Who first proposed using ROC curves in a psychological context?
I worked out the answer to the question just as I was about to post it.

Swets (1973) writes of a 1954 conference that  


  Peterson and Birdsall had presented it a year earlier in a technical
  report. So it is fair to say, from the vantage point of psychology,
  that Peterson and Birdsall showed us how to plot the data.


Unless Swets is mistaken, the answer is Peterson and Birdsall (1953).

Peterson, W. W., &amp; Birdsall, T. G. The Theory of Signal Detectability (1953). Technical report No. 13, Electronic Defense Group, University of Michigan, Ann Arbor.

Swets, J. A. (1973). The relative operating characteristic in psychology. Science, 182(4116), 990-1000.