Archive for the ‘Rat’ Category

By Tanya Lewis

Just as humans lament not pursuing a lover or bemoan having eaten that extra slice of chocolate cake, rats may experience feelings of regret, too, new research suggests.

When rats were given the option of visiting rooms that contained different foods, and they skipped a good deal for a worse one, they glanced back at the former room, rushed through eating the snack and were more likely to tolerate longer wait times for what they considered the more desirable food , researchers found.

Furthermore, the rats’ brain activity represented the missed opportunity, suggesting the animals were, in fact, experiencing regret over their choice.

“The rat is representing the counterfactual — the ‘what might have been,'” David Redish, a neuroscientist at the University of Minnesota in Minneapolis, and senior author of the study detailed today (June 8) in the journal Nature Neuroscience.

No other studies have shown convincingly that any animal besides humans experience regret, though some studies hinted it was possible, the researchers said.

How do you define regret? You can’t exactly ask a rat if it feels regret, but even if you could, it wouldn’t be proof, just as it can be difficult to tell if a human feels regret just by asking them.

It’s important to distinguish between regret and disappointment, Redish told Live Science. Regret occurs when you make a mistake, but recognize there’s an alternate action you could have taken that would have resulted in a better outcome, he said. Disappointment happens when “the world’s just not as good as you hoped, but it’s not necessarily your fault,” he said.

To test whether rats could feel regret, Redish and his graduate student Adam Steiner designed a kind of “restaurant row” for the animals — a circular enclosure with pathways leading off it to “restaurants” with different kinds of food, which were dispensed after some delay.

As a rat passed each pathway, it heard a tone that told the animal how long it would have to wait for the food (like being told the wait time at a restaurant). Each rat had its own favorite food, such as banana or chocolate, and would wait longer to get it, Redish said. Each rat was given an hour to explore the enclosure, during which it could only move in one direction between restaurants.

If the rat passed up a good deal — for instance, bypassing a food it liked in favor of a shorter wait time — and encountered a worse deal at the next restaurant, it would glance backward at the one it passed up. Not only that, the rat rushed through eating its chosen food, much like a regretful human would, and was more likely to take a “worse deal” in the future, the researchers said.

But the rats’ behavior was only part of the story. The researchers also made electrical recordings of the rats’ brains during the task, from neurons in the orbitofrontal cortex, the part of the brain that is active in human brain scans when people feel regret. Decoding these signals allowed the researchers to “read the rat’s mind,” Redish said.

Surprisingly, when the rats were looking back at the restaurant they ultimately passed up, their brains showed a representation of entering that restaurant — not of the food they missed. The findings suggest the animals were expressing regret over their actions, rather than just disappointment, the researchers said.

If rats can feel regret, what about other animals? Redish speculates that any mammal might be capable of the feeling, because they have many of the same brain structures as rats and humans.

“Regret is something we think of as very human and very cognitive,” Redish said, but “we’re seeing that the rats are much more cognitive than we thought.”

http://www.livescience.com/46184-rats-experience-regret.html

The world’s first brain-to-brain connection has given rats the power to communicate by thought alone.

“Many people thought it could never happen,” says Miguel Nicolelis at Duke University in Durham, North Carolina. Although monkeys have been able to control robots with their mind using brain-to-machine interfaces, work by Nicolelis’s team has, for the first time, demonstrated a direct interface between two brains – with the rats able to share both motor and sensory information.

The feat was achieved by first training rats to press one of two levers when an LED above that lever was lit. A correct action opened a hatch containing a drink of water. The rats were then split into two groups, designated as “encoders” and “decoders”.

An array of microelectrodes – each about one-hundredth the width of a human hair – was then implanted in the encoder rats’ primary motor cortex, an area of the brain that processes movement. The team used the implant to record the neuronal activity that occurs just before the rat made a decision in the lever task. They found that pressing the left lever produced a different pattern of activity from pressing the right lever, regardless of which was the correct action.

Next, the team recreated these patterns in decoder rats, using an implant in the same brain area that stimulates neurons rather than recording from them. The decoders received a few training sessions to prime them to pick the correct lever in response to the different patterns of stimulation.

The researchers then wired up the implants of an encoder and a decoder rat. The pair were given the same lever-press task again, but this time only the encoder rats saw the LEDs come on. Brain signals from the encoder rat were recorded just before they pressed the lever and transmitted to the decoder rat. The team found that the decoders, despite having no visual cue, pressed the correct lever between 60 and 72 per cent of the time.

The rats’ ability to cooperate was reinforced by rewarding both rats if the communication resulted in a correct outcome. Such reinforcement led to the transmission of clearer signals, improving the rats’ success rate compared with cases where decoders were given a pre-recorded signal. This was a big surprise, says Nicolelis. “The encoder’s brain activity became more precise. This could have happened because the animal enhanced its attention during the performance of the next trial after a decoder error.”

If the decoders had not been primed to relate specific activity with the left or right lever prior to the being linked with an encoder, the only consequence would be that it would have taken a bit more time for them to learn the task while interacting with the encoder, says Nicolelis. “We simply primed the decoder so that it would get the gist of the task it had to perform.” In unpublished monkey experiments doing a similar task, the team did not need to prime the animals at all.

In a second experiment, rats were trained to explore a hole with their whiskers and indicate if it was narrow or wide by turning to the left or right. Pairs of rats were then connected as before, but this time the implants were placed in their primary somatosensory cortex, an area that processes touch. Decoder rats were able to indicate over 60 per cent of the time the width of a gap that only the encoder rats were exploring.

Finally, encoder rats were held still while their whiskers were stroked with metal bars. The researchers observed patterns of activity in the somatosensory cortex of the decoder rats that matched that of the encoder rats, even though the whiskers of the decoder rats had not been touched.

Pairs of rats were even able to cooperate across continents using cyberspace. Brain signals from an encoder rat at the Edmond and Lily Safra International Institute of Neuroscience of Natal in Brazil were sent to a decoder in Nicolelis’s lab in North Carolina via the internet. Though there was a slight transmission delay, the decoder rat still performed with an accuracy similar to those of rats in closer proximity with encoders.

Christopher James at the University of Warwick, UK, who works on brain-to-machine interfaces for prostheses, says the work is a “wake-up call” for people who haven’t caught up with recent advances in brain research.

We have the technology to create implants for long-term use, he says. What is missing, though, is a full understanding of the brain processes involved. In this case, Nicolelis’s team is “blasting a relatively large area of the brain with a signal they’re not sure is 100 per cent correct,” he says.

That’s because the exact information being communicated between the rats’ brains is not clear. The brain activity of the encoders cannot be transferred precisely to the decoders because that would require matching the patterns neuron for neuron, which is not currently possible. Instead, the two patterns are closely related in terms of their frequency and spatial representation.

“We are still using a sledgehammer to crack a walnut,” says James. “They’re not hearing the voice of God.” But the rats are certainly sending and receiving more than a binary signal that simply points to one or other lever, he says. “I think it will be possible one day to transfer an abstract thought.”

The decoders have to interpret relatively complex brain patterns, says Marshall Shuler at Johns Hopkins University in Baltimore, Maryland. The animals learn the relevance of these new patterns and their brains adapt to the signals. “But the decoders are probably not having the same quality of experience as the encoders,” he says.

Patrick Degenaar at Newcastle University in the UK says that the military might one day be able to deploy genetically modified insects or small mammals that are controlled by the brain signals of a remote human operator. These would be drones that could feed themselves, he says, and could be used for surveillance or even assassination missions. “You’d probably need a flying bug to get near the head [of someone to be targeted],” he says.

Nicolelis is most excited about the future of multiple networked brains. He is currently trialling the implants in monkeys, getting them to work together telepathically to complete a task. For example, each monkey might only have access to part of the information needed to make the right decision in a game. Several monkeys would then need to communicate with each other in order to successfully complete the task.

“In the distant future we may be able to communicate via a brain-net,” says Nicolelis. “I would be very glad if the brain-net my great grandchildren used was due to their great grandfather’s work.”

Journal reference: Nature Scientific Reports, DOI: 10.1038/srep01319

 

Rats use a sense that humans don’t: whisking. They move their facial whiskers back and forth about eight times a second to locate objects in their environment. Could humans acquire this sense? And if they can, what could understanding the process of adapting to new sensory input tell us about how humans normally sense? At the Weizmann Institute, researchers explored these questions by attaching plastic “whiskers” to the fingers of blindfolded volunteers and asking them to carry out a location task. The findings, which recently appeared in the Journal of Neuroscience, have yielded new insight into the process of sensing, and they may point to new avenues in developing aids for the blind.
The scientific team, including Drs. Avraham Saig and Goren Gordon, and Eldad Assa in the group of Prof. Ehud Ahissar and Dr. Amos Arieli, all of the Neurobiology Department attached a “whisker” – a 30 cm-long elastic “hair” with position and force sensors on its base – to the index finger of each hand of a blindfolded subject. Then two poles were placed at arm’s distance on either side and slightly to the front of the seated subject, with one a bit farther back than the other. Using just their whiskers, the subjects were challenged to figure out which pole – left or right – was the back one. As the experiment continued, the displacement between front and back poles was reduced, up to the point when the subject could no longer distinguish front from back.
On the first day of the experiment, subjects picked up the new sense so well that they could correctly identify a pole that was set back by only eight cm. An analysis of the data revealed that the subjects did this by figuring the spatial information from the sensory timing. That is, moving their bewhiskered hands together, they could determine which pole was the back one because the whisker on that hand made contact earlier.
When they repeated the testing the next day, the researchers discovered that the subjects had improved their whisking skills significantly: The average sensory threshold went down to just three cm, with some being able to sense a displacement of just one cm. Interestingly, the ability of the subjects to sense time differences had not changed over the two days. Rather, they had improved in the motor aspects of their whisking strategies: Slowing down their hand motions – in effect lengthening the delay time – enabled them to sense a smaller spatial difference.
Saig: “We know that our senses are linked to muscles, for example ocular and hand muscles. In order to sense the texture of cloth, for example, we move our fingers across it, and to seeing stationary object, our eyes must be in constant motion. In this research, we see that changing our physical movements alone – without any corresponding change in the sensitivity of our senses – can be sufficient to sharpen our perception.”
Based on the experiments, the scientists created a statistical model to describe how the subjects updated their “world view” as they acquired new sensory information – up to the point at which they were confident enough to rely on that sense. The model, based on principles of information processing, could explain the number of whisking movements needed to arrive at the correct answer, as well as the pattern of scanning the subjects employed – a gradual change from long to short movements. With this strategy, the flow of information remains constant. “The experiment was conducted in a controlled manner, which allowed us direct access to all the relevant variables: hand motion, hand-pole contact and the reports of the subjects themselves,” says Gordon. “Not only was there a good fit between the theory and the experimental data, we obtained some useful quantitative information on the process of active sensing.”
“Both sight and touch are based on arrays of receptors that scan the outside world in an active manner,” says Ahissar, “Our findings reveal some new principles of active sensing, and show us that activating a new artificial sense in a ‘natural’ way can be very efficient.”  Arieli adds: “Our vision for the future is to help blind people ‘see’ with their fingers. Small devices that translate video to mechanical stimulation, based on principles of active sensing that are common to vision and touch, could provide an intuitive, easily used sensory aid.”
 

 

Alexandra’s discarded piles of rotting food and leaking sewage have become a perfect breeding ground for rats.
 
As it was in medieval Hamelin, so it is today in the South African township of Alexandra: wherever you go, you are never far from a rat.

But residents of the Johannesburg suburb have been offered a deal unavailable in the era of the Pied Piper – a free mobile phone for every resident who catches 60 of the rodents.

Alexandra has just turned 100 years old and was the young Nelson Mandela’s first home when he moved to Johannesburg. Its cramped shacks and illegal rubbish dumps sit in brutal contrast with neighbouring Sandton, dubbed the wealthiest square mile in Africa.

The crumbling structures, leaking sewage and discarded piles of rotting food are a perfect breeding ground for rats, much to the torment of residents. There have reportedly been cases of children’s fingers being bitten while they sleep.

In an attempt to fight back, city officials have distributed cages and the mobile phone company 8ta has sponsored the volunteer ratcatchers.

Resident Joseph Mothapo says he has won two phones and plans to get one for each member of his family. “It’s easy,” he told South Africa’s Mail & Guardian newspaper, wielding a large cage containing rats. “You put your leftover food inside and the rats climb in, getting caught as the trap door closes.”

But there were signs that the PR stunt could backfire, as animals rights activists criticised the initiative on social networks.

On Monday 8ta denied responsibility for the initiative. It said it was a long-time sponsor of a charity called Lifeline, which had taken the decision to hand out phones.

“You will have to ask Lifeline why they decided to use these promotional products,” said Pynee Chetty, an 8ta spokesman. “They do a lot of good community work, including in Alexandra. They used the promotional material to incentivise members of the community. I wasn’t aware this is how they were going to resolve the problem [of rats].”

He added: “We won’t distance ourselves from Lifeline. It is a charity that does a lot of good work and our support for them is steadfast. I don’t want to deny the story. What I’m saying is that it’s not our initiative.”

The Mail and Guardian reported that thousands of rats have been gassed to death by a specialist, Ashford Sidzumo, at the local sports centre. “We record all the people’s details so we can see where the rats are causing the biggest problem,” he was quoted as saying. “We use this to send fumigation teams there.”

Local councillor Julie Moloi told the Mail & Guardian there had been no choice but to carry out the drastic experiment. “We are afraid these rats will take over Alex and it will become a city of rats,” she said.

In another measure, owls have been given to three local schools because of their rat-catching prowess. But wider deployment of the birds may be difficult: Moloi said people kill them because of traditional beliefs that they are to be feared.

The German city of Hamelin may be in need of another Pied Piper – it seems the rats are back.

City officials say a popular fountain has been put out of service after the rodents gnawed through a power cable, according to the Sueddeutsche Zeitung newspaper.

The Lower Saxony city is where, legend has it, the Pied Piper led all the rats out in 1284 with his magic pipe into the Weser River, where they drowned.

But more than 700 years later, city officials say such drastic measures may not be necessary. The fountain was due to be permanently closed anyway because of the high upkeep costs.

And the solution in the fictitious Piper story isn’t practical anyway: rats are actually pretty good swimmers.

http://hosted.ap.org/dynamic/stories/E/EU_ODD_GERMANY_PIED_PIPER?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT

The Rat Temple

Posted: February 8, 2012 in Rat, Religion

India Rat Temple Is Home To 15,000 Revered Rodents Worshipped As Reincarnated Family Members

On the surface, this temple in northern India appears like any other. But there’s a main difference: there are 15,000 deities living inside it and they happen to be rats.

Believed by locals to be the reincarnation of former family members, the rats are allowed to run rampant in and around the temple — a notion that would seem impossible to those living in the West.

But if you want to experience these revered rodents, you must remove your shoes and walk and sit among them.

Read the whole story: http://video.nationalgeographic.com/video/places/culture-places/buildings-landmarks/india-rattemple-pp/

The act of helping others out of empathy has long been associated strictly with humans and other primates, but new research shows that rats exhibit this prosocial behavior as well.
In the new study, laboratory rats repeatedly freed their cage-mates from containers, even though there was no clear reward for doing so. The rodents didn’t bother opening empty containers or those holding stuffed rats.

 
To the researchers’ surprise, when presented with both a rat-holding container and a one containing chocolate — the rats’ favorite snack — the rodents not only chose to open both containers, but also to share the treats they liberated.
 
Peggy Mason, a neuroscientist at the University of Chicago and lead author of the new study, says that the research shows that our empathy and impulse to help others are common across other mammals.
 
“Helping is our evolutionary inheritance,” Mason told LiveScience. “Our study suggests that we don’t have to cognitively decide to help an individual in distress; rather, we just have to let our animal selves express themselves.”
 
Empathetic rats
In previous studies, researchers found that rodents show the simplest form of empathy, called emotional contagion — a phenomenon where one individual’s emotions spread to others nearby. For example, a crying baby will trigger the other babies in a room to cry as well. Likewise, rats will become distressed when they see other rats in distress, or they will display pain behavior if they see other rats in pain.
 
For the new study, Mason and her colleagues wanted to see if rats could go beyond emotional contagion and actively help other rats in distress. To do so, the rats would have to suppress their natural responses to the “emotions” of other rats, the result of emotional contagion. “They have to down-regulate their natural reaction to freeze in fear in order to actively help the other rat,” Mason explained.
 
The researchers began their study by housing rats in pairs for two weeks, allowing the rodents to create a bond with one another. In each test session, they placed a rat pair into a walled arena; one rat was allowed to roam free while the other was locked in a closed, transparent tube that could only be opened from the outside.
 
The free rat was initially wary of the container in the middle of the arena, but once it got over the fear it picked up from its cage-mate, it slowly began to test out the cage. After an average seven days of daily experiments, the free rat learned it could release its friend by nudging the container door open. Over time, the rat began releasing its cage-mate almost immediately after being placed into the arena.
 
“When the free rat opens the door, he knows exactly what he’s doing — he knows that the trapped rat is going to get free,” Mason said. “It’s deliberate, purposeful, helping behavior.”
 
The researchers then conducted other tests to make sure empathy was the driving force in the rats’ behavior. In one experiment, they rigged the container so that opening the door would release the captive rat into a separate arena. The free rat repeatedly set its cage-mate free, even though there was no reward of social interaction afterwards. [Like Humans, Chimps Show Selfless Behaviors]
 
True motivations
While it appears that the rats are empathetic, questions about the rodents’ true motivations still remain.
 
“It is unclear whether the rats sympathize with the distress of their cage-mates, or simply feel better as they alleviate the perceived distress of others,” Jaak Panksepp, a psychologist and neuroscientist at Washington State University, wrote in an article accompanying the study.
 
Mason says they don’t yet know if the free rats are acting to relieve their own distress, the distress of their cage-mates, or a combination of both, but this is definitely a topic for further research. She’s also looking to study if the rats would behave the same way if they weren’t cage-mates, and she would like to tease out the brain areas and genes involved in the behavior.
 
But, she says, “We now have this incredibly controlled, reproducible paradigm.” Other scientists should be able to use the model they developed to see if empathy and prosocial behavior are present in other animals, she said.
 
The study was published today in the journal Science.
 
 

UK Woman Gnawed by Rats in Her Bed

Posted: August 2, 2011 in Rat

Southcote, UK has a rat infestation that is forcing many people from their homes.

A bedbound woman who needed hospital treatment after her home was one of several plagued by rats has died.

The 80-year-old was in bed following a stroke and is believed to have been attacked by the creatures in her home at the end of June.

http://www.reading107fm.com/news/local-news/rat-infestation-in-southcote-397/

http://www.getreading.co.uk/news/s/2096650_rat_attack_woman_dies_in_hospital

http://www.getreading.co.uk/news/s/2095945_woman_gnawed_by_rats_in_her_bed