MAE EXPERIMENT

MAE Experiment

MAE Experiment

Intrduction

In the proposed research, first we will examine whether the motion- fading effect can occur over stimuli at high speed. To our knowledge, motion fading over stimuli moving at high speeds has not been carefully examined. However, it has been shown that a flickering spot/grating presented in the peripheral visual field appears to lose contrast and stop flickering. (Ashida, 2005) Given that moving and flickering stimuli share similar spatiotemporal properties, it is reasonable to hypothesize that motion fading can also occur over stimuli moving at high speed.

The motion aftereffect (hereafter: MAE)

After prolonged viewing of a slowly drifting or rotating pattern under strict fixation, the pattern appears to slow down and then momentarily stop. Here, we show that this motion fading occurs not only for slowly moving stimuli, but also for stimuli moving at high speed; after prolonged viewing of high-speed stimuli, the stimuli appear to slow down but not to stop. We report psychophysical evidence that the same neural adaptation process likely gives rise to motion fading and to the motion aftereffect. (Campbell, 2009)

Big Picture

According to the motion aftereffect (MAE) hypothesis tested here, motion fading arises because of adaptation among cortical motion-tuned neurons that are the same as those that underlie the well-known MAE, where illusory motion is perceived to occur over a stationary object or image following prolonged exposure to visual motion. For example, it has been shown that the MAE is based on neural adaptation (i.e., modulation of gain control) near or at the input of MT. The MAE mechanism is realized in the motion pathway, not the form pathway, which is consistent with the phenomenology of motion fading, where only the motion component appears to vanish from consciousness, while the form component remains visible. Together, these findings are consistent with the hypothesis that adaptation among motion-tuned neurons underlies motion fading.

Literature Review

The motion aftereffect (MAE) is a visual illusion that occurs when an individual observes a moving (adapting) pattern for a period of time followed immediately by the viewing of a physically stationary (test) pattern which appears to move in the opposite direction. (Campbell, 2001) A variation of the MAE, called storage, temporally separates the adapting pattern and test pattern with an unrelated visual stimulus, leaving a residual MAE. (Bonneh, 2001) The dominant explanation is gain control theory, which posits that the residual MAE is the result of gain control mechanisms normalizing the motion sensing cells in the visual system. (Cavanagh, 2004) One method for testing this gain control explanation of the MAE is to employ a diverted-attention manipulation during adaptation, which results in a reduced MAE duration and is generally described as interacting with the gain control mechanisms. (Gerrits, 2000)

One of the more interesting motion perception phenomena is an illusion of motion called the motion aftereffect. The motion aftereffect (MAE) occurs when an individual observes a moving (adapting) pattern for a period of time and then the moving pattern is replaced by a similar, though non-moving (test), ...