Frey Scott H
Department of Psychology, University of Oregon, Eugene, OR 97403-1227, USA.
Cortex. 2007 Apr;43(3):368-75. doi: 10.1016/s0010-9452(08)70462-3.
An influential theory suggests that the dorsal (occipito-parietal) visual stream computes representations of objects for purposes of guiding actions (determining 'how') independently of ventral (occipito-temporal) stream processes supporting object recognition and semantic processing (determining 'what'). Yet, the ability of the dorsal stream alone to account for one of the most common forms of human action, tool use, is limited. While experience-dependent modifications to existing dorsal stream representations may explain simple tool use behaviors (e.g., using sticks to extend reach) found among a variety of species, skillful use of manipulable artifacts (e.g., cups, hammers, pencils) requires in addition access to semantic representations of objects' functions and uses. Functional neuroimaging suggests that this latter information is represented in a left-lateralized network of temporal, frontal and parietal areas. I submit that the well-established dominance of the human left hemisphere in the representation of familiar skills stems from the ability for this acquired knowledge to influence the organization of actions within the dorsal pathway.
一种有影响力的理论认为，背侧（枕顶叶）视觉流为指导行动（确定“如何做”）而计算物体的表征，独立于支持物体识别和语义处理（确定“是什么”）的腹侧（枕颞叶）流过程。然而，仅背侧流解释人类最常见的行动形式之一——工具使用的能力是有限的。虽然依赖经验对现有背侧流表征的修改可以解释在各种物种中发现的简单工具使用行为（例如，用棍子来延长够取范围），但熟练使用可操纵的人工制品（例如，杯子、锤子、铅笔）还需要获取物体功能和用途的语义表征。功能性神经成像表明，后一种信息在颞叶、额叶和顶叶区域的左侧化网络中得到表征。我认为，人类左半球在熟悉技能表征方面已确立的主导地位源于这种后天知识影响背侧通路内行动组织的能力。
