Imprinting, learning, and memory.

If a visually naive chick is exposed to one of a wide range of conspicuous objects, the chick may learn its characteristics. A series of biochemical studies has implicated a restricted part of the forebrain in this process of imprinting; a specific region (IMHV) has been identified which may be a site of information storage. Changes in the morphology of synapses occur in this region as a consequence of training. The left and right IMHV regions play different roles in the imprinting process. Exposure to a simple artificial object, a rotating red box, has different neural consequences from those associated with exposure to a complex object, a rotating stuffed jungle fowl, which resembles a conspecific. These differences may be related to the differences in complexity of the two training objects. Another possibility is that two neural systems are implicated in imprinting: (a) a system that underlies a predisposition to approach objects resembling conspecifics and (b) a learning system, of which IMHV is a crucial component, that is engaged by particular objects and that in "natural" circumstances also allows the chick to learn the characteristics of its mother. (PsycINFO Database Record (c) 2010 APA, all rights reserved)