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[SOUND] [MUSIC] So today we will discuss six major approaches to investigate the activity of the brain. So why do we need so many methods to investigate the neural methods of decision making? Simply because there is no one ideal method. So all methods can be characterized by the temporal and spatial resolution. Temporal resolution means how well in time we can differentiate different stages of decision making process. Spatial resolution means how well in space we can differentiate different neuronal populations involved into the decision making process. Unfortunately there is no one ideal neuroscientific method that would have perfect temporal and spatial resolution. We have to combine different methods to understand the dynamic of the neural mechanisms of decision making and the localization of those mechanisms inside the brain. So let's first discuss the facts of lesions on our decisions. So, lesions can trigger some changes in our behavior and also in, in the way we make our decisions. So, neuropsychology investigates the facts of lesions on our behavior. There are really famous cases, illustrating how the trauma in the specific brain area can lead to specific changes in our decision making. So, for example, we happen to know the famous case of Phineas Gage. So, he lost a portion of his prefrontal cortex. So during an accident, a huge iron rod penetrated his brain, and removed the part of his frontal cortex. So nowadays, we can reconstruct the place that was destroyed in the brain by this iron rod. So using the modern reconstruction technique, we can actually reconstruct that, this accident and here we clearly see that the portion of the medial frontal cortex was removed by this accident. Surprisingly, he survived. But his behavior, his decision-making process changed substantially. He became a very emotionally unstable person. He got a lot of problems in social interactions. He lost his job. So, the way he made social decisions, the way he behaved, changed dramatically. So, for example, Antonio Damasio was so interested in this case, that he collected patients with similar traumas, with similar lesions. So, this picture indicates the main focus of these traumas. So, in most of the cases, the orbitofrontal cortex or the medial portion, medial ventro prefrontal cortex was damaged. And as we will see during the course, the damage of this region leads to very important changes in decision making process. So, we know now that this portion of the orbitofrontal cortex is really critical for emotional learning, for optimal decision making, for evaluation of options for the comparison of options. So, how do we normally study patients with specific traumas? So we asked these patients to perform a task and we compared behavioral results with a control group. So we simply collect behavioral information and compare the results of two groups. Results of patients and results of the normal subjects. So in this graph, you see below an example that will be discussed in this course. So you see that normal people, during the test, quite quickly differentiate optimal and su, suboptimal decisions. But patients with the lesions in the ventromedial prefrontal cortex, they do not differentiate optimal and suboptimal decisions in this particular task. They make a lot of mistakes. We will discuss the results and very influential results during the course. So, lesions in specific brain regions can lead to very specific changes in our decision-making.