̽��ֱ�� of Cambridge - comparative cognition

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.

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Yes

Male Eurasian jays know that their female partners’ desires can differ from their own

jfp40 — Wed, 26 Mar 2014 10:52:41 +0000

Knowing what another person wants is not a trivial issue, particularly when the other’s desires are different from our own. ̽��ֱ��ability to disengage from our own desire to cater to someone else’s wishes is thought to be a unique feature of human cognition.

New research challenges this assumption. Despite wanting something different to eat, male Eurasian jays can disengage from their own current desire in order to feed the female what she wants even when her desires are different to his. ̽��ֱ��study, which was funded by the BBSRC, is published today in the Royal Society journal Biology Letters.

“We found that males could respond to the female’s desire even when their own desire was conflicting. That said, the males were also partially biased by what they wanted – a bias similar to one commonly found in human children and adults,” said Dr Ljerka Ostojić, who led the ̽��ֱ�� of Cambridge study.

For the study, nine male-female pairs of Eurasian jays (a member of the Corvid family) from two colonies were tested during the breeding season – the only time when jays share food. To manipulate what food the males and the females desired, the researchers used a phenomenon termed ‘specific satiety’ – after eating a particular food item to satiety, jays prefer to eat a novel food item that they are not currently sated on.

Once a day the females and males were placed in adjacent compartments with a mesh window in between. ̽��ֱ��male was then pre-fed either wax moth larvae or mealworm beetle larvae – both favourite treats for jays - until he did not want more. At the same time, the female’s desire was manipulated by giving her the same food as the male (meaning that their desires were matching), a different food from the male (meaning that their desires were conflicting), or her usual diet (meaning that the female’s desire was neutral towards the two types of larvae).

During the pre-feeding, the male had visual access to the female and saw her eat. At the end of pre-feeding, all food was removed. ̽��ֱ��males were then given 20 choices between a single wax moth larva and a mealworm beetle larva which they could either eat, cache (hide for later) or give to the female.

Not surprisingly, when the male and female birds’ preferences were the same, the male fed the female the food desired by both. However, when the female’s desire differed from the male’s, then he took his partner’s wishes into account, often feeding her the food that she desired. This ability to ascribe to another individual an internal life like one’s own and at the same time understand that the other’s internal, psychological states might differ from one’s own is called state-attribution.

Professor Nicky Clayton, whose Comparative Cognition lab at Cambridge ̽��ֱ��’s Department of Psychology conducted the study, said: “As humans, we ‘put ourselves into someone else’s shoes’ in order to respond to what the other person wants. Although we are biased by our own current desires, we can inhibit these to put the wants and desires of another before our own. ̽��ֱ��current findings show that the jays can also do this. So what this research suggests is that a common mechanism might underlie ‘desire-state attribution’ in humans and jays.”

New research shows that male jays are able to disengage from their own current desires to feed their female partner food that she wants.

We found that males could respond to the female’s desire even when their own desire was conflicting.

Dr Ljerka Ostojić

Male Eurasian jay

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Yes

̽��ֱ��eyes have it

jfp40 — Wed, 05 Feb 2014 00:01:00 +0000

While what humans do with their eyes has been well studied, we know almost nothing about whether birds communicate with members of the same species with their eyes.

̽��ֱ��new study, published today in Biology Letters, shows that jackdaw eyes are used as a warning signal to successfully deter competitors from coming near their nest boxes.

Gabrielle Davidson of the ̽��ֱ�� of Cambridge, who led the study, said: “Jackdaw eyes are very unusual. Unlike their close relatives, the rooks and crows – which have very dark eyes – jackdaw eyes are almost white and their striking pale irises are very conspicuous against their dark feathers.”

While most birds have black or dark brown eyes, bright eyes are not unknown in the avian world, and around 10% of passerines (perching birds) have coloured irises. ̽��ֱ��question Davidson wanted to answer was do jackdaws use their bright eyes to communicate with fellow jackdaws?

Just before the spring breeding season arrived last year, Davidson installed one of four different pictures in 100 jackdaw nest boxes on the outskirts of Cambridge. ̽��ֱ��pictures were either black (the control), a pair of jackdaw eyes, a pair of jackdaw eyes in a jackdaw’s face, or a jackdaw’s face with a pair of black rook eyes. She then filmed the effect the different pictures had on the birds’ behaviour.

“Jackdaws are unique among the crow family in that they nest in cavities in trees. These hollows are natural – the birds cannot excavate their own nest cavities as some woodpeckers do – so they have to compete for a limited resource. And because jackdaws nest in close proximity to each other, they fight a lot to gain the best nesting sites,” she explained. Often what initiates these fights are jackdaws approaching nest boxes that are not their own.

After analysing 40 videos of jackdaws peeking into each other’s nest boxes, she found that compared with the other nest boxes, those that contained the picture of a jackdaw with its bright eyes was much more likely to deter the birds from landing on it, and that the birds spent less time near such a nest box.

Davidson’s study is the first to show the eyes being used as a means of communication between members of the same species outside primates.

“Before now we knew very little about why some birds have brightly coloured eyes. In jackdaws, the pale eyes may function to improve their ability to defend their nest and chicks from competitors. It also raises the question of whether this is unique to jackdaws, or if other cavity nesting birds also use their eyes in a similar way,” she added.

̽��ֱ��field research took place at the Cambridge Jackdaw Project, which was established by Dr Alex Thornton of the ̽��ֱ�� of Exeter.

To see the research in action, view video below:

Researchers in Cambridge and Exeter have discovered that jackdaws use their eyes to communicate with each other – the first time this has been shown in non-primates.

Unlike their close relatives, rooks and crows, jackdaw eyes are almost white and their striking pale irises are very conspicuous against their dark feathers.

Gabrielle Davidson

Richard Woods. Homepage banner credit: Вых Пыхманн

Jackdaw

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Yes

Royal Society announces new Fellows

bjb42 — Fri, 21 May 2010 00:00:00 +0000

̽��ֱ��new Fellows join the ranks of the UK and Commonwealth's leading scientists as the Society celebrates its 350th Anniversary.

Lord Rees, President of the Royal Society said: "These scientists follow in the footsteps of early Fellows such as Isaac Newton, Robert Boyle and Robert Hooke. ̽��ֱ��new Fellows announced today embody the spirit of enquiry, dedicated to 'the relief of man's estate' on which the Royal Society was founded. That spirit is as alive today as it was 350 years ago."

̽��ֱ��new Fellows are:

Professor Andrea Brand, Herchel Smith Professor of Molecular Biology at the Gurdon Institute and the Department of Physiology, Development and Neuroscience and a Fellow of Jesus College, is distinguished for her pioneering work on the development of the nervous system. Using Drosophila as a model organism, and using sophisticated live imaging techniques, she has explained how cell fate determinants become localised to one side of a cell, allowing neural precursors to divide asymmetrically in a stem cell-like fashion.

Professor Nicola Clayton, Professor of Comparative Cognition in the Department of Experimental Psychology and Clare College Graduate Tutor, has pioneered new procedures for the experimental study of memory, planning and social cognition in animals, all attributes that have been claimed to be uniquely human, and her work has changed our view of animal intelligence and its relationship to human memory and cognition.

Professor Ben Green, Herchel Smith Professor of Pure Mathematics and a Fellow of Trinity College, has proved a number of remarkable results in arithmetic combinatorics, the highlight of which is his proof, with Terence Tao, that the prime numbers contain arithmetic progressions of all lengths.

Professor Roger Hardie, Professor of Cellular Neuroscience in the Department of Physiology, Development and Neuroscience, is distinguished for his extensive studies on invertebrate visual transduction which have transformed our wider understanding of cell signalling. His demonstration that the Drosophila trp and trpl genes code for selective calcium channels was the seminal observation that launched the TRP channel field, now a major part of calcium signalling and a focus of medical research.

Dr Michael Hastings, MRC Staff Scientist at the MRC Laboratory of Molecular Biology, is distinguished for his highly influential contributions to our understanding of biological clocks through the study of the suprachiasmatic nucleus (SCN) of the hypothalamus. He was instrumental in taking circadian neurobiology to the molecular and cell biological level.

Professor Max Pettini, Professor of Observational Astronomy at the Institute of Astronomy, is distinguished for his extensive observational achievements and insightful interpretations of the chemical and physical conditions of interstellar matter seen in a wide range of cosmic environments. His early research led to the discovery that our Galaxy is surrounded by a halo of hot ionised gas, verifying a prediction made decades earlier.

Professor Wolf Reik, Honorary Professor of Epigenetics in the Department of Physiology, Development and Neuroscience, is distinguished for his fundamental discoveries of epigenetic mechanisms in mammalian development, physiology, genome reprogramming, and human diseases. His work led to the discovery of the molecular mechanism of genomic imprinting, and uncovered non-coding RNA and chromatin looping regulating imprinted genes, which he showed to be involved in foetal nutrition, growth, and disease.

Seven Cambridge researchers are among the 44 new Fellows announced by the Royal Society this week.

These scientists follow in the footsteps of early Fellows such as Isaac Newton, Robert Boyle and Robert Hooke.

Lord Rees, President of the Royal Society

Matt from London from Flickr

RSC busts

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Yes

Clever crows and dancing duets

bjb42 — Thu, 01 May 2008 00:00:00 +0000

Nicky Clayton has always been fascinated by birds – by their glamour and elegance, their movement and rituals, their melodies and labours. This abiding passion has taken her from studying birdsong in zebra finches to observing complex feats of cognition in members of the corvid (crow) family, which includes scrub-jays, British jays, ravens and crows. Moving from the ̽��ֱ�� of California Davis to Cambridge’s Department of Experimental Psychology in 2000 with her colony of scrub-jays, she embarked on a series of experiments with colleague Professor Tony Dickinson that was to break new ground in comparative cognition. Their inventive experiments have shown that birds hide (or cache) food, remember where to recover it from at a later date, and even steal it from each other. Not only this, but by remembering past events (such as whether or not they would find breakfast in a certain room in the morning), the birds could take action for their future (by moving breakfast into the empty room the night before).

̽��ֱ��widely held view had been that animals can learn things through experience but not through memory; this ability to mentally travel back through time – so-called episodic memory – was thought to be something unique to the human race. For the first time ever, these experiments showed that humans are not alone in being able to remember a past experience in terms of what happened, where and when.

Nicky Clayton’s research has already branched out to cognitive studies comparing corvids with great apes through a collaborative project with her husband, Dr Nathan Emery (Queen Mary, ̽��ֱ�� of London). She is now also embarking on similar studies in young children with Dr Jim Russell in the Department of Experimental Psychology. These incredibly productive collaborations hold great promise for our future understanding of the workings of the brain in animals and humans.

What would others be surprised to learn about you?

A large part of my life is spent dancing – ballet, jazz, and particularly Latin dance like salsa and tango. Of course birds dance too: I have a favourite video clip that I show my students of the dance of the Swallow-tailed Manakin – it’s the avian equivalent of tango, and not surprisingly therefore they are found in Argentina! Two males perform a duet, a fabulous, showy double-act in which they display their beautiful plumage and synchronised movements. ̽��ֱ��males spend 90% of their time for nine months of the year dancing – a pretty intense avian dance school. This example encapsulates why I love dance: the elegance of movement, the colours, form, intensity and dedication – it strikes the core of my soul.

Who or what inspires you?

What inspires me is the curiosity and creativity of science, and the social and serendipitous meetings between people that lead on to discoveries. My academic hero is the late Bill Thorpe, Professor of Animal Ethology and founder of Cambridge’s Sub-Department of Animal Behaviour. He was an incredibly wise man and in many ways ahead of his time: he suggested that because bird brains are structurally different from the classic mammalian structure people shouldn’t assume that they are creatures of instinct. We now know of course that birds have quite impressive cognitive abilities.

Have you ever had a Eureka moment?

I suppose when Tony Dickinson and I first met – at the International Comparative Psychology meeting in Montreal in 1996 – and he said animals don’t need episodic memory. That got us talking and we began asking questions in a way that nobody else had been doing before. Out of that developed a wonderfully fruitful collaboration, with the result that four years later I moved here and we have been collaborating ever since.

What’s the best piece of advice you’ve ever been given?

Lord Krebs of Wytham, whom I worked with in Oxford, always emphasised the importance of balance in your life. His maxim was ‘healthy minds need healthy bodies’.

If you could wake up tomorrow with a new skill, what would it be?

I’d like to be able to dance flamenco. And I’d like to be reincarnated as a scrub-jay – imagine what it must be like to experience being part of this clever family of birds and find out what they really are thinking!

What motivates you to go to work each day?

That’s really easy: I love what I do. I love my days spent in research, in teaching undergraduates and graduates, in running a wonderfully supportive family-style lab, and last but by no means least, these long-term collaborations with my two best friends – Nathan, who is my husband and soulmate, and dear Tony. And I love releasing steam by dancing tango and salsa.

What is your favourite research tool?

My eyes and ears. For so much of the work I do what’s essential is detailed observation – looking and listening. It’s also important for dancing – being a good observer and a good listener helps you to copy the nuances of the rhythms.

Nicky Clayton, Professor of Comparative Cognition in the Department of Experimental Psychology, has thrown the doors wide open on animal cognition. Where once the idea would have been dismissed that animals can re-experience the past and plan for the future, her imaginative studies have shown this inherent cleverness in crows.

What inspires me is the curiosity and creativity of science, and the social and serendipitous meetings between people that lead on to discoveries.

Professor Nicola Clayton

Philip Mynott

Nicola Clayton

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Yes