NATURE
A Cephalopod Has Passed a Cognitive Test Designed For Human Children
MICHELLE STARR
3 MARCH 2021
A new test of cephalopod smarts has reinforced how important it is for us humans to not underestimate animal intelligence.
Cuttlefish have been put to a new version of the marshmallow test, and the results appear to demonstrate that there's more going on in their strange little brains than we knew.
Their ability to learn and adapt, the researchers said, could have evolved to give cuttlefish an edge in the cutthroat eat-or-be-eaten marine world they live in.
The marshmallow test, or Stanford marshmallow experiment, is pretty straightforward. A child is placed in a room with a marshmallow. They are told if they can manage not to eat the marshmallow for 15 minutes, they'll get a second marshmallow, and be allowed to eat both.
This ability to delay gratification demonstrates cognitive abilities such as future planning, and it was originally conducted to study how human cognition develops; specifically, at what age a human is smart enough to delay gratification if it means a better outcome later.
Because it's so simple, it can be adjusted for animals. Obviously you can't tell an animal they'll get a better reward if they wait, but you can train them to understand that better food is coming if they don't eat the food in front of them straight away.
Some primates can delay gratification, along with dogs, albeit inconsistently. Corvids, too, have passed the marshmallow test.
Last year, cuttlefish also passed a version of the marshmallow test. Scientists showed that common cuttlefish (Sepia officinalis) can refrain from eating a meal of crab meat in the morning once they have learnt dinner will be something they like much better - shrimp.
As a team of researchers led by behavioural ecologist Alexandra Schnell of the University of Cambridge point out in a new paper, however, in this case it's difficult to determine whether this change in foraging behaviour in response to prey availability was also being governed by an ability to exert self-control.
So they designed another test, for six common cuttlefish. The cuttlefish were placed in a special tank with two enclosed chambers that had transparent doors so the animals could see inside. In the chambers were snacks - a less-preferred piece of raw king prawn in one, and a much more enticing live grass shrimp in the other.
The doors also had symbols on them that the cuttlefish had been trained to recognise. A circle meant the door would open straight away. A triangle meant the door would open after a time interval between 10 and 130 seconds. And a square, used only in the control condition, meant the door stayed closed indefinitely.
Source:
https://www.sciencealert.com/cuttlefish-can-pass-a-cognitive-test-designed-for-children/amp