Fig 1.

Expected value as a function of odds against receiving or losing $10. For probabilistic gains (top panel), the EV function divides the space into two domains: risk-seeking, when subjective value is greater than EV, and risk-averse, when subjective value is less than EV. For probabilistic losses, the EV function again divides the space into two domains: risk-seeking, when subjective value is less than EV, and risk-averse, when subjective value is greater than EV. Examples of subjective values that deviate from EV are plotted at Θ  =  1 (EV  =  +/−$5).