Juvenile Homing Strikes: Sensory Decoding, Motor Pattern Selection & Innate KnowledgeRebecca E. Westphal (North Shore Community College, Lynn MA) and Donald M. OMalley (Northeastern University, Boston MA)Increased PerformanceConclusions: (1) Late Larvae are freed from the constraints of early larval routines. (2) LL randomness is akin to Mammalian play? (3) Reward and Basal Ganglia systems likely contribute to emergence of JHSs.Maturation of Zebrafish Prey CaptureKey Questions

Innate Early Larval Behaviors How has evolution stored object recognition, serial decision-making and distinct motor programs (J-turns, slow swims, capture swims) in the zebrafish genome?

How are Late Larvae Freed from Evolutions Dictates? After two weeks, automaton larval programs are overridden, although they may still be flexibly incorporated into compositional predatory schemes.

How are infinitely-varied predatory episodes produced? During the transitional late-larval stage, ZF use an increasingly diverse set of predatory episodes, including variations of elemental maneuvers and extremely varied maneuver sequences.

Are Zebrafish Intelligent? While early hominids spent 2 million years banging rocks together, zebrafish, within 4 - 5 weeks, demonstrate great computational and motor prowess and vastly better survival skills than 1 month old primates.

Juvenile Homing Strikes How are extremely diverse and exquisitely efficient strikes computed and implemented by juveniles and adults? This poster suggests that emerging (developing) motor skills (via Basal Ganglia and Cerebellar maturation), in conjunction with early innate knowledge, provide a means for the emergence of strategic computations and implementation of highly varied and sophisticated strike strategies. Conventional error-correction based motor learning strategies do not seem sufficient to account for JHSs. Westphal and OMalley, 2013, FINSEarly-Larval Prey Capture Juvenile / Adult Homing StrikesStaccato, long duration episodes Continuous, short duration3 distinct maneuvers, w/ pauses Extremely diverse motor patternsSerial decision-making; iterative Pre-computed trajectories & maneuversAccurate, close range strikes Superb Accuracy, distant strikesInnate O.R. & motor programs Innate K. or Fast Motor Learning?Reflections for Aficionados & Savants

- How does evolution store New Knowledge in the genetic code?

Ancestral predators likely used turns and forward swims long before the complex features of J-turns and Capture Swims were invented. How was this new IK (innate knowledge) stored in the ZF genome, along with O.R. (object recognition, of suitable prey), serial decision making (e.g. young larvae can reject Artemia) and winner-take-all (WTA) computations, where e.g. one prey item must be selected and responses to other prey suppressed (see Fajardo et al., 2013). Quite a number of groups are investigating the neural controls of early larval prey capture and visual info processing (Niell and Smith, 2005; Gahtan et al., 2005; Del Bene et al., 2008; Douglass et al., 2008; Orger et al., 2008; Naumann et al, 2010; Bianco et al., 2011; Green and Hale, 2012; McClenahan et al., 2012; Ahrens et al., 2013; Patterson et al., 2013) but we are interested in what genetic changes enabled these specific behaviors to be added to the ancestral developmental scheme and genome.

- How many bits of information are required for O.R. by larval ZF?

McDonnell et al. (2011) report that 35 or 44 bits per second can be reliably transmitted along an axon (given their model parameters), and so I would like to know how many bits are required for larval ZF to recognize a prey item (or predator, where an escape can be initiated in 4 msec). This will likely depend upon the coding and O.R. schemes, but specialized cells (ala Niell and Smith, 2005) should make O.R. easier, wherein any given patch of retinorecipient optic tectum can distinguish prey from many other items via size and relative movement.

- Nature vs. Nurture Zebrafish Style:Serial Emergence of Innate Capabilities?

Early larval predation is entirely nature in that no prior experience is necessary for highly-successful, well-formed strikes. The rapid advance of ZF strike capabilities might be due to developmental learning (niche nurture), but if the learning space is too large (i.e. effective solutions too rare), many ZF will die. The complexity of the solution space and the high strike accuracy seen across ontogeny together suggest an evolutionary boost to larval performance, enabling rapid emergence of JHSs. [Asides: Can the niche be seen as playing an instructive role to train ZF and other animals? Does Tenenbaum address innate contributions to human IQ?]. While the implementation of complex, yet selectable innately-stored motor programs might seem unlikely, the fine axial motor control of early larvae (Borla et al., 2002) shows that this may be possible.Neural Coding Operations

Early Visual Processing motion & object detection, visual coordinates DSGC signals, tectal object segmentation, directionality/coordinates early-lzf: left/right discrimination. late-lzf: angle estimation

Neural Decision Making early-LZF: (1) prey O.R., (2) J-turn or SS, (3) Cswim/strike on contact late-LZF: (1) prey O.R., (2) calculate J-turn or RT angle, (3) close & strike coding in Late Larvae is needed to produce: -- major scythe or little -- single bend or 7 cycle swim -- backing and diving -- etc. etc. Juveniles employ strategic computation (emerges in Late Larvae)Applicability of Popular Computational Approaches?

Shannon Information Theory no evidence yet for Shannon compression or code modification to maximize channel capacity during Prey Capture (PC).

Mutual Information / Entropy if communication channels not near capacity, then noise considerations / signal corruption might not factor into PC info processing.

Grandmother Cell Coding dedicated circuits likely play key roles, especially in early larvae (Liu and Fetcho, 1999; Orger et al., 2008); possible means of embedding Innate Knowledge / Universal Physics in CNS. Sparse Coding fits with such schemes.

Distributed Codes widespread evidence in zebrafish and lamprey of widely distributed processing of sensory signals (Zelenin et al., 2001; Gahtan et al., 2002). But distributed and dedicated codes seen incompatible.

Bayesian Inference Specific optimal decisions may have been learned over evolutionary time and this knowledge integrated into zebrafish genome. ZF brains presumably cannot actively represent P values and compute with them.Coding and Computation of ZF Prey Capture- What new capabilities come on line in Late Larval Prey Capture? Freedom, Precision & Fusion

Early larval ZF make rote use of canned maneuvers (J-turns, slow swims and capture swims). Within a few weeks, larvae exhibit diving, vigorous backwards swims, non-SS forward swims, merged-turn/swim behaviors, long and unusual sequences, contorted maneuvers and extremely varied means of striking at Artemia. While these episodes fall well short of JHSs (Westphal and OMalley, 2013; FINS) they foreshadow the flexibility and fusion exhibited by juvenile and adult zebrafish. This late larval freedom from earlier constraints implies an ability that is both exploratory and compositional.

- How are maneuvers merged and angles computed?

Late larvae can conjoin forward swimming and turn maneuvers into single movement bouts, which means they have escaped the earlier requirement to select ONE behavior, pause, then select the NEXT behavior. If sensors suggest they should both TURN and MOVE CLOSER (by virtue of tectal activation indicating the need for both), the weaker signal is not canceled: instead a turn is implemented and motion continues as forward swimming. This may be enabled by better sensory computations (calculating angle AND distance) and by the ancestral basal ganglia directing the sequence (perhaps with the help of persistent neural activity in brainstem). Early optic tectum may utilize inhibitory paths that accomplish WTA of one action (turn vs. swim) by suppressing the weaker need, whereas late larvae may store the additional information. It also appears that more precise turns are now made at the outset of episodes, i.e. large initial turns (RTs) are often seen that approach proper orientation (whereas early larva J-turns are more repetitive and iterative in their angle homing).

- How many GENES are required?

It is unknown how the newly exhibited capabilities are acquired, i.e. the contributions of motor learning or the emergence of new behaviors from ongoing developmental processes. Human brains are so complex and capable of learning so many different things, that we cannot simply specify each capability with a gene: the number of genes is vastly fewer. However, what genes CAN do is constrain the solution spaces to problems and provide organisms with stored motor programs and knowledge (like fears of snakes and cliffs). While some genes can be used to construct general purpose learning algorithms (within e.g. neocortex and hippocampus, apparently), other genes must, at least in zebrafish, specify the object recognition, serial decision making and stored motor programs. Such specification (dedicated circuits) can greatly constrain the solution space of ecological problems (such as hunt faster). Such constraints must, of necessity impose limitations, but late larvae seem quite flexible and compositional. The genetic and neural circuit basis of this rapid emergence of predatory capability is quite relevant to understanding mammalian systems and indeed human intelligence, given the many conserved aspects of vertebrate brain structure and the abysmal understanding we have of mammalian systems.Miscellaneous Items

Long Early Larval Pauses: what kind of computation is going on during long larval pauses?

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POSTER / MEETING TO DO LIST:1. GOLF CLUBS2. Print Niell and Smith; Holszchuh; copies of Westphal and OMalley3. Write bibliography; print posters and biblios4. Bring CN13 collection, laptop, charger, phone/charger, bathing suit.5. Print other cited papers, Excel file of feeds.6. Create movie sequence to show on laptop.

Role of Neural Systems in ZF Prey Capture

Retina and Optic Tectum primary means for selecting attack strategies / computing turns, initiating action. [See citations in Westphal & OMalley, 2013 + info on Lateral Line inputs]

Basal Ganglia Ancestral basal ganglia of ZF might initiate & sequence distinct maneuvers in LL & juveniles (although see Borla et al., 2002 re: FAMC in larvae).

Cerebellum is active in larval learning (Bae et al., 2009; Aizenberg and Schuman, 2011) and must contribute to general motor coordination, but error-correction of faulty prey strikes seems unlikely to account for JHSs.

Evolution / Development Evolution has (perhaps) performed Bayesian selection for optimal decision makers and possibly stored great amounts of world knowledge and decision sequences in the genetic code (source code), which is expressed via development as dedicated neuronal circuits (compiled code).

ZF Learning Systems Motor Learning (Portugues and Engert, 2011; Ahrens et al., 2012), Cerebellar Learning (Aizenberg and Schuman, 2011) and Operant Learning (Valente et al., 2012). Presentation

there is a great transition from EL to juvy PC; highlights = xyz. Some highlights are time, no pause and strike performance (angle & distance)

raises a bunch of questions about both larvae and juveniles (go down list). While our 2013 paper focused on Adult-like performance, there are some very curious things happening in the transition (freedom, variability) I interject IQ here because this fits w/in my broader interest in evol of IQ and 1 month zf are pretty impressive, especially in relation to 1 mo. Humans. H. can write and build spaceships, but we did spend 2 M. years banging rocks together, then we got lang. and culture & now we think were so much smartertopic for another day.

main question here is how do we go from rote behaviors to flexible, pre-computed JHSs. Skip over to Transitional Period (LL stage; see stages below) xxx and yyy happen in transitional period

for the transition to occur there have to be changes in neural circuits and I am interested in the nature of the neural coding that is changing and how the predatory computations are being implemented. Provided here is a short laundry list of popular coding/computation topics, and just for fun I am trying to relate these to the emerging strike capabilities of Juvys.

but first, it is worthwhile to layout some aspects of the lzf neural circuitry, which has identified brainstem and spinal neurons implicated in a variety of behaviors. While lateral line contributes to zf predation, PC is mainly visual, so retinal and tectal neurons are the primary source of information being routed to the DMCS, that is based on innate O.R. and DM leading to JTs, SSs and Cswims. What neuronal changes occur at transition is at present entirely unknown, but the early larval fxs are subsumed into a much richer assortment of sequences/strategies.

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