Topic: motion-direction discrimination

Weber’s law concisely describes a mapping between a true change in a physical stimulus and the resulting perceived change. It states that the perceived change governing the behavior is a relative difference, i.e. the true change divided by the magnitude of the two stimuli (Fechner, 1966). This psychophysical phenomenon is observed in domains as varied as time, weight, numerosity, length, brightness, and statistical inference (Dehaene, 2003; Namboodiri et al., 2014). In sequential decision-making, on the other hand, it is usually assumed that behavior reflects the true physical evidence, even w

Perceptual decisions are ubiquitous and essential in life, and even in their simplest forms open a window into the neural mechanisms underlying cognition. However, the properties of decision mechanisms inferred in simple behavioral paradigms are not independent of the properties of employed stimuli and task. One key task property is the type of information provided by a single stimulus, which can be either stationary or dynamic. Stationary paradigms are based on evidence with fixed central tendency, often obscured by noise, whereas in dynamic paradigms the mean of the evidence can vary within