Three reasons may explain the difference between the study of de Grave, Smeets et al. A mismatch of attentional demands cannot explain the perception-action dissociation. Vision Research , 27, — Stimulus parameters were chosen so that saccade targets within M-L figures appeared to be equidistant from the movement launch point, when in reality one target was 1. You can manage this and all other alerts in My Account. Thus, not finding a visual illusion in haptics is an argument in favour of specific haptic processes. Experiment 1 revealed a modest but reliable influence of the M-L illusion on reflexive saccade programming.
Why are saccades influenced by the Brentano illusion? This was interpreted as evidence for a center of gravity effect. Journal of the Optical Society of America , 8, — Subjects were instructed to carry out a saccade to the other end of the horizontal shaft right after the appearance of the figure. Latency dependence of colour-based target vs nontarget discrimination by the saccadic system. Are perception and action affected differently by the Titchener circles illusion? Human Movement Science ,
The participants were asked to explore the display made of two arrowheads fixed at the end of rod which pointed to their left. After three seconds, the cross disappeared and a MF was presented for two seconds, resulting in the fixation of the right end or the left end of the horizontal shaft.
For closer analysis, voluntary and reflexive movements were submitted to separate three-way ANOVAs with saccade latency, stimulus configuration, and target distance as factors. Perception and Psychophysics62, — With respect to the assumptions about the COGE as spelled out in this study, some further points need to be addressed.
McCarley ; Arthur F.
Literature review on muller lyer illusion
If the slopes differ, one can divide the perceptual and action effects by the slope that characterizes the respective method of measurement and thereby correct for these differences. Looking forward to looking: In Oxford Psychology Series. The role of location probability in the programming of saccades: One possibility is that these mul,er are not evidence of a functional difference between voluntary and reflexive saccades, but were produced by differences in saccade latency.
Relations among modes of visual orienting. On the basis of self-reports, participants had no visual or somaesthetic disorders.
Thus, to the extent that saccade amplitudes were modulated by the M-L illusion, the difference between saccade amplitudes for near and far targets should have been smaller than in the control conditions. Various reasons may explain this discrepancy. Subjects were instructed to adjust the MF to the TF indicated by the color of the figures until the lengths of the two shafts appeared to be equal.
Literature review on muller lyer illusion
Follow us RSS feed. However, it is possible that these two effects cannot be disentangled that easily. Psychological Science14, — A model of saccade inititiation based on the competitive integration of exogenous and endogenous signals in the superior colliculus. Second, is the influence of the M-L illusion on reflexive saccades modulated by the strength of the visual go-signal?
The M-L illusion is extended in time, persisting for as long as the stimulus figure remains visible ignoring gradual declines of the illusion that may occur with very long periods of extended viewing, e. The adjustment was carried out using the keyboard.
The Visual and the Haptic Müller-Lyer Illusions: Correlation Study
Shaft lengths of 4 cm or 6 cm were used for the SCA figures. Past research has indicated that the strength or contrast of a flashed target has little effect on saccade accuracy Deubel, Two of the subjects were the authors.
Concerning the vertical saccades along the shaft of the Brentano illusion, de Grave and colleagues could not differentiate between effects of the perceived size and a possible additional COGE. Programming of endogenous and exogenous saccades: Evidence for a competitive integration model.
We showed that the action effect AE was considerably larger than the perceptual effect. Journal of Vision3, Similarly, the illusion was of the same magnitude for low-contrast target signals as for high-contrast signals. Finally, it is useful to consider the apparent contradiction between the current results and those revie Wong and Mackwho found no effect of an induced motion illusion on reflexive saccade revidw.
To test these possibilities, Experiment 2 employed a reflexive saccade task similar to that of Experiment 1, but manipulated target location probabilities to induce observers to prepare movements prior to onset of the go-signal.
Yet, illueion seems also plausible that the difference might be due to a COGE, since it is in accordance with the expectations for such an effect. Latency dependence of colour-based target versus non-target discrimination by the saccadic system. Though counterintuitive, the strong separate representation model has received support from findings suggesting that visually guided behavior is uninfluenced by illusions that are evident in subjective reports.