PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Heads or tails? Random fluctuations in brain cell activity may determine toss-up decisions

2013-12-05
(Press-News.org) Contact information: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
Heads or tails? Random fluctuations in brain cell activity may determine toss-up decisions

Life presents us with choices all the time: salad or pizza for lunch? Tea or coffee afterward? How we make these everyday decisions has been a topic of great interest to economists, who have devised theories about how we assign values to our options and use those values to make decisions.

An emerging field of study known as neuroeconomics is combining the economists' insights with scientific study of the brain to learn more about decision-making processes and how they can go awry. In the Dec. 8 issue of Neuron, one of the field's founders reports new links between brain cell activity and choices where two options have equal appeal.

"Neuroeconomics is not only helpful for the development of better economic theory, it is also relevant from a clinical point of view," said author Camillo Padoa-Schioppa, PhD, assistant professor of neurobiology, economics and of biomedical engineering at Washington University School of Medicine in St. Louis. "There are a number of conditions that involve impaired economic decision-making, including drug addiction, brain injury, some forms of dementia, schizophrenia and obsessive-compulsive disorder."

Scientists know that the orbitofrontal cortex, a region of the brain behind and above the eyes, plays a key role in making decisions. Patients with injuries to this part of the brain are often spectacularly bad at making decisions. They may do things like abandon longstanding relationships, gamble away money or lose it to swindlers, or become addicted to drugs.

To study the roles brain cells play in decision-making, Padoa-Schioppa developed a system for presenting primates a choice between two drinks, such as grape juice or apple juice. The type and amount of the drink varies, and researchers record the activity of individual brain neurons as the primates choose.

Based on the decisions of a single animal over multiple trials, scientists infer the subjective value the animal assigns to each drink and then look for ways this value is encoded in brain cells.

"For example, if we offer a larger amount of apple juice versus a smaller amount of grape juice, and the primate chooses each option equally often, we infer that this primate likes the grape juice better than the apple juice," he explained. "The primate could be getting more juice by choosing the cup with apple juice, but it doesn't always do so. That implies that the primate values grape juice more than apple juice."

In 2006, Padoa-Schioppa and Harvard colleague John Assad, PhD, won international attention for using this system to identify brain cells whose firing rates encoded the subjective value of drink choices.

In a new analysis of data from the original experiment, Padoa-Schioppa showed that different groups of cells in the orbitofrontal cortex reflect different stages of the decision-making process.

"Some neurons encode the value of individual drinks; other neurons encode the choice outcome in a binary way ‒ these cells are either firing or silent depending on the chosen drink," he explained. "Yet other neurons encode the value of the chosen option."

Padoa-Schioppa then examined how different groups of cells determine decisions between options of equal value. He showed that toss-up decisions seemed to depend on changes in the initial state of the network of neurons in the orbitofrontal cortex.

"The fluctuations in the network took place before the primates were even offered a choice of juices, but they seem to somehow bias the decision," Padoa-Schioppa said. "Neuronal signals are always noisy. In essence, close-call decisions are partly determined by random noise."

He also found that decisions on choices of equal value were linked to the ease or difficulty with which nerve cells in parts of the orbitofrontal cortex communicate with each other. This property, known as synaptic efficacy, can be adjusted by the brain as part of the process of encoding information.

According to Padoa-Schioppa, these results provide new insights into the neuronal circuits that underlie economic decisions. He and his colleagues are using them to create a computational model of decision-making.

"The next step is to test that model," Padoa-Schioppa said. "For example, we would like to bias decisions by artificially manipulating the activity of specific groups of cells."



INFORMATION:

Funding from the National Institute on Mental Health (R03-MH093330) and the National Institute on Drug Addiction (R01-DA032758) supported this research.

Padoa-Schioppa C. Neuronal origins of choice variability in economic decisions. Neuron, December 8, 2013.

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.



ELSE PRESS RELEASES FROM THIS DATE:

An ecosystem-based approach to protect the deep sea from mining

2013-12-05
An ecosystem-based approach to protect the deep sea from mining Five hundred miles southeast of Hawai'i, in international waters far out of sight of any land, there are vast mineral resources 5,000 meters below the sea. Manganese nodules, rich in commercially ...

New insights into how human skin attracts mosquitoes could lead to better repellants and traps

2013-12-05
New insights into how human skin attracts mosquitoes could lead to better repellants and traps Every time a mosquito is lured to the scent of your skin, you're at risk of contracting malaria, dengue fever, West Nile virus, or another deadly disease. A study published by ...

Gut bacteria linked to autism-related behavior in mice

2013-12-05
Gut bacteria linked to autism-related behavior in mice Mice whose mothers suffered from infection or inflammation during pregnancy are at greater risk for developing behaviors similar to those seen in people with autism spectrum disorders (ASD). Now, researchers reporting in ...

Those fruit flies are pickier than you think

2013-12-05
Those fruit flies are pickier than you think On your kitchen counter, it might seem as though fruit flies will show up for just about any type of fruit you leave around for them. But when given a choice about where to lay their eggs, those flies will go for citrus most ...

Scientists accelerate aging in stem cells to study age-related diseases like Parkinson's

2013-12-05
Scientists accelerate aging in stem cells to study age-related diseases like Parkinson's Stem cells hold promise for understanding and treating neurodegenerative diseases, but so far they have failed to accurately model disorders that occur late in life. A study published by ...

Electrical brain stimulation may evoke a person's 'will to persevere'

2013-12-05
Electrical brain stimulation may evoke a person's 'will to persevere' VIDEO: What gives some people the ability to persevere through difficult situations that others may find ...

Tracking exercise as vital sign associated with weight loss and better glucose control for patients

2013-12-05
Tracking exercise as vital sign associated with weight loss and better glucose control for patients Asking patients about their exercise habits was associated with weight loss in overweight patients and improved glucose control for patients with diabetes, according ...

How mosquitoes are drawn to human skin and breath

2013-12-05
How mosquitoes are drawn to human skin and breath UC Riverside researchers identify affordable, safe and pleasant-smelling compounds that can help control spread of mosquito-borne diseases RIVERSIDE, Calif. — Female mosquitoes, which can transmit deadly ...

New finding shows that mother sharks 'home' to their birthplace to give birth, like salmon and sea turtles

2013-12-05
New finding shows that mother sharks 'home' to their birthplace to give birth, like salmon and sea turtles Research suggests local shark conservation efforts by individual nations can have an impact Research conducted in Bimini in The ...

Laser light at useful wavelengths from semiconductor nanowires

2013-12-05
Laser light at useful wavelengths from semiconductor nanowires Nanowire lasers could work with silicon chips, optical fibers, even living cells Thread-like semiconductor structures called nanowires, so thin that they are effectively one-dimensional, ...

LAST 30 PRESS RELEASES:

Different types of depression linked to different cardiometabolic diseases

Ketogenic diet may protect against stress experienced in the womb

Adults 65 years and older not immune to the opioid epidemic, new study finds

Artificial intelligence emerging as powerful patient safety tool in pediatric anesthesia

Mother’s ZIP code, lack of access to prenatal care can negatively impact baby’s health at birth, new studies show

American Society of Anesthesiologists honors John M. Zerwas, M.D., FASA, with Distinguished Service Award

A centimeter-scale quadruped piezoelectric robot with high integration and strong robustness

Study confirms that people with ADHD can be more creative. The reason may be that they let their mind wander

Research gives insight into effect of neurodegenerative diseases on speech rhythm

Biochar and plants join forces to clean up polluted soils and boost ecosystem recovery

Salk scientist Joseph Ecker awarded McClintock Prize for Plant Genetics and Genome Studies

ADHD: Women are diagnosed five years later than men, despite symptoms appearing at the same age.

Power plants may emit more pollution during government shutdowns

Increasing pressures for conformity de-skilling and demotivating teachers, study warns

Researchers develop smarter menstrual product with potential for wearable health monitoring

Microwaves for energy-efficient chemical reactions

MXene current collectors could reduce size, improve recyclability of Li-ion batteries

Living near toxic sites linked to aggressive breast cancer

New discovery could open door to male birth control

Wirth elected Fellow of American Physical Society

The Journal of Nuclear Medicine Ahead-of-Print Tip Sheet: October 10, 2025

Destined to melt

Attitudes, not income, drive energy savings at home

The playbook for perfect polaritons

‘Disease in a dish’ study of progressive MS finds critical role for unusual type of brain cell

Solar-powered method lights the way to a ‘de-fossilized’ chemical industry

Screen time linked to lower academic achievement among Ontario elementary students

One-year outcomes after traumatic brain injury and early extracranial surgery in the TRACK-TBI Study

Enduring outcomes of COVID-19 work absences on the US labor market

Affirmative action repeal and racial and ethnic diversity in us medical school admissions

[Press-News.org] Heads or tails? Random fluctuations in brain cell activity may determine toss-up decisions