====================================================================== Let's express cerebrum of human brain. Surface of cerebrum is cerebral cortex. Brain is 1.4 kg but since it's floated in the fluid, weight of brain is almost 50 gram as much as weight of golf ball. By center horizontal left-right line, frontal area is in charge of movement (execution functionality), rear part is in charge of sensory (visual, auditory, somatosensory). Center area of brain is complex body with some organs like hippocampus. ====================================================================== There is somatic primary area simply called S1 area as band shape in the very rear area from center horizontal left-right line. ====================================================================== There is visual primary area simply called V1 in occipital lobe. ====================================================================== There is temporal lobe in brain. Cerebral cortex can be categorized into "frontal lobe", "parietal lobe", "temporal lobe", "occipital lobe" Temporal lobe is located in both left and right side area. There is auditory primary area called A1 in temporal lobe. ====================================================================== These primary areas is already formed when human is born. These primary areas is areas which gene participates in much. So, there is no huge variance in these primary areas in people, and you can say these areas are common areas for human beings. ====================================================================== And there are secondary areas. ====================================================================== There is somatic sensory association area. ====================================================================== There are a lot of modules that process "visual process" in brain cortex. Primary visual area processes "visual" continuously like wave-shape. ====================================================================== Let's say "visual association area" is located around here. And we'll call visual association area as VA. ====================================================================== Association area (uditory association) for auditory sense is formed like visual association area. We'll call this as AA. Three association areas associate each sense (somatosensory, visualsensory, auditorysensory) ====================================================================== Somatosensory, visualsensory, auditorysensory are associated in each corresponding association areas, then associated sensories are further associated. Associated somaticsensory arrvies like this, visual one arrvies like this, same for auditorysensory one. Areas which are formed by 3 kinds of associated sensories are called multi sensory association (MA). ====================================================================== 신경계에서는 위험한 상황에 관한 감각입력은 시상을 거친 후 편도체에서 즉각적으로 행동으로 출력하며, 자세한 분석이 필요한 자각은 시상에서 감각피질을 순차적으로 거치면서 다중적으로 처리한다. 일차 감각 피질에서 연합 감각피질로 시각, 청각, 체감각의 개별 감각이 더욱 세부적으로 처리되어 다중연합감각영역으로 하나의 대상에 대한 모든 감각이 모인다. ====================================================================== 이렇게 모인 연합감각은 전두엽, 특히 전전두엽(PFC, Pre Frontal Cortext: 작업기억, 집행기능)으로 간다. 어떤 움직이는 물체를 봤을때, 색깔/형태/움직임등 시각정보가 다 연합된다. 자동차 경적소리/주변사람소리 등 다 합쳐진다. 주변온도/걸음 등 다 연합된다. 이 3개의 연합된게 다시 연합되어 전두엽으로 온다. ====================================================================== 오는 이 정보중에서 무엇이 중요한가를 판단해야되는데 그 과정은 연합감각영역 SA, VA, AA 에서 옛날의 경험에 의해서 형성된 각각의 기억들을 전두엽으로 다시 불러온다. 각각의 연합영역에서 기억을 불러오는 이과정을 점선으로 표시한다. 그러면 MA 를 거쳐서 PFC 에 들어온 새로운 정보와 옛날에 있던 정보들을 비교하는 행위가 가능해진다. 이것이 작업기억이다. 그래서 우리가 뭘 지각하게 되는 것이다. 옛날에 어땟는데 하고 순간적으로 비교하게 되는 것이다. 비교해서 그 중에서 중요한 정보는 내측두엽(medial temporal lobe : 측두엽 안쪽으로 말려 들어간 해마형성체) 에서 처리를 한다. 안쪽에 있으니까 점선으로 표시해보겠다. 해마가 이렇게 안에 있다. 아래에는 공포반응을 중심으로 처리하는 편도체가 있다. 새롭거나 중요한 정보는 기억을 해야한다. 다 모아진 정보가 해마 영역으로 들어가야한다. 위험요소가 있는 공포반응을 포함하는 정보는 편도체로 간다. 편도체와 해마는 다중으로 상호 연결되어 있다. 해마에서 저장된 기억된 코딩된 기억으로 바뀌어진 정보는 어디로 가냐면, 이점이 굉장히 중요한데, 생존에 중요한 감각경험정보는 해마에서 코딩되어 짧게는 서너시간 길게는 몇달동안 유지되는 기억으로 굳혀지고 실제 이 기억을 저장하는 장소는 대뇌신피질, 그중에서 3개의 감각연합영역에 주로 저장이 된다. 해마에서 형성된 경험중에서 중요한 다시 3개의 감각 연합영역으로 가서 저장된다. 이 과정이 상당히 중요하다. 책을 보든지 경치를 보든지 뭘 해서 정보를 입력했을때 감각정보들이 최종적으로 저장되는 영역은 감각연합영역 피질 SA, VA, AA 이다. ====================================================================== You dream during REM sleep state. You can see video even if you're closing eyes. Friends in elementary school, monsters show up. The reason that those videos show up is that there can be no perception (comparing new stimulus to existing memory) in V1 area. That means that since visual sensory stimulus you'd experiences is stored in Va (visual associated area), you can recall those visual sensory stimulus If you consider above mechanism, you also can know that experiences that you'd had are also stored in sensory association area. Memories which are stored in sensory association area are accumulated. Strictly speaking, common pattern of those experiences is stored. This is called "categorization of concept" "Categorization of concept" is stored in SA, VA, AA. So, categorization of perception happens. ====================================================================== Categorization of concept: Stimulus is passed to circuit of from "sensory association cortext" to "association cortext" of prefrontal cortex, parietal lobe, temporal lobe, resulting in "perceived picture of world" And then, categorization of concept is formed by "perceived picture of world" being converted into property of abstractive relationship. You reconstruct "picture of outside world" around first and second cortex of visual, auditory, and somatic (I personally think this is related concept what I. Kant said in his recognition theory Even if there is true Universe, each one has different "picture of Universe") So, step where brain constructs "picture of world" is called as "categorization of perception" ====================================================================== When you say apple, you think of your own category of apple. each apply perceive step recall categorical memory of apple each real world apple you're seeing In step where you perceive "that's apple" when you see apple, first, you recall your own categorized memory of apple, second, you compare categorized memory of apple to current each apple you're seeing. This step is called perception. Perception is step where you recall stored memory subconsciously. ====================================================================== Step of working memory working is step where your brain compares "passed input stimulus into prefrontal cortex" to "categorized existing memories" Once working memory is formed via perception mechanism, next step is for perceived stimulus to move "pre motor" area to create movement response. If stimulus is the one which comes from outside (stimulus can be created from inside in body), it generally goes to PM area. From PM area, it goes to Primary Motor Area (M1) area to create movement response. From that M1 area, movement response goes along spinal cord, resulting in movements in hands, feet, and body. ====================================================================== Summary of recognition process. Let's call incoming thing as stimulus. Cerebral cortex can hold stimulus by storing stimulus into sensory memory for short time like 200 miliseconds to 500 miliseconds. To make above stimulus go into deeper process, you should pay attention to it. From attention, you'll analyze out of seen objects and heard sounds. In this process, perception mechanism should happen. To make perception mechanism happen, you should proceed steps where you refer, you compare stimulus to long-term memory by calling long-term memory. But also note that in this perception mechanism, you should still pay attention to stimulus. Mental phenomena only happens when you can pay attention to important factor out of entire stimulus, with comparing important factor and pattern of stimulus to existing long-term memory. ====================================================================== After perception, you need to select response. Is it possible perception happens without intervention of prefrontal cortex? It's possible. When people are in rem sleep, they have dream, doing perception. When people see object, anamal in dream, they know like that is wild boar, that is tiger. The reason that people can know object and animal in dream where activity of prefrontal cortex almost doesn't run is because perception mechanism happens. Since noradrenaline and serotonin are almost not released in prefrontal cortex during rem sleep, prefrontal cortex is not normal mode at that time. However, phenomenon where you can distinguish object and animal indicates that perception mechanism is possible using SA, VA, AA, even if prefrontal cortext almost doesn't run. It's because long-term memory is stored in SA, VA, AA ====================================================================== Response selection is not simple. It needs comparison step. It needs memory reference step where you compare current coming stimulus to past memory We call above step as working memory, which is generated and ocurred in prefrontal cortex, more specifically dorsolateral prefrontal cortex out of prefrontal cortex For this step, siginals which are categorized memory should come into to prefrontal cortext from 3 association areas You compare current coming stimulus to existing memory, as a result, you can select response. ====================================================================== 그 동안에 attention 이 워킹 메모리를 계속 장악하고 있어야 한다. response selection 하는 과정도 계속 attention 하고 있어야 한다. 그 과정에서 작업 메모리는 장기기억을 계속 붙잡고 있어야 한다. 한문제가 명쾌하게 인식이 되고 반응을 선택하는결과가 생길때까지 이 전체 정보의 흐름을 attention 이 계속 주의를 하고 감독을 해야한다. attention 기능이 핵심적인 기능이다. ====================================================================== If attention occurs in PFC area, which one is more inteligent betwen cat and dog? This is question which has answer in terms of neuroscience. Dogs are more inteligent than cats. To entire cerebral cortex, ratio of frontal lobe of cat is 3 percent. Dogs has 7 percent of frontal lobe out of entire cerebral cortex. Monkey has 11 percent, human has 30 percent. As this ratio of cerebral cortex, it's time for attention. ====================================================================== Cats jump and run to stimulations like ping-pong ball. Dogs have attention for long time when pet owner gives the meal. And even dogs follow the owner. In case of monkey, when you give some stimulations, they pay attention to them, when more strong stimulation comes, monkey can go there, and also back to previous stimulations. When another stimulation comes, those attentions become distracted again. ====================================================================== To achieve difficult job, you should grap attention for long time. That means you should continuously run and seize above attention circuit. In the end, you can select most proper response, and you can execute that proper response. Finally, response is made. Above theory is known as "human information process" by experimental psychologist Wickens from Illinois university. It's overall flow about how human can process stimulus in cerebral cortex. ====================================================================== 이 흐름에서 몇몇 파트가 작동하지 않을때 그 의미를 알수있다. 반응을 선택하는데 attention 을 하고 반응을 실행한다. 사람은 놀랍게도 선택된 반응을 실행하지 않을 때가 많다. 담배 끊겠다고 주장한다. 그런데 작심삼일. 하기로 했는데 못한다. 왜 그럴까? attention 이 약해서 그런거다. 중요한 일을 끝까지 하기위해서는 response execute 까지 attention 을 해야한다. ====================================================================== There is one mental disease where people know what happens, for example, why that person had diabete, why that person had obesity, and even that person knows how to resolve those problems, for example, by doing exercise, diet, but that person can't make it in action. This is essence of human stories. The reason that person can't make in action even if that one knows all of things is that attention functionality is weak. The bigger frontal lobe is, the better this attention functionality becomes. ====================================================================== From "response execute" step, it feedbacks to sensory stimulation again recursively. Since this circuit runs continuously, human can exercise, becoming painter like Picasso, novelist like Proust. The reason that person like Einstein shows up is that people can run above step of circuit continuously with feedbacks. ====================================================================== Semiconductor does precise memory. But memory of human is ambiguous memory. Since memory of human is ambiguous, the way that human does is to extract similar and common patterns. This way is called categorization. Only categorized information from sensory inputs is stored in 3 association areas. ====================================================================== Sensory stimulation is comming. But what is processed by perception is not entire sensory stimulation. Partial of them is processed by perception. Not all cognized information are processed in perception. People and cars go by (all information which are cognized), but people pay attention to traffic light. It means that small part from entire information is paid attention to. ====================================================================== Since LTM reference is required for perception, there is LTM in below level, then area which processes attention is working memory.