Anzola G P, Casco C, Luppino G, Rizzolatti G, Umiltà C
Boll Soc Ital Biol Sper. 1980 Jul 15;56(13):1420-5.
Lateralized presentations of verbal stimuli yield faster reaction times in the right visual field-left hemisphere, whereas nonverbal stimuli yield faster reaction times in the left visual field-right hemisphere. However, the problem of how lateral asymmetries in response latency are determined is still unsolved. The hypothesis of an absolute functional specialization of the two hemispheres suggests that information presented in the visual field connected with the unspecialized hemisphere has to travel along a less direct pathway, implying a crossing through the forebrain commissures, to reach the processing center. The hypothesis of a relative functional specialization assumes that stimuli are processed by the hemisphere contralateral to the field of presentation but speed of processing varies as a function of hemispheric specialization. The present study tried to find empirical evidence in favor of one of the two hypotheses. Choice reaction times to lateralized verbal stimuli were studied in normal subjects. In half of the trials the subjects had to carry out a concomitant task known to interfere selectively with mechanisms responsible of the organization of the responses of the left hemisphere. Both with and without concomitant task reaction times were significantly faster in the right visual field-left hemisphere. While the concomitant task produced an overall lengthening of reaction time, it did not affect interhemispheric asymmetry. This finding was discussed as evidence in favor of the absolute specialization hypothesis.
言语刺激的偏侧化呈现方式在右视野-左半球会产生更快的反应时间，而非言语刺激在左视野-右半球会产生更快的反应时间。然而，反应潜伏期的侧化不对称是如何确定的问题仍然没有解决。两个半球绝对功能特化的假说表明，在与未特化半球相连的视野中呈现的信息必须沿着一条不太直接的路径传播，这意味着要穿过前脑连合，才能到达处理中心。相对功能特化的假说则假定，刺激由与呈现视野对侧的半球进行处理，但处理速度会根据半球特化而变化。本研究试图找到支持这两种假说之一的实证证据。在正常受试者中研究了对偏侧化言语刺激的选择反应时间。在一半的试验中，受试者必须执行一项已知会选择性干扰负责左半球反应组织机制的伴随任务。无论有无伴随任务，右视野-左半球的反应时间都显著更快。虽然伴随任务导致反应时间总体延长，但它并未影响半球间的不对称性。这一发现被作为支持绝对特化假说的证据进行了讨论。
