The Future of Memory: Remembering, Imagining, and the Brain

During the past few years, there has been a dramatic increase in research examining the role of memory in imagination and future thinking. This work has revealed striking similarities between remembering the past and imagining or simulating the future, including the finding that a common brain network underlies both memory and imagination. Here, we discuss a number of key points that have emerged during recent years, focusing in particular on the importance of distinguishing between temporal and nontemporal factors in analyses of memory and imagination, the nature of differences between remembering the past and imagining the future, the identification of component processes that comprise the default network supporting memory-based simulations, and the finding that this network can couple flexibly with other networks to support complex goal-directed simulations. This growing area of research has broadened our conception of memory by highlighting the many ways in which memory supports adaptive functioning.

Re-Timer ready to reset sleep

Today saw the launch of Re-Timer, a wearable green light device invented by Flinders University sleep researchers to reset the body’s internal clock.

The portable device, which is worn like a pair of sunglasses and emits a soft green light onto the eyes, will help to counter jet lag, keep shift workers more alert and get teenagers out of bed by advancing or delaying sleeping patterns.

Psychologist Professor Leon Lack, the device’s chief inventor, said that the light from Re-Timer stimulates the part of the brain responsible for regulating the 24-hour body clock.

The device has been designed with the benefit of 25 years of sleep research at Flinders University.

“Body clocks or circadian rhythms influence the timing of all our sleeping and waking patterns, alertness, performance levels and metabolism,” Professor Lack said.

“Photoreceptors in our eyes detect sunlight, signal our brain to be awake and alert, and set our rhythms accordingly. These rhythms vary regularly over a 24-hour cycle. However, this process is often impaired by staying indoors, traveling to other times zones, working irregular hours, or a lack of sunlight during winter months.

“Our extensive research studies have shown that green light is one of the most effective wavelengths for advancing or delaying the body clock, and to date is the only wearable device using green light.”

Professor Lack recommended wearing the glasses for three days for 50 minutes each day either after awakening in the morning to advance the body clock, or before bed for those wanting to delay the body clock to wake up later.

He said that Re-Timer’s light therapy offers a safer and, in many cases, more effective treatment for mistimed sleep than drug alternatives.

The device is being produced by local manufacturing firm SMR Components.

Glowing Vulcan ears reveal brain’s lost neurons

These glowing shapes aren’t the ears of a rave-happy Vulcan - they’re slices from a mouse’s brain.

The slice on the right is from a mouse that lacks a gene called Arl13b - the same gene whose mutation causes Joubert syndrome in humans. This is a rare neurological condition that is linked with autism-spectrum disorders and brain structure malformations.

Without Arl13b, the nerve cells known as interneurons can’t find the right destination in the cerebral cortex during the brain’s development. Since the interneurons don’t end up in the right places, they can’t be wired up properly later on. This causes the disrupted brain development, typical of Joubert syndrome, visible in the image on the right.

The researchers hope that their findings will lead to better treatments for people who have the syndrome. 

"Ultimately, if you’re going to come up with therapeutic solutions, it’s important to understand the biology of the disease," says Eva Anton of the University of North Carolina in Chapel Hill, who worked on the research, which was published in Developmental Cell last week.

Follow-up study finds lasting benefit from MDMA for people with PTSD

The follow-up study was based on an original trial held in 2010 where 20 patients suffering from long term PTSD were given MDMA (the main ingredient in the party drug ecstasy) as part of their psychotherapy sessions. The researchers reported at the time that 83% of the participants showed improvements in their condition two months later.

In this new work, the researchers revisited the original patients three and a half years later (one refused to participate leaving just 19) to see how well they were doing. They found that just two of the patients had suffered a relapse – the rest they say maintained the relief they had found in the original trial.

The research was sponsored by the group Multidisciplinary Association for Psychedelic Studies (MAPS), whose mission is to seek out treatments for a variety of mental ailments using non-traditional drug therapies. In addition to providing funds for the trials they also worked out agreements with the government to allow for legal testing of the drug (it currently has as a Schedule I status.)

Study leads Michael and Ann Mithoefer conducted the original trial out of their private practice office. Each trial was conducted with a single patient at a time and involved a non-pharmaceutical therapy session followed by one where the patient was given a dose of MDMA. Another traditional session was held later – the sessions that included use of the drug lasted up to eight hours because the effects of the drugs last that long.

The researchers believe that MDMA helps PTSD sufferers by allowing them to relive the emotionally traumatic experience that led to their condition in a more relaxed and receptive way. Because of the promising results, MAPS is calling on the government to relax its rules on the testing and use of MDMA for medical applications.

Brain waves encode rules for behavior

One of the biggest puzzles in neuroscience is how our brains encode thoughts, such as perceptions and memories, at the cellular level. Some evidence suggests that ensembles of neurons represent each unique piece of information, but no one knows just what these ensembles look like, or how they form.

A new study from researchers at MIT and Boston University (BU) sheds light on how neural ensembles form thoughts and support the flexibility to change one’s mind. The research team, led by Earl Miller, the Picower Professor of Neuroscience at MIT, identified groups of neurons that encode specific behavioral rules by oscillating in synchrony with each other.

The results suggest that the nature of conscious thought may be rhythmic, according to the researchers, who published their findings in the Nov. 21 issue of Neuron.

“As we talk, thoughts float in and out of our heads. Those are all ensembles forming and then reconfiguring to something else. It’s been a mystery how the brain does this,” says Miller, who is also a member of MIT’s Picower Institute for Learning and Memory. “That’s the fundamental problem that we’re talking about — the very nature of thought itself.”

Fetuses yawn in the womb, according to new research

We know that unborn babies hiccup, swallow and stretch in the womb but new observational research concludes that they also yawn.

The 4D scans of 15 healthy fetuses, by Durham and Lancaster Universities, also suggest that yawning is a developmental process which could potentially give doctors another index of a fetus’ health.

While some researchers have suggested that fetuses yawn, others have disagreed and claim it is simple mouth opening.

But the new research clearly distinguished ‘yawning’ from ‘non-yawn mouth opening’ based on the duration of mouth opening. The researchers did this by using the 4D video footage to closely examine all events where a mouth stretch occurred in the fetus.

Using their newly developed criteria, the research team found that over half of the mouth openings observed in the study were classed as yawns.

The study was carried out on eight female and seven male foetuses from 24 to 36 weeks gestation. The researchers found that yawning declined from 28 weeks and that there was no significant difference between boys and girls in yawning frequency.

Although the function and importance of yawning is still unknown, the study findings suggest that yawning could be linked to fetal development, and as such could provide a further medical indication of the health of the unborn baby.

Researchers find decline in availability and use of key treatment for depression

Electroconvulsive therapy (ECT) is considered the most effective treatment option for patients with severe depression who cannot find symptom relief through antidepressant medications or psychotherapy. In a new study, researchers at Butler Hospital and Bradley Hospital in Rhode Island found a sharp decline in the availability and use of ECT in general hospitals across the U.S. The findings were published online in the journal Biological Psychiatry on October 10, 2012.

The researchers analyzed data from a nationally representative survey of US general hospitals, the Nationwide Inpatient Sample (NIS), conducted annually by the Agency for Healthcare Research and Quality (AHRQ). They took information from between five and eight million patient discharge records at 1,000 hospitals nationwide between the years 1993 through 2009 and found that the annual number of hospital stays in which ECT was administered fell 43 percent over the 17 year period, from more than 1.2 million to 720,000. Researchers also found a dramatic decline in the percentage of hospitals conducting ECT, from 55 percent to 35 percent of facilities with a psychiatric unit. The percentage of inpatients with severe, recurrent major depression treated in hospitals conducting ECT fell from 71 to 45 percent. But for depressed patients treated in hospitals that conduct ECT, the proportion who received the procedure remained stable.

"The data strongly support the impression that psychiatric units in general hospitals are discontinuing use of ECT and that this is driving the decline in the number of severely depressed inpatients receiving the procedure," said Brady Case, MD, an assistant professor of psychiatry and human behavior at Brown University and director of the Health Services Research Program at Bradley Hospital. "Growing pressures to avoid the inpatient treatment costs and length of stay associated with ECT may be one factor associated with this trend. We didn’t have information on provider and patient attitudes, but as facilities cease conducting ECT, we can expect that fewer clinicians and inpatients are exposed to the option, reinforcing the turn away from ECT." Researchers also note the FDA approval of new treatment alternatives, like vagus nerve stimulation and transcranial magnetic stimulation, as possible influences.

Discovery offers new treatment for epilepsy

New drugs derived from components of a specific diet used by children with severe, drug-resistant epilepsy could offer a new treatment, according to research published today in the journal Neuropharmacology.

Scientists from Royal Holloway, in collaboration with University College London, have identified specific fatty acids that have potent antiepileptic effects, which could help control seizures in children and adults.

The discovery could lead to the replacement of the ketogenic diet, which is often prescribed for children with severe drug-resistant epilepsy. The high fat, low carbohydrate diet is thought to mimic aspects of starvation by forcing the body to burn fats rather than carbohydrates. Although often effective, the diet has attracted criticism, as side effects can be significant and potentially lead to constipation, hypoglycaemia, retarded growth and bone fractures.

By pinpointing fatty acids in the ketogenic diet that are effective in controlling epilepsy, researchers hope that they can develop a pill for children and adults that could provide similar epilepsy control, but lacks the side effects of the diet.

Professor Robin Williams from the Centre of Biomedical Sciences at Royal Holloway said: “This is an important breakthrough. The family of medium chain fatty acids that we have identified provide an exciting new field of research with the potential of identifying, stronger, and safer epilepsy treatments.”

The study tested a range of fatty acids found in the ketogenic diet against an established epilepsy treatment. Researchers found that not only did some of the fatty acids outperform the drug in controlling seizures, they also had fewer side effects.

(Source: alphagalileo.org)