Average person can keep 3-4 things in working memory

Study could help with ADD and other attention difficulties

A mind is a terrible thing to waste, but humans may have even less to work with than previously thought. University of Missouri researchers found that the average person can keep just three or four things in their “working memory” or conscious mind at one time. This finding may lead to better ways to assess and help people with attention-deficit and focus difficulties, improve classroom performance and enhance test scores.

“Most people believe the human mind is incredibly complex,” said Jeff Rouder, associate professor of psychology in the MU College of Arts and Science. “We were able to use a relatively simple experiment and look at how many objects can be in maintained in the human conscious mind at any one time. We found that every person has the capacity to hold a certain number of objects in his or her mind. Working memory is like the number of memory registers in a computer. Every object takes one register and each individual has a fixed number of registers. Limits in working memory are important because working memory is the mental process of holding information in a short-term, readily accessible, easily manipulated form where it can be combined, rearranged and stored more productively.”

“We know that this kind of memory is really important in daily life,” said co-author Nelson Cowan, psychology professor at Mizzou and an expert in working memory theory. “If a person is trying to do a math problem, there are partial results to keep in mind as that person solves the problem. When people are going to do any tasks in the house–like remembering the location of keys, turning off the stove, combining ingredients for a cake or recalling a phone number–they use working memory to keep in mind all the different aspects of the tasks.”

Rouder said that to remember a series of items, people will use “chunking,” or grouping, to put together different items. It can be difficult for someone to remember nine random letters. But if that same person is asked to remember nine letters organized in acronyms, IBM-CIA-FBI, for example, the person only has to use three slots in working memory. The difficulty in measuring working memory capacity is assuring that each item presented cannot be grouped together with others to form a larger chunk.

The researchers conducted a simple experiment involving an array of small, scattered, different-colored squares, to test their theory of working memory. The participant saw two, five or eight squares in the array, depending on the trial. The array was then “wiped out” by another display consisting of the same squares, minus the colors. Finally, the participant was shown a single color in one location and was asked to indicate whether the color in that spot had changed from the original array.

“How an individual does this test depends on working memory,” Cowan said. “The results indicating that people have a fixed capacity provide evidence of simplicity in the mind. Many other theorists have suggested that the amount of working memory is circumstance-dependent, depends on a particular test, that there is nothing general we can get out of it, and that it’s complex. We found the mind to be less complex in this case and that should be of great use in the future.”

Working memory is closely related to attention because it requires attention to hold a number of items in mind at once. People with high working memory capacity have more focus. Those with a lower attention span are more easily distracted. This fact may help researchers help people with attention deficit disorders.

The researchers emphasized that the unique result of their study was that “the data were explained to surprising accuracy by a very simple mental model in which participants either used a register of working memory or, if all registers were full, guessed randomly.”

Improving Mental Health Services For Prison Inmates

The House Judiciary Committee on Wednesday by voice vote approved a bill (HR 3992) sponsored by Rep. Robert Scott (D-Va.) that seeks to improve services for prison inmates with mental illnesses, CQ Today reports. The legislation would reauthorize a grant program that provides treatment for inmates with mental illnesses and training for law enforcement officers who handle such inmates.

The bill would authorize $75 million annually for the program from fiscal year 2008 to FY 2013, compared with $50 million annually from FY 2006 to FY 2009. In addition, the bill also would authorize an additional $35 million annually from FY 2008 to FY 2013 for new grant programs that focus on treatment for female inmates with mental illnesses; tests, identification and assessment of inmates with mental illnesses; and improved coordination of treatment and services for such inmates after their release.

The legislation also would require the attorney general to report on the rate of serious mental illness and homelessness among individuals in custody (Webber, CQ Today, 11/7).

Reprinted with permission from kaisernetwork. org. You can view the entire Kaiser Weekly Health Disparities Report, search the archives. The Kaiser Weekly Health Disparities Report is published for kaisernetwork. org, a free service of The Henry J. Kaiser Family Foundation. 2007 Advisory Board Company and Kaiser Family Foundation. All rights reserved.

People With Learning Disabilities Underdiagnosed, Poorly Managed

The NHS is failing people with learning difficulties, according to an editorial published in the BMJ today.

The authors say the health needs of this group of patients often go unmet because mental or physical illness is incorrectly attributed to the person’s intellectual disability.

According to the authors, doctors are less likely to diagnose psychiatric problems among this group of people, even though in reality they are more likely to suffer from mental illness. They are also more likely to develop chronic disorders such as epilepsy or cerebral palsy.

They point to two significant reports from the Disability Rights Commission (DRC) and MENCAP which both highlighted widespread inequalities encountered by people with learning disabilities and/or mental illness.

They say these reports raise issues about the low priority given to the health needs of this group, the lack of appropriate training given to medical staff, the disregard for the views of carers and the misconceptions among many doctors about the value of the lives of people with learning disabilities.

Hope for improvements in treatment lies with the recently implemented Mental Capacity Act. They argue it should improve the care of vulnerable patients as it sets out a process for ensuring that medical decisions are no longer made in isolation and are made in the ‘best interests’ of the patient.

They call for improved communication and liaison between GPs, hospital doctors and intellectual disability services, and joint working between the medical bodies. They conclude: "This may help to reduce morbidity and mortality and improve quality of life."

Feeding Tubes Help/Harm In Advanced Dementia

Family members grappling with the decision to allow a feeding tube for a relative with advanced dementia will find little comfort from a new review of evidence.

Poor food intake is common in individuals with dementia for a variety of reasons. In advanced dementia, health care providers might intervene by feeding patients artificially, usually by inserting a feeding tube through the stomach. This decision is emotional, controversial and influenced by complex ethical issues.

But do feeding tubes actually help people with degenerative dementia? In a new Cochrane review from London, doctors searched for evidence that this intervention was beneficial.

“We found that there is no research evidence that tube feeding prolongs survival or improves the quality of life for people with advanced dementia,” said lead author Elizabeth Sampson, M.D. “In fact, some studies suggest that tube feeding may have an effect opposite to the desired and actually increase mortality, morbidity and reduce quality of life.”

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

At first glance, it appears counterintuitive that individuals fail to benefit from tube feeding, but the way that the body utilizes food is complex, Sampson said. With some forms of dementia, the body might be unable to metabolize food properly.

Especially worrisome for families is the pain typically associated with prolonged hunger and thirst.

“In a study with patients terminally ill with advanced cancer and unable to eat, however, few experienced painful feelings of hunger and thirst,” Sampson said. “If they did, this pain was alleviated by simple measures, such as pain relief or small sips of water. Compassionate nursing and medical care — similar to that which underlies the philosophy of the hospice movement — can alleviate a great deal of suffering and should be available to people with dementia, too.”

Sampson and colleagues are at the Marie Curie Palliative Care Research Unit, Royal Free and University College Medical School.

This research encompassed a review of 452 studies in seven health care databases, five from the United States. Overall, the studies included 1821 people, 409 of whom received some form of tube feeding and 1467 who did not. The researchers found no randomized controlled studies, considered the gold standard of studies.

“Just because we found insufficient evidence of benefit does not mean that for some individuals with advanced dementia, tube feeding is the wrong decision,” Sampson said. “Each case needs to be considered individually. We would hope that family members will feel better informed about the pros and cons of tube feeding in persons with advanced dementia because of this paper.”

Artificially feeding individuals with dementia is a relatively new phenomenon that evolved after development of the percutaneous endoscopic gastrostomy tube, or feeding PEG, in the early 1980s, said Stephen Post, Ph.D., a professor of preventive medicine at Stony Brook University. Their intent was to nourish seriously ill children until they got well, but by 1985, PEGs became widely used as a cost-saving measure in nursing homes, which lacked sufficient staff to do assisted oral feedings.

“As Dr. Sampson found, there is no evidence that the feeding tube benefits patients with advanced dementia,” Post said. “Indeed, as she details in this paper, there are all sorts of considerations for not using feeding PEGs. The most serious reason, perhaps, is physical restraint, which is terrible. One study shows, in fact, that 71 percent of persons with advanced dementia, who receive feeding tubes, are physically restrained.”

It is important to realize, he adds, that the gastrointestinal system of patients close to death often shuts down and a feeding tube can cause considerable suffering.

The choice is not either a feeding PEG or nothing, said Post, who is also president of the Institute for Research on Unlimited Love, and the author of a book on moral issues in Alzheimer’s disease. He said there is a third option that people have been using since the beginning of time: assisted oral feeding.

“My grandmother had Alzheimer’s disease in the 1970s and I regularly helped feed her soft foods like applesauce and gave her something to drink.”

Post said the most important thing a loved one can do is to routinely stop by the nursing home on the way to or from work, and spend a half an hour doing assisted oral feeding. There is also an emotional connectedness that goes on, he believes, and countless benefits of giving for the giver.

“The most humane thing is assisted oral feeding,” he said. “There is almost a sacred quality to it in my mind.”

The memories you want to forget are the hardest ones to lose

Painful, emotional memories that people would most like to forget may be the toughest to leave behind, especially when memories are created through visual cues, according to a new study by the University of North Carolina at Chapel Hill.

"When you are watching the news on television and see footage of wounded soldiers in Iraq or ongoing coverage of national tragedies, it may stick with you more than a newspaper headline," said the study’s lead author, Keith Payne, an assistant professor of psychology in the College of Arts and Sciences.

It is adaptive to be able to intentionally forget neutral events such as wrong directions, a friend’s outdated phone number or a switched meeting time. Intentional forgetting helps update memory with new information, Payne said.

But Payne and former psychology graduate student Elizabeth Corrigan found that even "mild" emotional events, like getting a bad grade on a test or a negative comment from a coworker, can be hard to forget. Their study, "Emotional constraints on intentional forgetting," appears in the September 2007 print issue of the Journal of Experimental Social Psychology.

When people are trying to intentionally forget information, they need to mentally segregate that information and then block off the information they don’t want to retrieve, Payne said.

Emotion undermines both of those steps. "You make a lot of connections between emotional events and other parts of your life, so it might be difficult to isolate them. As far as blocking retrieval of an unwanted event, emotion makes events very salient and therefore highly accessible," Payne said.

Their results contrast with previous studies of emotional events and intentional forgetting, but those studies used emotion-laden words as stimuli, like "death" and "sex." The UNC study took a new approach, asking 218 participants to react to photographs instead of text.

"The word ‘murder,’ for instance, may or may not make you afraid, but if you see a graphic, violent picture, it may be powerful enough emotionally to change the way you feel," Payne said.

The researchers found that their subjects could not intentionally forget emotional events as easily as mundane ones. They also found that both pleasant and unpleasant emotional memories were resistant to intentional forgetting.

The UNC findings contribute to understanding the ways that emotion constrains mental control and to the question of whether intentional forgetting can be helpful in coping with painful or traumatic experiences.

"Our findings add to accumulating evidence that emotion places limits on the ability to control the contents of the mind," Payne said. "Our results suggest that even a relatively mild emotional reaction can undermine intentional forgetting. But this doesn’t necessarily mean that emotional memories can never be intentionally forgotten. If the motivation to forget is powerful enough, individuals might be able to overcome the effects of emotion by enlisting additional coping strategies."

A different study would be needed to examine what treatment and coping strategies might be effective in helping people voluntarily forget an unwanted memory, he added.

Hello world!

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!