Ventromedial prefrontal cortex (vmPFC) lesions: helpful in medical science?

Flashback to days of lobotomy, which was a form of neurosurgery that scraped off some of the prefrontal cortex in order to reduce symptoms associated with various mental disorders.  Although lobotomy is no longer practiced today, due to its unpopular side effects, new findings associated with the vmPFC may provide insight for similar procedures.
Michael Koenigs et al. looked at FMRIs of patients with brain lesions in the vmPFC, and looked for effects on negative affect via its connection with the amygdala.  These findings suggest that there is a relationship between the vmPFC and the amygdala.  Furthermore, the FMRI shows that when aversive pictures are shown, subjects with brain lesions have more active amygdalae than "normal" subjects.  The relationship supports the idea that vmPFC activity inversely relates to amygdala; in this case when there is less vmPFC activity (as in the subjects with lesions), the amygdala's activity is "disinhibited," meaning there is less inhibition.  With less inhibition it is found that there are lower levels of negative affect (not lower levels of depressed feeling though).  In another research paper by Hänsel and Känel, it was found that the vmPFC might link to more than just negative affect, but affective disorders.  They found that there is a link between the vmPFC and the autonomic nervous system, which also is associated with depressive disorders, anxiety disorders, and other affective disorders.
In both studies it was determined that the vmPFC has an inverse relationship with the amygdala except for people who are suffering from depression.  This is particularly interesting in my opinion, because there must be something going on in a depression that creates this dysfunction.  This also creates difficulty when creating anti-depressants or coming up with treatments for depression.
Controversially, it was seen that people with lesions might have less anxiety, and also less post traumatic depressed feelings.  War heroes were observed in a study by Koenigs et al., and it was found that those with damage to the vmPFC were less likely to develop PTSD.
The key here is: vmPFC damage is increasing amygdala activity when presented with some stimulus, which then blunts emotional responses.  This creates conflict; when trying to solve one problem like PTSD, but the solution may lead to another problem like major depressive disorder.  Koenigs et al. say that vmPFC damage may lead to a personality change that can be comparable to psychopathic behavior--not good.  Hänsel and Känel say that vmPFC damage may affect ones rational thinking.  So maybe brain lesions aren't a new and improved form of lobotomy.  However, Koenigs et al. conclude that although lesions are not a cure, the relationship discovered between the vmPFC, the amygdala, and then its effects on emotion, may lead to some very interesting treatments down the line.  Hänsel and Känel feel that by looking at the effects of the vmPFC on the autonomic nervous system, we might be able to gain additional insight.
Lesions may blunt personality, but they have sparked neuroscientific research on emotional disorders.

Works Cited

Hänsel, Alexander, and Roland von Känel. “The Ventro-Medial Prefrontal Cortex: A Major Link between the Autonomic Nervous System, Regulation of Emotion, and Stress Reactivity?” Biopsychosocial Medicine 2 (2008): 21. PMC. Web. 1 Dec. 2015.

Motzkin, Julian C., Carissa L. Philippi, Richard C. Wolf, Mustafa K. Baskaya, and Michael Koenigs. "Ventromedial Prefrontal Cortex Is Critical for the Regulation of Amygdala Activity in Humans." Biological Psychiatry 77.3 (2015): 276-84. Web. 30 Nov. 2015.

Are You Smarter Than a 90 Year Old?

 Finals are coming up, and every student on college campuses around the world are starting to panic.  They are dreading the all-nighters spent cramming for the exams, anxious to pull up their grades at the last minute after a long semester of hard work.  Unfortunately, young people realize this fluid and plastic memory will not last long.  In fact, this is the prime time for memory formation.  It seems to be a grim future of decline in memory and other cognitive functioning.  But what if one could maintain this high cognitive efficiency?  There is a small population of people who actually do retain memory incredibly well as they continue aging.  This group of people, referred to as “Super-Agers,” maintain their superior cognitive functioning well into their 80’s and 90’s, even surpassing those in their 20’s or 30’s, the supposed peak of cognitive abilities.  These people live extremely active lives, continually engaging in intellectual pursuits at varying degrees of intensity.

            Researchers at Northwestern University have conducted a large study of Super-Agers to better understand what makes their brains different from the rest of the community similar in age.  In a study published in the Journal of Neuroscience this year done with 31 Super-Agers, MRI scans showed an unusual brain signature as compared to 21 people of similar age.  Super-Ager brains were shown to have a much larger and thicker region of the cortex known as the anterior cingulate cortex.  This area has been known to “influence cognitive control, conflict resolution, and perseverance.”¹  The enlargement may be part of an explanation as to their continual active lifestyles despite their aging.

Another significant find was the lack of neurofibrillary tangles, a marker of the dementia Alzheimer’s disease, which affects 35 million people worldwide.  Neurofibrillary tangles strangle healthy neurons and marks the significant decline in cognitive functioning in Alzheimer’s patients.  It was found that Super-Agers had up to 92% less of these tangles in their brains than those with mild cognitive impairment.  These tangles are not exclusively seen in Alzheimer’s patients, however; they are a part of the normal aging process.  When compared to an elderly control population, with neither Super-Aging qualities nor mild cognitive impairments, Super-Agers had up to 87% less of these neurofibrillary tangles.

Super-Ager brains were also found to have up to five times more of what are called von Echonomo neurons.  These neuron populations, also found in dolphins, whales, elephants, and some apes, are believed to be involved in the “rapid transmission of information during social interactions.”¹  The Northwestern researchers believe this could be related to their superior memory capacity. 

These three differences in the brains of Super-Agers can help scientists and doctors better understand memory loss as a result of the aging process.  Neuroscientists like Dr. Robert Morrison of Loyola University Chicago are attempting to understand the process of learning and memory to help find predictable markers for cognitive diseases such as Alzheimer’s, allowing a doctor to track a patient’s cognitive decline.  Dr. Morrison, in conjunction with the Cognitive Neurology and Alzheimer’s Disease Center (CNADC) at Northwestern University, studies rule-based category learning in the elderly.  Using a combination of both behavioral and functional neuroimaging techniques, his research group has found individual differences in both task performance and awareness of learning during the task.  He hopes to further explore the extent of this finding in both those with Alzheimer’s disease as well as in Super-Agers.  The goal he hopes to accomplish is to find a way for doctors to track cognitive function and decline using an EEG monitor to measure executive functioning, which can be used at home for patients at risk of dementia.  This could help detect the dementia at a much earlier stage, and thus begin treatment to slow down the effects before too much damage has been done.

Memory loss due to aging is an inevitable fact for most of the general population.  Understanding the general process by learning from Super-Agers, who lack the cognitive decline, can help scientists to learn more about dementias and other cognitive diseases.  This research can help make better and more effective treatment, possibly affecting the lives of millions of people worldwide.

References:

1. Fang, Janet. "How "SuperAger" Brains Are Different Than Everyone Else's." IFLScience. IFLScience, 04 Feb. 2015. Web. 23 Nov. 2015. <http://www.iflscience.com/brain/how-superager-brains-are-different-everyone-elses>.

2. Bharani, Krishna L., Ken A. Paller, Paul J. Reber, Sandra Weintraub, Jorge Yanar, and Robert G. Morrison. "Compensatory Processing during Rule-based Category Learning in Older Adults." Aging, Neuropsychology, and Cognition (2015): 1-23. Web.

3. Gefen, T., M. Peterson, S. T. Papastefan, A. Martersteck, K. Whitney, A. Rademaker, E. H. Bigio, S. Weintraub, E. Rogalski, M.- M. Mesulam, and C. Geula. "Morphometric and Histologic Substrates of Cingulate Integrity in Elders with Exceptional Memory Capacity." Journal of Neuroscience 35.4 (2015): 1781-791. Web. 22 Nov. 2015.

4. Morrison, Robert G. "Predicting Pathological Aging: Behavioral and Electrophysiological Biomarkers for Alzheimer's Disease." Neuroscience Seminar. Illinois, Chicago. 27 Oct. 2015. Lecture.

Picutre:  http://www.bayshorememorycare.com/wp-content/uploads/2015/08/alzehimer.jpg

Inside the Mind of a Psychopath

If a person cannot understand the negative impact of their action due to their biology, then how can they be prevented from doing so? Feelings of guilt and empathy are not present in the mind of a psychopath. Understanding the mind of a psychopath helps to devise a system designed to guide the individual to act in a way that is acceptable in society. Regular offenders, are quick-tempered, overly responsive to threat, and can be impulsively aggressive. In short, regular offenders are hyper-reactive. Psychopaths, on the other hand, are cold and calculating. They have mild responses to threats, or low emotional reactivity, and their aggression is premeditated. Many researchers are studying the difference in brain structures between these two groups in order to gain more insight on how to help these individuals become more cohesive members of society.

Researchers gathered participants in three conditions: offenders with antisocial personality disorder as well as psychopathy, offenders with antisocial personality disorder only, and a control sample of healthy non-offenders. Upon studying Magnetic Resonance Imaging results from all of the participants, researchers found a significant difference in psychopathic offenders in both the gray matter, which is responsible for processing information, and the white matter, which is responsible for connecting the flow of information throughout different parts of the brain. More specifically, significant differences were found in the scans of psychopathic offenders in the areas of the gray matter, specifically the anterior rostral prefrontal cortex and the temporal poles bilaterally. These areas are responsible for “empathy, the processing of pro-social emotions such as guilt and embarrassment, and moral reasoning”. In the white matter tracts, significant differences were found in a brain structure that links together the medial frontal cortex and the posterior cingulate cortex: the dorsal cingulum. These areas are important to the processing of empathy, so abnormalities to the connection of these areas diminishes empathy, a characteristic of psychopathy.

In addition, these findings also suggests that psychopaths do not learn from punishment. The participants were placed in a scanner and asked to play an image matching game in which the reward for correct response was not consistent. "Offenders with psychopathy may only consider the possible positive consequences and fail to take account of the likely negative consequences. Consequently, their behavior often leads to punishment rather than reward as they had expected," Hodgins said. Abnormalities in the response to punishment were found in the insula and posterior cingulate in psychopathic offenders. These areas have been shown to activate during instances of actually experiencing emotion and seeing another experience emotion; in other words, these areas help a person to feel empathetic for a person. The previous MRI results showed abnormalities in the white matter tract that connects these two areas: the dorsal cingulum. These findings support the idea that there is a difference in the neuronal mechanism of learning from punishment and feeling empathy in psychopathic individuals.  

These results help researchers understand psychopathy at the neuronal level, but how can this information be applied to reduce recidivism in psychopathic criminals? Extensive research suggests that these abnormalities can be greatly reduced with early childhood intervention. Studies have suggested that empathy is rooted in imitation and can be implemented early while infants are constantly mirroring behavior. Programs that teach parents how and when to properly punish their children have been shown to significantly reduce conduct problems in the future. Implementing behavioral learning programs during childhood that specifically target the mechanisms responsible for prosocial behavior, learning from punishments, empathetic responses has been shown to significantly reduce future crimes.

http://www.sciencedaily.com/releases/2015/01/150127212158.htm