Neuroscientist explores mechanism that can cause deficit in working memory

Neuroscientist explores mechanism that can cause deficit in working memory
Amy Griffin, a UD neuroscientist, is studying how a mechanism in the brain allows two regions to work together. Credit: Ambre Alexander Payne

Amy Griffin, associate professor of psychological and brain sciences at the University of Delaware, has received a five-year, $1.78 million grant from the National Institute of Mental Health to support her research into the brain mechanisms of working memory.

A neuroscientist, Griffin has been interested for some time in the interaction between the , located at the front of the brain, and the , a region in the temporal lobe of the brain. When the two areas fail to work together, that failure appears to be correlated with deficits in working memory, a condition that commonly occurs in schizophrenia, general anxiety and other psychiatric disorders.

The hippocampus is the portion of the brain responsible for memory, while the prefrontal controls executive function, a term that includes such cognitive abilities as problem-solving, planning and abstract thinking.

"These are two areas of the brain that are far apart, but their oscillations [rhythmic activities] are synchronized," Griffin said. "When one area is active, so is the other."

Working memory, sometimes called short-term memory, is "the kind of memory that fails when you walk into a room and forget why you came there," she said.

When the oscillations in the hippocampus and prefrontal cortex are out of sync, deficits of working memory occur. In those cases, Griffin said, "both regions are active, but they're not talking to each other." The mechanism that causes that lack of communication has not been well explored, and her research will seek to do that.

Griffin and her research team plan to conduct two types of experiments. One will inhibit activity in a brain region called the nucleus reuniens, a region that is hypothesized to synchronize the hippocampus and prefrontal cortex and is expected to cause impairments with working memory. In the other experiment, researchers will activate the nucleus reuniens to increase synchrony, hoping to learn if that improves working memory.

The research will employ a cutting-edge technique called optogenetics, a process that uses proteins to make neurons sensitive to light and then uses light to control them. 

"Optogenetics is becoming a common technique," Griffin said. "It's a way to study these processes on a millisecond timescale." 

A 2013 article in the journal Nature Neuroscience said optogenetics "is transforming the field of neuroscience. For the first time, it is now possible to use light to both trigger and silence activity in genetically defined populations of neurons with millisecond precision."

Griffin, using a rat model, will inject the light-sensitizing substance—a harmless virus—into the nucleus reuniens and then use a laser to inhibit or activate this region. The rats then perform tasks that assess their . Synchronization between the hippocampus and prefrontal cortex will also be recorded, with the prediction that the degree of the working impairment will be correlated with reductions in synchrony.

"Our experiments will not be interfering with the activities of the hippocampus or the prefrontal cortex within themselves," Griffin said. "We want to affect only the ability of the structures to talk to each other." 


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Journal information: Nature Neuroscience

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Sep 11, 2014
Working memory, sometimes called short-term memory, is "the kind of memory that fails when you walk into a room and forget why you came there," she said.


This is a good "definitive example" of Working Memory.

The test a doctor psychologist does in an evaluation does not detect my working memory problem, because it is all remembering sequences of numbers, playing them backwards, and sorting them. All things I'm very good at.

Walking into a room and forgetting why I went there? Happens every day or two.

Walk into a room and you're like, "Why did I come in here?" Look around for anything to jog your memory, go back into the other room where you came from and try to re-trace your actions and thoughts, sometimes never remember, sometimes you're lucky and something jogs your memory.

Forget what internet site I was just on, immediately after clicking off it, never to remember again? That's happened about 5 or 6 times in the past 2 years.

Sep 11, 2014
Funny Lrrkrrr I didn't see anything in the article about you. Do you think everything in the world is about you?

Sep 11, 2014
If you spit out random digits and ask me to recite them, recite them backwards, or sort them, I can recite them backwards better than forward, and I can sort them, and I don't really have a problem until 8 to 10 digits. Sometimes I'll sort 10 digits, and other times I get confused and lost on just 8 digits.

I've never had a job where I was required to sort 10 random digit numbers. I've had jobs where forgetting what you were supposed to be doing when you walked into a room could get you fired after one or two incidences. Checklists don't always help, because if you forget to do a checklist, or forget to read it, then you're screwed anyway.

This is the second time I've had this done, and it's the same every time.

GLA (I.Q): 142
Verbal: 124
Numerical: 130
Spatial: 146
Form Perception: 141
Clerical Perception: 155

I got all the Raven's Squares questions correct.

Evaluation is the same:
Social Anxiety
Generalized Anxiety
Major Depression.

Sep 11, 2014
Funny Lrrkrrr I didn't see anything in the article about you. Do you think everything in the world is about you?


No, Ghost:
I was demonstrating experiential knowledge that the existing "working memory" tests are flawed. They over-emphasize "digit span" and similar tasks, which don't necessarily reflect what happens to a person's memory in real-world situations, where you are remembering two or three tasks at once, particularly when they aren't necessarily even related tasks.

Example:
There is a potential contamination problem on production line 4, meanwhile line 5 is making a color change. You need to pull a full sample of 2 sets of bottles from the line 5 as part of standard procedure, but you also need to test line 4 (again) to make sure there is no more contamination (typically comes from dirt/dust in the re-grinder). You also can't forget to take your normal samples from all the other 7 lines, and check in on all the production worker's paperwork as well. Then enter data.

Sep 11, 2014
No Lrrkrrr
Youre a self-centered egomaniac who thinks the world is all about him.
Social Anxiety
Generalized Anxiety
Major Depression.
WHO CARES. This is not the place to discuss personal problems or elicit sympathy.

There are indeed places for such things. Here is one such place
http://www.na.org/

"Rarely have we seen a person fail who has thoroughly followed our path. Those who do not recover are people who cannot or will not completely give themselves to this simple program, usually men and women who are constitutionally incapable of being honest with themselves. There are such unfortunates. They are not at fault; they seem to have been born that way. They are naturally incapable of grasping and developing a manner of living which demands rigorous honesty. Their chances are less than average. There are those, too, who suffer from grave emotional and mental disorders, but many of them do recover if they have the capacity to be honest."

-Think you have the balls to be honest?

Sep 14, 2014
Working memory, sometimes called short-term memory, is "the kind of memory that fails when you walk into a room and forget why you came there," she said.


This is incorrect.

The event, act, or process of forgetting is not memory. The events, acts or processes of forgetting are incomplete processes of access and/or retrieval not memory.

Case in point:
All rooms are empty.
Entering any one of those rooms always harbors the potential for the processes of access or retrieval for completion of the tasks or functions attributed to access or retrieval (of memory) to fail.

All memory is indelible or permanent ink figuratively speaking.

All paths or routes to memory are potentially error prone to detours, severance, interruptions, and strength (of retrieval/access signals).

Not by the room (storage) or the content of the room (storage stored).

The meaning of what the researchers are using as labels changes.
The correlations of the research asserted remain unchanged.


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