Table 1.

Summary of Studies on Mechanisms and Models Underlying Effort-Based Decision Making Related Negative Symptoms (PFC, Prefrontal Cortex; ACC, Anterior Cingulate Cortex; THC, Tetrahydrocannabinoid; GlyT, Glycine 1 Transporter)

Study Type	Domain	Manipulation	Brain Region	Effect on Behavior	Ref.
Mechanistic	Cost/benefit decision making	GABAa antagonist	PFC	Impaired decision making	32
	Physical/ cognitive effort	Dopamine D1- or D2-family receptor antagonists	Systemic	Decreased physical effort, little effect on cognitive effort	33
	Cognitive effort	THC/CB1 receptor agonist	Systemic	Decreased cognitive effort	35
	Reward learning	Suppression of dopamine D1 receptor expression	Striatum	Impaired probabilistic learning; effort unaffected	36
	Physical effort	Dopamine D1-family receptor antagonist	ACC	Impaired physical effort	37
	Physical effort	Dopamine D2-family receptor antagonist	Systemic	Impaired physical effort	38
	Physical effort	Dopamine D2 receptor overexpression	Nucleus accumbens	Increased physical effort expenditure	39
	Physical effort	Dopamine D2 receptor overexpression	striatum	Impaired physical effort	40,41
	Physical effort	GlyT1 inhibition	N/A	No effect	52
Animal Models of Negative Symptoms	Reward learning	Knockout of α7 nicotinic acetylcholine receptors	N/A	Impaired probabilistic learning	43
	Physical effort	Maternal immune activation	N/A	Increased breakpoints	50
	Physical effort	Repeated phencyclidine	N/A	Increased breakpoint
	Reward learning	Social Isolation Rearing	N/A	Impaired probabilistic reversal learning	51
	Physical effort	Reduced Sp4 expression	N/A	Reduced physical effort	53
	Reward learning	Reduced Sp4 expression	N/A	Impaired reward associative learning	53
	Reward learning	Social defeat	Striatum, VTA	Blunted response bias	54