Podcast with Frank Grasso on biomimetic robotics and lobster olfaction

How does a lobster find food in a turbulent ocean where chemical signals vanish for minutes at a time , and what can a robot lobster teach us about the strategies that work and fail? Frank Grasso explores the neuroscience of olfactory search through biomimetic robotics. Subscribe for more from the Convergent Science Network podcast series. Frank Grasso studies "crunchies and squishies", lobsters and octopuses, not because they resemble us, but precisely because they do not. These animals face the same physical challenges as vertebrates but solve them with completely different brain and body architectures, revealing the true design space for adaptive behavior. His laboratory at Brooklyn College builds robot models of these animals, tests them under identical conditions to the real organisms, and uses the animal's performance as a yardstick for evaluating hypotheses about neural control. The lobster work centers on olfactory search in turbulent water. Seventy percent of the lobster brain is dedicated to olfactory processing, and its chemical sensors are extraordinarily sensitive , capable of detecting concentrations equivalent to a teaspoon of rose water dissolved in Lake Champlain. But the real challenge is not sensitivity; it is intermittency. Even directly within a chemical plume, sensors may detect nothing for minutes at a time, punctuated by staccato bursts of odor pulses. Grasso's team measured these environments directly and found that the temporal structure of the signal, its rhythm and patterning, carries spatial information that pure concentration measurements cannot provide. When robot lobsters equipped with biologically matched sensors were tested using algorithms that biologists had proposed for a century, the robots failed dramatically. Simple chemotaxis strategies that work in smooth gradients collapse in turbulent plumes. Adding flow-sensing information improved performance, but only in specific regions of the plume. The robots revealed that different distances from the source present qualitatively different information landscapes, requiring different strategies , a finding that would have been difficult to establish from animal observation alone. The octopus work addresses a different frontier: controlling a body with no hard parts. Octopus arms are muscular hydrostats , enclosed bags of water that reshape themselves through muscle-against-muscle contraction, with no skeleton at all. Three-fifths of the octopus's half-billion neurons reside outside the central brain, distributed in a brachial plexus that may allow arms to negotiate with each other rather than requiring centralized executive control. Combined with the animal's exceptional learning abilities , possibly an adaptation to both a complex body and exponential growth from milligrams to 90 kilograms in a single year , the octopus represents a radically different solution to the problem of embodied intelligence.