brief research paper on cognitive neuroplasticity, and it's relation to Dopamine and working memory

[veritas]

Abstract
This paper briefly outlines the concepts of Neuroplasticity, and then working memory and Dopamnine’s relation to working memory. Next this paper elaborates upon the reliability and validity of Soderqvist et al.’s 2012 research into training induced plasticity and dopamine’s affects upon working memory. Lastly, this paper investigates the article’s scientific merit.



Intro

Cognitive Neuroplasticity is the name given to the brain’s ability to organize and re-organize itself. Cognitive Neuroplasticity posits that the brain is able to not only learn new things, but get better at learning these things the more it is asked. Cognitive Neuroplasticity is the science behind the old adage about what practice makes. The phenomenon of Cognitive Neuroplasticity also provides a glaring contradiction of the old adage about the elderly canine and its relationship towards new tricks. It will be the goal of this paper to elaborate upon the findings of a group of researchers who asked whether plasticity could take effect upon a brain trained in the skills which required working memory, as well as what, if any, were the dopaminergic properties of this process.
Cognitive Neuroplasticity, or Plasticity as it will be deemed from henceforth for brevity’s sake, flies in the face of pre-established dogma. For many years, our psychological forefathers believed the brain, and it’s intelligence to be a fixed commodity. With the advent of neuroscience, researchers quickly learned this was far from true. Experiments were set up where individuals who suffered various brain injuries were able to still learn and perform tasks that were traditionally thought to be governed by the affected brain area exclusively. The individuals, through challenging practice, were able to learn the skills, which scientific understanding up till that point would have deemed impossible. Most importantly, it appeared that new areas of the brain were governing these actions. The brain had re-organized itself, and was better for it.
The concept of Plasticity is built off of another concept called Neurogenesis. Neurogenesis also flies in the face of traditional scientific dogma. Many teenagers will remember various adults educating them to the horrors of alcohol usage, in that alcohol will eliminate brain cells. Neurogenesis proves that this is simply not the case. Neurogenesis proves that Neurons do regenerate. Plasticity is the reformation of the brain as neurogenesis occurs.
The concept of Plasticity has become a buzz word in today’s information age. A quick google search returns 950,000 results. Plasticity is also becoming big business, with innumerable companies marketing their own versions of brain training software. The logic is that the brain is a muscle, and it must be trained to gain. In the rush of the propensity of options for the everyday man to engage the brain in its own natural growing process, it becomes easy to lose sight that this is in fact a legitimate physiological principle, with important applications for the future of humanity, as well as their micro-cellular evolution.
Plasticity is becoming involved as a solution for many problems that individuals suffer with today, be it attention deficit disorder, substance abuse and addiction, the biological path to enlightenment, as some groups believe meditation bolsters the brain hemispheres to rewire together, and this syncing produces enlightenment. Plasticity is even having a hand in depression.
Major Depressive Disorder or MDD, is a chronic and recurring illness that is potentially life threatening. MDD is the 4th leading cause of disability worldwide, more importantly, by the year 2020 it is slated to take its place as the second leading cause ( Julien, 2008, pg. 199). Julien in 11th edition of his book entitled “A primer of drug action, a comprehensive guide to the actions, uses, and side effects of psychoactive drugs” links plasticity and neurogenesis to depression, positing that the Neurogenic theory of Depression is that which shows how depression exists because the brain actually becomes less able to regenerate and reorganize and this state depresses the brain. Julien summarizes saying “In summary, several lines of evidence suggest that depression is a consequence of stress that, like any injury, disease, or other type of physical trauma, damages the brain and weakens its ability to recover” (Julien, 2008, pg. 203). This brief snippet shows just how important and far reaching the implications for plasticity truly are.
Brief introduction to the concept of Plasticity aside, this paper focuses upon the work of Soderqvist, Nutley, Peyrard-Janvid, Matsson, Humphreys, Kere, and Klingberg’s 2012 research into Dopamine, Working memory, and training-induced plasticity. The researcher’s quest was two-fold. First they set up research to find if plasticity would extend it’s effects to the realm of working memory. Secondly, they wished to examine if there was a chemical relation to plasticity and working memory, specifically looked for in the levels of Dopamine in the individuals participating in the study, and questioned whether Dopamine affected the brains plasticity ability as applied to working memory. This query is reasonable, as Julien states plainly that “All of our thoughts, actions, memories, and behaviors result from biochemical interactions that take place in and between neurons” (Julien, 2008, pg. 63). Since memory then is governed by chemical interactions and chemical interactions happen amidst neurons, plasticity and dopamine’ correlation to working memory appears to be, at least from the outset, a possibility.
With the concept of plasticity adequately and accurately covered, a brief synopsis of the other two major components of the research will be elaborated upon before the research is summarized and evaluated. The researchers describe working memory as: “The ability to manipulate and keep task relevant information in mind for a short period of time” (Soderqvist, Nutley, Peyrard-Janvid, Matsson, Humphreys, Kere, and Klingberg. 2012). Dopamine plays a role in this research as it appears to have effect upon both working memory and plasticity. The researchers state that “Dopamine has been suggested to be important for plasticity by enhancing neural sprouting and synaptogenesis” (Soderqvist et al. 2008 ) In addition, the researchers state that Dopamine’s D1 receptor has shown that it has a direct affect on visuospatial working memory in primates. Furthermore, this has been shown in humans as well, in that the D1 receptor agonist Pergolide was conducive to greater performance of working memory tasks (Soderqvist et al. 2008.)
Reliability
The course’s required text, the 10th edition of “Practical research, planning and design” by Leedy and Ormund have much to say about reliability. Reliability’s textbook definition is “The consistency with which a measuring instrument yields a certain, consistent result when the entity being measured has not changed” (Leedy and Ormund, 2013. Pg. 91). There are different forms of reliability. Interrater reliability refers to the extent of which multiple evaluators will produce the same judgment with all other things being equal. Test-Retest reliability is concerned with whether or not a single measure will produce the same results for the same people at differing times. Equivalent forms of reliability measures whether two different forms of the same instrument (an A vs. B form of a measure) will bring forth similar results. Lastly, there exists what is called internal consistency reliability; this is the extent to which all items within a single instrument will yield similar results (Leedy and Ormund, 2013. Pg 91).
The text continues to show how for each of these four measures of reliability there must two steps achieved to produce a ruling on whether or not reliability exists. First, the researchers need to get at least two measures for each individual in a reasonably large group of individuals This can be done either with using two separate raters giving their evaluation of the same performance to measure interrater reliability, or having the same instrument administered to the same individuals at different points in time to measure test-retest reliability. The other two measures of reliability’s processes are explained as well. The text states that researchers should give each individual two parallel versions of the same instrument to measure equivalent forms reliability. Lastly the researchers can give out one instrument, but calculate multiple sub scores, for an example measure all of the odd number scores versus all of the even numbered score to test for internal consistency reliability. After one of these procedures has been enacted the researchers then need to calculate a correlational coefficient to determine the degree of similarity amongst the measures ( Leedy and Ormund, 2013 pg. 91-92).
Using these summarized criteria of reliability to evaluate the Soderqvist et al. research the following becomes obvious. This research exhibits interrater reliability because the researchers tasked with conducting the tests, both pre, post, and post-post all tabulated consistent results. Furthermore, the differing teachers of the working memory training classes, both experimental and control, yielded consistent results as well (Soderqvist et al. 2012.). In terms of test-retest reliability, this research is exceedingly compliant. The experiment features three tests given to both the control and the experimental group. A pre-test, before the groups received their working memory training classes, a post-test immediately after the training dispelled, and lastly, a post-post test approximately eighteen months after the post test was given. The researchers found that their experimental group posted scores indicative of a statistically significant difference in ability of working memory in the experimental group versus the control group not only after the post test, but after the post-post test as well (Soderqvist et al. 2008.).
In terms of equivalent forms reliability this research is also compliant. The control group received a test containing similar exercises as the control group. These tasks featured exercises that measured the different aspects of working memory. The caveat is that the control group’s forms gave problems that although different from week to week of the five week training, were static in difficulty. Whereas the experimental group’s test forms during their five week training featured problems that gradually increased in difficulty as the weeks progressed. The researchers did find consistent results from this set up. Every member of the control group performed on the same level of ability spanning from pre test to post test to post post test. Contradictorily, every member of the experimental group showed improvement from pre-test to post post test. Lastly, the matter of internal consistency is also achieved in this research because all of the tests given to the control group were identical in from week to week and produced the same results. The same with the experimental group, each test was the same, although the difficulty was progressively higher as the weeks carried on, and this too, presented a homogenous result of increase in ability (Soderqvist et al. 2008.). According to the above mentioned criteria, this research can be evaluated as Reliable.

Validity

Leedy and Ormund describe Validity as “The extent to which an instrument measures what it is intended to measure” (Leedy and Ormund, 2013.) There are different forms of validity, which the text describes, to summarize: Face validity, is a subjective judgment about the surface, or face, of a particular instrument’s ability to actually measure what it says that it will measure. Content Validity describes whether or not a measurement instrument tessts a representative model that accurately represents the issue or content which it is measuring. A instrument to measure graduate school stress levels would be appropriate for graduate school students, not undergraduate students, for an example. There also exists what is called Criterion validity, or the extent to which the measurement correlates with other logically related measurements. The instrument that measures a baseball players on-base percentage, should not register at over 30 percent if the player’s batting average is below 300, this is simply impossible, and thus not of criterion validity. Lastly, there exists what is termed Construct Validity, this measures how abstract concepts that cannot be measured directly are able to be measured by logically applicable criteria that can expose patterns that tie in visibly to the invisible construct. (Leedy and Ormund, 2013. Pg. 89-90).
Upon analysis of the summary of Validity when applied to this research, the following conclusions can be drawn: This research has face validity, because on the surface the tests used to measure working memory all appear to indeed measure working memory, or at least aspects of intelligence that are adjacent to working memory. Tests such as the Leiter Battery, Raven’s colored progressive matrices, automated working memory assessment, word span test, and the Wechsler preschool and primary scale of intelligence, all measure accurately the construct,
These tests are also valid in terms of content in that the subjects taking the tests fell within the age constraints of various tests given, in other words, the testers were an appropriate population to take the measurements. This research’s chosen test batteries meet the point of criterion validity in that the scores are consistent amongst the various tests. If an individual performed poorly on the spatial test of the progressive matrices, this corresponded to a poor performance in the spatial aspect of the Wechsler. In other words, all of the tests were in harmony with one another. Lastly, this research achieved construct validity in that while plasticity was not able to be measured directly, the statistical difference in scores between the pre test and the post test of the control and experimental groups proved that the brain did in fact strengthen and get better in it’s performance, thus inferring that plasticity did in fact happen in the experimental group.

Scientific Merit

As aforementioned earlier in this paper, there exists a myriad of information regarding plasticity. Plasticity articles such as Muhlig-Versen, Bowen, and Staudinger’s 2012 research into personality plasticity in later life. The conception that an individual’s golden years are one of a crystallized intelligence, habits, and personality, they have proved otherwise, instead showing through extensive research that the elderly are in fact able to take advantage of the brains’ plasticity and form new beliefs, and exhibit personality changes (Muhlig-Versen, Bowen, and Staudinger, 2012.) Soderqvist et al.’s research advances the knowledge that the brains ability to improve working memory could also be applied to the same population in the hopes of reducing, if not eliminating dementia.
Also interesting is the research of Lovden, Backman, Lindenberger, Schaefer, and Schmiedeck who in 2010 established the following framework to define plasticity: “According to our framework, adult cognitive plasticity is driven by a prolonged mismatch between functional organism supplies and environmental demands and denotes the brain's capacity for anatomically implementing reactive changes in behavioral flexibility”(Lovden, Backman, Lindenberger, Schaefer, and Schmiedeck. 2010).
Soderqvist et al.’s research advances this by showing that difficulty is the key. In other words, difficulty adds to, better yet, is the main proponent of creating the mismatch between oraganismic supplies and environmental demands. This makes sense, if something is difficult; it pushes one’s cognitive resources into overdrive, and forces the brain to compensate for the difference.
Dahlin, Nyberg, Backman, and Neely conducted research in 2008 which proved that young adults and older adults could experience not only immediate but also long-term gains in their executive functioning with plasticity training, quoting: “Transfer effects were in general limited and restricted to the young participants, who showed transfer to an untrained task that required updating (3-back). The findings demonstrate substantial and durable plasticity of executive functioning across adulthood and old age, although there appear to be age-related constraints in the ability to generalize the acquired updating skill” ( Dahlin, Nyberg, Backman, and Neely. 2008).
Their research shows that while all ages can make gains, only the younger participants were able to transfer the gains to unpracticed, but similar tasks. Soderqvist et al.’s research advances this by showing that plasticity is in effect in school age children, who were the focus of their study. This advances the research into showing that plasticity is truly a timeless phenomenon.
Beaver, Wright, Delisi, and Vaughn conducted research in 2012 concerning Dopaminergic polymporphisms, specifically how higher dopamine levels correspond to greater levels of educational achievement, quoting: “Although educational attainment has been found to be moderately heritable, research has yet to explore candidate genes for it. Drawing on data from the National Longitudinal Study of Adolescent Health, in the current study, we examined the association between polymorphisms in three dopaminergic genes (DAT1, DRD2, and DRD4), a dopamine index, and educational attainment. Statistically significant effects were found for DAT1, DRD2, DRD4, and the dopamine index for highest level of education. This study is the first to our knowledge that links measured genes to educational attainment” ( Beaver, Wright, Delisi, and Vaughn. 2012). Soderqvist’s research adds an additional piece to the puzzle of how academic achievement could have a genetic precursor, in that DAT1 is directly concerned with working memory. Logic dictates that the upper schools of education certainly require greater levels of working memory.
In addition to the advances of knowledge above stated, Soderqvist et al.’s work contributes to the theory of plasticity by adding yet another avenue of which it affects, working memory. Furthermore it advances the theory in that it adds a genetic component, the role of Dopamine. This opens up all sorts of avenues of research. Should ADD children and demented elderly receive dopamine supplements? Instead of teaching to the test, should grades in elementary school teach to the test of the next grade ahead of them, to spur on plasticity? The main key to this research adding to the theory, is that it makes the picture of how we learn in totality, appear to be almost entirely dependent upon the process of plasticity.
There is two problems with the research which are not evident of possessing the hallmarks of sound research. The first is that Soderqvist et al. plainly state that their research did not contain a large enough sample to make an accurate determination of the results in genetic sampling as all individuals genetic levels vary to a degree, thus, the more in the sample, the more accurate the average. Secondly, Soderqvist research results do not translate across the board. The writer was able to find another research article directly contradicting the findings. The 2013 research of Redick, Shipstead, Harrison, Hicks, Fried, Hambrick, Kane, and Engle showed that there was no evidence of intelligence improvement after working memory training.
They used the following tests for their battery: Cattell Culture-Fair Test ,Raven Advanced Progressive Matrices, Letter Sets Task, Number Series Task, Inferences Task ,Analogies Task, SynWin Task ,Control Tower Task ,ATClab Task, Symmetry Span Task, Running Letter Span Task, Letter Comparison Task, Number Comparison Task, Beery Picture Vocabulary Test, Paper Folding Test General Knowledge Test, and the Raven Standard Progressive Matrices and found that after a pre-test, mid-test, and post-test, the individuals showed no transfer of any intellectual gains ( Redick, Shipstead, Harrison, Hicks, Fried, Hambrick, Kane, and Engle. 2008).
The final word is that since this research came out after the main study of the paper, honest investigation upon future studies of the same purpose, must be examined and compared/contrasted.

References

Mühlig-Versen, A., Bowen, C. E., & Staudinger, U. M. (2012). Personality plasticity in later adulthood: Contextual and personal resources are needed to increase openness to new experiences. Psychology And Aging, 27(4), 855-866. doi:10.1037/a0029357

Lövdén, M., Bäckman, L., Lindenberger, U., Schaefer, S., & Schmiedek, F. (2010). A theoretical framework for the study of adult cognitive plasticity. Psychological Bulletin, 136(4), 659-676. doi:10.1037/a0020080

Redick, T. S., Shipstead, Z., Harrison, T. L., Hicks, K. L., Fried, D. E., Hambrick, D. Z., & ... Engle, R. W. (2013). No evidence of intelligence improvement after working memory training: A randomized, placebo-controlled study. Journal Of Experimental Psychology: General, 142(2), 359-379. doi:10.1037/a0029082

Dahlin, E., Nyberg, L., Bäckman, L., & Neely, A. (2008). Plasticity of executive functioning in young and older adults: Immediate training gains, transfer, and long-term maintenance. Psychology And Aging, 23(4), 720-730. doi:10.1037/a0014296

Beaver, K. M., Wright, J., DeLisi, M., & Vaughn, M. G. (2012). Dopaminergic polymorphisms and educational achievement: Results from a longitudinal sample of Americans. Developmental Psychology, 48(4), 932-938. doi:10.1037/a0026313

Leedy, P., Ormrod, J. Practical research planning and design 10th ed. Pearson. Upper Saddle River, NJ. 2013

Soderqvist, S., Peyrard-Janvid, M., Humphreys, K., Kere, J., & Klingberg, T. Dopamine,working memory, and training induced plasticity: implications for developmental research. Developmental psychology, 48, 3, 836-843. 2012.
Julien, R. A primer of Drug Action 11th ed. Worth Publishers. New York, NY. 2008

[dead man]

bookmarked and will read later. but i am surprised at how few references you cite for this. fascinating subject matter

are you involved in any experimental research or just archival stuff?

[veritas]

you do not need alot of sources when you can accuratly synthesize and evaluate what specific sources give you (dad?)

experimental. Also sometimes I go to the hospital's archives and study for qualitative patterns, but not officialy, just for my own knowledge.

[Diode]

*its

[veritas]

Originally Posted by Diode

*its

true. my bad big homey. No beef.

[Rawn MD]

I MA y read latet

depends how slow work is

[Geno]

Dopamine ass high

[Rawn MD]

A yo @VERITAS before I read this how do u feel about neurofeedback n noetic sciences?

[zygote]

Why did you write it, for publication in a journal or for some class?
"The course’s required text, the 10th edition of “Practical research, planning and design” by Leedy and Ormund have much to say about reliability." - Makes me think it is for some class, if so it probably shouldn't be uploaded online anonymously for plagiarism concerns.

"Cognitive Neuroplasticity is the science behind the old adage about what practice makes. The phenomenon of Cognitive Neuroplasticity also provides a glaring contradiction of the old adage about the elderly canine and its relationship towards new tricks. " "Neurogenesis also flies in the face of traditional scientific dogma." "Train brain to gain." The jokes seem unnecessary and the overall tone is too conversational. Also, deadman has a good point.

[PancakeBrah]

"The course’s required text, the 10th edition of “Practical research, planning and design” by Leedy and Ormund have much to say about reliability."

has*

strong proofreading

[veritas]

It was a paper I did for class. Took an hour. Only needed 7 sources and it was ten pages. Thanks for the honest feedback. Good call on the conversational tone switch

[oats]

What zygote said is exactly how I thought. This was interesting, but hard to take seriously in terms of scientific merit (tonally, at least).

Also, I tend to be grumpier with sources. Is there any other verification aside from the 2012 study you frequently cite? Neuroscience is nebulous, as you certainly know, so further study seems to be in order. I appreciated this post though, I'll be back to reread.

[veritas]

too be honest guys I the bulk of sources in the last section. I only needed to use 7.

you don't want to too many sources and you don't want too many. the sources serve as synthesis.....this is what is known, this is how it applies to this paper. ya dig?

and yes, When I am writing seriously I do sometimes get a little conversational. guilty.

[PancakeBrah]

I just wrote a paper too. I got an A+! YIPPEEEE. Now I can get a treat :)))

[Rawn MD]

Adressed my noetic science question

[PancakeBrah]

Oats is more smarter than you v, listen to him

[veritas]

Originally Posted by PancakeBrah

Oats is more smarter than you v, listen to him

lolz. ask him if he feels the same. I used the same source because the assignement was to elaborate upon the reliability, validity, and the scientific merit of an article. I probably should have made note of that.

[Rawn MD]

Ain't @oats an English teacher or something?

[veritas]

He could be my editor lol. I have been writing papers for so long that it is automatic. I could knock out a paper now in minutes. I do make some grammar errors here and there, and I do drift from the formal tone.

[Rawn MD]

Noetic science question!!!