Patterns of individual stimulus history biases across environments.
A. Impact of previous choices versus impact of previous stimulus categories on current choice for lag 1. Green dots and blue triangles refer to values from individual participants in Repetitive and Alternating, respectively. Grey lines connect values from both environments. Green and blue arrows indicate shift of group averages from Neutral (red x) during Repetitive and Alternating, respectively. Positive weights corresponded to tendency to repeat, and negative weights to tendency to alternate previous choice (x) or stimulus category (y). Angles of vectors from the origin to individual data points differed from uniform in Neutral (z = 7.536, p = 0.0004; Rayleigh’s test). Individual vector angles of shift from Neutral differed from uniform in Repetitive (z =19.382, p < 0.0001) and Alternating (z=21.287, p < 0.0001; Rayleigh’s test), with a difference in shift between both environments (F(2,34) = 75.79, p < 0.0001, Hotelling test). B. History kernels quantifying the impact of previous stimulus categories on current choice as a function of lag, for the three environments. Circles and thin lines, individual subjects; thick lines, group average. Circles are drawn for subjects whose best-fitting lag is 1. The predominant effect of sensory environment is evident at lag 1.