Greater connectivity between the two was positively associated with a desire to consume high-calorie food.
In people of normal weight, the same stimulus prompted more connection between other parts of the brain, such as the ventral putamen and orbitofrontal cortex.
Further research showed that 11 per cent of weight gain in obese individuals over a period of three months could be predicted by the presence of higher dorsal caudate-somatosensory cortex connectivity.
"There is an ongoing controversy over whether obesity can be called a 'food addiction', but in fact there is very little research which shows whether or not this might be true," Lead researcher, Dr Oren Contreras-Rodriguez, from the University of Granada in Spain, said.
"The findings in our study support the idea that the reward processing following food stimuli in obesity is associated with neural changes similar to those found in substance addiction.
"These findings provide potential brain biomarkers which we can use to help manage obesity, for example through pharmacotherapies and brain stimulation techniques that might help control food intake in clinical situations."
• The findings were presented at the European College of Neuropsychopharmacology's annual meeting in Amsterdam.
