Adaptive staircase performance of an older subject (age 56) in two sessions conducted 7 days apart.

<p><b>A. i.</b> Subject performance on 6 staircases in session 1: trial number vs. angle of the white line relative to true index finger angle (0°). Black: staircases that began with a leftward trial. Grey: staircases that began with a rightward trial. <b>ii.</b> Proportion of rightward responses at each tested angle (black circles) with fitted function. Perceptual boundary (proprioceptive bias) was -12.4°, proprioceptive sensitivity (width of grey shaded area on x-axis) was 3.3°. <b>B. i.</b> Subject performance 7 days later on 6 staircases. <b>ii.</b> Both perceptual boundary and sensitivity (-9.6° and 2.5°, respectively) appear similar to the first session.