Four is the “magic” number

According to psychological lore, when it comes to items of information the mind can cope with before confusion sets in, the “magic” number is seven. But a new analysis by a leading Australian psychiatrist challenges this long-held view, suggesting the number might actually be four.

In 1956, American psychologist George Miller published a paper in the influential journal Psychological Review arguing the mind could cope with a maximum of only seven chunks of information. The paper, “The Magical Number Seven, Plus or Minus Two. Some Limits on Our Capacity for Processing Information”, has since become one of the most highly cited psychology articles and has been judged by the Psychological Review as its most influential paper of all time.

But UNSW professor of psychiatry Gordon Parker says a re-analysis of the experiments used by Miller shows he missed the correct number by a wide mark. Writing in the journal Acta Psychiatrica Scandinavica, Scientia Professor Parker says a closer look at the evidence shows the human mind copes with a maximum of four ‘chunks’ of information, not seven.

“So to remember a seven numeral phone number, say 6458937, we need to break it into four chunks: 64. 58. 93. 7.   Basically four is the limit to our perception.

“That’s a big difference for a paper that is one of the most highly referenced psychology articles ever – nearly a 100 percent discrepancy,” he suggests.

Professor Parker says the success of the original paper lies “more in its multilayered title and Miller’s evocative use of the word ‘magic’,” than in the science.

Professor Parker says 50 years after Miller there is still uncertainty about the nature of the brain’s storage capacity limits: “There may be no limit in storage capacity per se but only a limit to the duration in which items can remain active in short-term memory”. “Regardless, the consensus now is that humans can best store only four chunks in short-term memory tasks,” he says.

Moral evaluations of harm are instant and emotional

People are able to detect, within a split second, if a hurtful action they are witnessing is intentional or accidental, new research on the brain at the University of Chicago shows.

The study is the first to explain how the brain is hard-wired to recognize when another person is being intentionally harmed. It also provides new insights into how such recognition is connected with emotion and morality, said lead author Jean Decety, the Irving B. Harris Professor of Psychology and Psychiatry at UChicago.

“Our data strongly support the notion that determining intentionality is the first step in moral computations,” said Decety, who conducted research on the topic with Stephanie Cacioppo, a research associate (assistant professor) in psychology at UChicago. They published the results in a paper, “The Speed of Morality: A High-Density Electrical Neurological Study,” to be published Dec. 1 and now on early preview in the Journal of Neurophysiology.

The researchers studied adults who watched videos of people who suffered accidental harm (such as being hit with a golf club) and intentional harm (such as being struck with a baseball bat). While watching the videos, brain activity was collected with equipment that accurately maps responses in different regions of the brain and importantly, the timing between these regions. The technique is known as high-density, event-related potentials technology.

The intentional harm sequence produced a response in the brain almost instantly. The study showed that within 60 milliseconds, the right posterior superior temporal sulcus (also known as TPJ area), located in the back of the brain, was first activated, with different activity depending on whether the harm was intentional or accidental. It was followed in quick succession by the amygdala, often linked with emotion, and the ventromedial prefrontal cortex (180 milliseconds), the portion of the brain that plays a critical role in moral decision-making.

There was no such response in the amygdala and ventromedial prefrontal cortex when the harm was accidental.

New Studies Show Moral Judgments Quicker, More Extreme than Practical Ones—But Also Flexible

Judgments we make with a moral underpinning are made more quickly and are more extreme than those same judgments based on practical considerations, a new set of studies finds. However, the findings, which appear in the journal PLOS ONE, also show that judgments based on morality can be readily shifted and made with other considerations in mind.

“Little work has been done on how attaching morality to a particular judgment or decision may affect that outcome,” explains Jay Van Bavel, an assistant professor in New York University’s Department of Psychology and one of the study’s co-authors. “Our findings show that we make and see decisions quite differently if they are made with a morality frame. But, despite these differences, there is now evidence that we can shift judgments so they are based on practical, rather than moral, considerations—and vice versa.”

“Our findings suggest that deciding to frame any issue as moral or not may have important consequences,” said co-author Ingrid Haas, an assistant professor of political science at the University of Nebraska-Lincoln. “Once an issue is declared moral, people’s judgments about that issue become more extreme, and they are more likely to apply those judgments to others.”

“Ultimately, the way that people make decisions is likely to affect their behavior,” said co-author Dominic Packer, an assistant professor at Lehigh University. ”People may act in ways that violate their moral values when they make decisions in terms of pragmatic concerns - dollars and cents - rather than in a moral frame. In ongoing research, we are examining factors that can trigger moral forms of decision making, so that people are more likely to behave in line with their values.”

Scientists identify depression and anxiety biomarker in youths

Scientists have discovered a cognitive biomarker – a biological indicator of a disease – for young adolescents who are at high risk of developing depression and anxiety. Their findings were published in the journal PLOS ONE.

The test for the unique cognitive biomarker, which can be done on a computer, could be used as an inexpensive tool to screen adolescents for common emotional mental illnesses.  As the cognitive biomarker may appear prior to the symptoms of depression and anxiety, early intervention (which has proven to be one of the most effective ways of combatting mental illness) could then be initiated.

For the study, 15-18 year old participants underwent genetic testing and environmental assessment, an exercise which would currently be too expensive and take too long to use as a widespread method of screening.  The adolescents were then given a computer test to gauge how they process emotional information. The test had the participants evaluate whether words were positive, negative or neutral (examples included ‘joyful’ for positive, ‘failure’ for negative, and ‘range’ for neutral).

Those adolescents with a variation of one gene (the short form of the serotonin transporter) as well as exposure to intermittent family arguments for longer than six months and violence between parents before the age of six were shown to have marked difficulty in evaluating the emotion within the words, indicating an inability to process emotional information. Previous research associated a maladjusted perception and response to emotions, as seen here, with a significantly increased risk of depression and anxiety.

Professor Ian Goodyer, Principal Investigator on the study from the University of Cambridge, said:  “Whether we succumb to anxiety and depression depends in part on our tendencies to think well or poorly of ourselves at troubled times. How it comes about that some people see the ‘glass half full’ and think positively whereas other see the ‘glass half empty’ and think negatively about themselves at times of stress is not known.

The evidence is that both our genes and our early childhood experiences contribute to such personal thinking styles. Before there are any clinical symptoms of depression or anxiety, this test reveals a deficient ability to efficiently and effectively perceive emotion processes in some teenagers – a biomarker for low resilience which may lead to mental illnesses.”

Risk of childhood obesity can be predicted at birth

A simple formula can predict at birth a baby’s likelihood of becoming obese in childhood, according to a study published in the open access journal PLOS ONE.

The formula, which is available as an online calculator, estimates the child’s obesity risk based on its birth weight, the body mass index of the parents, the number of people in the household, the mother’s professional status and whether she smoked during pregnancy.

The researchers behind the study hope their prediction method will be used to identify infants at high risk and help families take steps to prevent their children from putting on too much weight.

Trichuris suis ova (porcine whipworm eggs) as treatment for autism

Autism spectrum disorders are characterized by impairments in three core domains: social interaction, communication and restricted or repetitive behaviors. These impairments are frequently accompanied by disruptive behaviors, such as marked irritability, aggression, self-injury, impulsivity and temper tantrums. There is no treatment for the core symptoms, and only one class of medication — atypical antipsychotics — is approved by the U.S. Food and Drug Administration for treating these disruptive behaviors.

There is evidence for activation of pro-inflammatory processes and a positive family history of autoimmune illness in people with autism spectrum disorders. Therefore, a hygiene hypothesis has emerged for both autoimmune illness and autism, suggesting that in urban hygienic environments where there is a paucity of certain parasites that dampen immune activation, there is an increase in autoimmune processes.

People with autism have also been reported to improve when they have fevers. Given that fever is an immune-inflammatory response, Eric Hollander and his colleagues are investigating the use of immunomodulatory treatments such as Trichuris suis ova (TSO), or porcine whipworm eggs, for treating symptoms of autism. TSO has been shown to be effective in autoimmune disorders such as Crohn’s disease, ulcerative colitis and allergic rhinitis. A case series has also shown it to be effective in reducing symptoms of autism.

The researchers plan to complete a 28-week randomized crossover trial of TSO, including 12 weeks of TSO treatment, 12 weeks of placebo and a 4-week washout period. The investigators plan to compare the effects of TSO versus placebo on repetitive behaviors, aggression and irritability, and global functioning. They also plan to explore the relationship among clinical features, immune mechanisms and treatment response.

Work with immunomodulatory treatments such as TSO may be one way to test both the hygiene hypothesis as well as the fever hypothesis, and to develop alternative treatments for core and associated symptoms of autism spectrum disorders.

(Image credit: Wikimedia Commons)

In Alzheimer’s Disease, Maintaining Connection and ‘Saving Face’

I’ve decided that all older men with gray beards must look alike, because each week I am mistaken for someone else. But, if I were to shave my beard - which I have worn for over 40 years - I believe that my friends and colleagues would fail to recognize me. I would be a different person to them because of this small, physical change.

If such a small change affects the way people see me, then the larger mental changes that Alzheimer’s patients experience must truly and deeply change the way their loved ones see them. Dr. Daniel Potts, a neurologist at the University of Alabama, has begun studying the concept of “saving face” and preserving the “person” in people with dementia.

Dr. Potts’ father, Lester Potts, became an acclaimed watercolor artist after his Alzheimer’s diagnosis. He had lost his verbal abilities but could express his feelings through his art. This bolstered his retention of self-worth and dignity. His paintbrush let him bypass the part of his brain that Alzheimer’s blocked, and communicate in a new way.

But before we find out more about art and Alzheimer’s patients, let’s go back to the “face” part of saving face for just a moment.

Read more

(Source: The Atlantic)

Re-learning words lost to dementia

A simple word-training program has been found to restore key words in people with a type of dementia that attacks language and our memory for words.

This ability to relearn vocabulary indicates that even in brains affected by dementia, some recovery of function is possible.

The study, led by Ms Sharon Savage at NeuRA (Neuroscience Research Australia), utilised a simple computer training-program that paired images of household objects such as food, appliances, utensils, tools and clothing, with their names.

“People with this type of dementia lose semantic memory, the memory system we use to store and remember words and their meanings,” says Ms Savage.

“Even the simplest words around the house can be difficult to recall. For example, a person with this type of dementia usually knows what a kettle does, but they may not know what to call it and may not recognize the word ‘kettle’ when they hear it,” she says.

Ms Savage found that after just 3 weeks of training for 30–60 min each day, patients’ ability to recall the name of the items improved, even for patients with more advanced forms of the dementia.

“Semantic dementia is a younger-onset dementia and because sufferers lose everyday words life can be very frustrating for them and their families. By relearning some of these everyday words, day to day conversations around the house may become less frustrating, improving patient well-being,” Ms Savage concludes.

This paper is published in the journal Cortex.

Alcohol Drinking Behavior Reduced By Inhibiting Brain Protein in Rodents

Decreasing the level of a key brain protein led to significantly less drinking and alcohol-seeking behavior in rats and mice that had been trained to drink, according to a study by researchers at the Ernest Gallo Clinic and Research Center at UCSF.

The scientists identified the protein, known as H-Ras, as a promising target for development of new medications to treat alcohol abuse disorders in humans.

The study, which was published on Nov. 7 in the Journal of Neuroscience, was recommended as being of special significance in its field by the Faculty of 1000, an online service that identifies great peer-reviewed biomedical research.

The researchers, led by Gallo investigator Dorit Ron, PhD, first demonstrated that alcohol intake significantly increased H-Ras activity in the animals’ nucleus accumbens, a brain region that in both rodents and humans is part of the reward system that affects craving for alcohol and other addictive substances.

They then showed that suppressing H-Ras levels in the nucleus accumbens with a targeted virus reduced alcohol consumption among mice that had been trained to seek out and drink alcohol in an animal model of binge drinking.

The researchers then administered FTI-276, an experimental compound that has been shown to inhibit H-Ras production, to binge-drinking rats. They observed a significant reduction in alcohol consumption after the compound was given.

The scientists also found that H-Ras inhibition reduced alcohol-seeking behavior among rats that had been trained to receive a drink of alcohol when they pressed a lever. When alcohol was withheld, rats that had received FTI-276 discontinued pressing the lever significantly sooner than rats that did not receive the compound.

Importantly, the rodents’ consumption of water, sugar solution, saccharine solution and quinine was not reduced when H-Ras was inhibited, indicating that H-Ras activity is specific to alcohol.

Relief of Pain is a Reward

Scientists have learned a lot about pain, but this has not led to the discovery of many new medications to help the millions of people whose lives are affected by chronic pain.

In an effort to improve pain management, Frank Porreca, PhD, and his research group from the Department of Pharmacology at the University of Arizona College of Medicine – Tucson have been exploring new preclinical measures that may better reflect features of the human experience of pain and that can be used to find new therapies.

Relief of pain is rewarding, according to Dr. Porreca and his colleagues. They have demonstrated that treatments that relieve the unpleasant feeling of pain also activate reward circuits and reinforce behaviors that result in relief of pain. Their study, “Pain relief produces negative reinforcement through activation of mesolimbic reward/valuation circuitry,” is reported in the Nov. 26 Early Edition issue of the Proceedings of the National Academy of Sciences.

“Determining how we feel, including knowing if we are in pain, depends on a brain neural representation of information that is gathered by a multitude of sensors that monitor the body and its tissues for local temperature, blood flow, blood pressure, heart rate, pH, carbon dioxide level and other states,” says Dr. Porreca. “These ‘interoceptors’ constantly evaluate and report the state of the body to the brain, generating specific conscious sensations that tell us that we are hungry, thirsty or cold, or that something is wrong. Nociceptors are a special class of interoceptors that produce sensations of pain. They ‘sound the alarm’ to tell us that our tissues have been – or soon may be – damaged.”

Thirst, hunger, itch, cold, heat, pain and other states of imbalance are unpleasant feelings that demand a behavioral response to correct the problem, Dr. Porreca says. If you feel cold, you want to get warm; if you are thirsty, you want to drink; if you are in pain, you want relief.

What motivates an organism to respond to these feelings? Things that are essential to the life of an organism or the survival of the species, such as food or drink, are rewarding. Rewards activate neural circuits in the brain and produce pleasant and positive feelings that reinforce behaviors that increase our ability to survive, notes Dr. Porreca.

The UA researchers have demonstrated that treatments that relieve the unpleasant feeling of pain also result in activation of these same reward circuits and reinforce behaviors that result in relief of pain. The novel demonstration of pain relief as a reward provides an entirely new way to discover medicines for patients.

“The activation of the reward circuit by pain relief provides an output measure for assessment of the potential effectiveness of novel molecular targets,” Dr. Porreca explains. “The activation of these ancient and evolutionarily conserved circuits by pain relief can serve as a basis for translation of treatments that will likely be effective in humans.”