Geraci Carlo, Gozzi Marta, Papagno Costanza, Cecchetto Carlo
Dipartimento di Psicologia, Università di Milano Bicocca, Piazza dell'Ateneo Nuovo 1, Edificio U6, 20126, Milano, Italy.
Cognition. 2008 Feb;106(2):780-804. doi: 10.1016/j.cognition.2007.04.014. Epub 2007 May 29.
It is known that in American Sign Language (ASL) span is shorter than in English, but this discrepancy has never been systematically investigated using other pairs of signed and spoken languages. This finding is at odds with results showing that short-term memory (STM) for signs has an internal organization similar to STM for words. Moreover, some methodological questions remain open. Thus, we measured span of deaf and matched hearing participants for Italian Sign Language (LIS) and Italian, respectively, controlling for all the possible variables that might be responsible for the discrepancy: yet, a difference in span between deaf signers and hearing speakers was found. However, the advantage of hearing subjects was removed in a visuo-spatial STM task. We attribute the source of the lower span to the internal structure of signs: indeed, unlike English (or Italian) words, signs contain both simultaneous and sequential components. Nonetheless, sign languages are fully-fledged grammatical systems, probably because the overall architecture of the grammar of signed languages reduces the STM load. Our hypothesis is that the faculty of language is dependent on STM, being however flexible enough to develop even in a relatively hostile environment.
众所周知，美国手语（ASL）的广度比英语短，但这种差异从未使用其他手语和口语语言对进行过系统研究。这一发现与表明手语的短期记忆（STM）具有与单词STM相似的内部组织的结果不一致。此外，一些方法学问题仍然悬而未决。因此，我们分别测量了聋人和听力匹配的参与者对意大利手语（LIS）和意大利语的广度，控制了所有可能导致差异的变量：然而，聋人手语使用者和听力正常的说话者之间的广度差异仍然存在。然而，在视觉空间STM任务中，听力受试者的优势消失了。我们将较低广度的原因归因于手语的内部结构：事实上，与英语（或意大利语）单词不同，手语包含同时性和顺序性成分。尽管如此，手语是成熟的语法系统，可能是因为手语语法的整体结构减轻了STM负荷。我们的假设是，语言能力依赖于STM，然而它足够灵活，即使在相对不利的环境中也能发展。
