Abstract
Language | English |
---|---|
Pages | 901-924 |
Number of pages | 24 |
Journal | Perception |
Volume | 31 |
Issue number | 8 |
Publication status | Published - 2002 |
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Global and local contributions to the optical specification of time to contact: Observer sensitivity to composite tau. / Bootsma, R.J.; Craig, Cathy.
In: Perception, Vol. 31, No. 8, 2002, p. 901-924.Research output: Contribution to journal › Article
TY - JOUR
T1 - Global and local contributions to the optical specification of time to contact: Observer sensitivity to composite tau
AU - Bootsma, R.J.
AU - Craig, Cathy
PY - 2002
Y1 - 2002
N2 - First-order time remaining until a moving observer will pass an environmental element is optically specified in two different ways. The specification provided by global tau (based on the pattern of change of angular bearing) requires that the element is stationary and that the direction of motion is accurately detected, whereas the specification provided by composite tau (based on the patterns of change of optical size and optical distance) does not require either of these. We obtained converging evidence,for our hypothesis. that observers are sensitive to composite tau in four experiments involving, relative judgments of, time to, passage with forced-choice methodology. Discrimination performance was enhanced in the presence of a local expansion component, while being unaffected when the detection of the direction of heading was impaired. Observers relied on the information carried in composite tau rather than on the information carried in its constituent components. Finally, performance was similar under conditions of observer motion and conditions of object motion. Because composite tau specifies first-order time remaining for a large number of situations, the different ways in which it may be detected are discussed.
AB - First-order time remaining until a moving observer will pass an environmental element is optically specified in two different ways. The specification provided by global tau (based on the pattern of change of angular bearing) requires that the element is stationary and that the direction of motion is accurately detected, whereas the specification provided by composite tau (based on the patterns of change of optical size and optical distance) does not require either of these. We obtained converging evidence,for our hypothesis. that observers are sensitive to composite tau in four experiments involving, relative judgments of, time to, passage with forced-choice methodology. Discrimination performance was enhanced in the presence of a local expansion component, while being unaffected when the detection of the direction of heading was impaired. Observers relied on the information carried in composite tau rather than on the information carried in its constituent components. Finally, performance was similar under conditions of observer motion and conditions of object motion. Because composite tau specifies first-order time remaining for a large number of situations, the different ways in which it may be detected are discussed.
M3 - Article
VL - 31
SP - 901
EP - 924
JO - Perception
T2 - Perception
JF - Perception
SN - 0301-0066
IS - 8
ER -