Excitatory-inhibitory tone shapes decision strategies in a hierarchical neural network model of multi-attribute choice

Abstract

We are constantly faced with decisions between alternatives defined by multiple attributes, necessitating an evaluation and integration of different information sources. Time-varying signals in multiple brain areas are implicated in decision-making; but we lack a rigorous biophysical description of how basic circuit properties, such as excitatory-inhibitory (E/I) tone and cascading nonlinearities, shape attribute processing and choice behavior. Furthermore, how such properties govern choice performance under varying levels of environmental uncertainty is unknown. We investigated two-attribute, two-alternative decision-making in a dynamical, cascading nonlinear neural network with three layers: an input layer encoding choice alternative attribute values; an intermediate layer of modules processing separate attributes; and a final layer producing the decision. Depending on intermediate layer E/I tone, the network displays distinct regimes characterized by linear (I), convex (II) or concave (III) choice indifference curves. In regimes I and II, each option’s attribute information is additively integrated. In regime III, time-varying nonlinear operations amplify the separation between offer distributions by selectively attending to the attribute with the larger differences in input values. At low environmental uncertainty, a linear combination most consistently selects higher valued alternatives. However, at high environmental uncertainty, regime III is more likely than a linear operation to select alternatives with higher value. Furthermore, there are conditions where readout from the intermediate layer could be experimentally indistinguishable from the final layer. Finally, these principles are used to examine multi-attribute decisions in systems with reduced inhibitory tone, leading to predictions of different choice patterns and overall performance between those with restrictions on inhibitory tone and neurotypicals.

Modality-specific tracking of attention and sensory statistics in the human electrophysiological spectral exponent

“…Recently, momentary trade-offs between both modes of thalamic activity have been suggested to give way to attention-related modulations of alpha power and E:I balance, as captured by EEG spectral exponents ( Kosciessa et al, 2021 ). Here, task difficulty remained constant throughout the experiment an fluctuations between both modes might not follow momentary demand ( Kosciessa et al, 2021 ; Pettine et al, 2021 ) but varying sensory-cognitive resources.…”

Coupling of pupil- and neuronal population dynamics reveals diverse influences of arousal on cortical processing

“…We found this relationship of E/I and pupil-linked arousal in the majority of regions, thus suggesting a global and uniform effect. In sum, pupil-linked arousal may provide a window into yet another cortical circuit property, cortical E/I, relevant for cognitive computation (Cavanagh et al, 2020; Kosciessa et al, 2021; Lam et al, 2017; B. K. Murphy & Miller, 2003; Pettine et al, 2021; Pfeffer et al, 2020).…”

“…In sum, pupil-linked arousal may provide a window into yet another cortical circuit property, cortical E/I, relevant for cognitive computation (Cavanagh et al, 2020;Kosciessa et al, 2021;Lam et al, 2017;B. K. Murphy & Miller, 2003;Pettine et al, 2021;Pfeffer et al, 2021).…”

Modality-specific tracking of attention and sensory statistics in the human electrophysiological spectral exponent

“…Recently, momentary trade-offs between both modes of thalamic activity have been suggested to give way to attention-related modulations of alpha power and E:I balance, as captured by EEG spectral exponents (Kosciessa et al, 2021). Here, task difficulty remained constant throughout the experiment an fluctuations between both modes might not follow momentary demand (Kosciessa et al, 2021;Pettine et al, 2021) but varying sensorycognitive resources.…”