Scientists have located the conscience 🙂
| TNN | Jan 31, 2014, 05.56 AM IST
London Scientists from the Oxford University have for the first time identified an area of the human brain that appears unlike anything in the brains of other primates. It is part of the Ventrolateral Frontal Cortex, a region of the brain known for over 150 years for being involved in many of the highest aspects of cognition and language.
To look into which part of this region actually controls our superior decision making , scientists carried out MRI scans in both humans and monkeys. They found one area of the cortex that had no equivalent in the macaque monkeys — an area called the lateral frontal pole prefrontal cortex.
Scientists also believe that lateral frontal pole prefrontal cortex is the loud (inner ) voice that pricks whenever we are inclined towards evil or blunder in our lives. Oxford scientists say this is the region that tells us when we go wrong and whether we have been well advised to do something better.
MRI imaging of 25 adult volunteers was used to identify key components in the cortex area of the human brain, and how these components were connected up with other brain areas.
The results were then compared to equivalent MRI data from 25 macaque monkeys.
http://www.ox.ac.uk/news/2014-
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Patients with bilateral lesions of the vmPFC develop severe impairments in personal and social decision-making even though most of their intellectual ability is preserved.
For instance, they have difficulties in choosing between options with almost uncertain outcomes, whether the uncertainty is in the form of a risk or of an ambiguity. After their lesion, these patients have an impaired capacity to learn from their mistakes, making the same decisions again and again even though they lead to negative consequences.
These patients choose alternatives that give immediate rewards, but seem to be blind to the future consequences of their actions. However, the underlying mechanisms of this behaviour are not yet fully understood.
Damage to the ventromedial prefrontal cortex (especially in the right hemisphere) has been connected with deficits in detecting irony, sarcasm, and deception. Subjects with damage in this area have been found to be more easily influenced by misleading advertising. This has been attributed to a disruption of a “false tagging mechanism” which provides doubt and skepticism of new beliefs.
People with damage to the ventromedial prefrontal cortex still retain the ability to consciously make moral judgments without error, but only in hypothetical situations presented to them. There is a gap in reasoning when applying the same moral principles to similar situations in their own lives.
The result is that people make decisions that are inconsistent with their self professed moral values. People with early damage to the ventromedial prefrontal cortex are more likely to endorse self-serving actions that break moral rules or cause harm to others. This is especially true for patients whose damage occurred the earliest in life.
Regulation of Emotion
Activation of the vmPFC is associated with successful suppression of emotional responses to a negative emotional signal.
Patients with vmPFC lesions have shown defects both in emotional response and emotion regulation. Their emotional responsivity is generally diminished and they show markedly reduced social emotions such as compassion, shame and guilt. These are emotions that are closely associated with moral values. Patients also exhibit poorly regulated anger and frustration tolerance in certain circumstances.
Patients with focal lesions in the vmPFC show personality changes such as lack of empathy, irresponsibility, and poor decision making. These traits are similar to psychopathic personality traits.
The right half of the ventromedial prefrontal cortex was associated with regulating the interaction of cognition and affect in the production of empathic responses. Hedonic (pleasure) responses were also associations to orbitofrontal cortex activity level by Morten Kringelbach.
This finding contributes findings suggesting ventromedial prefrontal cortex being associated with preference judgement, possibly assigning the ventromedial prefrontal cortex a key role in constructing one’s self. Studies with PTSD also supported the idea that the ventromedial prefrontal cortex is an important component for reactivating past emotional associations and events, therefore essentially mediating pathogenesis of PTSD.
Treatments geared to the activation of the ventromedial prefrontal cortex were therefore suggested for PTSD. The right half of the ventrolateral prefrontal cortex, being active during emotion regulation, was activated when participants were offered an unfair offer in a scenario.
The capacity for mature defense mechanisms such as intellectualization, compensation, reaction formation, .and also isolation. has been tied .to proper functioning of the right ventromedial prefrontal cortex, while more primitive defense mechanisms ….such as…. projection, splitting, verbal denial, and fantasy have been found to rely on other regions, primarily in the left hemisphere. How does human conscious helps us heal!!!!
Mar 31 2014
Does a mouse think like a human? Does a cat? Or Does a macaque monkey? These are fascinating questions to ask on a philosophical level, but they are also of immense practical importance.
Current regulations on drug development mean that animal research plays a huge role in deciding what substances might be safe and beneficial to humans. This has lead to great success in understanding many aspects of how the body works, and using that to develop treatments.
But is the nervous system different? If it contains the main adaptations that mean humans can do many more complex things than other animals, can working out how an animal’s brain works reap the same rewards? Many drug companies have spent a lot of money on compounds that worked very well on mouse behaviours, but did not have the desired effect in humans. This has contributed to some of them pulling out of neuroscience research altogether. It means that finding ways to better understand how similar/different animals’ brains are from each other can offer both the hope of better treatments for humans, and fewer animals used to find those treatments.
Using imaging to do this allows for more humane studies of animals close to us the evolutionary tree. It also offers the opportunity for speculation about the areas of the brain that ‘make us human’. Whilst it is impossible that there is one area of the brain that contains the essence of humanity, the differences between species offers vital clues as to how the brain functions.
Researchers from Oxford have been combining data from humans and macaque monkeys across a series of studies, and the one we are focusing on today is on a part of the frontal lobe (see figure 1).
The ventral, inferior frontal cortex (vIFC) has been linked with a range of functions, but seems to be heavily involved in modelling the potential consequences of actions and selecting appropriate behaviours for the situation. It includes Broca’s area, long recognised as part of the system that understands and produces speech.
Figure 1 – Click on the image to see a bigger version
Methods
The study had three goals:
- Split up the human vIFC based on where each sub-region connects to anatomically
- See what the pattern of functional connectivity is for these areas
- Compare this pattern to macaque monkeys
In order to do this the researchers scanned 25 healthy humans using MRI. They used two types of MRI scanning: examining the white matter connections in the brain (anatomical connectivity) and functional MRI at rest (functional connectivity). They also scanned 25 macaque monkeys using fMRI while they were anaesthetised.
The researchers used some very sophisticated analysis methods to meet their goals. Every tiny area (a 5x5x5mm voxel) in the vIFC was examined for its connection patterns to the rest of the brain. These connection patterns were then compared to each other and the voxels that had similar pattern were grouped together. Finally these groups were fitted back onto the anatomy of the brain. Figure 1 shows the subdivisions found.
A different method was used to subdivide the monkey’s putative equivalent brain areas. This was done by using already published maps subdividing the macaque brain. These maps are made by identifying areas that have similar patterns of cells, not anatomical connections. This has been done with humans as well (Broadman areas) and the areas described overlap substantially with the imaging findings in this study, but by no means exactly.
Finally the functional connectivity was compared from region to region to see if the human and monkey regions of the brain match up in how they connect to the rest of the brain.
Results
There was both substantial overlap between human and monkey brain function, and key differences. The detail for each area is fascinating and if your neuroanatomy is up to it I’d highly recommend looking at the paper’s figures, e.g. figure 2 for two of the subdivisions of the motor part of the vIFC
- In areas associated with using visual information for motor control and planning the humans and macaques were very similar
- Some human areas implicated in language showed very similar patterns to equivalent monkey areas, despite macaques not having sophisticated language skills.
- This provides support for the idea that there is not a specific/separate language network in humans. Language processing probably ‘built upon existing mechanisms for sensory –motor mapping, sequential motor learning or multimodal sensory integration’
- But there was a crucial difference in how much auditory processing impacted on the frontal areas
- There was much, much more in humans and we are much better at auditory tasks than macaques
- There was an area in the very front of the brain (labelled FPI on figure 1) that was only found in humans. It was highly correlated with other areas of the frontal lobe but its contribution to brain function is not entirely clear.
Figure 2 – Click on the image to see a bigger version
Sum Up
- This study offers a fascinating insight into cutting edge research into how human brains and macaque monkey brains compare
- Despite differences in how they were studied, the human and macaque brains demonstrated a striking level of similarity in some areas
- But there were clear differences in others, especially regarding auditory processing
- It is far too simplistic to say that one area is the root of the difference between humans and monkeys
- Improved understanding of how human brains relate to animal brains will hopefully allow us to use less animals in research and find better treatments, quicker
The first rule of blogging: Never pass up the chance to include cute photos of monkeys 🙂
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Many cognitive scientists believe that humans’ ability to innovate by varying syntax engenders much of the richness and complexity of our thoughts and ideas. This gulf between humans and our nearest primate relatives is but one of many. Stance Humans are bipedal, and except for short bouts of uprightness, great apes walk on all fours. It’s a profound disparity.
Kevin Hunt, director of the Human Origins and Primate Evolution Lab at Indiana University, thinks humans’ ancestors stood upright in order to reach vegetation in low-hanging tree branches. “When Africa started getting drier … about 6.5 million years ago, our ancestors were stuck in the east part, where the habitat became driest,” Hunt told Life’s Little Mysteries. “Trees in dry habitats are shorter and different than trees in forests: In those dry habitats, if you stand up next to a 6-foot-tall tree, you can reach food. In the forest if you stand up, you’re 2 feet closer to a tree that’s 100 feet tall and it doesn’t do you the least bit of good.” Thus, our ancestors stood up in the scrubby, dry areas of Africa. Chimps in the forests did not. Charles Darwin was the first to figure it out why the simple act of standing up made all the difference in separating man from ape. One word: tools. “Once we became bipedal, we had hands to carry tools around. We started doing that only 1.5 million years after we became bipedal,” Hunt explained. Give it a couple million years and we turned those chipped stones into iPads. [Read: Why Haven’t All Primates Evolved into Humans?] Strength According to Hunt, if you shave a chimp and take a photo of its body from the neck to the waist, “at first glance you wouldn’t really notice that it isn’t human.” The two species’ musculature is extremely similar, but somehow, pound-for-pound, chimps are between two and three times stronger than humans. “Even if we worked out for 12 hours a day like they do, we wouldn’t be nearly as strong,” Hunt said. Once, in an African forest, Hunt watched an 85-pound female chimp snap branches off an aptly-named ironwood tree with her fingertips. It took Hunt two hands and all the strength he could muster to snap an equally thick branch. No one knows where chimps get all that extra power. “Some of their muscle arrangement is different — the attachment points of their muscles are arranged for power rather than speed,” Hunt said. “It may be that that’s all there is to it, but those who study chimp anatomy are shocked they can get that much more power out of subtle changes in muscle attachment points.” [Read: Planet of the Apes: Can Chimps Really Shoot Guns?] Alternatively, their muscle fibers may be denser, or there may be physiochemical advantages in the way they contract. Whatever the case may be, the outcome is clear: “If a chimp throws a big rock and you go over and try to throw it, you just can’t,” Hunt said. Conversation Herb Terrace, the primate cognition scientist who led Project Nim, thinks chimps lack a “theory of mind”: They cannot infer the mental state of another individual, whether they are happy, sad, angry, interested in some goal, in love, jealous or otherwise. Though chimps are very proficient at reading body language, Terrace explained, they cannot contemplate another being’s state of mind when there is no body language. “I believe that a theory of mind was the big breakthrough by our ancestors,” he wrote in an email. [Video: Trailer for ‘Project Nim’ Documentary] Why does he think that? It goes back to Nim the signing chimp’s linguistic skills. Like an infant human, Nim spoke in “imperative mode,” demanding things he wanted. But infantile demands aren’t really the hallmark of language. As humans grow older, unlike chimps, we develop a much richer form of communication: “declarative mode.” “Declarative language is based on conversational exchanges between a speaker and a listener for the purpose of exchanging information,” Terrace wrote. “It is maintained by secondary rewards such as ‘thank you,’ ‘that’s very interesting,’ ‘glad you mentioned that.’ In the case of declarative language, a theory of mind is clearly necessary. If the speaker and the listener could not assume that their conversational partners had a theory of mind there would be no reason for them to talk to each other. Why bother if there is no expectation that your audience would understand what you said?” He added, “I know of no example of a conversation by non-human animals.” This limitation, perhaps more than any other, prevents a series of events like that in the new film “Rise of the Planet of the Apes.” In the film, chimps learn sign language — a realistic scenario. But it’s a stretch to imagine them using their new skill to discuss and plan a world takeover. Genes The chimpanzee genome was sequenced for the first time in 2005. It was found to differ from the human genome with which it was compared, nucleotide-for-nucleotide, by about 1.23 percent. This amounts to about 40 million differences in our DNA, half of which likely resulted from mutations in the human ancestral line and half in the chimp line since the two species diverged. [Read: How Many Genetic Mutations Do I Have?] From those mutations come the dramatic differences in the species that we see today — differences in intelligence, anatomy, lifestyle and, not least, success at colonizing the planet.  |
Why you should listen
Laurie Santos runs the Comparative Cognition Laboratory (CapLab) at Yale, where she and collaborators across departments (from psychology to primatology to neurobiology) explore the evolutionary origins of the human mind by studying lemurs, capuchin monkeys and other primates. The twist: Santos looks not only for positive humanlike traits, like tool-using and altruism, but irrational ones, like biased decisionmaking.
In elegant, carefully constructed experiments, Santos and CapLab have studied how primates understand and categorize objects in the physical world, for instance, that monkeys understand an object is still whole even when part of it is obscured. Going deeper,b their experiments also search for clues that primates possess a theory of mind — an ability to think about what other people think.
Most recently, the lab has been looking at behaviors that were once the province mainly of novelists: jealousy, frustration, judgment of others’ intentions, poor economic choices. In one experiment, Santos and her team taught monkeys to use a form of money, tradeable for food. When certain foods became cheaper, monkeys would, like humans, overbuy. As we humans search for clues to our own irrational behaviors, Santos’ research suggests that the source of our genius for bad decisions might be our monkey brains.
What others say
“Through a series of groundbreaking experiments, Santos has seen in her primates a humanlike propensity for hoarding, larceny, and competitiveness. By exploring the inner lives of primates, she has offered persuasive evidence that monkeys are capable of sophisticated insight, complex reasoning, and calculated action.” Laurie Santos looks for the roots of human irrationality by watching the way our primate relatives make decisions. A clever series of experiments in “monkeynomics” shows that some of the silly choices we make, monkeys make too.
Preview TEDxTalk Laurie Santos A Monkey Economy as Irrational as Ours
| Dr. Heather Berlin | TEDxYouth@KC
