Term
What do you call the process of combining similar contours in the images of each eye into a unified binocular percept? |
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Definition
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Term
| What is it called when two different objects appear to occupy the same location in visual space? |
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Definition
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Term
What is the failure to allow some monocular portion of the binocular field to contribute to the combined binocular percept? |
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Definition
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Term
| Does suppression happen instantaneously? |
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Definition
| No, it may take betwee 75 and 150 ms for suppression to begin. |
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Term
| Why is suppresion necessary even for normal vision? |
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Definition
| Suppression helps prevent the majority of the visual scene from appearing diplopic. |
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Term
| Strabismic patients are often unaware that they switch dominance between eyes. Can strabismics consciously control which eye is dominant? |
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Definition
| Even though strabismics are often unaware of when they switch dominance between eyes, they can consciously control it. |
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Term
| Name one way in which suppression differs from binocular rivalry? |
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Definition
1. In binocular rivalry, the rate of change of the visibility of targets in each eye is not under voluntary control. 2. In binocular rivalry, although it is not consciously perceived, the region of an image that is momentarily suppressed during rivalry maintains an influence over the visual system. 3. Rivalry requires that images be different in each eye while suppression, especially pathological suppression can occur when identical stimuli are presented to each eye. 4. The suppression in normal binocular rivalry tends to be stronger than that of pathological suppression in strabismus. |
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Term
| Name one way in which suppression is similar to binocular rivalry? |
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Definition
1) Removal of some portions of the visual field from perception. 2) Similary types of dominant visual stimuli |
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Term
| How do we know that pathological suppression is probably not due to the same neural network as binocular rivalry? |
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Definition
| In pathological suppression, the subject does not experience wavelength specific drops in senstivity, while normal patients undergoing binocular rivalry do. |
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Term
| How do we know that pathological and physiological suppression do not reflect the same neural pathways? |
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Definition
Physiological suppression has a fast onset time of under 200 ms, while patholgical suppression has a slow onset time of 1-2 minutes. |
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Term
| How do we know that dichoptic masking and binocular rivalry do not reflect the same phenomenon? |
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Definition
| 1) Dichoptic masking is when one stimulus is presented to one eye and a mask that reduces the visibility of the first stimulus is presented to the fellow eye. The effects of dichoptic masking and binocular rivalry can be combined, suggesting they do not in fact represent the same phenomenom. |
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Term
| How do we know that rivalry takes place at stages beyond which adaptation occurs? |
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Definition
| During suppression when the stimulus is not seen, spatial and motional adaptation to the stimulus can occur. |
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Term
What determines which particular mechanism of combining information between the two eyes is used, that is, under what conditions do we fuse suppress or undergo binocular rivalry? |
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Definition
| The most important determinant is the similarity of the targets in each eye. |
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Term
| What phenomenon occurs when corresponding retinal points get the same contour information but different luminance or color information? |
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Definition
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Term
| Do patients with pathological suppression experience binocular luster? |
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Definition
| No, this is why luster is useful in vision therapy. During anaglyphic presentations luster is only perceived if the patient exhibits binocular fusion. |
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