Biology and Cognitive Science

Modified: 2024-01-02 12:01 PM CST

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Biology and cognitive science are natural partners. Biology, the study of the natural world, includes a wide variety of topics. Only some of those topics are relevant to cognitive science, however. Botany, for example, has little to do with cognitive science other than how plant materials affect thinking and behavior. Neuroscience is the main such topic given that the brain is a kind of biological computer. In addition, the very tasks of living demand that organisms monitor and adapt to an ever changing environment.

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History

• Aristotle
• The first biologist
• Under Aristotle's theoretical category were:
  • biology, psychology, physics, and metaphysics.
  • Aristotle studied hundreds of species.
• Aristotle was one of the first to carefully describe the structure and development of many species.
• His biological studies led him to study psychological topics as well.
  • In De Anima (On the Mind or On the Soul), he investigated psychological topics such as memory, learning, sleep and dreams, sensation and perception, and motivation connecting them to biological explanations.
• All animals were governed by nutritive, perceptive, and locomotor functions, meaning they had to eat, engage the world with their senses, and move.
• Humans, along with a few other animals, had an additional function—a rational one.
• Aristotle, however, did not experiment as modern scientists do. Instead, he was a skilled and careful observer but stopped short of applying experimental manipulations and measuring their effects.
• Hippocrates
• The "father" of medicine
  • He defined health as a balance of the four humors, internal fluids he believed were vital to well-being. When the humors were out of balance, illness resulted. The four humors were: blood, black bile, yellow bile, and phlegm. The humors, in turn, were linked to the four Greek elements: blood with air, black bile with earth, yellow bile with fire, and phlegm with water
• Hippocratic Oath
  • Physicians should never do harm, administer poison, induce abortions, have sex with their patients, or violate confidences
• William Harvey
• Closed circulation of blood
  • first to observe that the heartbeat was composed of two phases: systolic (when the heart contracts), and diastolic (when the heart relaxes and expands).
  • showed that the heart was a muscle.
  • proved that the body only contained a relatively small amount of blood but circulated it continuously.
  • He also demonstrated that arterial blood (blood pumped out of the heart) and venous blood (blood returning to the heart) were the same substance.
• Immutability of species
  • The old belief that all species had existed since the beginning of the earth
    • The discovery of dinosaur bones in the 19th century was one of the first challenges to that kind of thinking
• The age of the earth
• 6,000 year old earth
  • Calculated from Biblical accounts
    • Much older earth
      • Lord Kelvin had calculated the age of the earth based on the assumption that it had cooled from molten rock to its present state.
      • The age he calculated was far less than Darwin’s 300 million years. This was a serious problem for the successful operation of natural selection,
      • The discovery of radioactivity in the late 19th century showed that Kelvin’s calculations had not taken into account the fact that radioactivity added heat to the earth.
• Modern geologists now estimate the age of the earth to be around 4.5 billion years
• Carl Linnaeus (taxonomy)
  • Taxonomy is the classification of species into related groups
    • One reason is to specify with a scientific name every species
    • That avoids the confusion caused by local names
      • Amia calva is the scientific name for a fish
        • Here, you may have caught one and called it a Grinnell or Cypress Bass
        • But, if you caught in South Louisiana you called it a Choupique
        • It's also called a bowfin, mud pike, and swamp trout
      • Now do you see why taxonomy is important
• Charles Darwin
• After trying careers in medicine and the ministry he embarked on:
  • HMS Beagle
    • He spent early 5 years circumnavigating globe
    • He collected many specimens (animals/plants) and shipped them home
    • Captain Fitz-Roy was the captain of the ship
      • He was looking for a gentleman to accompany him on the voyage to serve as a naturalist and companion.
      • The previous captain had committed suicide on its last mission, apparently due to loneliness combined with the strain of command.
      • The rules and regulations of the Royal Navy prohibited captains from engaging in any personal interactions with officers and crew.
      • Darwin was "supercargo" or not part of the Navy so he and Fitz-Roy could converse as "gentlemen"
      • After Darwin published The Origin of the Species Fitz-Roy took to London street corners railing against the theory of evolution and his part in it.
  • Darwin too a long time pondering his results at home, but he received a letter from:
    • Alfred Russel Wallace in 1858 where Wallace was proposing similar ideas to Darwin about evolution
    • So that Darwin would not lose priority, his paper and Wallace's were read in 1858
      • No one really took notice, but:
    • In 1859 Darwin published Origin of the Species
      • The first edition of 1250 volumes sold out in one day!
  • Gave biology its "marching orders"
    • The theory of evolution
    • Darwin, however, did not know evolutions mechanism
• Gregor Mendel
  • Performed research on English peas
  • Discovered genetic transmission
  • Largely ignored until 20th Century
  • He was not aware of Darwin nor was Darwin aware of Mendel

Modern Synthesis

• The modern synthesis of biology combined:
  • Genetics and Evolutionary Theories
• Later:
  • DNA structure was discovered by Watson, Crick, Wilkins, Franklin
    • It revealed a nearly universal biological "code" (Note CS connection!)
      • Each of us is the possesses a unique DNA code (with the exception of twins and other multiple monozygotic individual)
      • The odds of two unrelated people having the same DNA code is one in 70 trillion
      • You should all now be aware how DNA can be used in forensics
  • Process: DNA->RNA->Proteins->Structure or Behavior

Fields of Biology

• Biochemistry
  • Some linkage with CS
• Botany
  • Plants don't behave or have brains
  • But plant chemicals can alter behavior
• Cellular biology
  • Little linkage to CA
• Ecology* (especially behavioral ecology)
  • Another 'Umbrella Science"
  • Covers a lot of knowledge (e.g., ponds to continents)
  • Analogous to CS in many ways in that many sub disciplines of biology contribute to ecology
• Evolutionary biology*
  • Accounts for organismic change (e.g., speciation)
• Genetics*
  • Biological code
  • Nearly universal
• Molecular biology
• Physiology (video)*
  • "Organismic robotics"
    • Meaning that most species (except the sessile ones such as oysters) must successfully navigate their environment
    • Later, we'll look at animals that locomote in water, on land, or in the air
  • Robotics in AI
    • Robots, too, must successfully locomote
      • Here is a catastrophic Hollywood failure (video) from RoboCop movie
        • Obviously, if you are going to build a police robot it has to be able to get through doors and use stairs!
      • Interestingly, real police robots tend to be small (unlike the one in RoboCop)
      • FYI, humans are also prone to stairway accidents.
      • Lawyer's page estimates 12,000 fatalities per year from stairway accidents [show graphic]
  • "Evolved structures and behaviors"
    • Evolution is conservative: horse's hoof, bat's wing
      • The horse's hoof is your middle finger
        • Although in embryo horses have all five vertebrate digits, only one remains
      • The bat's wing is your index finger
        • Look at the illustration in the web page above to see how human arms, bat wings, and bird wings all adapted the vertebrate hand
      • Evolution must take existing structures and alter them to new purposes via natural selection
    • Engineering need not be conservative: GMC ad (video)
      • In the GMC ad above the engineer can start over again from scratch (and he does, over and over)
      • On the other hand, evolution cannot start over from scratch
        • Which is why humans have two arms and two legs. Teleost fish, our distant ancestors evolved two sets of fins. Those eventually evolved into arms and legs.
        • Again, look at the examples above: horse's hoof and bat's wing.
        • Evolution is conservative in its design.
• Zoology* (especially animal behavior)
  • Hardwired behaviors
    • When environments are stable or when responses to stimuli are life preserving, behaviors can be coded genetically as instincts
      • Good examples are:
        • Negative phototaxis
          • Cockroaches fleeing when lights come on
        • Prepping for sleep
        • Dogs circling in their pet bed before sleeping
      • In the second instance, think of reflexes
        • The human startle response.
        • If I make the same loud noise a few more times and you would not exhibit the same response because you were expecting it.
  • Learned behavior
    • When environments change rapidly or often then learning is adaptive
    • Types of learning:
      • Habituation and Sensitization
        • Habituation: not responding to a low grade, repetitive stimulus
        • Sensitization: responding more and more strongly to an intermittent, strong stimulus
      • Classical and Operant conditioning
        • Classical: associating a neutral stimulus to a an unconditioned one
        • Operant: repeating a response following a stimuls
      • Imitation Learning
        • Paying attention to another and performing the same action(s)
      • Insight Learning
        • Coming to a rapid solution after some thought and/or exposure to a complex situation

*Has connection to CS

• Again, the following biology subfields have a connection to CS
  • Ecology
  • Evolutionary biology
  • Genetics
  • Physiology
  • Zoology

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