MPDiR (version 0.1-15)

Context: Psychometric Functions for the Effects of Context on Contrast Detection

Description

Yes-No psychometric functions in which observers reported whether a vertical bar (the target) was present on each trial in the presence of contextual bars.

Usage

data(Context)

source

Data kindly provided by Li Zhaoping

Details

The number of trials on which the target was detected is reported as a function of its contrast. The target bar was presented in the context of 6 aligned vertical bars (3 above and 3 below) and the 4 conditions correspond to 4 levels of contrast of the contextual bars, including a 0 contrast condition, i.e., no contextual bars.

References

Zhaoping L. & Jingling L. (2008) Filling-in and suppression of visual perception from context---a Bayesian account of perceptual biases by contextual influences, PLoS Computational Biology 4(2): e14 doi:10.1371/journal.pcbi.0040014

Examples

data(Context)
Context <- within(Context, Pc <- NumYes/(NumYes + NumNo))
lattice::xyplot(Pc ~ TargCntr | ContCntr, data = Context, 
	groups = Obs,	type = c("l", "p"),
	auto.key = list(space = "right"))