A new test of cephalopod intelligence has strengthened how important it is for us humans not to underestimate animal intelligence.
Sepia has undergone a new version of the marshmallow test, and the results seem to show that more is happening in their strange brains than I knew.
Their ability to learn and adapt, the researchers said, could have evolved to give cuttlefish an edge in the marine world of the food or food in which they live.
The Stanford marshmallow test or marshmallow experiment is quite simple. A child is placed in a room with a marshmallow. They are told if they manage not to eat the yolk for 15 minutes, they will receive a second yolk and will be allowed to eat both.
This ability to delay satisfaction demonstrates cognitive skills, such as future planning, and was originally developed to study how human knowledge develops; specifically, at what age a man is smart enough to delay satisfaction if it means a better result later.
Because it is so simple, it can be adjusted for animals. Obviously, you can’t tell an animal that they will receive a better reward if they wait, but you can train them to understand that. better the food comes if they do not immediately eat the food in front of them.
Some primates may delay satisfaction with dogs, although inconsistently. And the Corvids passed the marshmallow test.
Last year, cuttlefish also passed a version of the marshmallow test. Scientists have shown that common cuttlefish (Sepia officinalis) can refrain from eating a meal of crab meat in the morning once they have learned dinner will be something they like much better – shrimp.
As a team of researchers led by behavioral ecologist Alexandra Schnell of the University of Cambridge points out in a new paper, however, in this case it is difficult to determine whether this change in feeding behavior in response to prey availability was due to also governed by an ability. to exercise self-control.
So they designed another test, for six ordinary cuttlefish. The cuttlefish was placed in a special tank with two closed chambers, which had transparent doors so that the animals could see inside. There were snacks in the rooms – a less favorite piece of raw shrimp in one and a much more attractive live grass shrimp in the other.
The doors also had symbols that the cuttlefish had been trained to recognize. A circle meant that the door would open immediately. A triangle meant that the door would open after a time interval of 10 to 130 seconds. And a square, used only under control conditions, meant that the door remained closed indefinitely.
Under the test conditions, the shrimp were placed behind the open door, while the live shrimp were accessible only after a delay. If the cuttlefish went after the shrimp, the shrimp were removed immediately.
Meanwhile, in the control group, the shrimp remained inaccessible behind the door with a square symbol that would not open.
The researchers found that all the cuttlefish in the test state decided to wait for their favorite food (live shrimp), but did not bother to do so in the control group, where they could not access it.
“The cuttlefish in this study were able to expect a better reward and tolerated delays of up to 50-130 seconds, which is comparable to what we see in large-brained vertebrates such as chimpanzees, crows and parrots,” said Schnell. .
The other part of the experiment was to test how good the six cuttlefish were in learning. They were shown two different visual cues, a gray square and a white one. When they approached one, the other would be taken out of the tank; if they made the “right” choice, they would be rewarded with a snack.
Once they learned to associate a square with a reward, the researchers changed the clues so that the other square now became the reward indicator. Interestingly, the cuttlefish that learned to adapt to this change the fastest was also the cuttlefish that could wait the longest for the shrimp reward.
It seems that sepia can exercise self-control, well, but what is not clear is why. In species such as parrots, primates, and corvids, delayed satisfaction was linked to factors such as tool use (because it requires advance planning), caching of food (for obvious reasons), and social competence (because prosocial behavior – such as ensuring all has food – benefits social species).
Sepia, as far as we know, does not use tools or food caches, nor are they particularly social. Researchers believe that this ability to delay satisfaction may, in turn, have something to do with how cuttlefish feed on their food.
“Sepia spends most of its time camouflaging itself, sitting and waiting, punctuated by short feeding periods,” Schnell said.
“They break camouflage when they feed, so they are exposed to every predator in the ocean that wants to eat them. We speculate that delayed satisfaction could have evolved as a byproduct of it, so cuttlefish can optimize feeding by waiting for better quality. food.”
It is a fascinating example of how very different lifestyles in very different species can lead to similar behaviors and cognitive abilities. Future research should, according to the team, try to determine if cuttlefish is really capable of planning for the future.
The team ‘s research was published in The works of the Royal Society B.