Sensitive Persons Perception Moderates Responses-a Brain Study

General University News
--------------------------------------------------------------------------------
Press Release

Contact: · 631.632.6310 · FAX: 631.632.6313
Stony Brook University, · 310 Admin · Stony Brook, NY 11794-0701


SBU Brain Study: Sensitive Persons’ Perception Moderates Responses Based On Culture
Reported in Social Cognitive and Affective Neuroscience, the Study Links Traits to Thinking

May 3, 2010 - 10:22:39 AM


STONY BROOK, N.Y., May 3, 2010 – Building on previous brain imaging research that revealed cultural influences play a role in neural activation during perception, Arthur Aron, Ph.D., Professor of Psychology at Stony Brook University, and colleagues, completed a study that suggests individuals who are highly sensitive have cognitive responses that appear to not be influenced by culture at all. Reported in advance online in Social Cognitive and Affective Neuroscience, and scheduled for print in the June issue, the study could serve as a foundation for the direction of study in the emerging field of cultural neuroscience.


A composite brain of the selected study participants shows areas of brain activation during tasks that required effortful perception.
“Our data suggest that some categories of individuals, based on their natural traits, are less influenced by their cultural context than others,” says Dr. Aron. He adds that the study is the first to analyze how a basic temperament/personality trait, called sensory processing sensitivity (SPS), interacts with culture and neural responses.

SPS is characterized by sensitivity to both internal and external stimuli, including social and emotional cues. Scientists estimate that something like high sensitivity is found in approximately 20 percent of more than 100 species, from fruit flies and fish to canines and primates and has evolved as a particular survival strategy that differs from the majority. The standard measure in humans is the Highly Sensitive Person (HSP) Scale, previously developed by Dr. Aron and his wife, Dr. Elaine Aron. An example of one item on the HSP scale is “do you seem to be aware of subtleties in your environment.”

Dr. Aron says those who score high on the scale report being easily overwhelmed when too much is happening, startle easily, are conscientious, enjoy the arts more, and have a lower pain threshold. They are more emotionally reactive and more affected by the environment compared to those who score low on the scale.

The researchers measured SPS in 10 East Asian individuals temporarily in the U.S. and and 10 Americans of Western-European ancestry. In a previous study, these same 20 individuals had undergone brain functional magnetic resonance imaging (fMRI) while performing a cognitive task of comparing the length of lines inside boxes. The participants’ responses to the task tested their perception of the independence versus interdependence of objects as the fMRI measured the neural basis of their responses.

The major finding of that study was that the frontal-parietal brain region (see Figure) known to be engaged during attention-demanding tasks was more activated for East Asians when making judgments ignoring context, not their specialty, but was more activated for Americans when making judgments when they had to take context into account, not their specialty. This discovery, says Dr. Aron, illustrated that each group engaged this attention system more strongly during a task more difficult for them because it is not generally supported by their cultural context. That is, even when doing a simple, abstract cognitive task, culture influences perception.

In the SPS study, Dr. Aron and colleagues took the brain activations in these two groups from the previous study and considered them in light of the SPS scores of the same individuals. They found SPS as a trait yielded a very clear pattern of results:

“The influence of culture on effortful perception was especially strong for those who scored low on the scale measuring sensitivity, but for those who scored high on the measure (highly sensitive individuals), there was no cultural difference at all,” says Dr. Aron. Regarding the fMRI, Dr Aron adds: “Culture did not influence the degree of activation of highly sensitive individuals’ brains when doing the two kinds of perceptual tasks used in the previous study. Also, how much they identified with their culture had no effect. It was as if, for them, culture was not an influence on their perception.”

Dr. Aron emphasized that the new research suggests that characteristics possessed by high SPS individuals, such as being emotionally reactive or conscientious, actually flow out of or are side effects of the overriding feature of processing information more thoroughly than low SPS individuals.

While the results showed a clear, statistically significant connection between SPS, cognitive processing, and culturally-based thinking, Dr. Aron indicates that the small numbers of participants does not rule out the possibility that these results could be sample specific, so conclusions must be taken as preliminary and only as suggestive. Replications of the study and larger sample sizes, he adds, would help to further the research.

Co-authors of the study titled, “Temperament trait of sensory processing sensitivity moderates cultural differences in neural response,” include: Sarah Ketay, Ph.D., Mount Sinai School of Medicine; Trey Heddan, Ph.D., Massachusetts Institute of Technology (MIT); Elaine N. Aron, Ph.D., Stony Brook University; Hazel Rose Markus, Ph.D., Stanford University, and John D.E. Gabrieli, MIT.

The study was funded in part by the National Institutes of Health.

Stony Brook University 2009

15 years of brain research has been invalidated by a software bug, say Swedish scientists
Mary-Ann Russon

Scientists from Sweden and the UK have analysed the data produced by the three most common software packages for scanning the brain, and have found that the data is so unreliable – due to bugs in the software – that 15 years' worth of fMRI brain research could be invalidated.

fMRI stands for functional magnetic resonance imaging. It is a functional neuroimaging procedure that makes use of MRI technology to measure brain activity by detecting changes associated with cerebral blood flow – ie, when a specific area of the brain is being used, blood flow to that region will increase too.

Read more about software flaws on IBTimes UK:

Symantec security bugs: Users urged to update as critical flaws uncovered in 25 systems
US teen hacks Pentagon websites, gets thanked for finding bugs and offered internships
Google, Red Hat discover critical DNS security flaw that enables malware to infect entire internet

fMRI software works by dividing an image scan of the brain into tiny voxels (units of graphic information that define a specific point in three-dimensional space). The computer searches the voxels looking for clusters in order to map the blood flow in various regions of the brain.

Researchers from Linköping University in Sweden and the University of Warwick in the UK, led by neuroscientist Anders Eklund, gathered the fMRI brain activity data of 499 healthy people when their brains were in resting state from databases all over the world, and split the information into 20 groups.
70% chance of finding a false positive

The scientists then measured the data from all the groups against each other, which resulted in 3 million random comparison pairs, and then they tested the comparison pairs against the three most popular software packages that are used for fMRI analysis – namely SPM, FSL and AFNI.

The researchers expected that there would be about a 5% margin in difference between the fMRI software's analysis and the actual data, but they instead discovered that the three software packages were producing data with a 70% chance of finding at least one false positive.

A false positive is when a test result wrongly indicates that something is present when it is not, and the researchers discovered that this was caused by a software bug whereby an algorithm was reducing the size of the clusters being searched for, while also overestimating the clusters' significance.

This means that the fMRI software could have been producing data that showed brain activity in regions of the brain when in fact there was none, meaning that thousands upon thousands of fMRI studies could in fact have questionable results.
But the software bug only affects AFNI

"Functional MRI is 25 years old, yet surprisingly its most common statistical methods have not been validated using real data," the researchers wrote in their paper.

"In theory, we should find 5% false positives (for a significance threshold of 5%), but instead we found that the most common software packages for fMRI analysis (SPM, FSL, AFNI) can result in false positive rates of up to 70%. These results question the validity of some 40,000 fMRI studies and may have a large impact on the interpretation of neuroimaging results."

While this news is devastating for the global fMRI research community, Discover Magazine is sceptical about how serious the issue is, saying that although the bug is serious, it only affects the AFNI software package, but not the other two software packages.

Discover also points out that the researchers' findings only affect fMRI studies that affect activation mapping, but not all studies, and that even though there might be a 70% chance of the software finding at least one false positive in each analysis, this does not necessarily mean that 70% of all positive results are inherently false.

The paper, entitled Cluster failure: Why fMRI inferences for spatial extent have inflated false-positive rates, is published in the journal Proceedings of the National Academy of Sciences (PNAS).

M wrote:This is true of ALL MRI scans used in various studies of the brain.

RBM wrote:

M wrote:This is true of ALL MRI scans used in various studies of the brain.

While this will be a lot of work, I'll be looking for whether it actually makes significant differences to the data interpretations.