Michael Lamport Commons Patrice Marie Miller Harvard Medical School

1. What Animals Never Operantly Coordinate Actions with Sensory Input: The Earliest Stages of Animal Behavior Michael Lamport Commons Patrice Marie Miller Harvard Medical School

2. We describe developmental stages of the least complex animals • Several reasons for doing this are • Understand the most basic task actions and how they are controlled • Be more exact about how these basic units get combined to form more complex tasks • Better understand evolution

3. Commons et al have proposed the Model of Hierarchical Complexity (MHC) • This model can be used to determine behavioral stage • MHC orders tasks in terms of Hierarchical complexity • A task action is defined as more hierarchically complex when the higher order action • is defined in terms of the actions at the next lower order • organizes these lower-order actions • in a non-arbitrary way • Explains stages of development • A Stage name and number corresponds to the order of hierarchical complexity of a task it correctly completes

4. This paper will focus mainly on Stage 1 • Stage 1 describes that organisms complete tasks in which they are required to either act or sense, but they do not complete tasks that coordinate the two • First, we examine some Stage 1 tasks that animals might complete • Second, we examine evidence for animals that never progress further than Stage 1 in any area

5. Stage 0 – Calculatory • Before Stage 1, however, we describe stage 0 • At stage 0, both the detection of stimuli and the production of responses are exact • There is no generalization • All examples have to have been programmed • Robots and computers respond this way • For computers, only written programmed learning is possible • The exception are neural networks, especially stacked neural networks • We would assert that there are no animals that function at this stage

6. Stage 1 – Sensory or Motor • The criterion for classifying action as Stage 1 is • The organism engages in a single action at a time • These actions are not coordinated with other actions • There are coordinations of stimuli • Both the detection of stimuli or the production of responses are somewhat flexible • But the relationship between them is not • For example, when water moves, mollusks open their shells reflexively • If something touches their membrane, the shells close There is very little variability in these responses

7. Many subtypes of zooplankton behavior is confined to Stage 1 • Zooplankton are floating or weakly swimming • They rely on water currents to move great distances • Microzooplankton are usually less than 200 mm • Protozoa are a eukaryote subclass plankton • They are mobile and heterotrophic • They use organic substrates to get carbon for growth and development • Most protozoans are around 001–005 mm but up to 05 • They are predators upon unicellular or filamentous algae, bacteria, and microfungi

8. Possible Stage 1 behaviors seen in such organisms • A Taxis is an organism’s directed physical action in response to a specific stimulus • A taxis can be a directional response or a non-directional response (kinesis) • Phototaxis: flagellate protozoans of the genus Euglena move towards a light source • Chemotaxis: Cells such as the free-living amebas or the wandering cells of the Metazoa may detect the direction of a potential food source through the chemicals that the food sheds • Other kind of Taxis behaviors include: anemotaxis (stimulation by wind), barotaxis (pressure), galvanotaxis (electrical current), geotaxis (gravity), hydrotaxis (moisture), phototaxis (light), rheotaxis (fluid flow), thermotaxis (temperature changes) and thigmotaxis (physical contact)

9. Example 2: Phagocytosis • Phagocytosis: a way of obtaining nutrients that involves an organism completely surrounding a food particle • Amoebae: food object surrounded by their pseudopods • In another protozoan, called a ciliate, there is a specialized groove in the cell where phagocytosis takes place

10. Example 3: Reflexes • The most complex stage 1 system are reflexes • A reflex is a biologically-based system linking stimulus to response • This may be mediated by a reflex arc only a few neurons long • Here, the stimulus and the response are coordinated • But the coordination is automatic • It is simply due to the neural connection • For animals without neurons, we do not believe there can be true reflexes

11. Some modification of a reflex is possible • For example, habituation of a reflex can occur • Habituation may be due simple process as neural fatigue • Likewise with sensitization • What about stimulus generalization? • Stimulus generalization results from similarity of the original eliciting stimulus to other stimuli • As a stimulus becomes less and less similar, it is less likely to elicit the same response • For simple, physical stimuli the degree of similarity can be measured quantitatively rather than in hierarchical terms • So, behavior remains at stage 1

12. Is respondent conditioning also Stage 1? • One stimulus precedes closely before another stimulus • It can come to elicit the same or similar response • Pairing of the unconditioned and stimulus to be conditioned is not a task that the animal must actively solve • This is so even though the stimuli must be salient • The two stimuli are arbitrarily paired, either by an accident of nature or by an experimenter • This does not constitute an increase in the hierarchical complexity of the task that must be solved • The organism does not temporally or in some other way organize actions in order to more adequately accomplish this

13. Stage 2 – Circular Sensory- Motor • Even very primitive animals differentially respond to stimuli, for example, rejecting non-food items • They do not change their behavior based • on this environmental consequences • feedback following those responses • Every encounter with a food or a non-food object is like a new encounter • Such animals may not operantly hunt for prey or forage • Some animals change their behavior in response to consequences • The consequences lead to them to Stage 2 behavior in which they coordinate action with sensory input

14. Coordinating perception and action or two or more actions • At Stage 2, animals coordinate operant action with perception or they coordinate two or more actions • Hunting behavior is controlled by consequences • (eg most predatory fish, insects) are performing at this stage • Corrette (1990) observed prey capture in the praying mantis • They coordinated capture and strike movements • Coordinating of multiple behaviors such as looking, reaching and grasping require Stage 2 circular sensory and motor action

15. Conclusion • We have described stage of actions by various simple organisms • The first two orders of hierarchical complexity adequately described the tasks they accomplish • Simple one-celled organisms that were not part of groups of cells, functioned at stage 1 • Some multiple cell organisms that operantly conditioned functioned at stage 2 • Some animals such as mammals probably never function only at stage 1