Where in the Brain Are Long Term Memories Stored

Learning Objectives

By the end of this section, you leave personify able to:

• Explicate the brain functions up to their necks in memory
• Recognize the roles of the hippocampus, amygdala, and cerebellum

Are memories stored in clean one component of the mind, operating theater are they stored in many disparate parts of the brainpower? Karl Lashley began exploring this trouble, about 100 years ago, by making lesions in the brains of animals much as rats and monkeys. He was searching for evidence of the engram: the group of neurons that serve as the "physical representation of storage" (Josselyn, 2010). Get-go, Lashley (1950) trained rats to find their way through a maze. Past, he used the tools available at the time—in this cause a soldering smoothing iron—to create lesions in the rats' brains, specifically in the intellectual cortex. He did this because he was trying to wipe out the engram, or the original memory trace that the rats had of the snarl.

Lashley did non find demonstrate of the memory trace, and the rats were still capable to find their way through the maze, regardless of the size or location of the lesion. Supported on his creation of lesions and the animals' reaction, he formulated the equipotentiality hypothesis: if part of unmatchable area of the mastermind involved in memory is damaged, other part of the same area tail take over that memory social function (Lashley, 1950). Although Lashley's proto work did not sustain the beingness of the memory trace, modern psychologists are making progress localisation information technology. Eric Kandel, for example, spent decades working on the synapse, the basic structure of the brain, and its role in controlling the flow of information through neural circuits needed to store memories (Mayford, Siegelbaum, & Kandel, 2012).

Many scientists believe that the entire brain is involved with memory. However, since Lashley's enquiry, other scientists own been fit to look more closely at the brain and memory. They have argued that memory is set in specific parts of the brain, and specific neurons can be recognized for their involvement in forming memories. The main parts of the brain involved with memory are the amygdala, the genus Hippocampus, the cerebellum, and the anterior cortex ([link]).

The amygdala is up to his neck in fear and fear memories. The hippocampus is associated with declarative and impermanent memory too as acknowledgment memory. The cerebellum plays a role in processing procedural memories, such as how to play the piano. The prefrontal cortex appears to be involved in remembering semantic tasks.

THE AMYGDALA

Early, let's look at the role of the amygdala in memory formation. The main Book of Job of the amygdaloid nucleus is to regulate emotions, so much as fear and aggression ([link]). The corpus amygdaloideum plays a part in how memories are stored because storage is influenced away stress hormones. For example, one researcher experimented with rats and the fear response (Josselyn, 2010). Using Pavlovian conditioning, a neutral intone was paired with a foot shock to the rats. This produced a fear retentivity in the rats. After being conditioned, each prison term they detected the tone, they would freeze (a defense response in rats), indicating a memory for the impending shock absorber. Then the researchers induced cell death in neurons in the distal amygdala, which is the peculiar arena of the brain responsible fear memories. They base the venerate store faded (became extinct). Because of its role in processing emotional selective information, the corpus amygdaloideum is likewise involved in memory consolidation: the process of transferring new encyclopaedism into LTM. The corpus amygdaloideum seems to alleviate encoding memories at a deeper even out when the issue is emotionally arousing.

Link to Learning

In this TED Talk called "A Mouse. A Laser Beam. A Manipulated Memory," Steve Ramirez and Xu Liu from MIT talk about using laser beams to manipulate fear memory in rats. Come up out why their work caused a media frenzy once it was promulgated in Science.

THE HIPPOCAMPUS

Other group of researchers as wel experimented with rats to learn how the genus Hippocampus functions in store processing ([link]). They created lesions in the hippocampi of the rats, and found that the rats demonstrated memory impairment on versatile tasks, such as objective credit and maze running. They concluded that the hippocampus is knotty in memory, specifically normal identification memory too every bit spatial retentiveness (when the memory tasks are like recall tests) (Clark, Zola, & Squire, 2000). Another subcontract of the hippocampus is to project information to cortical regions that give back memories meaning and connect them with other connected memories. It also plays a part in memory consolidation: the process of transferring new encyclopedism into LTM.

Injury to this surface area leaves us unable to process early declarative memories. One famous patient, known for years only as H. M., had both his left field and right-minded temporal lobes (hippocampi) removed in an set about to help master the seizures atomic number 2 had been suffering from for old age (Corkin, Amaral, González, Johnson, & Hyman, 1997). As a result, his declarative memory was importantly affected, and he could not form new linguistics knowledge. He lost the ability to form new memories, yet he could still remember information and events that had occurred preceding to the surgery.

Link to Learnedness

For a closer look at how memory kit and boodle, as well as how researchers are now studying H. M.'s brain, take a few minutes to aspect this video from Nova PBS.

THE CEREBELLUM AND Anterior Cerebral mantle

Although the hippocampus seems to be more of a processing domain for explicit memories, you could still lose information technology and be able to produce implied memories (procedural memory, efferent acquisition, and classical conditioning), thanks to your cerebellum ([link]). For instance, one classical conditioning experiment is to habituate subjects to blink when they are presumption a puff of send. When researchers mutilated the cerebellums of rabbits, they discovered that the rabbits were not able to learn the conditioned middle-blink response (Steinmetz, 1999; Green & Woodruff-Pak, 2000).

Other researchers have used brain scans, including positron emission imaging (PET) scans, to learn how people outgrowth and keep on data. From these studies, it seems the anterior cortex is involved. In unrivalled canvas, participants had to complete two different tasks: either looking for the letter a in words (considered a perceptual task) OR categorizing a noun as either surviving or non-living (considered a semantic task) (Kapur et aluminium., 1994). Participants were past asked which words they had previously seen. Echo was practically better for the semantic task than for the sensory activity chore. According to Best-loved scans, there was much more energizing in the left inferior prefrontal pallium in the semantic task. In another work, encryption was associated with left frontal activity, while recovery of selective information was associated with the right frontal region (Craik et alibi., 1999).

NEUROTRANSMITTERS

There also appear to be specific neurotransmitters involved with the process of store, such as epinephrine, Intropin, serotonin, glutamate, and acetylcholine (Myhrer, 2003). There continues to be discussion and debate among researchers as to which neurotransmitter plays which specific role (Blockland, 1996). Although we don't yet make out which role apiece neurotransmitter plays in memory, we do make out that communication among neurons via neurotransmitters is life-threatening for developing inexperient memories. Repeated activity by neurons leads to increased neurotransmitters in the synapses and more effective and more conjugation connections. This is how memory consolidation occurs.

It is also believed that effective emotions set off the shaping of strong memories, and weaker schmalzy experiences form weaker memories; this is titled foreplay theory (Christianson, 1992). For example, well-set emotional experiences arse trigger the release of neurotransmitters, also As hormones, which strengthen memory; therefore, our store for an emotional event is normally better than our memory for a not-emotional event. When humankind and animals are stressed, the brainiac secretes more of the neurotransmitter glutamate, which helps them think back the stressful event (McGaugh, 2003). This is clear evidenced by what is known as the flashbulb memory phenomenon.

A flashbulb memory is an exceptionally clear recollection of an important consequence ([link]). Where were you when you first detected about the 9/11 terrorist attacks? Most likely you can remember where you were and what you were doing. In fact, a Pew Inquiry Center (2011) survey found that for those Americans who were eld 8 operating theatre older at the sentence of the event, 97% can recall the bit they well-educated of this event, even a decade after it happened.

Most people prat remember where they were when they first heard about the 9/11 violent attacks. This is an example of a flashbulb retention: a tape of an atypical and unusual event that has same strong emotional associations. (credit: Michael Foran)

Turn over Deeper: Inaccurate and False Memories

Even flashbulb memories toilet have decreased accuracy with the passage of time, still with very important events. For example, along leastwise tercet occasions, when asked how He heard about the terrorist attacks of 9/11, President George W. Bush responded inaccurately. In January 2002, less than 4 months after the attacks, the then sitting President Bush was asked how he heard about the attacks. Atomic number 2 responded:

I was sitting in that location, and my Chief of Staff—well, first, when we walked into the classroom, I had seen this plane fly into the first building. There was a TV correct on. And you know, I thought it was pilot erroneous belief and I was amazed that anybody could make so much a wicked mistake. (Greenberg, 2004, p. 2)

Contrary to what Prexy Bush recalled, no one saw the first plane hit, leave off people on the ground near the twin towers. The first of all plane was not videotaped because it was a normal Tuesday aurora in New York Metropolis, until the first plane hit.

Some multitude attributed Bush's wrong recall of the case to conspiracy theories. However, there is a much more benign account: human memory, flatbottom flash lamp memories, lav be frail. As a matter of fact, memory can be so delicate that we can convert a somebody an event happened to them, justified when information technology did not. In studies, enquiry participants will recall listening a word, even though they never detected the give voice. For example, participants were given a tilt of 15 sleep-related words, but the word "nap" was not on the list. Participants recalled earshot the word "sleep" even though they did not in reality hear it (Roediger & McDermott, 2000). The researchers who ascertained this onymous the theory after themselves and a fellow researcher, calling it the Deese-Roediger-McDermott paradigm.

Summary

Beginning with Karl Lashley, researchers and psychologists take up been searching for the engram, which is the physical trace of memory. Lashley did non find the engram, but helium did suggest that memories are distributed throughout the entire brain rather than stored in matchless specific area. Now we know that three brain areas do take on significant roles in the processing and storage of different types of memories: cerebellum, genus Hippocampus, and amygdala. The cerebellum's caper is to march procedural memories; the hippocampus is where new memories are encoded; the amygdala helps limit what memories to store, and it plays a break u in crucial where the memories are stored based on whether we have a strong or weak schmalzy response to the event. Strong emotional experiences can trigger the sack of neurotransmitters, as well as hormones, which tone memory, so that memory for an emotional event is ordinarily stronger than memory for a non-emotional outcome. This is shown by what is called the flashbulb storage phenomenon: our ability to remember evidential life events. Yet, our memory for life events (autobiographical memory) is non always accurate.

Self Check Questions

Critical Thought Interview

1. What might happen to your memory system if you sustained harm to your hippocampus?

Personal Application Question

2. Describe a flashbulb memory of a significant event in your life.

Answers

1. Because your hippocampus seems to be more of a processing area for your explicit memories, accidental injury to this area could leave you unable to action new declarative (unambiguous) memories; however, even with this loss, you would make up able to make over implicit memories (proceedings memory, motor learning and classical conditioning).

Glossary

rousing theory strong emotions trigger the formation of brawny memories and weaker emotional experiences form weaker memories

engram physical shadow of memory

equipotentiality supposition just about parts of the brain can bear for tarnished parts in forming and storing memories

flashbulb memory exceptionally semitransparent recollection of an important issue

Where in the Brain Are Long Term Memories Stored

Source: https://courses.lumenlearning.com/wsu-sandbox/chapter/parts-of-the-brain-involved-with-memory/

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