(Press-News.org) There are some bad memories -- whether of a crime or a painful life event -- that we'd rather not recall. New research shows that people can successfully inhibit some incriminating memories, reducing the memories' impact on automatic behaviors and resulting in brain activity similar to that seen in "innocent" participants.
The research is published in Psychological Science, a journal of the Association for Psychological Science.
"In real life, many individuals who take memory detection tests want to distort their results. Using a lab-based crime simulation, we examined whether people can indeed suppress guilty memories and avoid detection," explains lead researcher Xiaoqing Hu of the University of Texas at Austin. "Our study indicates that suppression can be effective in certain ways, helping us to limit unwanted memories' influence over our behavior."
This is a photo of a chair under a spotlight.Hu conducted the study when he was a Ph.D. student at Northwestern University with colleagues Zara M. Bergström of the University of Kent and Galen V. Bodenhausen and J. Peter Rosenfeld of Northwestern University.
The researchers recruited 78 undergraduate students and randomly assigned them to one of three groups. Two of the groups, both "guilty" groups, were instructed to find and steal a particular object from a faculty member's mailbox. The object was actually a ring, but the word "ring" was never mentioned in the instructions. This was to ensure that any evidence of ring-related memories would be the result of committing the actual crime and not from listening to the instructions.
A third group, the "innocent" group, was told to go to the same area and simply write their initials on a piece of poster board.
Some of the guilty students were then told that they shouldn't allow memory of stealing the ring come to mind at all during the following concealed-information test (CIT) -- that is, they were instructed to suppress the memory. The other guilty students and the innocent students were not given any suppression instructions.
The three groups completed a CIT, a brainwave-based test that can be used to evaluate whether an individual has specific knowledge suggesting involvement in a crime. On each trial, participants were presented with either the target item (e.g., the word "ring") or one of six crime-irrelevant items (e.g., "bracelet," "necklace," "watch," "cufflink," "locket," "wallet") while their brain activity was recorded using EEG. The researchers were specifically interested in looking at the P300, a brainwave that indicates conscious recollection.
The students also completed an autobiographical Implicit Association Test (aIAT) in which they had to indicate whether specific statements were true or false. Response times on the aIAT are thought to reflect the strength of a particular association -- the faster the response, the more strongly held that association is, regardless of the person's explicitly stated thoughts and feelings.
As expected, the researchers found that the guilty participants showed significantly larger P300 responses to the target than to the irrelevant stimuli -- but only if they hadn't been given instructions to suppress memories of the crime.
Those who suppressed crime-related memories showed no difference in P300 activity between the two types of stimuli, resulting in data that were indistinguishable from those of innocent participants.
In addition, suppressed-memory participants were also less likely than the other guilty participants to associate crime-related memories with the truth on the aIAT. However, the data suggested that guilty-suppressors could still be identified via another brainwave, known as the late posterior negativity.
Together, the findings suggest that memory suppression dampens neural activity associated with retrieving memories and also limits the influence of these memories on automatic behavioral responses.
The researchers are planning on exploring this memory suppression effect further, investigating whether it might be applied to other types of personally significant memories.
"For example, we can all recall times when we hurt others or behaved inappropriately and these memories can carry feelings of guilt and shame. Can we suppress these kinds of memories, and what are the consequences of such suppression?" says Hu.
While traumatic memories may seem like an obvious target for suppression, the researchers point out that these memories stem from emotional events involving strong physiological arousal and it's unclear whether suppression would be effective in reducing their impact.
INFORMATION:
Part of this research was supported by an American Psychological Association Dissertation Research Award to X. Hu.
For more information about this study, please contact: Xiaoqing Hu at xqhu@utexas.edu.
The article abstract is available online: http://pss.sagepub.com/content/early/2015/05/19/0956797615575734.abstract
The APS journal Psychological Science is the highest ranked empirical journal in psychology. For a copy of the article "Suppressing Unwanted Autobiographical Memories Reduces Their Automatic Influences: Evidence From Electrophysiology and an Implicit Autobiographical Memory Test" and access to other Psychological Science research findings, please contact Anna Mikulak at 202-293-9300 or amikulak@psychologicalscience.org.
This news release is available in French. The Drosophila, the so-called fruit fly, attends all day long to its activities. It flutters, has naps, lays its eggs or emerges from the pupa, the stage of metamorphosis preceding maturity. At the University of Geneva (UNIGE), Switzerland, the team of the researcher in biology Emi Nagoshi is closely interested in this insect, used as a model organism for the study of circadian rhythms in the animal kingdom. The researcher's group discovered that the main clock of the Drosophila, formed by neurons clustered in various regions ...
Viewed from above, our solar system's planetary orbits around the sun resemble rings around a bulls-eye. Each planet, including Earth, keeps to a roughly circular path, always maintaining the same distance from the sun.
For decades, astronomers have wondered whether the solar system's circular orbits might be a rarity in our universe. Now a new analysis suggests that such orbital regularity is instead the norm, at least for systems with planets as small as Earth.
In a paper published in the Astrophysical Journal, researchers from MIT and Aarhus University in Denmark ...
Beginning readers who focus on letter-sound relationships, or phonics, instead of trying to learn whole words, increase activity in the area of their brains best wired for reading, according to new Stanford research investigating how the brain responds to different types of reading instruction.
In other words, to develop reading skills, teaching students to sound out "C-A-T" sparks more optimal brain circuitry than instructing them to memorize the word "cat." And, the study found, these teaching-induced differences show up even on future encounters with the word.
The ...
(PHILADELPHIA) -- Despite advances in managing and curing some forms of breast cancer, women whose disease becomes metastatic have fewer effective options. A new phase 3 study in some of the most difficult-to-treat patients, women with endocrine-resistant disease, showed that the newly approved drug, palbociclib, more than doubled the time to cancer recurrence for women with hormone-receptor (HR+) positive metastatic breast cancer. The results will be presented at the 2015 annual American Society of Clinical Oncology (ASCO, abstract LBA-502) and published in the New England ...
Anastrozole provides a significant benefit compared with tamoxifen in preventing recurrence after a lumpectomy and radiation therapy in postmenopausal women ages 60 years or younger who had DCIS (ductal carcinoma in situ), a common diagnosis of non-invasive breast cancer. In women over age 60, it works as well as tamoxifen. These findings were presented today at the 2015 ASCO Annual Meeting in Chicago. The benefit reported in this trial appeared later in follow up of the women in the study.
"This study provides a new option for postmenopausal women undergoing treatment ...
DURHAM, N.C. - A modified poliovirus therapy that is showing promising results for patients with glioblastoma brain tumors works best at a low dosage, according to the research team at Duke's Preston Robert Tisch Brain Tumor Center where the investigational therapy is being pioneered.
The dosage findings for the first 20 patients in the phase 1 trial will be presented at the American Society of Clinical Oncology annual meeting in Chicago at the end of the month (abstract #2068).
"The purpose of a phase 1 trial is to identify the optimal dose to minimize toxicity," said ...
Queensland scientists have discovered two more species of suicidally-sexed marsupials and one is already destined for the threatened list.
Queensland University of Technology's (QUT) Dr Andrew Baker and his team have named two new species of Dusky Antechinus. One new species was discovered in remote, south-eastern Tasmania and another mainland form was raised to species status.
The team has now discovered five new species of antechinus in the past three years, a 50 per cent increase in diversity within this long-known genus of mammals.
However, the researchers believe ...
(New York - May 26, 2015) Mount Sinai Health System faculty will be presenting research updates on a lymphoma vaccine clinical trial, the best dosing for a drug against metastatic cancer, and new treatment strategies in relapsed multiple myeloma at the American Society of Clinical Oncology (ASCO) annual meeting, May 29 - June 2, 2015, in Chicago. ASCO is the world's largest oncology meeting, with more than 25,000 researchers presenting their latest study results.
Key abstract presentations include:
* In situ vaccine for low-grade lymphoma: Combination of intratumoral ...
This news release is available in German.
A team led by DESY scientists has designed, fabricated and successfully tested a novel X-ray lens that produces sharper and brighter images of the nano world. The lens employs an innovative concept to redirect X-rays over a wide range of angles, making a high convergence power. The larger the convergence the smaller the details a microscope can resolve, but as is well known it is difficult to bend X-rays by large enough angles. By fabricating a nano-structure that acts like an artificial crystal it was possible to mimic ...
A study analysing the Finnish homicide and prescription drug databases discovered that the use of certain drugs that affect the central nervous system are associated with an increased risk of committing a homicide. The greatest risk was associated with the use of painkillers and tranquillizing benzodiazepines, while anti-depressants were linked only to a slightly elevated risk. The study is the first one of its kind in the world.
Professor Jari Tiihonen's research group analysed the use of prescription drugs of 959 persons convicted of a homicide.
In the recent years, ...
