Fiona Kumfor, Neuroscience Research Australia and Sicong Tu, Neuroscience Research Australia
The brain is truly a marvel.
A seemingly endless library, whose shelves house our most precious memories as well as our lifetime’s knowledge. But is there a point where it reaches capacity? In other words, can the brain be “full”?
The answer is a resounding no, because, well, brains are more sophisticated than that. A study published in Nature Neuroscience earlier this year shows that instead of just crowding in, old information is sometimes pushed out of the brain for new memories to form.
Previous behavioural studies have shown that learning new information can lead to forgetting. But in this study, researchers used new neuroimaging techniques to demonstrate for the first time how this effect occurs in the brain.
The paper’s authors set out to investigate what happens in the brain when we try to remember information that’s very similar to what we already know. This is important because similar information is more likely to interfere with existing knowledge, and it’s the stuff that crowds without being useful.
To do this, they examined how brain activity changes when we try to remember a “target” memory, that is, when we try to recall something very specific, at the same time as trying to remember something similar (a “competing” memory). Participants were taught to associate a single word (say, the word sand) with two different images – such as one of Marilyn Monroe and the other of a hat.
They found that as the target memory was recalled more often, brain activity for it increased. Meanwhile, brain activity for the competing memory simultaneously weakened. This change was most prominent in regions near the front of the brain, such as the prefrontal cortex, rather than key memory structures in the middle of the brain, such as the hippocampus, which is traditionally associated with memory loss.
Allan Ajifo/Flickr, CC BY
The prefrontal cortex is involved in a range of complex cognitive processes, such as planning, decision making, and selective retrieval of memory. Extensive research shows this part of the brain works in combination with the hippocampus to retrieve specific memories.
If the hippocampus is the search engine, the prefrontal cortex is the filter determining which memory is the most relevant. This suggests that storing information alone is not enough for a good memory. The brain also needs to be able to access the relevant information without being distracted by similar competing pieces of information.
Better to forget
In daily life, forgetting actually has clear advantages. Imagine, for instance, that you lost your bank card. The new card you receive will come with a new personal identification number (PIN). Research in this field suggests that each time you remember the new PIN, you gradually forget the old one. This process improves access to relevant information, without old memories interfering.
And most of us will be able to identify with the frustration of having old memories interfere with new, relevant memories. Consider trying to remember where you parked your car in the same carpark you were at a week earlier. This type of memory (where you are trying to remember new, but similar information) is particularly susceptible to interference.
When we acquire new information, the brain automatically tries to incorporate it within existing information by forming associations. And when we retrieve information, both the desired and associated but irrelevant information is recalled.
If the hippocampus is the search engine, the prefrontal cortex is the filter determining which memory is the most relevant. Playing Futures: Applied No/Flickr, CC BY
The majority of previous research has focused on how we learn and remember new information. But current studies are beginning to place greater emphasis on the conditions under which we forget, as its importance begins to be more appreciated.
The curse of memory
A very small number of people are able to remember almost every detail of their life in great detail; they have hyperthymestic syndrome. If provided with a date, they are able to tell you where and what they were doing on that particular day. While it may sound like a boon to many, people with this rare condition often find their unusual ability burdensome.
Some report an inability to think about the present or the future, because of the feeling of constantly living in the past, caught in their memories. And this is what we all might experience if our brains didn’t have a mechanism for superseding information that’s no longer relevant and did indeed fill up.
At the other end of the spectrum is a phenomenon called “accelerated long-term forgetting”, which has been observed in epilepsy and stroke patients. As the name suggests, these people forget newly learnt information at a much faster rate, sometimes within a few hours, compared to what’s considered normal.
It’s believed this represents a failure to “consolidate” or transfer new memories into long-term memory. But the processes and impact of this form of forgetting are still largely unexplored.
What studies in this area are demonstrating is that remembering and forgetting are two sides of the same coin. In a sense, forgetting is our brain’s way of sorting memories, so the most relevant memories are ready for retrieval. Normal forgetting may even be a safety mechanism to ensure our brain doesn’t become too full.
The authors do not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article. They also have no relevant affiliations.
Two Australian brothers are preparing to see their mother jailed for arranging their father’s murder in Bali, and for the sentence to be lighter than they feel is just.
Prosecutors have recommended 15 years’ jail for Noor Ellis, who could receive the maximum penalty of death on Wednesday for planning the murder of Robert Ellis.
For their sons John and Peter, anything less than 20 years fails to recognise their loss, their father’s suffering and their mother’s betrayal.
“Anything below that is unjust,” Peter Ellis, 19, told AAP.
“For a sentence of premeditated murder to go from the death penalty down to 15 years was a shock to the entire family, and we’re still trying to come to terms with how it’s possible.”
The body of Mr Ellis, 60, was found wrapped in plastic in a rice field in Bali last October.
When his Indonesian wife of 25 years finally confessed to playing a role in the crime, she claimed she had only resorted to plotting the hit after years of neglect and being denied a divorce.
She first claimed she only wanted the men, whom she paid $14,000, to ambush her husband in their Sanur villa to “teach him a lesson”, but hadn’t wanted him killed.
By the time of a police re-enactment, she admitted she had ordered the successful businessman killed, but “not sadistically”.
Mr Ellis was held down on his kitchen floor and his throat slashed, by police accounts, “like killing a pig”.
In her defence, Ellis argued she deserved a chance to again care for her sons, who she hoped would forgive her.
But Peter Ellis says that’s impossible, particularly after she tried to smear his father’s name with allegations about their marriage that family and friends say are untrue.
“Our father was a loving, caring person, we know him best,” he said.
John Ellis, 23, who has dropped out of university since the crime, says their lives have been turned upside-down and there can be no going back.
“She has been lying to the court about supporting us, but she hasn’t done anything but make our lives a lot harder, basically hell,” he said.
Ellis’s defence even presented the court with a statement, purported to have been signed by John Ellis, asking for a lenient sentence – a document he says was a forgery.
He’s glad the trial is coming to an end, but in Indonesia’s unpredictable legal system, he is nervous about the result.
“I hope justice is done, but I have a feeling that it won’t be,” he said.
HOW NOOR ELLIS’ STORY CHANGED ABOUT THE DEATH OF HER HUSBAND ROBERT:
October 25 2014:
Lawyer for Noor Ellis, Nyoman Wisnu, argues it was never supposed to go that far: “This incident happened because Noor picked the wrong person to talk to about her problems.”
November 17 2014:
During a re-enactment of the crime: “I only told you that you could kill him but not sadistically.”
April 15 2015:
In court, asked who gave the order to have Mr Ellis murdered: “Probably me … I asked Martin’s help to teach a lesson.”
Queensland’s racing boards have been sacked with the state government announcing it will restructure the industry in response to shocking animal cruelty in greyhound racing.
Premier Annastacia Palaszczuk tabled a report in parliament on Tuesday which showed Racing Queensland could not manage the risk of cruelty against dogs and turned a blind eye to live baiting.
The report, compiled after a Commission of Inquiry led by barrister Alan MacSporran QC, indicated thousands of dogs had been shot, hanged and electrocuted because they couldn’t run fast enough.
Ms Palaszczuk says the state’s racing boards – including those responsible for thoroughbred and harness racing – failed in their duty and must be held responsible.
“Today we are starting with a clean slate,” she told parliament.
Racing Queensland chief executive officer Darren Condon has been stood aside and given five days to show cause why he shouldn’t be sacked.
KPMG has also been appointed to advise the government on the implementation of the report’s 15 recommendations, including the formation of a new statutory oversight body.
Ms Palaszczuk said the most confronting evidence was that between 2003-13 more than 24,000 greyhound pups were born, but only 16,978 were named and registered.
She said it meant that 30 per cent of all greyhounds were unaccounted for in Queensland.
“The report shows this industry has dismally failed those animals it relies upon for considerable profit,” Ms Palaszczuk said.
The premier said her government would consider all 15 of the commissioner’s recommendations, including that all dogs be monitored for their whole lives.
“All Queenslanders want a racing industry that is based on integrity and proper animal welfare,” she said.
“Not one that is characterised by cruelty, dishonesty and at-best dubious regulation and an environment in which there is a failure of simple compliance measures.”
Mr Condon has refused to comment on his dismissal and would not discuss whether he would fight the decision.
Racing Queensland said they would not be commenting at this stage.
Former world No 1 Adam Scott is looking to former caddie Steve Williams to return him to the glory days.
Scott has convinced Williams to come out of retirement to have another crack at the US Open, British Open, Bridgestone Invitational and PGA Championship.
The three remaining majors of the year presents the Queenslander with his best and last chance of winning another major with his famed broomstick putter, which will be banned from the Tour next year.
Scott said he had to talk Williams out of retirement for the next three months, having last worked together at the Tour Championship last year.
“Steve was adamant that he was not going to caddy in 2015 so he took some convincing but I am very happy he’s agreed to help out,” Scott said in a release.
“We’ve had great success together so I’m looking forward to being on the links with Steve again.”
Scott formed a winning partnership with Williams over four years on Tour and they last worked together at the Fed-Ex Cup playoffs eight months ago.
During this time Scott rose to No.1 in the world rankings and accomplished his greatest feat – winning the Masters.
But Williams called time on their partnership, saying he needed time to pursue other pursuits.
This led to Mike Kerr jumping on the bag, but the results have been disastrous.
While Scott finished tied fourth at Doral, he missed two cuts and has not finished better than a tie for 24th.
That was at the Colonial, when he fired Kerr.
The Australian has since slipped to No.12 in the rankings, struggled with his putting while recording just two top-10 finishes this season. He was 38th at the Masters.
Scott has previously said he derives some confidence from the presence of Williams, who enjoyed success as a caddie for Tiger Woods from 1999 to 2011.
Williams has been on the bag for 14 majors – 13 of them with Tiger Woods and the 2013 Masters with Scott.
8 Ben McCalman has become the second Wallabies player to secure a flexible contract allowing him to play in Japan, after agreeing to three more years in Australian rugby.
The new deal means 27-year-old McCalman will remain with the Western Force in Super Rugby until the end of the 2018 season.
His deal allows him to play the 2014-16 season in Japan’s Top League following this year’s Rugby World Cup.
It’s similar to the ground-breaking three-year deal given to Wallabies and NSW Waratahs five eighth Bernard Foley, although Foley is allowed two seasons in Japan.
Vying with Wycliff Palu for the Wallabies No.8 role, McCalman has played 38 Tests for Australia, including seven at the 2011 Rugby World Cup.
He played nine Tests last year, including every minute of all four Europe tour matches against Wales, France, Ireland and England under new coach Michael Cheika.
He has also played 79 Super Rugby matches in six season with the Western Force.
While the Force have struggled this season and are in danger of collecting the Super Rugby wooden spoon, McCalman said he was happy to stick with them.
“The Western Force gave me an opportunity early in my career and I have thoroughly enjoyed my experiences here in Perth over the past six years,” McCalman said in a statement.
“I feel it is the best place for me to play my rugby and continue to develop as a player over the next three years.
“The squad’s remained really tight and there’s still a lot of belief within the squad that we can play finals rugby in seasons to come, which I think we’re capable of doing.”
G20 leaders and finance ministers will receive guidelines on tackling multinational tax avoidance from the OECD at meetings in Turkey later this year.
Australian Tax Commissioner Chris Jordan told a Senate committee on Tuesday the existing international tax architecture was developed in the early 1920s and depended on physical presence in a country.
“With the digital delivery in a lot of services that is a growing part of our consumption … that old framework is being relied upon to assert that there is no taxing right in Australia,” Mr Jordan said.
The government flagged in the budget that it would be implementing the OECD’s country-by-country tax reporting from January 1, 2016.
Multinationals will be required to provide a global picture of their operations including income and tax paid in every country they operate.
The information will be shared among tax authorities worldwide.
The government will also work with business to develop a code on public disclosure of greater tax information by large corporates.
Treasury deputy secretary Rob Heferen said this was the first attempt by the government at a voluntary compliance code.
“If that doesn’t work then we will revisit the issue and possibly go another path,” he said.
Greens senator Christine Milne said she couldn’t understand the need to consult with business for two years rather than the tax office just applying it.
Mr Heferen said the government has tabled draft laws giving the tax commissioner powers to pursue profits shifted to another country from activity that should have been taxed in Australia.
Daniel Ricciardo is in love.
He can’t get enough of the curves, kisses and screams.
Of Montreal’s Circuit Gilles Villeneuve, that is.
The track was the site of his maiden Formula One victory and is the venue for this weekend’s Canadian Grand Prix.
“Winning has made me love it a little bit more, but really I’ve loved it since my first lap back when I was driving for Toro Rosso,” the Australian said in his race preview.
“I remember coming back into the pits and saying `what a circuit’. I was amazed at how good it was – and I’d only done an install (lap).”
The ability to jump across the kerbs and bounce the car around makes it a “ridiculous” amount of fun, Ricciardo says, which reminds him of his go-kart days.
“And I love that,” he said.
“You can get aggressive with it, and aim to just brush the wall.
“Some guys will play it safe and sacrifice half a 10th (of a second) to get through there cleanly; others will take a risk and go flat out trying to find a little bit.
“The nearer you are, the faster you’ll go. Give the wall a kiss and you feel pretty good; kiss it too hard and that’s it.
“It’d be wonderful if you were doing it in isolation but with 100,000 screaming fans urging you on, it’s just mega.”
It’s unlikely Ricciardo will be in contention for a second straight win at the venue, given Red Bull’s form in 2015.
There’s also a possibility he could be forced to wear a 10-spot grid penalty if the team decides to change his engine for a fifth time this year.
The 25-year-old finished fifth last start at Monaco, his best result this season, behind junior teammate Daniil Kvyat in fourth.
Andrew Bogut couldn’t resist a dig but there’s no doubting how glad his Golden State Warriors are that Klay Thompson is set to play game one of the NBA Finals.
All Star guard Thompson, who forms a lethal shooting combination with team-mate Stephen Curry, has been monitored for concussion since being kneed in the head in last week’s Western Conference Finals series-clinching victory over the Atlanta Hawks.
He only returned to training on Monday but was confident he was over the concussion and would be passed fit by doctors.
“I expect to be,” Thompson, when asked if he will be cleared to take on the Cleveland Cavaliers. “I’m well on my way there.”
Warriors’ Australian centre Andrew Bogut joked that he wasn’t sure if the notoriously laid-back Thompson was concussed or not.
“Hard to tell,” Bogut said.
“Pre and post concussion symptoms, he’s the same.”
Bogut has been full of one-liners in his chats with reporters in the lead-up to game one.
Tip-off is 11am AEST Friday and, with fellow Victorian Matthew Dellavedova suiting up for the Cavaliers, Bogut suggested Australia should mark the occasion.
“It should be a public holiday,” he said.
Two other Australians, Patty Mills and Aron Baynes, helped the San Antonio Spurs to the NBA Championship in 2014, but this year will be the first time two Australians face each other in the finals.
Bogut was in Melbourne last year during the Finals series after suffering a cracked rib and the undermanned Warriors bowed out early from the playoffs.
He said there was so much interest in the Spurs’ NBA Championship run that waiters in Melbourne restaurants would go AWOL to watch the game “out the back” on TV instead of bringing him food for his 213cm body.
“Everywhere you went to eat for lunch everything was slow because everyone was glued to the TV screen and everyone was talking about the NBA which was really cool,” he said.
“Hopefully that happens again.”
Bogut expects there will be nerves among both teams.
“Obviously the first quarter of game one there’s probably going to be some sprayed shots and nerves there because it’s human nature,” he said.
“Not just the whole country, but the whole world will be watching.”
Cardinal George Pell is a world leader in addressing child sexual abuse in the Catholic Church and doesn’t deserve to have his character attacked, the Archbishop of Melbourne says.
Denis Hart has offered a passionate defence of his colleague and friend Cardinal Pell, who will return from the Vatican later this year to appear before the second round of Ballarat hearings of the abuse royal commission.
Archbishop Hart says claims Cardinal Pell helped cover up pedophile activity in Australia couldn’t be further from the truth.
He’s rejected claims by a member of Pope Francis’s child protection commission, British abuse survivor Peter Saunders, who has called on the pope to sack Cardinal Pell as the Vatican’s financial chief.
“When he became Archbishop, he introduced the first system for dealing with child sex abuse, trying to bring relief to victims, trying to bring care and also some financial compensation,” Archbishop Hart told ABC radio on Tuesday.
“He was a world leader in this regard.”
Archbishop Hart said Mr Saunders is just one member of a 17-member panel tasked with addressing child protection issues within the church.
“He does not have a brief, he’s not the commissioner. He’s a member of a committee which is responsible for addressing broad-based issues,” he said.
“He’s making statements about a person who he doesn’t know, possibly being fed by the words and phrases that others are using. I think it’s a personal view and I think it needs to be seen as such.”
Cardinal Pell is seeking legal advice following Mr Saunders’ public attack earlier this week.
But Mr Saunders, who accused Cardinal Pell of an “almost sociopathic” lack of care towards victims, says he won’t be silenced.
Mr Saunders has also expressed concern that Cardinal Pell, in his role as the Vatican’s financial chief, is in charge of the resources of the panel.
“The commission will largely be dictated, to some extent, by the resources that are made available to it … and my understanding is that there is some financial pressure already in this particular area and I’m pretty appalled at that.”
Cardinal Pell has denied being part of any cover up of abuse, and says he’s always been willing to front the royal commission.
World surfing champion Stephanie Gilmore still believes she can defend her crown despite the knee injury that’s sidelined her for two months.
Gilmore has been forced to miss this month’s Fiji Open after sitting out the Rio Pro because she injured her knee during a free surf at the Margaret River Pro in Western Australia in April.
The six-time world champion says she did all she could to make this week’s event at Cloudbreak but had to listen to her body.
It means Gilmore, who was fourth in the rankings and over 13,000 points behind championship leader Carissa Moore heading into Fiji, has just six events to overhaul the American and defend the title.
Sitting out Fiji also means her ninth-place finish at Margaret River will now have to be part of her championship haul with the absences in Rio and Fiji to be her two throwaway rounds for the year.
“It means I’ll have to count the round four at Margaret … it’ll be pretty difficult but anything’s possible and obviously with Carissa losing early in Brazil and Sally (Fitzgibbons) as well, it’s left the door open,” Gilmore told AAP.
“Courtney (Conlogue) is definitely going to be a strong one but, yeah, I’m not completely counting myself out.
“I’ll still compete the rest of the tour and we’ll have to wait and see.”
Gilmore said she still can’t fully move her injured leg but is hopeful of a return to surfing in two weeks or so.
With the next stop on the world tour being the US Open of Surfing at Huntington Beach starting on July 27, Gilmore is confident she’ll be back competing at that event.
“I’ve got a bit of time up my sleeve,” Gilmore said.
“I’m just doing everything that I can. Working with the physios, just doing the rehab that I need to make sure my muscles aren’t getting overused or other parts of my body aren’t trying to compensate, stuff like that.
“It’s about doing simple things. The doctors seem to think that it’s probably another two weeks and I should be good to go for a surf and get into it.
“It’s not like you forget how to surf … it’s just a matter of staying positive really.”