̽��ֱ�� of Cambridge - Nicola Clayton

Blue and great tits deploy surprisingly powerful memories to find food, a new study shows

ta385 — Wed, 03 Jul 2024 14:58:00 +0000

Blue and great tits recall what they have eaten in the past, where they found the food and when they found it, a new study shows. In the first experiment of its kind to involve wild animals, blue and great tits demonstrated ‘episodic-like’ memory to cope with changes in food availability when foraging. ̽��ֱ��same study may suggest that humans leaving out seeds and nuts for garden birds could be contributing to the evolution of these memory traits.

Sleight-of-hand magic trick only fools monkeys with opposable thumbs

fpjl2 — Mon, 03 Apr 2023 14:27:26 +0000

By performing a famous magic trick for three species of monkey with differing hand structures, scientists have discovered that – in order to deceive – a conjuror needs the same anatomy as their audience.

Psychologists used a sleight-of-hand trick called the French drop, in which an object appears to vanish when a spectator assumes it is taken from one hand by the hidden thumb of the other hand.

̽��ֱ��study, carried out by the ̽��ֱ�� of Cambridge’s Comparative Cognition Lab, found that monkeys lacking opposable thumbs did not fall for the assumption – staying wise to the whereabouts of tasty treats a magician tried to make disappear.

̽��ֱ��research suggest that sharing a biomechanical ability may be necessary for accurately anticipating the movements of those same limbs in other individuals.

This is true even when those apparently accurate predictions end in befuddlement at the hands of an illusionist. ̽��ֱ��study is published today in the journal Current Biology.

“Magicians use intricate techniques to mislead the observer into experiencing the impossible. It is a great way to study blind spots in attention and perception,” said Dr Elias Garcia-Pelegrin, who has practiced magic for a decade, and conducted the experimental work during his PhD at Cambridge.

“By investigating how species of primates experience magic, we can understand more about the evolutionary roots of cognitive shortcomings that leave us exposed to the cunning of magicians.”

“In this case, whether having the manual capability to produce an action, such as holding an item between finger and thumb, is necessary for predicting the effects of that action in others,” said Garcia-Pelegrin, recently appointed an assistant professor at the National ̽��ֱ�� of Singapore.

̽��ֱ��French drop is often the first trick any budding magician sets out to master.

A coin is displayed in one hand. ̽��ֱ��other hand reaches over and grabs it. ̽��ֱ��palm of the second hand faces inwards, with the magician’s thumb concealed behind fingers.

̽��ֱ��audience knows the thumb is lurking – ready to grip – so assumes the coin has been taken when it is no longer visible. Their attention follows the second hand, only to find it empty at 'the reveal'. ̽��ֱ��magician had secretly dropped the coin into the palm of the original hand.

Food morsels replaced coins for the monkeys, and were given as rewards – but only if the animals guessed the correct hand. Scientists predicted that monkeys with opposable thumbs would act like human audiences: assume the hidden thumb had grabbed the item, and choose the wrong hand.

They repeatedly performed the French drop on 24 monkeys. Eight capuchins were dazzled with peanuts, eight squirrel monkeys with dried mealworms, and eight marmosets with marshmallows.

Capuchins are famed for dexterity, and use stone tools to crack nuts in the wild. They can waggle each finger, and have opposable thumbs allowing 'precision grip' between thumb and forefingers.

̽��ֱ��capuchins were regularly fooled by the French drop (81% of the time). They mostly chose the empty second hand, and experienced a paucity of peanuts as a result.

Squirrel monkeys are much less dextrous than capuchins, with limited thumb rotation, but can oppose their thumbs. As such, they are still familiar with a hidden thumb interacting with fingers. However, they cannot perform a ‘precision grip’ in the same way as capuchins and humans.

Yet squirrel monkeys were routinely misled by vanishing mealworms (93% of the time). “Squirrel monkeys cannot do full precision grips, but they were still fooled. This suggests that a monkey doesn’t have to be expert in a movement in order to predict it, just roughly able to do it,” said Garcia-Pelegrin.

Marmosets do not have opposable thumbs. Their thumbs align with their fingers to make five equidistant digits, ideal for climbing thick tree trunks. Marmosets were rarely taken in by magic (just 6% of the time). They simply chose the hand in which the marshmallow was initially placed, and stuck with it.

Previous work from the Cambridge team shows that species without hands at all, in this case birds from the corvid family, namely Eurasian jays, make similar choices as marmosets when confronted with the French drop.

̽��ֱ��team also tried nullifying the tricks by actually completing the hand-to-hand transfers, instead of misdirecting with a French drop. This time, the capuchins and squirrel monkeys anticipated correctly and dined out, and the marmosets missed out.

Finally, the scientists devised their own version of the French drop, which they call the “Power drop”. It utilises a hand action that all the monkey species can perform – essentially a full fist grab. ̽��ֱ��power drop fooled all of the monkey species the vast majority of the time.

“There is increasing evidence that the same parts of the nervous system used when we perform an action are also activated when we watch that action performed by others,” said Prof Nicola Clayton FRS, senior author of the study from Cambridge’s Department of Psychology.

“This mirroring in our neural motor system might explain why the French drop worked for the capuchins and squirrel monkeys but not for marmosets.”

“It’s about the embodiment of knowledge,” added Clayton. “How one’s fingers and thumbs move helps to shape the way we think, and the assumptions we make about the world – as well as what others might see, remember and anticipate, based on their expectations.”

“Our work raises the intriguing possibility that an individual’s inherent physical capability heavily influences their perception, their memory of what they think they saw, and their ability to predict manual movements of those around them.”

Another co-author of the study, Clive Wilkins, Artist in Residence at Cambridge’s Department of Psychology, is a professional magician and Member of the Magic Circle.

Illusion involving a hidden thumb confounds capuchin and squirrel monkeys for the same reason as humans – it misdirects the expected outcomes of actions they can carry out.

This mirroring in our neural motor system might explain why the French drop worked for the capuchins and squirrel monkeys but not for marmosets

Nicola Clayton

Not all monkeys are fooled by magic.

Elias Garcia-Pelegrin

A Humboldt's squirrel monkey is fooled by a French drop as part of the experiment.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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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

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Madingley aviaries saved from closure

cjb250 — Fri, 22 Jul 2022 11:00:05 +0000

We are very grateful to everyone who has contributed to helping the ̽��ֱ�� of Cambridge secure the future of this important research facility. We welcome any further donations to help us keep the facility open beyond this period.

̽��ֱ��aviaries have been the location of exceptional research led by Professor Nicky Clayton FRS that has transformed our understanding of the behaviour and intelligence of these bird species.

For more information on how you can support the aviaries, please visit our Clayton Corvid Lab fundraising page.

We are delighted to announce that due to a number of generous donations from both members of the public and the scientific community, together with support from the ̽��ֱ�� of Cambridge, we are able to keep the corvid aviaries at Madingley open for a further five years.

Nick Saffell ( ̽��ֱ�� of Cambridge)

Jays at Madingley

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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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Mind Over Chatter: What is the future?

ns480 — Thu, 27 May 2021 13:22:48 +0000

Season 2, episode 1

This second series of Mind Over Chatter is all about the future - and in this first episode we’re going to be considering what the future even is… Have you ever wondered how time works? It turns out, the answer is a lot more complicated than we thought.

Join our wondering and wonderful conversation with philosopher of science Dr Matt Farr, whose work focuses particularly on what it means for time to have a direction, professor of psychology Nicky Clayton, who looks at the evolution and development of intelligence in non-verbal animals and pre-verbal children, and professor of linguistics and philosophy, Kasia Jaszczolt whose research interests combine semantics, pragmatics, and the metaphysics of time

We’ll be talking about everything from physics to linguistics… and from broken eggs to Einstein’s theory of relativity.

Subscribe to Mind Over Chatter

Key points

[04:28] - Does time actually go from past to present to future? And does time really ‘flow’?

[09:53] - How do B-theorists deal with entropy? Can you un-break an egg?

[14:12] - Recap of the first portion of the episode, reviewing A-theory, B-theory and C-theory of time

[18:58] - How the mind understands the subjective concept of time

[27:11] - ̽��ֱ��Sapir-Whorf Hypothesis and how the way you talk about language affects the way you perceive and think about things

[30:21] - Recap of the second portion of the episode

[34:02] - How do the mental and linguistic concepts around time fit with philosophical concepts and physics of time?

[45:46] - Is there a conflict between the psychological and linguistic models of time and the way physics handles time?

[48:20] - Recap of the last portion of the episode

Mind Over Chatter: ̽��ֱ��Cambridge ̽��ֱ�� Podcast

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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It’s a kind of magic

cjb250 — Fri, 06 Mar 2020 08:29:21 +0000

How trickster birds are helping a psychologist and magician understand how our minds work.