We summarize the various strands of research on peripheral vision and relate them to
theories of form perception. After a historical overview, we describe quantifications of the …

Lu Sperling [Vision Res. 35, 2697 (1995)] proposed that human visual motion perception is
served by three separate motion systems: a first-order system that responds to moving …

Visual perception can be influenced by top-down processes related to the observer's goals
and expectations, as well as by bottom-up processes related to low-level stimulus attributes …

Abstract The Psychophysics Toolbox is a software package that supports visual
psychophysics. Its routines provide an interface between a high-level interpreted language …

The VideoToolbox is a free collection of two hundred C subroutines for Macintosh computers
that calibrates and controls the computer-display interface to create accurately specified …

Does attention alter appearance? This critical issue, debated for over a century, remains
unsettled. From psychophysical evidence that covert attention affects early vision—it …

A shape can be more difficult to identify when other shapes are near it. For example, when
several grating patches are viewed parafoveally, observers are unable to report the …

We introduce a new Bayesian adaptive method for acquisition of both threshold and slope of
the psychometric function. The method updates posterior probabilities in the two …

A letter in the peripheral visual field is much harder to identify in the presence of nearby
letters. This is “crowding.” Both crowding and ordinary masking are special cases of …

Seeking to understand how people recognize objects, we have examined how they identify
letters. We expected this 26-way classification of familiar forms to challenge the popular …