Term
| What is the order of muscular activation in the Ankle Strategy when pushed backwards? Forwards? |
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Definition
Ankle Strategy: Distal--> Proximal Backwards: Anterior Tibialis, Quadriceps and Abdominals Forward: Gastrocnemius, Hamstrings and Erector Spineae |
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Term
What is the order of muscular activation with the Hip Strategy when pushed backward? Forward? |
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Definition
Hip Strategy: Proximal to Distal Backward: Abdominals, Quadriceps Forward: Paraspinals, Hamstrings |
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Term
| What happens when the support surface is changed to a narrow beam? |
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Definition
| The hip strategy is necessary at a smaller perterbation magnitude. |
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Term
| What does the ability to adapt to postural responses suggest? |
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Definition
| That the automatic ankle/hip strategy can be modulated by higher cortical centers, so in subsequen tests, the reflex decreases. |
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Term
| During anticapatory postural contro what occurs? |
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Definition
| the passive unloading of the arm results in greater displacement than active unloading |
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Term
| Why does error increase with speed with eyes open, but remain steady as speed increase with eyes closed? |
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Definition
| The longer the movement allows for greater correction of error via visual feedback, but with eyes closed the error cannot be adjusted with visual feedback so the duration of the movement does not affect the error. |
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Term
| Grasping (prehension) takes longer than pointing because____________ |
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Definition
The pointing does not require a great deal of decelleration in order to grab the object. Hand posture during prehension is influenced by several characteristics of the target object. |
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Term
| What deficits occur with Ventral Stream damage? |
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Definition
Visual form agnosia, and inability to make the perceptual estimates of an objects width. Trouble making perceptual estimates of the objects orientation, but able to place an object with the correct orientation. However, the gripping (prehension) of the object remains intact. |
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Term
| Why do ventral lesion patients have trouble perceiving object features, but not with motor output dependent on those features? |
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Definition
The perception of objects and visual control of action are dissasociated. |
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Term
| What processes occur in the ventral stream? |
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Definition
| influences of illusion on perception |
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Term
| What processing occurs in the dorsal stream? |
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Definition
| The lack of influence of illusion on action |
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Term
| Perception of size is influenced by visual context, however, the gripping of an object is not influenced by visual context. |
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Definition
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Term
| Lesions to parietal areas contribute to what deficits? |
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Definition
| grasping deficits, however with visual feedback grasping is still feasible |
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