How Does the Octopus Efficiently Control Its Flexible, Multi-Armed Body?

How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent...

Octopus Conditioning: A Multi-Armed Approach to the LTP–Learning Question

A recent study shows that avoidance conditioning in the cephalopod Octopus vulgaris is mediated by long-term potentiation (LTP), a form of synaptic plasticity thought to be important in vertebrate associative learning. Thus, LTP appears to be an evolutionarily conserved learning mechanism.

How to Beat the Adaptive Multi-Armed Bandit

The multi-armed bandit is a concise model for the problem of iterated decision-making under uncertainty. In each round, a gambler must pull one of K arms of a slot machine, without any foreknowledge of their payouts, except that they are uniformly bounded. A standard objective is to minimize the gambler’s regret, de ned as the gambler’s total payout minus the largest payout which would have bee...

Pharmacokinetics: How Does the Body Handle Drugs?

Robust Control of the Multi-armed Bandit Problem

We study a robust model of the multi-armed bandit (MAB) problem in which the transition probabilities are ambiguous and belong to subsets of the probability simplex. We first show that for each arm there exists a robust counterpart of the Gittens index that is the solution to a robust optimal stopping-time problem. We then characterize the optimal policy of the robust MAB as a project-by-projec...