Interocular Transfer of the Motion After-Effect

Interocular Transfer of the Motion After-Effect

A prominent phenomenon in the field of visual science is the motion after-effect (MAE) which is believed to provide a way of bringing together current knowledge of neurophysiology with a measurable visual phenomenon. The MAE is described as a visual illusion produced by viewing any number of motion types (i.e. lateral or vertical linear, spiral, radial or rotation). By viewing a moving physical object for a period of time until the eyes is adapted to the motion. When the motion of the object is stopped, but viewing remains focussed on the object, the viewer may report a slower, reversed/negative movement of the now stationary object (Mather et al, 1998).

The history of recognition and research into the MAE phenomenon can be traced back as far as the Aristotelian era. Both Aristotle (330 B.C) and Lucretius (approx. Three centuries later) reported the visual phenomenon as an effect of the stimulus water (although Lucretius went further by describing a MAE direction). It was not until the early nineteenth century that further research was noted. Purkinje (1820) and Addams (1834) both reported the causation and directional flow of the MAE with reference to cavalry parades and waterfalls as their respective motion examples. From this period up until the mid-twentieth century further research had been sporadic. This is perhaps due to the fact that so little was known of the neuroanatomy of the visual system. Wohlgemuth (1911) had however reviewed many of his predecessors work as well as reporting many of his own studies. An important aspect of his research came with the discovery of the storage effect of MAE's. After adaptation to stimuli, the testing eye is closed for th...

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...ween viewing condition and eye adapted, although it can be seen that there is a consistency with reduction in MAE magnitude from monocular testing to interocular testing.

Discussion

Through analysis of the results, it may initially seem that the experimental hypothesis is supported. The encoding category shows that there is no significant main effect between recall scores for visual and auditory encoding preference subjects. The learning instruction method factor however, shows that performance between the two groups has a highly significant main effect at the 1% level. It can also be seen from Table 2. and the profile plot in Figure 1. that there is a significant interaction (at the 5%) between the visual and auditory encoding groups across the imagery and sentence conditions. This in turn suggests that the experimental hypothesis cannot be wholly accepted.