Friday, December 29, 2017

Do fish (and even plants) really exhibit intelligence and consciousness?

Here's some recent research that escaped my attention at the time, but which a friend brought to my attention last night. It seems that fish are more likely to be capabale kf thoughts and emotions than was previously thought.
Whether animals other than humans have consciousness (roughly defined as the ability to experience thoughts and emotions) had been debated for centuries, and fish, insects and plants have always been considered very low down on the scale of consciousness. Fish, for example, have small sinple brains and lack the cerebral cortex often considered a requirement for more high-level information processing and what we usually think of as consciousness. They show little capacity for learning and memory, and most of rheir responses are simple reflexes with little in the way of emotional content.
However, although a fish's brain is structured very diffrently from that if a mammal, it nevertheless has structures with the same evolutionary origin as the emotion-generating amygdala and the learning-controlling hippocampus of mammals, and appear to serve very similar functions. Some fish can memorize complex mental maps, and remember potential rivals' previous battles, and even use tools to crack open shells. They can perceive and respond to chemicals that might cause them pain.
It was always thought, though, that fish (unlike mammals, birds and reptiles) were not able to respond to a key consciousness test known as "stress-induced hyperthermia" or "emotional fever, whereby the body gets warmer in reponse to stress. Now, though, new research shows that stressed fish will move to warmer water where possible, suggesting that fish may be more sentient and conscious than we had previously thought.
Of course, some scientists (at the contentious end of the scale, but not complete whackos) also argue that plants exhibit a rudimentary consciousness. For example, plants have been shown to react to recordings of caterpillars munching on vegetation, by secreting defensive chemicals. Plants will shift growth direction in order to avoid obstacles. They have the ability to respond to 15 to 20 environmental variables.
While plants don't have a brain or nervous system or nerve cells like mammals, they do have a system for transmitting electrical signals, and they even produce neurotransmitters like dopamine, seratonin and other chemicals that mammal brains use to transmit signals. We are just not sure what they do with them. Now, it seems that plants also show some evidence of memory and learning skills. There is scientific evidence that plants can distinguish what is and is not a threat to them, and then remember that (for longer than some insects, for example).
Other studies have shown that individual trees as well as other plants like cacti) may protect and take care of their own offspring and seedlings, over and above those of other trees - make of that what you will.
This is contentious ground, and many scientists refuse to accept that this constitutes intelligence, much less consciousness. However, while they may not be self-conscious, they may show evidence of being conscious in the sense of knowing where they are in space. They may not engage in abstract reasoning, but they do exhibit a certain problem-solving ability. It all depends on your definitions of concepts like intelligence and consciousness, and your way of looking at things.
Either way, it's certainly food for thought (so to speak...)

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