Subjects were asked to rehearse word trigrams in a particular prefamiliarized male or female voice for 5, 10, or 15 sec. In Experiment 1, recognition performance improved with the amount of primary (maintenance) rehearsal only if the speaker’s voice at test matched the rehearsal voice, but recognition performance improved with the amount of secondary (elaborative) rehearsal regardless of the se...

We examined how observers discount perceived surface orientation in estimating perceived albedo (lightness). Observers viewed complex rendered scenes binocularly. The orientation of a test patch was defined by depth cues of binocular disparity and linear perspective. On each trial, observers first estimated the orientation of the test patch in the scene by means of a gradient probe and then mat...

Figure 1. Experimental procedures and results of visual rhythm discrimination training. (A) Schematic of a visual trial from the rhythm discrimination task. In this example, the patterns of the rhythm sequences are different. (B) Depiction of the experimental design. Sessions were completed 24 to 48 hours apart. For all groups, the preand post-test trials contained visual stimuli only. (C) Mean...

Older people need greater access to good eye care: 82% of people living with blindness worldwide are over 50, even though they only represent 19% of the world’s population.1 In South Africa, the 80% of people who are unable to afford expensive private medical insurance are reliant on the state to provide affordable health care.2 Older people have access to primary health clinics in the communit...

Macaque monkeys and normal human observers were tested on the same apparatus for the presence of a Purkinje shift. and for spectral sensitivity under scotopic and photopic conditions. The flicker fusion point for different lights was used as a measure of visual sensitivity in these tests and the testing procedure was a four-alternative forced choice. The results show that macaque monkeys and no...

BACKGROUND Current surgical robots provide no sense of touch and rely solely upon vision. This study evaluated the effect of new stereoscopic technology on the performance of robotic precision laparoscopy. METHODS Eight experienced laparoscopists with no experience in robotics performed five tasks of increasing complexity using a laparoscopic robot. The tasks were as follows: rope pass, paper...