No Longer an Island, the Insula Is Now a Hub of High Fashion

Islands of the World Fashion Week, designer Hupfeld Hoerder from Fiji.


Last month Neuroskeptic brought us This Season's Hottest Brain Regions. The insula was not among them.¹ And as we all know from watching Heidi Klum on Project Runway, "one week you're in, the next you're out." The journal Brain Structure and Function will soon have a Special Issue of 22 articles on insular cortex, introduced by Mr. Insula himself (A. D. "Bud" Craig, Ph.D.):

Once an island, now the focus of attention

The insula (originally called the “island of Reil”) is emerging from its hiding place inside of the human brain. It is easy to find articles and textbooks which show the lateral aspect of the brain but barely mention the insula, if at all (http://www.ninds.nih.gov/disorders/brain_basics/know_your_brain.htm) or treat it as a deep brain structure, like the amygdala (http://www.scientificamerican.com/article.cfm?id=faulty-circuits). In fact, in Brodmann’s famous map of cortical cytoarchitectonic areas, it was not even worthy of a number! [See Kurth et al. 2009, PMID: 19822572; Brodmann (1909) described only a posterior granular and an anterior agranular region in the human insular cortex.] Older neuroscientists remember the insula as a portion of the visceral brain, based on prominent writings by Penfield, Mesulam, Saper, and others (Penfield and Faulk 1955; Mesulam and Mufson 1982; Saper 2002); some investigators simply call it a multi-modal region and cite the brief reviews by Augustine (1985, 1996); but for many new investigators who find it unexpectedly activated in their functional imaging study, it is simply an enigma.

The trendiness of insular cortex, a region implicated in interoceptive awareness of bodily states (Craig, 2009),² has been rising for several years now. The 2008 meeting of the Cognitive Neuroscience Society featured a symposium on A Common Role of Anterior Insula in Feelings, Empathy, and Risk?

Craig's (2010) introductory article continues:

In order to provide an overview of this vast literature for a 2009 opinion article (Craig 2009), I compiled reports from disparate and unfamiliar branches of neuroscience. To my mind, this burgeoning literature compelled the hypothesis that the anterior insula engenders human awareness, yet only one article had directly addressed this possibility (Klein et al. 2007), and an astonishing number of authors had reported strong activation of the insula without comment. The immediate need for an anthology became obvious, in which leading primary investigators from these disparate fields could re-appraise the role of the insula in light of the new perspective provided by this extraordinary convergence of evidence.

It's an impressive collection of articles, covering a wide range of topics including clinical aspects, neuroanatomical organization, affective bodily feelings, subjective emotional feelings, perception, cognition, performance, and attention. Craig ends on a note of optimism and awe, encouraging contributions from junior investigators:

The overall goal of this set of articles is to provide a solid starting point for new investigators by identifying the issues and the opportunities for advances in our knowledge of this unique portion of the human brain. The authors were encouraged by the peer reviewers and the editors to be thorough and prospective, and to express their individual viewpoint as lucidly as possible. We hope that young neuroscientists will find fertile ground here. Indeed, we are all excited by the prospects for awe-inspiring discoveries in the convergence of these disparate fields of neuroscience.

Footnotes

¹ Which surprised me at the time:

For sheer volume you have to include the insula. From 1985-2009 there was a total of 197,256 articles (compare to 82,438 for the hippocampus). The number of PubMed hits for insula in 1985 was 3,906; in 2008 it was 13,375.

² Among many other behavioral domains...

Reference

Craig AD. (2009). How do you feel--now? The anterior insula and human awareness. Nat Rev Neurosci. 10:59-70.


Contents

Once an island, now the focus of attention
A. D. Craig
DOI: 10.1007/s00429-010-0270-0

The von Economo neurons in frontoinsular and anterior cingulate cortex in great apes and humans
John M. Allman, Nicole A. Tetreault, Atiya Y. Hakeem, Kebreten F. Manaye, Katerina Semendeferi, Joseph M. Erwin, Soyoung Park, Virginie Goubert and Patrick R. Hof
DOI: 10.1007/s00429-010-0254-0

Anterior insula degeneration in frontotemporal dementia
William W. Seeley
DOI: 10.1007/s00429-010-0263-z

Taste representation in the human insula
Dana M. Small
DOI: 10.1007/s00429-010-0266-9

Saliency, switching, attention and control: a network model of insula function
Vinod Menon and Lucina Q. Uddin
DOI: 10.1007/s00429-010-0262-0

The hidden side of intentional action: the role of the anterior insular cortex
Marcel Brass and Patrick Haggard
DOI: 10.1007/s00429-010-0269-6

Insula and drug cravings
Hugh Garavan
DOI: 10.1007/s00429-010-0259-8

Risk and risk prediction error signals in anterior insula
Peter Bossaerts
DOI: 10.1007/s00429-010-0253-1

The role of the human anterior insular cortex in time processing
P. Kosillo and A. T. Smith
DOI: 10.1007/s00429-010-0267-8

Anterior insula activations in perceptual paradigms: often observed but barely understood
Philipp Sterzer and Andreas Kleinschmidt
DOI: 10.1007/s00429-010-0252-2

The insula and drug addiction: an interoceptive view of pleasure, urges, and decision-making
Nasir H. Naqvi and Antoine Bechara
DOI: 10.1007/s00429-010-0268-7

The contribution(s) of the insula to speech production: a review of the clinical and functional imaging literature
Hermann Ackermann and Axel Riecker
DOI: 10.1007/s00429-010-0257-x

Right insula for our sense of limb ownership and self-awareness of actions
Hans-Otto Karnath and Bernhard Baier
DOI: 10.1007/s00429-010-0250-4

The insular cortex: a comparative perspective
Camilla Butti and Patrick R. Hof
DOI: 10.1007/s00429-010-0264-y

Conscious perception of errors and its relation to the anterior insula
Markus Ullsperger, Helga A. Harsay, Jan R. Wessel and K. Richard Ridderinkhof
DOI: 10.1007/s00429-010-0261-1

Clinical effects of insular damage in humans
Agustin Ibañez, Ezequiel Gleichgerrcht and Facundo Manes
DOI: 10.1007/s00429-010-0256-y

A link between the systems: functional differentiation and integration within the human insula revealed by meta-analysis
Florian Kurth, Karl Zilles, Peter T. Fox, Angela R. Laird and Simon B. Eickhoff
DOI: 10.1007/s00429-010-0255-z

The sentient self
A. D. (Bud) Craig
DOI: 10.1007/s00429-010-0248-y

Conjoint activity of anterior insular and anterior cingulate cortex: awareness and response
Nick Medford and Hugo D. Critchley
DOI: 10.1007/s00429-010-0265-x

Role of the anterior insula in task-level control and focal attention
Steven M. Nelson, Nico U. F. Dosenbach, Alexander L. Cohen, Mark E. Wheeler, Bradley L. Schlaggar and Steven E. Petersen
DOI: 10.1007/s00429-010-0260-2

Interoception in anxiety and depression
Martin P. Paulus and Murray B. Stein
DOI: 10.1007/s00429-010-0258-9

The role of anterior insular cortex in social emotions
Claus Lamm and Tania Singer
DOI: 10.1007/s00429-010-0251-3

Nu Woman magazine; Island fashion.