Wednesday, September 26, 2007

The Insulta and Anorexia


graphic adapted from the New York Times

Neurophilosophy points to a silly typo in a serious press release about a neuroimaging study in women who have recovered from anorexia nervosa:
Sense of taste different in women with anorexia nervosa

Imaging study finds brain changes associated with the regulation of appetite

Although anorexia nervosa is categorized as an eating disorder, it is not known whether there are alterations of the portions of the brain that regulate appetite. Now, a new study finds that women with anorexia have distinct differences in the insulta – the specific part of the brain that is important for recognizing taste – according to a new study by University of Pittsburgh and University of California, San Diego researchers currently on line in advance of publication in the journal Neuropsychopharmacology.
Oops!!

graphic adapted from the New York Times

The ORIGINAL press release from University of California, San Diego Medical Center spells "insula" correctly and goes on to state:
The study also implies that there may be differences in the processing of information related to self-awareness in recovering anorexics compared to those without the illness – findings that may lead to a better understanding of the cause of this serious and sometimes fatal mental disorder.

. . .

In response to both the sucrose and water, imaging results showed that women who had recovered from anorexia had significantly reduced response in the insula and related brain regions when compared to the control group. These areas of the brain recognize taste and judge how rewarding that taste is to the person. In addition, while the controls showed a strong relationship between how they judged the pleasantness of the taste and the activity of the insula, this relationship was not seen in those who had recovered from anorexia.
On the other hand, one could have expected the recovered anorexic women to show greater activity in the insula (Ellison et al., 1998), because this region is known to be activated in response to disgust.

References

Ellison Z, Foong J, Howard R, Bullmore E, Williams S, Treasure J. (1998). Functional anatomy of calorie fear in anorexia nervosa. Lancet 352:1192.

Wagner A, Aizenstein H, Mazurkewicz L, Fudge J, Frank GK, Putnam K, Bailer UF, Fischer L, Kaye WH. (2007). Altered Insula Response to Taste Stimuli in Individuals Recovered from Restricting-Type Anorexia Nervosa. Neuropsychopharmacology May 9; [Epub ahead of print].

Anorexia nervosa (AN) is an illness characterized by aversion to ingestion of normally palatable foods. We examined whether there is a primary disturbance of taste processing and experience of pleasure using a sucrose/water task in conjunction with functional magnetic resonance imaging (fMRI). To avoid confounding effects of illness, 16 women recovered from restricting-type AN were compared to 16 control women (CW). We used a region of interest-based fMRI approach to test the idea that individuals with AN have differential neural activation in primary and secondary taste cortical regions after sucrose and water administration. Compared to CW, individuals recovered from AN showed a significantly lower neural activation of the insula, including the primary cortical taste region, and ventral and dorsal striatum to both sucrose and water. In addition, insular neural activity correlated with pleasantness ratings for sucrose in CW, but not in AN subjects. Altered taste processing may occur in AN, based on differences in activity in insular–striatal circuits. These data provide the first evidence that individuals with AN process taste stimuli differently than controls, based on differences in neural activation patterns.

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