hunger and satiety in anorexia nervosa: fmri during cognitive processing of food pictures santel et...

Hunger and satiety Hunger and satiety in anorexia nervosa:

in anorexia nervosa:fMRI during cognitive processing of food picturesSantel et al., 2006

Maria Zuluaga

Bsc Psychology

14’

Brief overview0Anorexia nervosa- what is it?0Mental disorder0Fear of gaining weight0Mostly seen in adolescents (14 years

old)0More frequent in women-0amenorrhea (endocrine disorder)

0Lower activation in certain brain areas helps to maintain fasting

Introduction

0Objective: to test the different effects of visual stimuli of food on healthy and anorexic people.

0BUT- making a distinction between:0A Hungry state0A Satiated state

Hypothesis

0In anorexic patients- weaker activation in:0Inferior parietal lobe (IPL)0Occipital cortex

0Higher activation in:0Medial prefrontal cortex

Experimental Task020 practice trials08 am- 2 sessions (30 min)08 consecutive blocks 10

stimuli (colored pictures)0 food (320)0 non food (320)

Is the pictureA)Pleasant

B)Neutral

C)unpleasant

Results0Are you hungry?0Higher response when

hungry (both).0Anorexics had a lower

report overall.

0Anorexic- less pleased by food stimuli.

0Fmri- 0Anorexics (satiated)-

lower activation on IPL0 (-) correlation with

stornger dietary restrain.0 (+) correlation with

weaker disinihbition of eating and low BMI.

0Anorexic (hungry)- decreased activation of occipital cortex.

Discussion0Lower activation on IPL0This area controls: 0Appetite0Food related behaviors0Satiation

0Contains primary somatosensory neurons for body parts involved in eating.

0Facilitates fasting

0Lower occipital cortex activation0Attentional motivation0Focus on food stimuli when hungry to maintain

fasting

01° and 2° visual areas- importance of stimuli0Lower activation when anorexic patient was

hungry.

Strengths & Limitations

0Clear explanations0 Procedure0 Results

0Great build up on background information

0Sample size0 Non compliance

0Organization0 Hard to follow

Opinion

0Easy to understand overall0Explains why some behaviors may arise. (makes

sense)0Comparison to obese people

Enjoy what you have, it’s beautiful!