 Learning means acquiring knowledge, while memory involves encoding the knowledge which is acquired, storing it and retrieving it when needed. Memory is classified as working memory, short term memory and long term memory. So before going into the types of memory, let us see little bit fundamental so that we understand little bit about learning as well. So as I said memory is classified as working memory, short term memory and long term memory. See basically the distinction between these types of memory is based on the time for which any information can be stored and as the term indicates long term memory means that information can be stored for very long maybe for years as well. While working memory and short term memory are kind of taken similar to each other where a short term memory is where we can keep the information for some time and maintain it there. So suppose we are acquiring new information we can keep it in short term memory and the long term memory which has been stored we can even retrieve some information from the long term memory and keep it in short term memory for some time. And working memory is basically a type of short term memory where we are using the short term memory and manipulating it to fulfill some task. For example we have to solve an equation what that we need to retrieve some information from the long term memory keep it in short term memory and utilize that short term memory along with the task in hand to solve the task. So that is the main distinction between the different types of memory. By the way how do we actually learn? See we learn anything that is acquired knowledge about anything by mainly three pathways that is visual pathway for example seeing anything new then auditory pathway for example listening to podcast talking with other people and somatic information that is by means of touching anything and maybe walking on a new road and feeling the new road that is also a kind of new information. But as you might have guessed it's not that all these three different types of acquiring information work in isolated manner generally we are surrounded by all types of information and we are acquiring knowledge by multiple means. Now when we acquire new information this information passes to three polymodal association areas. So there is the main sensory area for the way of acquiring knowledge for example for vision it will be visual cortex and then there are the association area so basically the information is passing to three polymodal association areas and these areas are prefrontal cortex, limbic system and paritooccipitotemporal cortices. Now these areas are very important for synthesis of acquired information and by synthesis here we mean that we are seeing the new information along with any prior information which is stored in our long term memory. For example suppose there is a new information suppose you are looking at a colosseum where gladiators used to fight now you are acquiring new information. Now suppose there is another person who has already read a great deal about Rome and has some parts of it is stored in his memory already. The synthesis of new information which will occur in these two people one who has already read and there is another person who is not well read and he is just seeing it for the first time. The synthesis of information is different in these two people because this person with already some prior knowledge will draw in the existing information from his memory what is known as retrieval of memory and synthesis of newly acquired information with existing information will take place. But what about the first person? Is his brain blank? No it's not like that. See this person has some information about some other aspects maybe the size of the building, the types of the buildings and he will retrieve that kind of information anything associated with the new information and his synthesis of new information will take place in that particular context. Okay with this basics about learning and memory let's try to see the different types of memory. Memory as I told before it is working memory short term memory and long term memory and I also told the distinction between these two different types of memory. Now the types of memory is further divided into different types based on the type of information that is the different types of learning which are happening. Whether it is a skill, whether it is a factual knowledge and if it is a skill then what kind of skill it is. So based on whether conscious awareness is involved or not memory is broadly classified into implicit memory and explicit memory. Implicit memory is also known as non declarative memory that is a memory which cannot be recalled consciously and it is very difficult to declare it verbally. So this is for basically skills and procedures which we have long learnt for example suppose you have already acquired the skill of cycling right. So now after years if somebody asks you how you cycle explain it it will be very difficult to do it you will better write it and show it rather than explaining each and every word of it. On the other hand explicit memory is also known as declarative memory and it is for factual knowledge of peoples and places and meaning of things. And to add in that cycling example I will say that when we are learning about cycling then knowing about the factual knowledge about cycling, how to step, how to move your leg. That is all explicit memory while we are learning but after years when the skill has been learnt then it goes into implicit memory. So basically explicit memory is recalled by conscious effort. So we have to deliberately think about the phenomena and be conscious about it so that is explicit memory. Now these broad categories of implicit memory and explicit memory are further classified into different types. So implicit memory is classified into priming then procedural skills and habits and then there is associative learning which is acquired by classical and operant conditioning. And finally there is non associative learning acquired by habituation and sensitization. So implicit memory four types priming, procedural skills and habits. Then the information acquired by associative learning goes as implicit memory and the information acquired by non associative learning like in habituation and sensitization also goes into implicit learning. On the other hand for explicit memory we have two types one is episodic memory and semantic memory. So let us see what are these different types of information and memory and where they are actually stored. So priming is basically recall of information based on a cue. For example recall of words starting with a particular letter. This type of information is stored in neocortex. On the other hand procedural skills and habits like habit of sitting in a certain position in a certain way. These are stored in basal ganglia in striatum. Then associative learning that is a learning which happens when there is a relationship between two different stimulus as in classical conditioning or relationship between stimulus and response as in operant conditioning. Again are stored in different areas based on response to the stimulus or action involved. If the responses have an emotional component then the storage is occurring in amygdala. If the responses involuntary response like in saliva secretion in response to Bell the classical example which we see for classical conditioning. These are stored in other areas of limbic system and if the response involves skeletal muscle as a pressing liver provides food that is what we see in operant conditioning then they are stored in cerebellum. Then the next one is non-associative learning. Non-associative learning which involves habituation that is a decrease in response to repeated non-noxious stimulus and sensitization that is increased response to non-noxious stimulus after application of a noxious stimulus. These are basically reflex responses and are stored in reflex pathways in sensory and motor system. Now let's see the types of explicit memory. Explicit memories of two types we said episodic and semantic. So what do these words means? Semantic knowledge actually is knowledge of objects, facts and concepts. The meaning of words. What do the words actually mean? So that is semantic knowledge. So basically it is memory for facts. On the other hand episodic memory is for the episodes as the term indicates. So episode means for events and personal experience. So the term itself will tell you about the episodic memory. So for example if there is a party then what exactly happened in the party in what sequence? So that is an episode. Now both of these types of memory are stored in distributed fashion in neocortex and this happens via medial temporal lobe. There is a hippocampus in medial temporal lobe. So information goes via polymoral association areas which we discussed in the beginning to the hippocampus and then again from the hippocampus back into the polymoral association areas which we had spoken. So in different areas in the neocortex this memory is being stored. I'll just give you an example. Suppose you think about elephant. Then what comes in your mind? Well you think yes it is a large animal then the color of the elephant is grey. Then how it looks like, where it lives, what it eats, what kind of sound it makes. Now when we are thinking about elephant it's not that the entire information of elephant is stored in one particular place. Actually the information is bracketed into different different categories. For example the sound goes into a different area where it lives goes into a different area. How it looks is stored in a different area. However when we think about the name elephant because of the connections from here with the other areas of the neocortex we get holistic recall of the entire knowledge about the elephant. Similarly when we talk about some other animals similar the sound of that animal will go into the bracket of the sound. So there are various draws we can say like that which are storing different different kinds of information. And when any particular information is retrieved for example we were talking about the name of the elephant. But suppose you hear about the sound coming from an elephant you are sitting in one room and suddenly you hear that sound. You will immediately recall about elephant. So because these different informations are connected together by means of neurons you get a holistic recall of the entire information. So in summary basically there is storage of category specific knowledge in the neocortex. Fine. So in this video we basically learnt about fundamentals of learning and memory and the types of learning and memory. Well thanks for watching the video if you liked it do press the like button share the video with others and don't forget to subscribe to the channel Physiology Open. Thank you.