Peripheral and central components in variants of the Mueller-Lyer illusion

Self Cite

Observer errors of judged length when viewing the Miiller-Lyer illusion arise partially from distortions caused by lateral neural interactions in the retina. To assess the relative contribution of such lateral neural interactions to the total magnitude of the illusion, the Miiller-Lyer figure was presented to observers under a form of intermittent-light stimulation that enhances lateral inhibitory activity. In Experiment 1, intermittent-light conditions produced the largest increase in illusion strength for the standard variant of the Miiller-Lyer figure but not for a dot form in which contour interactions are minimized. The results of Experiment 2 showed that the hypothesized lateral inhibitory contribution varied as a function of wing-shaft angle. In addition to confirming the contribution of lateral neural interactions to illusion formation, these findings also suggest that exposure of illusion configurations under intermittent illumination may provide a method of determining the relative contribution of lateral inhibition to illusion configurations other than the Miiller-Lyer.

Section: Methodssupporting

confidence: 76%

A method to assess the relative contribution of lateral inhibition to the magnitude of visual-geometric illusions

Coren

Porac

Aks

et al. 1988

Self Cite

“…These were included solely to reduce the possibility of the subject's concluding that all the lengths presented were equal. The randomized presentation of figures was designed to distribute previously found, but limited, decrement effects (ranging from 25070 to 40070; see Coren & Girgus, 1972b& Girgus, , 1972cGirgus, Coren, Durant, & Porac, 1975;Girgus, Coren, & Horowitz, 1973) across the variations examined while permitting a within-subjects design. The design was chosen because it allows each subject to serve as his or her own control, an essential but conservative methodology appropriate to parametric investigations of the Mueller-Lyer illusion (cf.…”

Section: Methodsmentioning

confidence: 99%

The role of structural components in the Mueller-Lyer illusion

Greist-Bousquet

Schiffman

1981

In order to assess the role of the structural components of the Mueller-Lyer illusion, subjects reproduced the central extent of standard Mueller-Lyer figures and configural variations. Illusory magnitude of the underestimated wings-in and overestimated wings-out figures was examined with selective amputations of the oblique wings and central line segment (shaft). Varlations were presented at 0,45,90, and 135 deg from vertical. Orientation had no reliable effect on illusory magnitude. Elimination of the shaft effected a decrease in the apparent extent for all variations, presumably due to the addition of the filled-unfilled space illusory effect to the standard Mueller-Lyer effect. A second study corroborated this finding: The decrease in apparent extent consequent to shaft removal occurred independently of any response factor. Selective wing removal differentially decreased the illusory magnitude of the standard MuellerLyer figures; this was discussed with regard to a dual-illusion hypothesis. Finally, variations that contained no intersecting lines produced a significant illusion in the direction of the standard Mueller-Lyer figures, suggesting the involvement of higher level, nonperipheral distortion mechanisms.The familiar form of the Mueller-Lyer illusion pattern characteristically effects a measurable error in the apparent length of a central line segment when this segment is appropriately flanked by oblique angles (Figures lA and lB). Although a number of investigations have examined the contribution of various components (e.g., length of the Oblique angles, the angle of Oblique attachment, etc.; see Robinson, 1972, for a review of configural manipulations and a historical review of the Mueller-Lyer illusion), there has been little systematic study to determine the critical stimuli within the basic figure for effecting and affecting the magnitude of the illusion. The effect on

“…Bekesy (1967) and Ganz (1966) also utilize a structural source of illusory distortion when they propose that lateral inhibitory interactions operating on converging or intersecting line elements cause some of the obtained contour displacements and distortions. Coren (1970) and Girgus, Coren. and Horowitz (1973) have shown that removal of the converging line elements necessary for the operation of this mechanism does.…”

mentioning

confidence: 99%

The assessment of components involved in illusion formation using a long-term decrement procedure

Girgus

Coren

Durant

et al. 1975

Self Cite

Available evidence seems to indicate that illusion decrement represents reorganization of cognitive components involved in visual-geometric illusions. Observers viewed one of the two forms of the Mueller-Lyer illusion. containing differential opportunities for peripheral structural interactions, for a lO-min test session on each of 5 successive days. The magnitude of the distortion decreased to a different asymptotic level in each of the two configurations with the form, with more opportunity for structural interactions showing the higher asymptote. Thus, this asymptote probably represents the structural or physiological contribution to the illusory distortion.