Decision Making in Learned Associations and in Climate Change

The human brain’s ability to actively make decisions and infer possible outcomes based on prior experience or insight is a highly complex process that is still largely unknown. Additionally, researching how and what neural circuits are flexibly used in learned associations is a complex process. In the article “Neural circuits for inference-based decision-making”, Wang and Kahnt attempt to understand how humans rely on past experiences to predict future outcomes in novel context. Through the use of FMRI and ECG, Wang and Kahnt found that the OFC and HC neurons are largely responsible for the learned associations and inferences such as lab 13 explained, “The ability to flexibly utilize prior knowledge and experiences to mentally simulate probable outcomes is critical for making adaptive decisions” (et al. Wang, 2021). Throughout homosapien evolution decision and inference creation has been paramount in the survival and complex building of civilization. However, many decisions can become swayed or perverted through other neural processes that are more pleasurable or less complex such as positive and negative arousal. 

Climate change has become forefront in the world stage as a continuing and exponentially worsening issue. The decisions of world leaders and mega corporations to fix the man-made issues contributing to climate change have been researched in order to understand the neurological methods behind decision making processes of people. In the paper “Environmental neuroeconomics: how neuroscience can inform our understanding of human responses to climate change”, Sawe and Chawla examine how the study of neuroecconomics examines the factors that lead to environmental based decisions. Similarly to Wang and Kahnt, Sawe and Chawla examined literature that used fMRI and ECG to understand the mechanisms underlying individual and collective decision-making around climate change.

To best examine which brain areas are more active in positive climate change action, brain imagining has shown that positive arousal is correlated with activity in the ventral striatum, the reward pathway, because of the higher level region nucleus accumbens’ primary and secondary responses. However, the anterior insula’s activity correlates with negative arousal, such as loss, risks, physiologically and morally aversive situations. People’s responses, which lead to subjective valuation and assessment of benefit-cost tradeoffs, in the aforementioned areas are integrated in the medial prefrontal cortex. A concrete example shows that the “FMRI study of donations to protect state and national park lands from developmental land use threats shows environmental donation decisions are associated with anterior insula activity, and that this activity is amplified in those with stronger pro-environmental attitudes” (et al. Sawe and Chawla, 2021). There are other factors that contribute to the decision making process of climate change such as uncertainty associated with outcomes and impacts of climate change action. Furthermore, the psychology of what people cannot see directly in front of them does not immediately affect them plays a crucial role in the lack of action. Climate change is still viewed as something in the future which leads to indecision due to a lack of urgency to act on climate change. Future time perception and decisive future impact is subject to priming and is thus, malleable, which proves that advocating and educating populations about ways to fix climate change can work. Finally, social behavior effects the brains ability to make decisions due to wanting to “fit in” with societies norms. This behavior further creates a lack of indecision in communities about climate change.  

The direct observation and testing of brain regions to determine how the brain makes learned associations to predict future outcomes and make decisions, in addition to, observing what brain regions are active during positive and negative decision making allow researchers to understand and predict future human-based decisions and societal outcomes. Using this data, researchers can better inform educators and advocates about what works to change or affect people’s decisions and behaviors about climate change.

References

Wang, Fang, Kahnt, Thorsten. (2021, 02, 004). Neural circuits for inference-based decision-making. Science Direct, Elsevier. https://doi.org/10.1016/j.cobeha.2021.02.004 

Sawe, Niki, Chawla, Kiran. (2021, December). Environmental neuroeconomics: how neuroscience can inform our understanding of human responses to climate change. Science Direct, Elsevier. https://doi.org/10.1016/j.cobeha.2021.08.002 

There are More Neural Circuits for Inference Making than was Previously Thought

    Since the dawn of time, organisms have been making snap decisions based on what can be inferred from the environment around them. Humans are no exception, as our world is constantly changing around us. New Research has been done to see how we make those decisions based on what we can infer. In "Neural circuits for inference-based decision-making," Wang and Kahnt examine which areas of the brain could be used for inference during the use of learning associations. There are three areas that they found that play a role in inference making; the orbitofrontal cortex, the hippocampus, and the amygdala. Orbitofrontal cortex to hippocampus circuits seem to be used for inferring value of outcomes. Wang and kahnt's research has given us a glimpse into what parts of our brain make snap decisions when involving inferences.

    In "A cortical circuit mechanism for structural knowledge-based flexible sensorimotor decision-making." researchers Xin et al., suggested that there is another area of the brain involved in inference making. They suggested that the auditory cortex has been proven to encode information involving stimulus categorization. Xin et al. made use of two-photon imaging to find the area of the auditory cortex that is responsible for stimulus categorization. This area receives projections from the orbitofrontal region previously talked about. These projections played an important role specifically in stimulus re-categorization, which allows for behavioral flexibility when it comes to inferring. This area does not seem to play a role in discriminating between stimuli though.

    The finding of another area in the brain that has an impact on our inferencing abilities has a couple of possible implications. One of these implications is that all of our senses have circuits that allow for stimulus categorization. This would help us keep all of the stimuli straight inside of our heads. Another of these implications is that organisms evolved to have multiple circuits for inferencing so that we can have other ways of processing incase one gets damaged. This would also help us process information faster. This would make sense, as sometimes the ability to infer means the difference between life and death for us. The possibility of the existence of other neural circuits being used for inference making should be looked at more in the future. Who knows, we might be able to speed up our inference making even more.

Works Cited

Liu, Y., Xin, Y., & Xu, N.-long. (n.d.). A cortical circuit mechanism for structural knowledge-based flexible sensorimotor decision-making. Cell.com. Retrieved October 22, 2021, from https://www.cell.com/neuron/fulltext/S0896-6273(21)00280-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0896627321002804%3Fshowall%3Dtrue. 

Wang, F., & Kahnt, T. (2021). Neural circuits for inference-based decision-making. Current Opinion in Behavioral Sciences, 41, 10–14. https://doi.org/10.1016/j.cobeha.2021.02.004 

Orbitofrontal cortex use in inference based decision making and object reversal learning

     The Orbitofrontal Cortex (OFC) has been known to control impulsive behaviors as well as adjusting behaviors to have socially desirable responses. There is rapid study being done on the OFC to this date and many papers have been written to show the impact that it has with the decision making as well as learning. Research has also been showing how these 2 factors are directly impacted when their is damage done to the OFC. Thorsten Kahnt et. al studied how much the OFC, hippocampus (HC), and the Amygdala are being used in inference based decision making as well as association decision making. Rudebeck et. al studied how OFC lesions and Amygdala lesions impact object reversal learning in monkeys. 

    Kahnt et. al focused on association based decision making in humans and rats in this study. First, Kahnt conducted a study on humans and how they learn associations between different visual cues (Cue A -> Cue B, Cue C -> Cue D) then learned that one cue (Cue B) led to a reward and another cue (Cue D) did not lead to reward. After these 2 conditioning phases, they were asked in a probe test whether cue A or cue C would lead to a reward. These tasks where done under an fMRI to find where in the brain the most activity is occurring during these tasks. The data concluded that the OFC and HC were used the most together when both the conditioning tasks were being done and shown that these 2 regions of the brain are important to decision making in a human brain. The study then shifted to non-human primate subjects (rats) where a very similar study was done. These rodents and non-human primate subject learned that 2 objects led to 2 different rewards. The rewards consisted of 2 different foods, peanuts and M&Ms. The study showed that they were more likely to not choose the same object twice due to them learning that both objects led to two different rewards. They also found that OFC and the Amygdala were both used together to help learn what rewards came out of the objects. 

    Rudebeck et. al focused on how OFC lesions and Amygdala lesions effected object reversal learning in monkeys. In each trial, 2 objects where over food wells and the monkeys then had to displace one object and depending on the object that was displaced, a reward would be awarded. The reward object would not be changed in all of the trials and this led on for 30 trials. The study found that the monkeys who had OFC lesions where seen to have worse results than monkeys with Amygdala lesions or no lesions at all. The monkeys with Amygdala lesions were seen to have no impact compared to the no lesions group of monkeys. This shows that the OFC is crucial in learning tasks as well as association learning tasks and damage to the OFC can hinder learning. 

    These two research studies have shown that the Orbitofrontal cortex is important to both learning tasks as well as association tasks which include decision making and object reversal learning. Both of these studies have shown how much more the orbitofrontal cortex can truly do besides just impulsive behaviors and inducing socially desirable behaviors. 

References:

Rudebeck PH, Murray EA. Amygdala and orbitofrontal cortex lesions differentially influence choices during object reversal learning. J Neurosci. 2008;28(33):8338-8343. doi:10.1523/JNEUROSCI.2272-08.2008

Fang Wang, Thorsten Kahnt, Neural circuits for inference-based decision-making, Current Opinion in Behavioral Sciences, Volume 41,2021, Pages 10-14, ISSN 2352-1546, https://doi.org/10.1016/j.cobeha.2021.02.004.

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.