Reliability: Capable of being relied on; dependable.

The two perspectives: Is memory as a cognitive process reliable?

Perspective 1: Memory is reliable (our brain recalls the details of our experiences that are deemed “important”)

Perspective 2: Memory is not reliable (through false memories, cultural schemas, encoding failure, etc.)

Although many researchers argue that memory is reliable from the “personal” significance standpoint.

I will present a case of the unreliability of memory from multiple perspectives.

The brain's main depressant neurotransmitter GABA regulates how easily we form new neural connections when presented with new sensory information.

It has been known for some time that the connections between neurons in the hippocampus, the brain's main memory center, vary significantly in strength.

The variation in strength, however, turns out to correlate with the ability to form new memories, reports a Tel Aviv research team in the August 2010 issue of "Neuron."

The researchers found that GABA weakens synaptic connections between neurons in the hippocampus, allowing for new memories to form.

Impairments to the GABA pathway or an increase in chemicals that strengthen synaptic connections are thus significant predictors of encoding failure or memory loss.

Memory is often unreliable because we fail to encode the information. So the information never entered the long-term memory.

Encoding efficiency is affected by age, which explains age-related memory decline.

The brain areas that are active when encoding new information are more responsive in young adults than in old adults.

This would suggest that memory unreliability can be due to biological factors beyond our control (such as neurotransmission that may cause attention deficit, lesions in the hippocampus, etc.)

Nevertheless, young or old, we are selectively attentive. We encode some information automatically, but other types of information require effortful processing.

So without effort, many memories never form. For example, we have a hard time remembering how a real penny looks like because its details are not that critical or meaningful.

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We cannot remember what we do not encode.

The idea that we do not remember things as they actually happened is usually attributed to Sir Frederick Bartlett (1886-1969)

He describes the process of memory in his classic 1932 book, Remembering: A Study in Experimental and Social Psychology:

Bartlett stated:Remembering is not a completely independent function, entirely distinct from perceiving, imaging, or even from constructive thinking, but it has intimate relations with them all…

One’s memory of an event reflects a blend of information contained in specific traces encoded at the time it occurred, plus inferences based on knowledge, expectations, beliefs, and attitudes derived from other sources.

According to Bartlett, memories are organized within the historical and cultural frameworks (which Bartlett called ‘schemata’) of the individual, and the process of remembering involves the retrieval of information which has been unknowingly altered in order that it is compatible with pre-existing knowledge.

Thus, even the way we encode our experiences is subjective to the cultural and social context of the experience.

Bartlett’s research on reconstructive memories inspired many psychologist including Elizabeth Loftus.

Elizabeth Loftus, a professor of psychology and law at the University of California, Irvine, has devoted her career to studying the reconstructive nature of memory in relation to eyewitness testimony.

Her research strongly supports that idea that memories can be reconstructed and unreliable.

Loftus’ research has applied the idea of unreliability to memories to real world situations such as eye witness testimonies and false memories.

Loftus’ research has applied the idea of unreliability to memories to real world situations such as eye witness testimonies and false memories.

Loftus is concerned mainly with how the recollections of eyewitnesses can be deliberately manipulated by misinformation.

In extreme cases, this can lead to completely false memories of events that did not take place.

One of Loftus’s more famous studies addresses the use of ‘leading’ questions in the courtroom.

In the study, students were shown film clips of a car accident, and then asked a question about the accident.

Those asked “About how fast were the cars going when they smashed into each other?” gave answers which averaged about 39 mph, whereas those asked “About how fast were the cars going when they contacted each other?” gave answers with an average speed of 32 mph

Loftus’s research, like that of Bartlett’s, shows that our memories are quite often not as accurate as we would like to think they are.

The knowledge that memory is to some extent confabulation has very serious implications for the use in the courtroom of eyewitness testimonies, because if eyewitness testimonies can be unreliable, then the validity of criminal convictions based upon them is open to question.

Some people would have us think that the memory is like a tape recorder that records every event accurately and keeps it intact.

But, research on memory has debunked that myth and raised many questions about common misconceptions about remembering and even our creation of false memories.

For instance, how accurate are childhood memories? Does the vividness of the recall increase the validity of a memory?

The Swiss psychologist Jean Piaget describes a clear memory from his own early childhood:

“I can still see, most clearly, the following scene, in which I believed until I was about fifteen. I was sitting in my pram, which my nurse was pushing in the Champs Elysées, when a man tried to kidnap me. I was held in by the strap fastened round me while my nurse bravely tried to stand between me and the thief. She received various scratches, and I can still see vaguely those on her face. Then a crowd gathered, a policeman with a short cloak and a white baton came up, and the man took to his heels. I can still see the whole scene, and can even place it near the tube station.”

Notice the details of this memory. Nevertheless, Piaget then says his clear memory is of an event that never happened. His nurse had confessed when he was about fifteen years old. Piaget says:

She had made up the whole story, faking the scratches. I, therefore, must have heard, as a child, the account of this story, which my parents believed, and projected into the past in the form of a visual memory.

Thus, our brains can encode memories, erroneously, from other things that we experience.

Loftus begins her book Memory: Surprising New Insights into How We Remember and Why We Forget by describing her own memory of her father after he died. At first, her thoughts of him were filled with recent images of him suffering the final stages of cancer. She says:

Then, gradually, my thoughts of him began to include some happier images. I saw him standing in the yard, holding a scrawny cat. I saw him in the living room surrounded by smiling family. I even thought about him holding me on his lap when I was no older than four.

Then she realized the source of those memories. She had photographs of each event. She was remembering the pictures.

Thus, her memory was enhanced by additional visual information.

Remembering is not running an invisible tape recorder back to an event.

It is pulling together bits and pieces of information that logically fit together.

Even immediate recall may be inaccurate simply because of an initial failure to perceive accurately.

That is why two people who recall a particular event may have two completely different stories. Can our memories of the past change with clarity or suggestion from others?

Memories are also very malleable. They change even as we recall past events.

Loftus says:

With the passage of time, with proper motivation, with the introduction of special kinds of interfering facts, the memory traces seem sometimes to change or become transformed.

These distortions can be quite frightening, for they can cause us to have memories of things that never happened.

Further research:

Loftus Study on Reconstructive memorieshttps://webfiles.uci.edu/eloftus/LoftusPalmer74.pdfFalse memorieshttp://www.ishk.net/myth_of_repressed_memory.pdf

Attentional Bias – implicit cognitive bias defined as the tendency of emotionally dominant stimuli in one's environment to preferentially draw and hold attention.

Confirmation bias – the tendency to search for or interpret information in a way that confirms one's preconceptions

Hindsight bias – sometimes called the "I-knew-it-all-along" effect, the tendency to see past events as being predictable[31] at the time those events happened.(sometimes phrased as "Hindsight is 20/20")

Researchers employ a variety of techniques to investigate brain activity, though in the ever-changing landscape of technology, these methods continue to evolve.

Under the assumption that states “cognitive processes have a biological origin, we can investigate cognitive process through physiological processes.

Two of the more traditional methods used to study the brain include position emission tomography (PET) and functional MRI (fMRI) scans.

During a PET scan, a patient is injected with a dose of radioactive compound, typically flourodeoxyglucose (FDG), a type of glucose molecule.

Once the FDG is in a person's blood, it is carried to the brain, where it is absorbed. Glucose (a type of sugar) is the brain's primary energy source so the active regions soak it up -- the more active the area of the brain, the more glucose that is absorbed.

The FDG is radioactive, meaning radioactive elements are also absorbed by the brain.

The PET scan machine then detects the radioactive energy given off by this compound, and uses a computer to convert the data into 3-D images, with different colors highlighting which areas of a brain are most active.

PET scans on the brain are typically used to detect changes in the brain that may cause cognitive disorders such as Alzheimer's and Schizophrenia, and find cancerous tumors.

Alzheimer's disease is a progressive and irreversible neurological disorder which attacks brain cells and causes memory loss, confusion, language problems, and sometimes an incapacity to form new memories.

In Alzheimer's disease and other forms of dementia, the brain produces a metabolic pattern that is significantly different from the metabolic pattern of healthy brain cells.

PET scans taken in 2000 show the metabolic degeneration of the brain of a patient with Alzheimer's as it progressively reduces brain function.

(UCLA Center on Aging)

As PET imaging examines the metabolic activity of brain cells by tracing how FDG is absorbed, it is able to detect Alzheimer's disease and other forms of dementia.

PET scans have become a way in which doctors are able to confirm the presence of the disease in a noninvasive and painless way.

There is no cure for Alzheimer's however there are now new drug therapies which can delay the progression of the disease, but to perform this early detection is needed.

A PET scan enables us to see the biological changes in the brain caused by the disease.

Recent medical studies have suggested using PET scanning of the hippocampus as a way to detect Alzheimer's disease while in its early stages.

Hippocampal glucose metabolism reductions are found in both mild cognitive impairment and Alzheimer disease and contribute to their diagnostic classification.

A PET scan differs from other types of imaging technology (MRI, CT scan, and x-ray) in that it displays the chemical function of a particular organ or section of tissue.

PET scans are able to detect biochemical and metabolic changes suggesting disease before they are detected by standard imaging devices.

Another benefit associated with PET scanning is that the radiation dosage is relatively low, equivalent to about half that of a CT scan.

Functional magnetic resonance imaging, or fMRI, is a technique for measuring brain activity.

It works by detecting the changes in blood oxygenation and flow that occur in response to neural activity – when a brain area is more active it consumes more oxygen and to meet this increased demand blood flow increases to the active area.

fMRI can be used to produce activation maps showing which parts of the brain are involved in a particular mental process.

The development of FMRI in the 1990s, generally credited to Seiji Ogawa and Ken Kwong, is the latest in long line of innovations, including positron emission tomography (PET) and near infrared spectroscopy (NIRS), which use blood flow and oxygen metabolism to infer brain activity. As a brain imaging technique FMRI has several significant advantages:

1. It is non-invasive and doesn’t involve radiation, making it safe for the subject.2. It has excellent spatial and good temporal resolution.3. It is easy for the experimenter to use.

The development of FMRI in the 1990s, generally credited to Seiji Ogawa and Ken Kwong, is the latest in long line of innovations, including positron emission tomography (PET) and near infrared spectroscopy (NIRS), which use blood flow and oxygen metabolism to infer brain activity. As a brain imaging technique FMRI has several significant advantages:

1. It is non-invasive and doesn’t involve radiation, making it safe for the subject.2. It has excellent spatial and good temporal resolution.3. It is easy for the experimenter to use.

The attractions of FMRI have made it a popular tool for imaging normal brain function – especially for psychologists.

Over the last decade it has provided new insight to the investigation of cognitive processes such as how memories are formed, language, pain, learning and emotion. settings.

fMRIs have even been used to investigate cognitive functioning in criminals.