Weber's Law in Decision Making: Integrating Behavioral Data in Humans with a Neurophysiological Model

Abstract

Recent single-cell studies in monkeys (Romo et al., 2004) show that the activity of neurons in the ventral premotor cortex covaries with the animal's decisions in a perceptual comparison task regarding the frequency of vibrotactile events. The firing rate response of these neurons was dependent only on the frequency differences between the two applied vibrations, the sign of that difference being the determining factor for correct task performance. We present a biophysically realistic neurodynamical model that can account for the most relevant characteristics of this decision-making-related neural activity. One of the nontrivial predictions of this model is that Weber's law will underlie the perceptual discrimination behavior. We confirmed this prediction in behavioral tests of vibrotactile discrimination in humans and propose a computational explanation of perceptual discrimination that accounts naturally for the emergence of Weber's law. We conclude that the neurodynamical mechanisms and computational principles underlying the decision-making processes in this perceptual discrimination task are consistent with a fluctuation-driven scenario in a multistable regime.

The Ising Decision Maker: A binary stochastic network for choice response time.

“…The perceptual input, finally, is represented by a two-component external field. Each component excites the 10 At first glance, this appears to contradict the claim made by Deco et al (2007) that a constant Weber fraction can only be found in the region of three-state stability of the integrate-and-fire network proposed by Wong and Wang (2006). There are many possible reasons for this discrepancy: the dependence of the phenomenon on the specific parameter values of both models, the introduction of a nonselective part to the external field of the IDM, or a more intrinsic difference between the IDM and the integrateand-fire model.…”

“…or "Which of two lines is longer?" In such a situation, we may relate the IDM to Weber's law, as has been done before by Deco, Scarano, and Soto-Faraco (2007) for an integrate-and-fire network.…”

A decision-making Fokker–Planck model in computational neuroscience

“…As already explained and discussed in different works [9,10,18], the theory of stochastic dynamical systems offers a useful framework for the investigation of the neural computation involved in these cognitive processes. Noise is an important ingredient in these models since such neural families are comprised of a large number of spiking neurons, and then the fluctuations arise naturally through noisy input and/or disorder in the collective behavior of the network.…”

“…It is quite common to observe bi-stability of the 1 decisions taken in several psychological experiments widely used by neuroscientists. Archetypical examples of these multi-stable decision-making process are bistable visual perception, that is, two distinct possible interpretations of the same unchanged physical retinal image: Necker cube, Rubins face-vase, binocular rivalry and bistable apparent motion [6,10,16].…”

“…Noise is an important ingredient in these models since such neural families are comprised of a large number of spiking neurons, and then the fluctuations arise naturally through noisy input and/or disorder in the collective behavior of the network. Moreover, this is used to introduce finite-size effect of the neuron families as discussed in [9,10].…”