These neural circuits are composed of a number of neurons that communicate with one another through special junctions called synapses. Through a process involving the creation of new proteins within the body of neurons, and the electrochemical transfer of neurotransmitters across synapse gaps to receptors , the communicative strength of certain circuits of neurons in the brain is reinforced.
With repeated use, the efficiency of these synapse connections increases, facilitating the passage of nerve impulses along particular neural circuits, which may involve many connections to the visual cortex , the auditory cortex , the associative regions of the cortex, etc.
This process differs both structurally and functionally from the creation of working or short-term memory. Although the short-term memory is supported by transient patterns of neuronal communication in the regions of the frontal , prefrontal and parietal lobes of the brain , long-term memories are maintained by more stable and permanent changes in neural connections widely spread throughout the brain.
The hippocampus area of the brain essentially acts as a kind of temporary transit point for long-term memories, and is not itself used to store information. However, it is essential to the consolidation of information from short-term to long-term memory, and is thought to be involved in changing neural connections for a period of three months or more after the initial learning.
Unlike with short-term memory , forgetting occurs in long-term memory when the formerly strengthened synaptic connections among the neurons in a neural network become weakened, or when the activation of a new network is superimposed over an older one, thus causing interference in the older memory.
Over the years, several different types of long-term memory have been distinguished, including explicit and implicit memory , declarative and procedural memory with a further sub-division of declarative memory into episodic and semantic memory and retrospective and prospective memory.
Several studies have shown that both episodic and semantic long-term memories can be better recalled when the same language is used for both encoding and retrieval. Long-term memory encodes information semantically for storage, as researched by Baddeley. This is evidenced by the fact that the speed with which information is stored into long-term memory is determined by the amount of information that can be fit, at each step, into visual working memory.
Synaptic Consolidation is the process by which items are transferred from short-term to long-term memory. Within the first minutes or hours after acquisition, the engram memory trace is encoded within synapses, becoming resistant though not immune to interference from outside sources. This can happen quite naturally through reflection or deliberate recall also known as recapitulation , often dependent on the perceived importance of the material.
Using testing methods as a form of recall can lead to the testing effect , which aids long term memory through information retrieval and feedback.
Some theories consider sleep to be an important factor in establishing well-organized long-term memories. See also sleep and learning. Sleep plays a key function in the consolidation of new memories.
During waking life an executive function interprets long-term memory consistent with reality checking Tarnow It is further proposed in the theory that the information stored in memory, no matter how it was learned, can affect performance on a particular task without the subject being aware that this memory is being used. Newly acquired declarative memory traces are believed to be reactivated during NonREM sleep to promote their hippocampo-neocortical transfer for long-term storage.
The reactivation of memories during sleep can lead to lasting synaptic changes within certain neural networks. It is the high spindle activity, low oscillation activity, and delta wave activity during NREM sleep that helps to contribute to declarative memory consolidation.
In learning before sleep spindles are redistributed to neuronally active upstates within slow oscillations. Here, we examined the role of sleep in the object-place recognition task, a task closely comparable to tasks typically applied for testing human declarative memory: It is a one-trial task, hippocampus-dependent, not stressful and can be repeated within the same animal. The theory that sleep benefits memory retention is not a new idea. It has been around since Ebbinghaus's experiment on forgetting in More recently studies have been done by Payne and colleagues and Holtz and colleagues.
Both groups were given semantically related or unrelated word pairs, but one group was given the information at 9am and the other group received theirs at 9pm. Participants were then tested on the word pairs at one of three intervals 30 minutes, 12 hours, or 24 hours later. It was found that participants who had a period of sleep between the learning and testing sessions did better on the memory tests. This information is similar to other results found by previous experiments by Jenkins and Dallenbach It has also been found that many domains of declarative memory are affected by sleep such as emotional memory, semantic memory, and direct encoding.
Holtz  found that not only does sleep affect consolidation of declarative memories, but also procedural memories.
In this experiment fifty adolescent participants were taught either word pairs which represents declarative memory and a finger tapping task procedural memory at one of two different times of day. What they found was that the procedural finger tapping task was best encoded and remembered directly before sleep, but the declarative word pairs task was better remembered and encoded if learned at 3 in the afternoon.
The brain does not store memories in one unified structure, as might be seen in a computer's hard disk drive. Instead, different types of memory are stored in different regions of the brain. Long-term memory is typically divided up into two major headings: Explicit memory declarative memory refers to all memories that are consciously available.
These are encoded by the hippocampus , entorhinal cortex , and perirhinal cortex , but consolidated and stored elsewhere. The precise location of storage is unknown, but the temporal cortex has been proposed as a likely candidate.
Research by Meulemans and Van der Linden found that amnesiac patients with damage to the medial temporal lobe performed more poorly on explicit learning tests than did healthy controls. However, these same amnesiac patients performed at the same rate as healthy controls on implicit learning tests. This implies that the medial temporal lobe is heavily involved in explicit learning, but not in implicit learning. Episodic memory refers to memory for specific events in time, as well as supporting their formation and retrieval.
Some examples of episodic memory would be remembering someone's name and what happened at your last interaction with each other. Semantic memory refers to knowledge about factual information, such as the meaning of words.
Semantic memory is independent information such as information remembered for a test. Autobiographical memory refers to knowledge about events and personal experiences from an individual's own life. Though similar to episodic memory , it differs in that it contains only those experiences which directly pertain to the individual, from across their lifespan.
Conway and Pleydell-Pearce argue that this is one component of the self-memory system. Implicit memory procedural memory refers to the use of objects or movements of the body, such as how exactly to use a pencil, drive a car, or ride a bicycle.
This type of memory is encoded and it is presumed stored by the striatum and other parts of the basal ganglia. The basal ganglia is believed to mediate procedural memory and other brain structures and is largely independent of the hippocampus. Priming occurs when you do something faster after you have already done that activity, such as writing or using a fork.
Emotional memory , the memory for events that evoke a particularly strong emotion, is a domain that can involve both declarative and procedural memory processes. Emotional memories are consciously available, but elicit a powerful, unconscious physiological reaction. Research indicates that the amygdala is extremely active during emotional situations, and acts with the hippocampus and prefrontal cortex in the encoding and consolidation of emotional events.
Working memory is not part of long-term memory, but is important for long-term memory to function. Working memory holds and manipulates information for a short period of time, before it is either forgotten or encoded into long-term memory. Then, in order to remember something from long-term memory, it must be brought back into working memory.
If working memory is overloaded it can affect the encoding of long-term memory. If one has a good working memory they may have a better long-term memory encoding. Minor everyday slips and lapses of memory are fairly commonplace, and may increase naturally with age, when ill, or when under stress. Some women may experience more memory lapses following the onset of the menopause.
The majority of findings about memory have been the result of studies that lesioned specific brain regions in rats or primates, but some of the most important work has been the result of accidental or inadvertent brain trauma. The most famous case in recent memory studies is the case study of HM , who had parts of his hippocampus, parahippocampal cortices , and surrounding tissue removed in an attempt to cure his epilepsy.
His subsequent total anterograde amnesia and partial retrograde amnesia provided the first evidence for the localization of memory function, and further clarified the differences between declarative and procedural memory. Many neurodegenerative diseases can cause memory loss. Some of the most prevalent and, as a consequence, most intensely researched include Alzheimer's disease , dementia , Huntington's disease , multiple sclerosis , Parkinson's disease , and schizophrenia.
None act specifically on memory; instead, memory loss is often a casualty of generalized neuronal deterioration. Currently, these illnesses are irreversible, but research into stem cells, psychopharmacology, and genetic engineering holds much promise. Those with Alzheimer's disease generally display symptoms such as getting momentarily lost on familiar routes, placing possessions in inappropriate locations and distortions of existing memories or completely forgetting memories.
The DRM paradigm presents a list of words such as doze, pillow, bed, dream, nap, etc. In this case the theme word would have been sleep. Alzheimer's disease patients are more likely to recall the theme word as being part of the original list than healthy adults.
There is a possible link between longer encoding time and increased false memory in LTM. The patients end up relying on the gist of information instead of the specific words themselves. This gets worse over time and eventually leads to cognitive decline, after the loss of memory.
Long-term memory is, obviously enough, intended for storage of information over a long period of time. Despite our everyday impressions of forgetting, it seems likely that long-term memory actually decays very little over time, and can store a seemingly unlimited amount of information almost indefinitely.
Long-term memory refers to the storage of information over an extended period. If you can remember something that happened more than just a few moments ago whether it occurred just hours ago or decades earlier, then it is a long-term memory.
ROM, or read only memory, is a computer's long-term memory and is used to store data even after the computer is turned off. An example of ROM is a computer's hard drive, which is where most people choose to save documents, pictures, music and more. Long-Term Memory vs. Short-Term Memory. At the core of every computer is its capacity to remember things: sets of instructions, particular files you've created, how much memory is left, where you put your keys. Computers store all this memory in two distinct ways. The main memory bank is called the hard drive. It stores all the files you save.
One of the first signs of dementia is short-term memory loss. People who have been victims of or witnessed a traumatic event such as a violent crime or accident can also have their short-term memories affected. Short-term vs. long-term memory. Short-term memory is the information that a person is currently thinking about or is aware of. Bahrick et al. () investigated what they called very long term memory (VLTM). Nearly participants aged 17 – 74 were tested. There were various tests including: A free recall test, where participants tried to remember names of people in a graduate class. A photo recognition test, consisting of 50 nejigowejiri.ga: Saul Mcleod.