5. Impulsivity Flashcards
Which brain region is related to the motivation to consume ‘palatable’ food?
The mesolimbic dopaminergic system (VTA, Substantia Nigra)
What is hedonic hunger, and what is it probably for?
Hunger when there is no energy deficit. The evolutionary basis is probably for energy storage, which is why palatable food ignores satiety.
What is the difference between liking and wanting in consumption / addiction?
Liking = sensory pleasure. Wanting = incentive value.
Liking is mediated by opioid receptors in the NA.
Wanting is mediated by dopaminergic projections from the VTA and NA.
How does inhibition of these food stimuli mainly take place?
From the PFC, mainly the dlPFC which inhibits behaviour and matches behaviour to environmental cues.
The lateral PFC decreases motivation to consume after ingestion.
Succesful dieters show dPFC activation at ingestion of a meal.
How are the control mechanisms of the PFC negatively influenced?
In dieters a negative influence was found from challenges, either stressful or non-stressful.
What is one behavioural explanation for the difficulty in dieting that most people experience?
“Delay discounting”. Delayed or distant rewards are discounted / undervalued.
Between which two brain areas is there a possible antagonism taking place in hedonic feeding?
The PFC as inhibitor and the mesolimbic system as appetitive drive. The ACC allocates attention.
What is the reward deficit syndrome?
The fact that those who abuse substances tend to have lower levels of dopamine concentrations, and therefore respond more strongly to rewarding stimuli.
How are bulimia and binge eating explained?
As a ‘reash spontaneous impulsiveness’ leading to binge eating, but also a heightened reward sensitivity in their characters. (loss of control v.s. obsessive control – bulimia vs anorexia). Impulsiveness is seen as a general predisposition and not related to disordered eating.
Which brain areas are involved in response inhibition (movement), among others?
Pre-SMA, SMA, Pre-motor cortex, parietal cortex, ventrolateral PFC and insula, rIFC (inferior frontal cortex)
What is one of the most important recipients of cortical stopping commands, and how does the network look?
The subthalamic nucleus. It works through a hyper direct pathway which allows fast inhibition by increasing the globus pallidus signals and inhibiting the thalamus.
