsessive-compulsive disorder, and (5) PTSD.