Task 2 - Signal Detection Theory

Task 2 - Signal Detection Theory Some definitions from Perception: Absolute threshold - the minimum intensity of a stimulus that can be detected. Method of limits - the experimenter presents stimuli in either ascending order (intensity is increased) or descending order (intensity is decreased). Crossover point - the point where the stimulus becomes (un)detectable. It usually varies in different trials (in ascending trials i takes more intensity to report detection and in descending trials it takes more decreases in intensity to report non-detection), which is why the procedure is repeated a number of times and then the results are averaged. Method of constant stimuli - similar to the method of limits, except that the stimuli are presented in a random order, each stimulus being presented many times. The absolute threshold is usually defined as the intensity that results in detection on 50% of trials.