Spotted dolphin
size of this dolphin, body size and color differences are many, have been identified in two ways: a life in the coast of another dwelling in the open sea. Coast type generally larger size, more solid, spotted the body is greater
Dolphins are right-handed or left-handed?
This is a very cunning question, because the dolphin obviously has no hands. However, in the process of studying whether they have a preference problem, the researchers discovered strange phenomena in human perception.
Human behavior is asymmetrical: most of us are accustomed to and good at using a certain hand, it is easier to keep the focus on a certain leg when maintaining balance, and those who often need to rotate in work and life (such as gymnasts, dance Home or diving athletes), often prefer to spin in a certain direction.
Popular psychology has long discussed this view, and people sometimes describe this view as left-brain (analytic) thinking and right-brain (creative) thinking. Although this widely circulated statement is not supported by rigorous data, the advantages of one side of the brain’s two hemispheres have been clear, and scientists call it lateralization. For example, the language function is mainly located in the left hemisphere, while the spatial relationship of perception objects is mainly located in the right hemisphere.
Because each side of the brain controls the other side of the body, studying asymmetric behavior in animals can provide us with information about brain functions and a deeper understanding of the evolution of the brain.
Chinese white dolphins
while we have a “White Dolphin”, but born of Chinese white dolphins takes the shape of dark gray, childhood gray, adulthood is pink. It is mainly distributed in the Western Pacific and Indian Ocean, and is common in the southeastern coast of China. Belonging to the protection of animals at the national level, known as “The Little Mermaid,” “Water pandas,” said
hands-free asymmetric tendency
that people are most familiar with laterality is no doubt about handedness, which have done research on animals, such as monkeys Which hand to grab something, which paw the dog uses to pick food out of the bowl, and so on.
But what should you do when the animal you study has no hands (or claws)? How to study the lateralization of animals without hands like dolphins?
Facts have proved that there are many types of behavioral asymmetry, not only physical bias such as left and right hands, but also sensory asymmetry: for example, whether we use the left eye or the right eye, will affect our performance in the task, and steering preference: each We all habitually turn in the same direction during this rotation. Because the asymmetry of different behavior types may have different reasons, the more we study behavior asymmetry, the more we can understand the lateralization of the brain and its evolution.
What is turning right?
How to define “turn to the right” is the beginning of the problem.
When comparing animals, we must take into account that the steering of the body plan and the typical way of movement may be different. For example, when an animal walks upright (such as humans and birds), the long axis of its body is vertical, but when it walks on all fours, the long axis of its body is horizontal.
This means that steering can involve very different types of movement. For animals that walk on all fours, turning requires pressing the long axis of the body to one side; for animals that walk on two legs, turning is to rotate around the long axis of the body; and for animals like dolphins in three-dimensional space For animals wandering in the middle, both of the above-mentioned turns are possible.
Therefore, when starting to study the lateralization of dolphins, researchers need to carefully distinguish these two different types of turns. But when researchers have been disagreeing on what is “rightward” and “leftward” rotation, they ran into another problem. After a lot of discussion (and sometimes controversy), we realized that we stumbled upon a strange phenomenon of human perception: humans would explain the direction of animal rotation in the opposite way.
To feel this, try the following actions: First, stand up and “turn right.” Then lay face down on the floor and “roll to the right.” You are likely to be like most people. Turning to the right while standing is to move your right shoulder towards your back, and turning to the right while lying down is to move your right shoulder towards your chest.
In other words, in both cases, the same command will make you make two rotations in completely opposite directions. Is it weird? And you can’t use clockwise/counterclockwise to explain this problem, even in the above example, replace “turn right” with “clockwise”, you will still get the same result.
Prior to this, almost all scientific research on turning or lateralization of rotational motion was oriented to a single species in a single direction, such as human turning (upright) or whale jumping (horizontal), so this problem has never occurred. This means that, according to the turning orientation of different animals, previously published studies have actually been using the opposite coding system.
In studies on humans and birds walking, the rotation or turning of animals moving from the right to the front is usually coded as left/counterclockwise, but in studies of dolphins and whales, the same behavior is coded as right /Clockwise.
If we want to consider the lateralization of turning between different species, we must agree on the direction of turning. This means that we need a new coding system.
The new coding system
system researchers have proposed is actually inspired by a lot of people learned in high school or electromagnetic physics at the University of “right-hand rule” is.
According to this rule, if you point your right thumb in the direction of current flowing through a wire, the orientation of your finger will show the direction of the magnetic field flowing around the wire. The researchers adopted this model and created the right finger rotation (RiFS) and left finger rotation (LeFS) encoding systems.
In this system, when the thumb of the encoder is along the long axis of the animal, that is, pointing to the head of the animal, the curled fingers of the relevant hand can describe the direction of rotation. Regardless of the animal’s direction or movement direction, we can quickly encode these rotation or turning behaviors.
The researchers found that
some of the previous scientific papers claimed that the dolphins showed a strong rightist asymmetric behavior, human-like right-handed.
However, since “right” did not always mean the same direction in early coding systems, it is impossible to determine whether this statement is correct. In order to test the validity of this statement, the researchers observed different types of behavioral asymmetry among 26 dolphins, such as “Which direction do they swim around the lagoon”, “Which side of their bodies contact things” and so on.
On the basis of ensuring that different types of sports are distinguished, using a clear RiFS/LeFS coding system, we found that—contrary to previous statements—dolphins actually do not have a general right asymmetry tendency.
People often think that scientific progress will happen when we learn something new that we didn’t know before. But when we realize that there is a problem with the way we look at things, another scientific advancement is also happening. In this case, finding a different way of looking at it can allow us to see the essence of the matter more clearly.
As science fiction writer Isaac Asimov once pointed out: the most exciting phrase in science is not “I found it” but “this is interesting”.
