̽��ֱ�� of Cambridge - Alex Schnell

Just like humans, more intelligent jays have greater self-control

jg533 — Mon, 31 Oct 2022 00:01:12 +0000

This is the first evidence of a link between self-control and intelligence in birds.

Self-control - the ability to resist temptation in favour of a better but delayed reward – is a vital skill that underpins effective decision-making and future planning.

Jays are members of the corvid family, often nicknamed the ‘feathered apes’ because they rival non-human primates in their cognitive abilities. Corvids hide, or ‘cache’, their food to save it for later. In other words, they need to delay immediate gratification to plan for future meals. ̽��ֱ��researchers think this may have driven the evolution of self-control in these birds.

Self-control has been previously shown to be linked to intelligence in humans, chimpanzees and – in an earlier study by these researchers – in cuttlefish. ̽��ֱ��greater the intelligence, the greater the self-control.

̽��ֱ��new results show that the link between intelligence and self-control exists across distantly related animal groups, suggesting it has evolved independently several times.

Of all the corvids, jays in particular are vulnerable to having their caches stolen by other birds. Self-control also enables them to wait for the right moment to hide their food without being seen or heard.

̽��ֱ��results are published today in the journal Philosophical Transactions of the Royal Society B.

To test the self-control of ten Eurasian jays, Garrulus glandarius, researchers designed an experiment inspired by the 1972 Stanford Marshmallow test - in which children were offered a choice between one marshmallow immediately, or two if they waited for a period of time.

Instead of marshmallows, the jays were presented with mealworms, bread and cheese. Mealworms are a common favourite; bread and cheese come second but individuals vary in their preference for one over the other.

̽��ֱ��birds had to choose between bread or cheese - available immediately, and mealworm that they could see but could only get to after a delay, when a Perspex screen was raised. Could they delay immediate gratification and wait for their favourite food?

A range of delay times was tested, from five seconds to five and a half minutes, before the mealworm was made available if the bird had resisted the temptation to eat the bread or cheese.

All the birds in the experiment managed to wait for the worm, but some could wait much longer than others. Top of the class was ‘JayLo’, who ignored a piece of cheese and waited five and a half minutes for a mealworm. ̽��ֱ��worst performers, ‘Dolci’ and ‘Homer’, could only wait a maximum of 20 seconds.

“It’s just mind-boggling that some jays can wait so long for their favourite food. In multiple trials, I sat there watching JayLo ignore a piece of cheese for over five minutes – I was getting bored, but she was just patiently waiting for the worm,” said Dr Alex Schnell at the ̽��ֱ��’s Department of Psychology, first author of the report.

̽��ֱ��jays looked away from the bread or cheese when it was presented to them, as if to distract themselves from temptation. Similar behaviour has been seen in chimpanzees and children.

JayLo patiently ignores the cheese (in right box) to wait for the worm (in left box).

̽��ֱ��researchers also presented the jays with five cognitive tasks that are commonly used to measure general intelligence. ̽��ֱ��birds that performed better in these tasks also managed to wait longer for the mealworm reward. This suggests that self-control is linked with intelligence in jays.

“ ̽��ֱ��birds’ performance varied across individuals – some did really well in all the tasks and others were mediocre. What was most interesting was that if a bird was good at one of the tasks, it was good at all of them – which suggests that a general intelligence factor underlies their performance,” said Schnell.

̽��ֱ��jays also adjusted their self-control behaviour according to the circumstances: in another experiment where the worm was visible but always out of reach, the jays always ate the immediately available bread or cheese. And the length of time they were willing to wait for the worm fell if it was pitted against their second most preferred food as the immediate treat, compared to their third. This flexibility shows that jays only delay gratification when it is warranted.

Research by other scientists has found that children taking the Stanford marshmallow test vary greatly in their self-control, and this ability is linked to their general intelligence. Children that can resist temptation for longer also get higher scores in a range of academic tasks.

This research was approved by the ̽��ֱ�� of Cambridge Animal Ethics Review Committee, and performed in accordance with the Home Office Regulations and the ASAB Guidelines for the Treatment of Animals in Behavioural Research and Teaching.

̽��ֱ��research was funded by the Royal Society, Fyssen Foundation, and European Research Council.

Reference

Schnell, AK, Boeckle, M, Clayton, NS. ‘Waiting for a better possibility: delay of gratification in corvids and its relationship to other cognitive capacities.’ Philosophical Transactions of the Royal Society B, October 2022.

A study has found that Eurasian jays can pass a version of the ‘marshmallow test’ – and those with the greatest self-control also score the highest on intelligence tests.

It’s just mind-boggling that some jays can wait so long for their favourite food."

Alex Schnell

bazilfoto on iStock/Getty Images Plus

Jay

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Ageing cuttlefish can remember the details of last week’s dinner

jg533 — Wed, 18 Aug 2021 07:04:06 +0000

̽��ֱ��results, published today in the journal Proceedings of the Royal Society B, are the first evidence of an animal whose memory of specific events does not deteriorate with age.

Researchers from the ̽��ֱ�� of Cambridge, the Marine Biological Laboratory in Woods Hole, Massachusetts, and the ̽��ֱ�� of Caen, conducted memory tests on 24 common cuttlefish, Sepia officinalis. Half of these were 10-12 months old – not-quite adult, and the other half were in old age at 22-24 months – equivalent to humans in their 90s.

“Cuttlefish can remember what they ate, where and when, and use this to guide their feeding decisions in the future. What’s surprising is that they don’t lose this ability with age, despite showing other signs of ageing like loss of muscle function and appetite,” said Dr Alexandra Schnell in the ̽��ֱ�� of Cambridge’s Department of Psychology, first author of the paper.

As humans age, we gradually lose the ability to remember experiences that happened at particular times and places – for example, what we had for dinner last Tuesday. This is termed ‘episodic memory’, and its decline is thought to be due to deterioration of a part of the brain called the hippocampus.

Cuttlefish do not have a hippocampus, and their brain structure is dramatically different to ours. ̽��ֱ��‘vertical lobe’ of the cuttlefish brain is associated with learning and memory. This does not deteriorate until the last two to three days of the animal’s life, which the researchers say could explain why episodic-like memory is not affected by age in cuttlefish.

To conduct the experiment, the cuttlefish were first trained to approach a specific location in their tank marked with a black and white flag. Then they were trained to learn that two foods they commonly eat were available at specific flag-marked locations and after specific delays. At one spot, the flag was waved and a piece of king prawn, their less preferred food, was provided. Live grass shrimp, which they like more, was provided at a different spot where another flag was also waved - but only every three hours. This was repeated for four weeks.

Then the cuttlefishes’ recall of which food would be available, where, and when was tested. To make sure they hadn’t just learned a pattern, the two feeding locations were unique each day. All the cuttlefish – regardless of age – watched which food first appeared at each flag and used that to work out which feeding spot was best at each subsequent flag-waving. This suggests that episodic-like memory does not decline with age in cuttlefish, unlike in humans.

“ ̽��ֱ��old cuttlefish were just as good as the younger ones in the memory task – in fact, many of the older ones did better in the test phase. We think this ability might help cuttlefish in the wild to remember who they mated with, so they don’t go back to the same partner,” said Schnell.

Cuttlefish only breed at the end of their life. By remembering who they mated with, where, and how long ago, the researchers think this helps the cuttlefish to spread their genes widely by mating with as many partners as possible.

Cuttlefish have short lifespans – most live until around two years old – making them a good subject to test whether memory declines with age. Since it is impossible to test whether animals are consciously remembering things, the authors used the term ‘episodic-like memory’ to refer to the ability of cuttlefish to remember what, where and when specific things happened.

This research was funded by the Royal Society and the Grass Foundation.

Reference
Schnell, AK et al: ‘Episodic-like memory is preserved with age in cuttlefish.’ Proceedings of the Royal Society B, August 2021. DOI: 10.1098/rspb.2021.1052

Cuttlefish can remember what, where, and when specific things happened – right up to their last few days of life, researchers have found.

̽��ֱ��old cuttlefish were just as good as the younger ones in the memory task

Alexandra Schnell

Ageing cuttlefish can remember the details of last week’s dinner

Phuket@photographer.net

Cuttlefish

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Cuttlefish show their intelligence by snubbing sub-standard snacks

jg533 — Wed, 03 Mar 2021 00:00:01 +0000

̽��ֱ��results, published on 3 March in the journal Proceedings of the Royal Society B, provide the first evidence of a link between self-control and intelligence in a non-primate species.

To conduct the experiment, common cuttlefish (Sepia officinalis) in tanks were presented with two foods they commonly eat, each in a separate Perspex chamber. In one chamber was a piece of king prawn, which they could eat immediately. In the other was a live grass shrimp, their preferred food, but they could only have the shrimp if they waited and didn’t eat the prawn.

A range of delays were tested, starting at 10 seconds and increasing by 10 seconds each time. All six cuttlefish in the experiment showed self-control, waiting for the grass shrimp and ignoring the king prawn. Those with the most self-control could wait 130 seconds for the grass shrimp to be released – an ability comparable with large-brained animals like chimpanzees.

“It was quite astonishing that the cuttlefish could wait for over two minutes for a better snack. Why would a fast-growing animal with an average life-span of less than two years be a picky eater?” said Dr Alexandra Schnell in the ̽��ֱ�� of Cambridge’s Department of Psychology, first author of the paper.

̽��ֱ��learning ability of each cuttlefish was then tested in a different task. A dark grey marker and a white marker were placed in random positions in the tank. After learning to associate one colour with a reward, the reward was switched to be associated with the other colour. ̽��ֱ��cuttlefish that were both quicker to learn the association and quicker to realise the switch were the same ones showing more self-control in the first task.

“We found that cuttlefish with better learning performance - an indicator of intelligence - also showed better self-control. This link exists in humans and chimpanzees, but this is the first time it has been shown in a non-primate species,” said Schnell.

̽��ֱ��researchers suggest that self-control in cuttlefish is the by-product of another behaviour: staying camouflaged on the sea bed for long periods of time to avoid predators. These periods are punctuated by brief foraging bouts in the open. Self-control may help the cuttlefish optimise their foraging by only striking prey of better quality.

“ ̽��ֱ��ability to exert self-control is an important element of the ability to plan for the future, which is quite a sophisticated behaviour,” said Professor Nicola Clayton FRS in Cambridge’s Department of Psychology, senior author of the report.

She added: “Self-control requires an understanding that ‘less is sometimes more’ - that avoiding temptation now might lead to a better future outcome. This is a critically important building block for the evolution of complex decision-making.”

̽��ֱ��researchers also noticed that the cuttlefish in the self-control task turned their bodies away from the immediately available food, as if to distract themselves from eating it.

Self-control - the ability to resist temptation in favour of a better but delayed reward – is a vital skill that underpins effective decision-making, goal-directed behaviour and future planning. Amongst animals, apes and their clever feathered cousins the corvids and parrots have relatively high self-control when it comes to eating. Rats, chickens and pigeons find it much more difficult not to eat food immediately.

̽��ֱ��experiments were conducted with collaborators including Professor Roger Hanlon at the Marine Biological Laboratory in Woods Hole, Massachusetts. Their design was inspired by the 1972 Stanford marshmallow test, in which children were offered a choice between one marshmallow immediately, or two if they waited for a period of time.

Two additional cuttlefish were recruited to the study but refused to take part.

This research was funded by the Royal Society.

Reference

Schnell, A.K. et al: ‘Cuttlefish exert self-control in a delay of gratification task.’ Proceedings of the Royal Society B, March 2021. DOI: 10.1098/rspb.2020.3161

A study has found that cuttlefish can pass a fishy version of the ‘marshmallow test’ – and those that can delay gratification the longest are the most intelligent.

It was quite astonishing that the cuttlefish could wait for over two minutes for a better snack. Why would a fast-growing animal with an average life-span of less than two years be a picky eater?

Alex Schnell

Alex Scnhell

Cuttlefish

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