Vallortigara G
Istituto di Filosofia, Pedagogia, Didattica delle Lingue Moderne, Università di Udine, Italy.
Neuropsychologia. 1992 Sep;30(9):761-8. doi: 10.1016/0028-3932(92)90080-6.
Recognition of familiar and unfamiliar conspecifics was studied in pair-reared chicks tested binocularly or with only one eye in use. Chicks were tested on day 3 in pairs composed of either cagemates or strangers. Social discrimination, as measured by the ratio "number of pecks at the strangers/total number of pecks" was impaired in right-eyed chicks with respect to left-eyed and binocular chicks. Male chicks showed higher levels of social pecking than females, and chicks that used both eyes showed higher pecking than monocular chicks. There were no significant differences in the total number of pecks (i.e. pecks at companions plus pecks at strangers) between right- and left-eyed chicks: the impairment in social discrimination of right-eyed chicks seemed to be due partly to a reduction in pecking at strangers and partly to an increase in pecking at companions. It is suggested that neural structures fed by the left eye (mainly located at the right hemisphere) are better at processing and/or storing of visual information which allows recognition of individual conspecifics. This may be part of a wider tendency to respond to small changes in any of a variety of intrinsic stimulus properties.
在成对饲养的雏鸡中研究了对熟悉和不熟悉同种个体的识别，这些雏鸡通过双眼或仅用一只眼睛进行测试。在第3天，将雏鸡以同笼伙伴或陌生鸡配对进行测试。用“对陌生鸡的啄击次数/总啄击次数”的比率来衡量的社会辨别能力，右眼雏鸡相对于左眼雏鸡和双眼雏鸡有所受损。雄性雏鸡的社会啄击水平高于雌性，使用双眼的雏鸡比单眼雏鸡表现出更高的啄击频率。右眼雏鸡和左眼雏鸡之间的总啄击次数（即对同伴的啄击次数加上对陌生鸡的啄击次数）没有显著差异：右眼雏鸡社会辨别能力的受损似乎部分是由于对陌生鸡啄击次数的减少，部分是由于对同伴啄击次数的增加。有人认为，由左眼提供信息的神经结构（主要位于右半球）在处理和/或存储视觉信息方面更擅长，而这些视觉信息有助于识别个体同种个体。这可能是对各种内在刺激特性中任何一种的微小变化做出反应的更广泛倾向的一部分。
