Enhanced learning of natural visual sequences in newborn chicks.

To what extent are newborn brains designed to operate over natural visual input? To address this question, we used a high-throughput controlled-rearing method to examine whether newborn chicks (Gallus gallus) show enhanced learning of natural visual sequences at the onset of vision. We took the same set of images and grouped them into either natural sequences (i.e., sequences showing different viewpoints of the same real-world object) or unnatural sequences (i.e., sequences showing different images of different real-world objects). When raised in virtual worlds containing natural sequences, newborn chicks developed the ability to recognize familiar images of objects. Conversely, when raised in virtual worlds containing unnatural sequences, newborn chicks' object recognition abilities were severely impaired. In fact, the majority of the chicks raised with the unnatural sequences failed to recognize familiar images of objects despite acquiring over 100 h of visual experience with those images. Thus, newborn chicks show enhanced learning of natural visual sequences at the onset of vision. These results indicate that newborn brains are designed to operate over natural visual input.

An automated controlled-rearing method for studying the origins of movement recognition in newly hatched chicks.

Movement recognition is central to visual perception and cognition, yet its origins are poorly understood. Can newborn animals encode and recognize movements at the onset of vision, or does this ability have a protracted developmental trajectory? To address this question, we used an automated controlled-rearing method with a newborn animal model: the domestic chick (Gallus gallus). This automated method made it possible to collect over 150 test trials from each subject. In their first week of life, chicks were raised in controlled-rearing chambers that contained a single virtual agent who repeatedly performed three movements. In their second week of life, we tested whether chicks could recognize the agent's movements. Chicks successfully recognized both individual movements and sequences of movements. Further, chicks successfully encoded the order that movements occurred within a sequence. These results indicate that newborn visual systems can encode and recognize movements at the onset of vision and argue for an increased focus on automated controlled-rearing methods for studying the emergence of perceptual and cognitive abilities.