日本研究人員3月26日說,，老鼠等嚙齒動物經(jīng)過訓練,，也能學會使用工具并理解工具的用途?？茖W家此前普遍認為,，只有靈長類動物和一些鳥類能使用工具。
日本理化研究所研究人員選取6只成年八齒鼠作為實驗對象,，訓練它們用微型T型耙取食物,。八齒鼠原產(chǎn)智利，是一種體型較小的老鼠,。整個實驗為期60天,。這些八齒鼠在實驗最后階段全部能夠熟練使用T型耙，它們能抓住T型耙,，順利將前方的食物耙到自己身邊,。
研究人員認為，這項研究顯示,，動物能否使用工具,，最重要的是“社會-生態(tài)學”因素。主持這項研究的岡屋和夫(音譯)說：“傳統(tǒng)觀點認為,，使用工具是一種高級能力,。但屬于嚙齒動物綱的動物如果經(jīng)過相應訓練，也可以做到這一點,。”岡屋說,，這項研究意味著種類相當廣泛的動物存在學會使用工具的可能。
研究人員還發(fā)現(xiàn),，八齒鼠還能識別有用的工具,。在一項測試中，他們在這些八齒鼠面前放上兩種耙子,，一種耙子可以實際使用,，八齒鼠也較為熟悉,；另一種耙子沒有耙釘，或者耙釘凸起,，沒有實際功能,。
結果發(fā)現(xiàn)，在大多數(shù)情況下,，八齒鼠會毫不猶豫地選擇具有實際功能的耙子,，而且它們在作出正確選擇時，不會受工具顏色或大小的干擾,。
研究人員說,，成功使用系統(tǒng)方法訓練嚙齒動物操作工具、理解工具用途,，這在世界上尚屬首次,。
這項研究成果發(fā)表在美國《公共科學圖書館·綜合》（PLoS ONE）上。（來源：新華網(wǎng)）
生物谷推薦原始出處：
（PLoS ONE）,，doi:10.1371/journal.pone.0001860,，Kazuo Okanoya，Atsushi Iriki
Tool-Use Training in a Species of Rodent: The Emergence of an Optimal Motor Strategy and Functional Understanding
Kazuo Okanoya1, Naoko Tokimoto1,2, Noriko Kumazawa2, Sayaka Hihara2, Atsushi Iriki2*
1 Laboratory for Biolinguistics, Brain Science Institute, RIKEN, Saitama, Japan2 Laboratory for Symbolic Cognitive Development, Brain Science Institute, RIKEN, Saitama, Japan
Abstract
Background
Tool use is defined as the manipulation of an inanimate object to change the position or form of a separate object. The expansion of cognitive niches and tool-use capabilities probably stimulated each other in hominid evolution. To understand the causes of cognitive expansion in humans, we need to know the behavioral and neural basis of tool use. Although a wide range of animals exhibit tool use in nature, most studies have focused on primates and birds on behavioral or psychological levels and did not directly address questions of which neural modifications contributed to the emergence of tool use. To investigate such questions, an animal model suitable for cellular and molecular manipulations is needed.
Methodology/Principal Findings
We demonstrated for the first time that rodents can be trained to use tools. Through a step-by-step training procedure, we trained degus (Octodon degus) to use a rake-like tool with their forelimbs to retrieve otherwise out-of-reach rewards. Eventually, they mastered effective use of the tool, moving it in an elegant trajectory. After the degus were well trained, probe tests that examined whether they showed functional understanding of the tool were performed. Degus did not hesitate to use tools of different size, colors, and shapes, but were reluctant to use the tool with a raised nonfunctional blade. Thus, degus understood the functional and physical properties of the tool after extensive training.
Conclusions/Significance
Our findings suggest that tool use is not a specific faculty resulting from higher intelligence, but is a specific combination of more general cognitive faculties. Studying the brains and behaviors of trained rodents can provide insights into how higher cognitive functions might be broken down into more general faculties, and also what cellular and molecular mechanisms are involved in the emergence of such cognitive functions.
