The Two Visual Systems Hypothesis: New Challenges and Insights from Visual form Agnosic Patient DF.

摘要: Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision adjust the configuration of her grasping hand geometry a goal object. This striking dissociation between perception and action in DF provided key piece evidence for formulation Goodale Milner’s Two Visual Systems Hypothesis (TVSH). According TVSH, ventral stream plays critical role constructing our percepts, whereas dorsal mediates control action, such as visually guided grasping. In this review, we discuss recent studies that provide new insights into functional organization streams. We confirm has well brain damage – dorsal-stream lesions surrounding atrophy have increased size since first published scan. argue DF’s explains deficits directing actions at targets periphery. then focus on ability accurately in-flight aperture changes width objects (grip scaling) whose dimensions she cannot explicitly report. An examination several grip scaling under natural conditions reveals modest though significant deficit. Importantly, however, continues show robust action. also review explore online feedback terminal haptic programming These make it clear no more reliant or than are neurologically-intact individuals. short, grasp depends feedforward processing carried out by visuomotor networks function much same way they do