7.3: The Biology of Memory

It can be difficult for researchers to draw conclusions about people's life histories.

Our current psychological state can affect our memories.
People with clinical depression report being treated more harshly by their parents than people without depression.
There is an explanation for the Ruling Out Rival Hypotheses finding.

The depressed participants recalled their parents as rejecting and domineering towards them as children than did the other two groups.

Participants' moods seem to have an effect on their evaluations of how their parents treated them.

To overcome the challenges posed by retrospective biases arising from mood-related disorders, researchers are increasingly turning to methods that monitor participants' recollections in real time, such as by beeping them during the day at random intervals.

The impairments of Alzheimer's disease are identified.

The biology of memory plays a significant role in our daily lives, whether it's remembering where we left our keys or the name of the friendly person we met at last night's party.
Understanding how our brains store memory may help us find ways of treating devastating diseases that impair our ability to recall everyday events.

Locating a library book is fairly easy.

We look it up in our library's online system, write down its number, and then go to the shelf to find it.
It is on the shelf where it is supposed to be.
As we'll soon see, memory storage in the brain isn't quite this cut and dry.

Rats were taught how to run mazes and had their brains looked at to see if they forgot how to find their way.

Lashley wanted to find out where memory is stored in the brain.
He came up empty-handed after years of hard work.

Lashley learned two things.

The worse the rats performed on the maze, the more brain he removed.

Rats' cortices didn't erase the memory even if half of Watch Neuroscience of Memorial was removed.

V is not located in a single place like a library book is.

Scientists have learned that memories of different features of experiences, like sound, sight, and smell, are stored in different brain regions.

There are groups of brain cells.

Hebb states that one neuron becomes connected to another when it is repeatedly activated.

Our experience of the world is transformed into lasting, perhaps even lifelong, memories by the interplay of neurotransmitters and sensory information.

Can the results be duplicated?

Hebb was correct to a large extent.

Ruling Out Rival Hypotheses is unresolved because of the question of whether LTP is directly responsible for the storage of memories or if it affects learning indirectly by increasing arousal and attention.

Most scientists agree that LTP plays a key role in learning and that the hippocampus plays a critical role in forming lasting memories.

A research team was able to create a "super smart mouse" by manipulating its genes.

The super smart mouse is an especially quick and effective learner.

The hippocampus is important to memory.

Some researchers have identified the neurons in the hippocampus that fire in response to certain celebrities, such as actress Halle Berry.
Clark's nutcracker, a remarkable North American bird, is a source of evidence for the role of the hippocampus in memory.
Clark's nutcracker has a large hippocampus, which may explain its exceptional spatial memory.

With some certainty, we can say that the answer is no.

Studies show that learned information isn't permanently stored in the hippocampus.
The prefrontal cortex seems to be one of the major "banks" from which we withdraw our memories.
Lashley discovered that damage to isolated areas of the prefrontal cortex doesn't wipe out long-established memories.

We learned about implicit and explicit memory.

Two forms of memory are governed largely by different brain systems, although memory systems across the brain interact to shape our experiences and memories, whether they're implicit or explicit.

Contrary to popular belief, generalized amnesia--in which people can't remember anything from their past life--is very rare.

People with brain damage are more likely to have retrograde amnesia than other people.
Recovery from amnesia tends to occur gradually, if at all, despite the fact that many Hollywood films depict it as abrupt.

H. M., a man from Connecticut, was the best-known person with amnesia because of his epileptic seizures.

In a last-ditch attempt to eliminate these seizures, surgeons removed large chunks of H. M.'s temporal lobes, including his left and right hippocampi, where they had reason to believe the seizures originated.
H. M was 26 years old at the time.
H. M. developed complete anterograde amnesia after the operation.
His memories from the first 15 years of his life were unaffected by retrograde amnesia he experienced for 11 years prior to the surgery.

H. M.'s life was frozen in time after his surgery.

He was oblivi to H. M.

The current date is March 1953, two years after the operation.

The task is used to assess the same jigsaw puzzles over and over again without any awareness of having seen implicit memory.
He didn't remember meeting physicians who he met just a few minutes after looking at a mirror.

Each time he was told of his uncle's death, he showed a lot of grief.

The identity of H. M. was revealed after his death in December of 2008.
He had no new explicit memories for 55 years.
According to one author, H. M may have suffered damage to his brain during surgery, which may explain his memory impairment.

The tragic case of H. M., like that of Damasio's patient David, shows a dis sociation between explicit and implicit memory.

H. M. was asked to trace simple geometric shapes from a mirror, a task that just about all people find hard to do.
H. M. had no recollection of performing this task before, but his performance improved over time.
H. M. had no memory for this task, but he displayed implicit memory for it.

H. M.'s brain was found to have been damaged when researchers looked at it using techniques.

The case of Clive Wearing, a former music producer in Great Britain who lost his brain in 1985 due to a herpes virus, shows that there is a distinction between explicit and implicit memory.

Like H. M., Clive has anterograde amnesia.
Figure 7.16 Emotional Memories and the Brain shows how he showers his wife with affection when she leaves the room.

According to Clive Research, the amygdala helps us remember the fear associated with scary and the hippocampus helps us remember the experiences themselves.

He ignores why he says that when his wife says "St.

Mary's."
St. Mary's Paddington was the hospital where Clive Wearing was taken after he got sick.

implicit memory is unaffected by damage to the hippocampus.

We think of memories as our good friend, a lifelong companion that helps us to store useful information, so that we can cope with our environment.

During the rape scene, she had vivid visions of leather, alcohol, and Old Spice, which caused her to retreat to a closet and engage in selfdestructive behavior.

The emotional components of these and other memories are stored in the amygdala.

Each structure contributes different information when the amygdala interacts with the hippocampus.
Two patients identified by their initials, S. M. and W. S., suffered damage to the amygdala and hippocampus, respectively.
The patient with amygdala damage who is featured in the chapter-opening video for Chapter 11 did not experience the fear that he remembered.
The patient with hippocampal damage experienced fear, but not the facts surrounding it.
The amygdala and hippocampus help us remember fear-inducing events, while the hippocampus helps us remember the events themselves (Fitzgerald et al., 2011; Marschner et al., 2008).

Erasing painful memories.

Even if emotional memories become distorted over time, they can still persist.
In the face of stress, the hormones adrenaline and norepinephrine are released into the air and stimulated on nerve cells, which solidify emotional memories.

The staying power of emotional memories was demonstrated by Lawrence and James McGaugh.

They told two stories about the slides they showed.
Half of the participants were told a story about a boy's visit to the hospital where his father works.
In the middle of the story, they told participants that the boy was injured and had to have his legs reattached.
After participants returned for a memory test 24 hours later, they were asked what they remembered.
The best recall for the part of the story about the boy's trauma was displayed by participants who heard the emotionally arousing story.
The participants who heard the neutral story recalled the same amount of detail.

The experiment was conducted with an interesting twist.

The participants didn't show good recall for the emotional part of the story when their adrenaline was reduced.
Individuals who listened to the emotionally neutral story recall the same thing.

According to Roger Pitman, propranolol might hurt the memories of real-life traumas.

After a traumatic event, such as a car accident, Pitman and his colleagues gave people propranolol for 10 days and then looked at their physical reactions to individually prepared tapes.
Forty percent of participants who received a placebo showed a physical response to the tape.
None of the people who received the drug did.
There is a suggestion that propranolol be used in combination with psychotherapy to prevent the development of long- lasting stress reactions after a traumatic event.

The effects of traumatic memories were only mitigated by Pitman's pill.

The findings have been replicated by other investigators using different designs.

Can the results be duplicated in difficult questions about whether the procedures are ethical?

When we reach the ripe old age of 65, we begin to experience memory problems and some brain damage.

Despite what many people believe, senility isn't an unavoidable part of aging, and some can make it past 100 with only modest amounts of forgetfulness.
Scientists don't agree on how much memory loss is normal during the advanced years.
Some people argue that we don't need to accept memory impairment as normal.
A longitudinal study of participants aged 59 to 84 years at baseline showed small but consistent reductions in the overall area of the cortex.
We might assume that subtle cognitive decline would accompany these tissue losses.
The amount of tissue loss can be ruled out by a criti Ruling Out Rival Hypotheses.

Many people think that senility is related to Alzheimer's disease.

The Alzheimer's Association says Americans will develop Alzheimer's disease every 33 seconds.

The risk for Alzheimer's disease is higher for people older than 65 years of age.
14 to 16 million Americans are projected to develop Alzheimer's disease by mid-century if a cure can't be found, with the "graying" of the U.S. population expected to become even more of a concern.

Changes in the Brain of Patients with both memory and language related impairments correspond to Alzheimer's Disease.

The changes include enlargement of the ventricles and the loss of memory begins with recent events.

They don't know where they are, what year it is, or who the current president is.

Language tangles are seen in LO 3.1d.

Ventricle is related to intellectual status with greater loss as the disease progresses.

This result doesn't necessarily mean that the reduction in Correlation causes the memory decline.