A number of studies have resulted in the finding of a 3-D perceptual anisotropy, whereby
spatial intervals oriented in depth are perceived to be smaller than physically equal intervals …

Investigated (a) the relative contribution of visual and postural factors in determining the
apparent vertical and (b) the scope of differentiation of 2 spatial reference systems. 90 …

The horizontal-vertical illusion is the illusion that vertical lines appear longer than horizontal
lines of identical physical length. Several experiments have shown that the HV illusion is …

The effect of systematic changes to the visual field, upon judgements of eye-level, was
investigated. The psychophysical concepts of gradients of texture density and perspective …

We report a series of nine experiments which show that a single roll-tilted line in darkness
induces changes of the orientation perceived as vertical (VPV) that are similar in magnitude …

The overestimation of the vertical direction was studied in a series of investigations (2, 4, 5,
6, 7). We found that this overestimation is due to the oval shape of the visual field which is …

Can subjects voluntarily set an internal coordinate frame in such a way as to facilitate the
detection of symmetry about an arbitrary axis? If so, is this internal coordinate frame the …

for the Training of Z'eachers. Page 1 PSYCH() I. ()(I("AI, THEO) RIES () F THE H() RIZ()NTAL.
VERTICAL, ILLUSI () N. By CW VALENTINE, /ecturer in Psychology, etc., to the St Andrews …

This study addressed the issue of how a stereo-specified surface influences the perceived
twodimensional orientation of a monocularly viewed line. In a series of three experiments, it …

Wenderoth's (1978) comments on my paper (Hartley, 1978) contain a serious oversight that
taints the interpretation offered. Briefly, I showed observers dots placed within a square or an …