Hungry pigeons prefer sooner rare food over later likely food or faster information.

Introduction: Making decisions and investing effort to obtain rewards may depend on various factors, such as the delay to reward, the probability of its occurrence, and the information that can be collected about it. As predicted by various theories, pigeons and other animals indeed mind these factors when deciding.

Methods: We now implemented a task in which pigeons were allowed to choose among three options and to peck at the chosen key to improve the conditions of reward delivery.

Overmatching under food uncertainty in foraging pigeons.

One major survival-related activity of organisms is to seek food in their environment. To this end, they exploit previously rewarding locations and attempt to approach the cues predictive of the edible items they detect or expect. But foraging is unlikely to be a matter of reinforcement only.

Mirror Self-Recognition in Pigeons: Beyond the Pass-or-Fail Criterion.

Spontaneous mirror self-recognition is achieved by only a limited number of species, suggesting a sharp "cognitive Rubicon" that only few can pass. But is the demarcation line that sharp? In studies on monkeys, who do not recognize themselves in a mirror, animals can make a difference between their mirror image and an unknown conspecific. This evidence speaks for a gradualist view of mirror self-recognition.

Neuropsychological Markers of Medial Perirhinal and Entorhinal Cortex Functioning are Impaired Twelve Years Preceding Diagnosis of Alzheimer's Dementia.

Neurofibrillary pathology in Alzheimer's dementia (AD) is associated with cognitive impairments and cortical thinning, and begins in medial perirhinal cortex (mPRC) before entering entorhinal cortex (ERC). Thus, mPRC dysfunction (e.g.

Differentiation of anal sphincters with high-resolution magnetic resonance imaging using contrast-enhanced fast low-angle shot 3-dimensional sequences.

Objective: The imaging of the anal apparatus is becoming more and more important in the management of patients who suffer from anorectal disease. The exact differentiation of the sphincter muscles is a major requirement for the detection of disorders of the anal canal. The purpose of this study was to evaluate a new magnetic resonance (MR) imaging protocol using contrast-enhanced, high-resolution, fast low-angle shot, 3-dimensional (3D) sequences and image subtraction regarding the visualization and differentiation of the internal and external sphincter muscles.