No abstract

In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative relative judgment model (RJM) in which the elemental perceptual units are representations of the differences between current and previous stimuli. These differences are used, together with the previous feedback, to respond. Without using long-term representations of absolute magnitudes, the RJM accounts for (a) information transmission limits, (b) bowed serial position effects, and (c) sequential effects, where responses are biased toward immediately preceding stimuli but away from more distant stimuli (assimilation and contrast).

There has been discussion over the extent to which delay discounting -as prototypically shown by a preference for a smaller-sooner sum of money over a larger-later sum -measures the same kind of impulsive preferences that drive non-financial behavior. To address this issue a dataset was analyzed, containing 42,863 participants' responses to a single delaydiscounting choice, along with self-report behaviors that can be considered as impulsive.Choice of a smaller-sooner sum was associated with several demographics: younger age, lower income, lower education; and impulsive behaviors: earlier age of first sexual activity and recent relationship infidelity, smoking, and higher body mass index. These findings suggest that at least an aspect of delay discounting preference is associated with a general trait influencing other forms of impulsivity, and therefore that high delay discounting is another form of impulsive behavior.