Abstract:<\/b> <\/span> My 1967 paper focussed on \u201csize-dependent\u201d coding of shape discriminations by fish. I soon presented other evidence for spatial mechanisms underlying object discrimination in fish and then showed that humans show some \u201cshape invariance\u201d during hand-shaping. This discovery anticipated the Goodale-Milner formulation by 10 years.<\/p>\n In monkey, temporal lobe is not necessary for discrimination of mirror-image shapes (a spatial task in my view) so that one must ask whether parietal cortex plays a critical role features spatial location. Data from both lesion studies & brain scans in humans show that processes related to perceptual rotation of shapes are linked to parietal areas.<\/p>\n I add a new source of information which distinguishes spatial & feature-representation in man. My own \u201cvisual persistences\u201d are vivid afterimages which remain fixed in body-centered coordinates (following eye-closure) as I can translate these images throughout the field or exchange them from hand to hand. However, I find that larger configurations rotate with the hand, but smaller features do not. This form\/space dissociation parallels observations of both Richard Held & Ivo Kohler: prismatic \u201cadaptation\u201d applies to the localizing mode of vision but does not alter percepts based on local features.<\/p>\n The ability to move detailed visual images up to 180 deg. within the frontal field implies tight collaboration of identification & spatial systems. While I\u2019m not aware of evidence for direct coordination between T & P regions, both areas project to prefrontal cortex, where a higher level synthesis of the 2 VS\u2019s could occur. A top-down influence of PFC or premotor regions on parietal cortex may account for my motor-to-visual phenomena.<\/p>\n Furthermore the developmental construction of space may depend on the role of PFC & premotor region in guiding eye & hand movements.<\/p>\n in Room 203, 44 Cummington St. David Ingle Abstract: In 1967 4 of us co-authored the \u201c2 visual system\u201d hypothesis: identifying vs. localizing systems. I stressed that both visual modes must be subcortical in lower vertebrates. Held\u2019s contrasting functions were both cortical, without anatomical underpinning. Ungerleider & Mishkin (1982) added anatomical data to crystalize established clinical concepts of temporal vs. parietal […]<\/p>\n","protected":false},"author":15420,"featured_media":0,"parent":0,"menu_order":157,"comment_status":"closed","ping_status":"closed","template":"page-templates\/no-sidebars.php","meta":[],"_links":{"self":[{"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/pages\/703"}],"collection":[{"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/users\/15420"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/comments?post=703"}],"version-history":[{"count":1,"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/pages\/703\/revisions"}],"predecessor-version":[{"id":704,"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/pages\/703\/revisions\/704"}],"wp:attachment":[{"href":"https:\/\/www.bu.edu\/bravi\/wp-json\/wp\/v2\/media?parent=703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nIn 1967 4 of us co-authored the \u201c2 visual system\u201d hypothesis: identifying vs. localizing systems. I stressed that both visual modes must be subcortical in lower vertebrates. Held\u2019s contrasting functions were both cortical, without anatomical underpinning. Ungerleider & Mishkin (1982) added anatomical data to crystalize established clinical concepts of temporal vs. parietal lobe \u2018perceptual\u2019 functions. Goodale & Milner (1995) advanced the 2VS concept by showing that parietal lobe functions include a primitive kind of \u201cobject vision\u201d used for grasping of objects. I take issue with their attempt to strip parietal cortex of \u201cperceptual\u201d functions, using both clinical & scan evidence.<\/span><\/p>\n
\nThe lecture will take place:<\/h4>\n
\non Thursday, April 18, 2002
\nat 12:15 pm<\/p>\n","protected":false},"excerpt":{"rendered":"