Christina Cordero 

Professor Zayas 

Writing for the sciences 

Literature review FINAL draft

4/9/25 

What affects your brain can be hard to obtain

 

Brain Functions In Cognitive Tests 

 All cognitive tests measure a variety of different brain processes that include learning, thinking, using judgment as well as language. One commonality that is recurrent in these exams are their ability to measure out the way the brain carries out different cognitive functions. One may think they could be more efficient in one intelligence than the other, however, these types of intelligence fluctuate throughout one’s life and vary among age. Fluid intelligence is said to decline through adulthood although crystallized abilities show greater gains in older people (Tucker – Drob, 2022). These two types of intelligence work together as fluid intelligence in how able someone can retain new information and solve problems. Many psychologists utilize cognitive tests in order to view problems with how the brain processes thoughts and it is important to realize they are testing pertaining to specific cognitive processes.

 

 Not all cognitive tests are going to look the same; that’s the opening for inconsistencies because even though they are not the same, all cognitive tests seek for results revolving around thinking processes. For example, a person with Alzheimers would show changes in their executive functions including problem-solving, memory, and their ability to perform tasks (Stanford Medicine, 2017). When a psychologist administers the exam, they have to take into account how old their patient is and any disabilities they may have. Cognitive functioning is something every brain experiences, however each one works differently;  cognitive exams help assess how the brain processes information, which is important for making accurate diagnoses.

 

Memory  

Psychology encompasses so many different parts of the brain so it’s important to gain a richer understanding of psychology so individuals could gain insights into their own actions and start to gain a better understanding of other people. Your memory is the continued process of information that you collect over time. Memory allows individuals to draw upon past events and be able to connect those memories to tests they would potentially have to take in the present. The working memory specifically references a function in your brain that uses temporary storage and manipulates different pieces of information that is a necessity for complex cognitive tasks (Baddeley, 1992). The most important changes of the brain that have to do with age consist of declines in performance on cognitive tasks like the process of transferring information in order to make a decision. 

 

Piaget mentions that the last stage is the ability to understand theories and abstract ideas; however, he fails to establish that the formal operational stage is really broken down further because of the way the brain develops depending on what age a person is currently at (Feldman, 2005). As an older person would complete a cognitive test, their sensory perception and processing speed declines with their age which would impact their test performance in many of their cognitive domains (Murman, 2015). There is a clear decline within cognitive functions in older adults, because they perform cognitive activities slower than young adults as they cannot focus on specific information while simultaneously ignoring information that is irrelevant.

 

A Meta-Analysis Effect Size

A meta-analysis is used in order to see if there is any statistical significance within any research. Meta-analyses use effect sizes to identify consistent relationships between variables or differences among age groups (Durlak, 2009). Effect sizes can vary from small to large; the smaller the effect size, the more limited the findings will be and the larger effect size the more significance your research has because it reaches out to varying audiences. As Zhongheng Zhange 2013 conducted a meta-analysis on critical care medicine, his larger trials showed to have a significantly better responding quality than his smaller trials in sample size collection, intention to treat, sequence generating etc. (Zhange et al, 2013). Effect sizes are important because it helps the meta-analysis become plausible, showing why it connects to the majority and not just a selective amount of people.

 When a meta-analysis establishes their effect size they have to back themselves up in why and how they chose that specific group otherwise their studies cannot be done by another researcher. Many primary studies fail to provide information on how effect sizes are selected and computed which leads to the calculations of mean effect sizes to encounter small discrepancies (Maassen, 2020). Effect sizes need to be conducted to show that your research does not have any inflicted biases and it reaches out to more than one specific audience. 

 

Types Of Meta-Analyses
Meta-analyses are written on many things like teaching, psychotherapy, formal language – children and more. However, based on the provided literature within this review there seems to be a lack of studies that include any sort of meta-analysis conducted on the study of other cognitive tests. Many of the cognitive tests studied in this research all look for the same results in cognition however many of them fail to showcase the differences in age. “The 5-cog cognitive test” was created to detect cognitive decline in older adults, it’s a collection of cognitive tests that measures attention, memory, visuospatial, language and reasoning (Sugiyama, 2015). The subtests that are within “The 5-cog” are highly correlated to neuropsychological exams that both measure for the same cognitive domain. As a result,“The 5-cog cognitive test” is a tool for groups that shows significant reliability and validity in detecting cognitive impairment in older adults (Sugiyama, 2015). However, this cognitive test fails to determine what they mean when they use the term “older people, which could mean that their effect size might have small discrepancies because they did not specify the tested group of people. 

 

There has in fact been a meta-analysis written on neuropsychological test performance on people who have Attention-Deficit/Hyperactivity Disorder (ADHD) written by Eric A. Youngstrom, 2004. This meta-analysis compared healthy participants with those who have ADHD in order to examine the differences in cognitive processes. As the participants who had ADHD showed a higher full scale IQ than the other participants, Youngstrom knew this raised a red flag, so he then took it a step further and computed the weighted mean effect size and the test for the significance in their effect size by comparing them in groups instead of individually. All ADHD groups showed a lower score when combined and then compared to the entire group of healthy participants (Youngstrom, 2004). This paper highlights the importance of calculating effect sizes by demonstrating that results can vary significantly when comparisons are made on a larger scale. 

 

This paper intends to add to continuing research by viewing the dynamics of a meta-analysis in greater detail, while also viewing how efficient cognitive tests are and whether they should still be considered for use today. Using a quantitative approach, the main goal is to examine how meta-analyses report and utilize effect sizes, particularly concerning different age groups. This includes a comparison of cognitive tests to determine which ones are most effective at assessing cognitive function in older adults. Since younger age groups generally perform at a significantly higher cognitive level, there’s little value in using them as a benchmark when evaluating the cognitive abilities of older populations.

 

                                                                                                     References

Baddeley, A. (1992). Working memory. Science, 255(5044), 556–559. https://doi.org/10.1126/science.1736359 

Cognitive and neuropsychological tests. (2017, September 11). Stanford Health Care. https://stanfordhealthcare.org/medical-conditions/brain-and-nerves/dementia/diagnosis/cognitive-neuropsychological-tests.html 

 Durlak, J. A. (2009). How to select, Calculate, and interpret effect sizes. Journal of Pediatric Psychology, 34(9), 917–928. https://doi.org/10.1093/jpepsy/jsp004

Feldman, D. H. (2005, January 26). Piaget’s stages: The Unfinished Symphony of Cognitive Development. New Ideas in Psychology. https://www.sciencedirect.com/science/article/pii/S0732118X04000327 

Maassen, E., Van Assen, M. A., Nuijten, M. B., Olsson-Collentine, A., & Wicherts, J. M. (2020). Reproducibility of individual effect sizes in meta-analyses in psychology. PLOS ONE, 15(5), e0233107. https://doi.org/10.1371/journal.pone.0233107 

  Murman, D. L. (2015, August). The impact of age on cognition. Seminars in hearing. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4906299/ 

Sugiyama, M., Ijuin, M., Ito, K., Sakuma, N., Inagaki, H., Miyamae, F., Okamura, T., & Awata, S. (2015, October 23). The five cognitive tests as a good assessment tool for screening mild cognitive impairment in community-dwellers . The Gerontologist. https://academic.oup.com/gerontologist/article-abstract/55/Suppl_2/189/2491244?redirectedFrom=fulltext 

Tucker-Drob, E. M., de la Fuente, J., Köhncke, Y., Brandmaier, A. M., Nyberg, L., & Lindenberger, U. (2022, February 4). A strong dependency between changes in fluid and crystallized abilities in human cognitive aging. Science advances. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8809681/#:~:text=On%20average%2C%20fluid%20abilities%20decline,fluid%20declines%20with%20crystallized%20gains. 

APA PsycNet. (n.d.). https://psycnet.apa.org/record/2004-16644-015 

Zhang, Z., Xu, X., & Ni, H. (2013, January 9). Small studies may overestimate the effect sizes in critical care meta-analyses: A meta-epidemiological study. Critical care (London, England). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4056100/