JUDGEMENT DECISIONS MORE THAN MEETS THE EYE

People make immediate judgments about images they are shown, which could impact on their decisions, even before their brains have had time to consciously process the information, a study of brainwaves led by The University Of Melbourne has found.

Published in PLOS ONE, the study is the first in the world to show that it is possible to predict abstract judgments from brain waves, even though people were not conscious of making such judgments. The study also increases our understanding of impulsive behaviors and how to regulate it.

It found that researchers could predict from participants' brain activity how exciting they found a particular image to be, and whether a particular image made them think more about the future or the present. This is true even though the brain activity was recorded before participants knew they were going to be asked to make these judgments.

Lead authors Dr Stefan Bode from the Melbourne School of Psychological Sciences and Dr Carsten Murawski from the University of Melbourne Department of Finance said these findings illustrated there was more information encoded in brain activity than previously assumed.

"We have found that brain activity when looking at images can encode judgments such as time reference, even when the viewer is not aware of making such judgments. Moreover, our results suggest that certain images can prompt a person to think about the present or the future," they said.

The authors said the results contributed to our understanding of impulsive behaviors, especially where those behaviors were caused by 'prompts' in the world around us.

"For instance, consider someone trying to quit gambling who sees a gambling advertisement on TV. Our results suggest that even if this person is trying to ignore the ad, their brain may be unconsciously processing it and making it more likely that they will relapse," he said.

The researchers used electroencephalography technology (EEG) to measure the electrical activity of people's brains while they looked at different pictures. The pictures displayed images of food, social scenes or status symbols like cars and money.

After the EEG, researchers showed participants the same pictures again and asked questions about each image, such as how exciting they thought the image was or how strongly the image made them think of either the present or the future.

A statistical 'decoding' technique was then used to predict the judgments participants made about each of the pictures from the EEG brain activity that was recorded.

Co-author Daniel Bennett said just as certain prompts might cause impulsive behavior, images could be used to prompt people to be more patient by regulating impulse control.

"Our results suggest that prompting people with images related to the future might cause processing outside awareness that could make it easier to think about the future. In theory, this could make people less impulsive and more likely to make healthy long-term decisions. These are hypotheses we will try to test in the future," he said. The research was done in collaboration with the University of Cologne, Germany.

A GLIMPOSE IN TO THE 3 D BRAIN HOW MEMORIES FORM

People who wish to know how memory works are forced to take a glimpse into the brain. They can now do so without bloodshed: RUB researchers have developed a new method for creating 3D models of memory-relevant brain structures. They published their results in the journalFrontiers in Neuroanatomy.

The way neurons are interconnected in the brain is very complicated. This holds especially true for the cells of the hippocampus. It is one of the oldest brain regions and its form resembles a see horse (hippocampus in Latin). The hippocampus enables us to navigate space securely and to form personal memories. So far, the anatomic knowledge of the networks inside the hippocampus and its connection to the rest of the brain has left scientists guessing which information arrived where and when.

Signals spread through the brain

Accordingly, Dr Martin Pyka and his colleagues from the Mercator Research Group have developed a method which facilitates the reconstruction of the brain's anatomic data as a 3D model on the computer. This approach is quite unique, because it enables automatic calculation of the neural interconnection on the basis of their position inside the space and their projection directions. Biologically feasible network structures can thus be generated more easily than it used to be the case with the method available to date.

Deploying 3D models, the researchers use this technique to monitor the way neural signals spread throughout the network time-wise. They have, for example, found evidence that the hippocampus' form and size could explain why neurons in those networks fire in certain frequencies.

Information become memories

In future, this method may help us understand how animals, for example, combine various information to form memories within the hippocampus, in order to memorise food sources or dangers and to remember them in certain situations.

STOMACH IS THE WAY TO A WOMANS HEART

You've heard that romance starts in the kitchen and not in the bedroom. Well, researchers at Drexel University finally have the science to support that saying -- but not the way you might think.

In a new study published online in the journal Appetite, researchers found that women's brains respond more to romantic cues on a full stomach than an empty one. The study explored brain circuitry in hungry versus satiated states among women who were past-dieters and those who had never dieted.

The study's first author Alice Ely, PhD, completed the research while pursuing a doctoral degree at Drexel, and is now a postdoctoral research fellow at the Eating Disorders Center for Treatment and Research, part of the UC San Diego School of Medicine. Michael R. Lowe, PhD, a professor in the College of Arts and Sciences at Drexel University, was senior author.

"We found that young women both with and without a history of dieting had greater brain activation in response to romantic pictures in reward-related neural regions after having eaten than when hungry," said Ely.

Ely said the results are contrary to several previous studies, which showed that people typically demonstrate greater sensitivity to rewarding stimuli when hungry. Such stimuli may include things like food, money and drugs.

"In this case, they were more responsive when fed," she said. "This data suggests that eating may prime or sensitize young women to rewards beyond food. It also supports a shared neurocircuitry for food and sex."

The latest finding, based on a small pilot study, grew from Ely and her Drexel colleagues' earlier work investigating how the brain changes in response to food cues. Specifically, the researchers looked at whether the brain's reward response to food differed significantly in women at risk for future obesity (historical dieters) versus those who had never dieted. All of the study participants were young, college-age women of normal weight.

In that study, published in Obesity in 2014, the researchers found that the brains of women with a history of dieting responded more dramatically to positive food cues when fed as compared to women who had never dieted or who were currently dieting.

"In the fed state, historical dieters had a greater reaction in the reward regions than the other two groups to highly palatable food cues versus neutral or moderately palatable cues," she said. Highly palatable cues included foods like chocolate cake; neutral cues were things like carrots.

Ely said the data suggests historical dieters, who longitudinal studies have shown are more at risk for weight gain, may be predisposed by their brain reward circuitry to desire food more than people who have not dieted.

"Based on this study, we hypothesized that historical dieters are differentially sensitive -- after eating -- to rewards in general, so we tested this perception by comparing the same groups' brain activation when viewing romantic pictures compared to neutral stimuli in a fasted and fed state," she said. Testing was done using MRI imaging.

While both groups' reward centers responded more to romantic cues when fed, the historical dieters' neural activity noticeably differed from the non-dieters in one brain region that had also turned up in the earlier food studies.

"The pattern of response was similar to historical dieter's activation when viewing highly palatable food cues, and is consistent with research showing overlapping brain-based responses to sex, drugs and food," said Ely.