Newborn chickens generate invariant object representations at the onset of visual object experience

To recognize objects quickly and accurately, mature visual systems build invariant object representations that generalize across a range of novel viewing conditions (e.g., changes in viewpoint). To date, however, the origins of this core cognitive ability have not yet been established. To examine how invariant object recognition develops in a newborn visual system, I raised chickens from birth for 2 weeks within controlled-rearing chambers. These chambers provided complete control over all visual object experiences. In the first week of life, subjects’ visual object experience was limited to a single virtual object rotating through a 60° viewpoint range. In the second week of life, I examined whether subjects could recognize that virtual object from novel viewpoints. Newborn chickens were able to generate viewpoint-invariant representations that supported object recognition across large, novel, and complex changes in the object’s appearance. Thus, newborn visual systems can begin building invariant object representations at the onset of visual object experience. These abstract representations can be generated from sparse data, in this case from a visual world containing a single virtual object seen from a limited range of viewpoints. This study shows that powerful, robust, and invariant object recognition machinery is an inherent feature of the newborn brain.     

Duodenum is important for the sphincter of Oddi motor response to cholecystokinin octapeptide in conscious dogs

Background We investigated the role of the duodenum in the sphincter of Oddi response to cholecystokinin-octapeptide (CCK-OP), using conscious dogs.Methods In controls, a cannula was inserted into the duodenum opposite the papilla for retrograde manometry. In the duodenectomy group, the entire duodenum was resected, while preserving the papilla, which was implanted into the jejunum, and the cannula was placed. Sphincter motility was recorded after bolus injections of 20 and 100ng/kg of CCK-OP.Results CCK-OP at 20ng/kg produced sphincter relaxation followed by contraction in the controls, but produced no changes after duodenectomy. CCK-OP at 100ng/kg caused strong contractions followed by relaxation in the controls, but caused only contractions after duodenectomy.Conclusions (1) Relaxation and delayed contraction of the sphincter induced by 20ng/kg of CCK-OP require the presence of the duodenum; (2) early contractions of the sphincter induced by 100ng/kg of CCK-OP do not require the duodenum; (3) the duodenum plays an important role in the actions of CCK-OP on sphincter motility.