Smarter than humans: rationality reflected in primate neuronal reward signals

Rational choice, in all its definitions by various disciplines, allows agents to maximize utility. Formal axioms and simple choice designs are suitable for assessing rationality in monkeys. Their economic preferences are complete and transitive; the dopamine signal follows transitivity. Dopamine signals also satisfy first-order stochastic dominance that unequivocally defines the better option. Neurons in orbitofrontal cortex (OFC) reflect the unchanged preferences when an irrelevant option is removed from the option set, thus satisfying Arrow’s Weak Axiom of Revealed Preference (WARP) concerning the Independence of Irrelevant Alternatives (IIA). While monkeys, with their reward neurons, may not be more rational than humans, the constraints of controlled experiments seem to allow them to behave rationally within their informational, cognitive and temporal bounds

Scalable switched slab coupler based optical phased array on silicon nitride

A two-dimensional optical-phased array is demonstrated by using a multiple-input star coupler, compatible with FMCW LiDAR. Previous approach using a single-input design achieves two-dimensional beam-steering by relying on a tunable laser source, taking advantage of grating coupler radiation angle wavelength dependance and variation of the waveguide refractive index. While implementing a convenient way to distribute power in a single step, star coupler architecture is inefficient in terms of employed waveguide length and thus, optical loss and footprint. Multi-input approach partially alleviates this by condensing several single-input devices into one, permitting to reduce the footprint proportionally to the employed number of inputs. We fabricated in silicon nitride technology a proof of concept steerer with beam waist 0.36 deg x 0.175 deg addressing a field of view of 15 deg x 2.8 deg. A new design iteration is also reported with and 0.24 deg x 0.16 deg beam waist and 15 deg x 11.2 deg field of view. Implications of this optical-phased array chips from a LiDAR system perspective are also presented.Comment: Accepted for publication in the IEEE Journal of Selected Topics in Quantum Electronics. Copyright 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other use