Evaluation of Blumenfeld and D'esposito's Study - Essay Example

Evaluation of Blumenfeld, Lee, and Despositos Study Evaluation of Blumenfeld, Lee, and Despositos Study From the time in memorial, memory has been the most important and complex cognitive function. The memory shows some subtypes that require several brain systems. Due to these, researchers have been influenced to perform tests and studies concerning neuroimaging. The studies have led to the advancement of knowledge of the neuroanatomical bases that are in the various memory subtypes. The studies have shown in various ways that the frontal cortex has a major role during memory processes. During the neuroimaging study, an activation of the frontal cortex during long-term episodic memory tasks was found. The study further explained that cerebellum could have some repercussions on some verbal memory processes. To stimulate the cerebral cortex in humans, repetitive transcranial magnetic stimulation is. When done repetitively, the effects could easily spread to other cortical regions such as the prefrontal area (Blumenfeld, & Ranganath, 2006). The study concentrates more on the memory and the response it gives to different tests and substances. The elements and the substances also used have different varying effects. One of the studies shows that rTMS affect different cognitive functions, which include language, memory, and executive functions although they are contradictory. According to empirical research on neuroimaging, it indicates that, the left ventrolateral prefrontal cortex is in long-term memory encoding for associated items. Dorsolateral prefrontal cortex is lesser times, and for this reason, the theory that has clearly explained and gained support on this discrepancy is DLPFC. The theory involved in forming item-to-item relational but not item long-term memory. Since neuroimaging results are has a mutual relationship, approved methods, which include repetitive transcranial magnetic stimulation, have been used to test and explain data generated from imaging data. Most transcranial magnetic stimulation studies of long-term memory encoding indicate that the interruption of lateral PFC activity destroys subsequent memory. In addition, the neuroimaging results obtained were consistent with two possibilities. First possibility is that the DLPFC enhances processes, which contribute to working memory, but it does not promote successful long-term memory. In another possibility, the study argued that DLPFC had a major contribution to long-term memory formation, which previous studies failed to detect (Blumenfeld, & Ranganath, 2006). However, these studies in some way have lacked methods to clearly and accurately localize and directly compare transcranial magnetic stimulation effects from frontal sub-regions brought about by the neuroimaging literature. In this case, the target is specific sub-regions of lateral PFC with Transcranial magnetic stimulation. The simulation tests the prediction from the database relationship framework that temporarily disrupts the VLPFC during encoding will weaken or damage subsequent memory. Transcranial magnetic stimulation to DLPFC during item encoding will not. Frontal TMS was used on participants prior to a long-term memory-encoding task in which participants were presented with a list of different words and were questioned on whether each word was concrete or abstract. Item recognition memory was tested after a forty minutes delay. Fromm the results, it is clear that VLPFC and DLPFC TMS affects subsequent item memory differently. VLPFC Transcranial magnetic stimulation greatly interrupted subsequent item memory. On the other hand, DLPFC transcranial magnetic stimulation caused numerical enhancement in item memory, relative to TMS to a control region (Maneti, Cotelli, Robertson, & Miniussi, 2012). The study has various limitations and implications. First, schizophrenia may be partially attributed to a lack in activity in the frontal lobe. Dorsolateral prefrontal cortex is hypoactive when an individual suffers from chronic schizophrenia and lack of the dopamine neurotransmitter in the frontal lobe. There are many dependencies by the working memory upon DLPFC’S stability and functionality. For this reason, reduced activation of DLPFC causes patients affected by schizophrenia to perform poorly on tasks or tests that involve the execution memory. Low performance causes capacity drawbacks the execution memory that surpasses the deceptions on the normal patients (Neurosci, 2011). Damage in the DLPFC may also be linked to severe exposure to stress. In addition, severe stress negatively affects the higher cognitive function known as working memory, which is a function of the DLPFC according to the study. The study indicates that Substance abuse of drugs relates to the diminishing of executive functions of the dorsolateral prefrontal cortex. Individuals who abuse drugs according to the study exhibited increased engagement in risky behavior, which correlated with a dysfunction of the DLPFC. Alcohol, on the other hand, significantly affects the functionality of the Prefrontal Cortex and contributes to the regulation of alcoholism. The ACC works to prevent any unwanted behaviors through processing information to the most superior network of the DLPFC. The disruption in communication can lead to these actions being made as indicated above (Maneti, Cotelli, Robertson, & Miniussi, 2012). The study wasmuchfocused on the investigation of the prefrontal activity when performing of two different working memory tasks. The method used in testing of the above study was functional magnetic resonance imaging. The test was done in two different categories which are rehearsing and reorder. During rehearse, on a brief delay, participants could actively maintain triplets of words while, during reorder trials, participants could actively organize each triplet on every delay. Another method was used in the test of long-term memory was done on words presented on both rehearse and reorder working memory tasks. In this stage, the behavioral results showed that working memory processing in the reorder condition facilitated long-term memory by strengthening the inter-item associations. Other methods that were useful in the study were behavioral studies, transcranial magnetic stimulation, and quantitative graph-theoretical analyses. The methods gave similar results as above which indicates that dorsolateral and ventrolateral prefrontal cortical sub regions support distinct cognitive control and long-term memory encoding operations. In addition, dorsolateral, ventrolateral and dorsomedial frontal areas are functionally connected along parallel rostro-caudal gradients according to the study. In support and improvement of the study, Blumenfeld and his colleagues developed python-based software tools which will help in the building and analyzing large-scale connectivity datasets. The datasets were obtained from the corpus of extant anatomical studies in the macaque non-human primate compiled in the database of Cocomac (Blumenfeld, & Ranganath, 2006). The study was performed in two contiguous laboratory rooms where the subjects were examined by a neuropsychologist. The neuropsychologist administered cognitive tests and noted subject responses whereas the neurologist was in another room. The rooms were in a way that microphones were used for examiners instructions and subject or specimen responses. To from rTMS, all the stimuli were presented on the screen. The only members allowed in the study were those who have never participated in the test ever again, no psychiatric or physical illness, and should not be on any medication according to previous studies. Their educational level ranged from ten to fifteen years, and they mean age was 26.63. According to the average score of the participants, they were right handed. The researchers prior to the study requested the consent from the participants who were expected to submit them in a written form (Neurosci, 2011). During the neuroimaging study, it indicated that dorsolateral prefrontal cortex is responsible for the implementation process of organizing items in working memory. Due to the role performed by the dorsolateral prefrontal cortex in working memory, the study suggested that it should also contribute to long-term memory formation through strengthening associations that are in the working memory. According to a study on firm, results obtained indicate that dorsolateral prefrontal cortex activity was predictive of subsequent long-term memory specifically during the reorder condition. On the contrary, long-term memory for words studied on both rehearse and recover conditions was predicted on an activity in the posterior ventrolateral cortex. The results obtained supported the fact that dorsolateral prefrontal cortex mostly contributed to long-term formation that was through its role in organization information in working memory (Blumenfeld, & Ranganath, 2006). In another study, indications were that long-term memory and episodic memory processing was and is supposed to involve the prefrontal cortex asymmetrically. Results were consistent using pictures obtained from previous studies that indicated that repetitive transcranial magnetic stimulation had a significant impact on episodic memory. However, the test was always disrupted whenever it was applied to the left or right of the dorsolateral prefrontal cortex during encoding and to the right during retrieval. The results were obtained only when used with unrelated word pairs. During encoding, the successful recovery of words from episodic memory highly relied on semantic processes. In addition, tests done through functional magnetic resonance imaging indicates that during semantic encoding, some changes occur in the left inferior prefrontal cortex, which predicts subsequent memory performances. Due to the result above, they indicate that LIPFC has a significant role in memory formation. Further results show that high-frequency parameters were in disagreement with direct and indirect blockade of some brain. The areas that are in the episodic memory located in the left DLPFC (Maneti, Cotelli, Robertson, & Miniussi, 2012). Similar studies have been conducted to compare the results of the various studies. The study was done in the Brain circuit’s lab that concentrated on cognitive control and prefrontal cortical function, which helped in the understanding of high-level language processing. Other studies on working verbal memory used numbers backwards in order to assess verbal working memory. Unlike in other studies, here the results were calculated by adding up all correct items. In assessing of the episodic memory, logical memory of the Rivermead behavioral memory test as opposed to other studies. The story was then presented in the screen for thirty seconds while the subjects read silently in an attempt to memorize the content. A test was then done by asking them to explain the information they had captured without observing it. For the immediate verbal memory, digits forwards were used, and different numbers presented on the screen that was situated in the front. A different task was performed on phonetic verbal fluency, which its objective was to assess the effect on language function. To assess the test above, controlled oral word association task was used. The participants were given a maximum of one minute to produce maximum words in their capability where they were to begin with a specific letter. Different letters were used to minimize the effect of practice. Repeated measures analysis of variance was used for statistical analysis performance. High-frequency parameters over the left DLPFC disrupted performance in the verbal episodic memory in the right-handed men who were healthy (Neurosci, 2011). Various things have to be done and put into consideration. The study lacked direct evidence on how to ensure that the stimulation affected the dorsolateral prefrontal cortex or the right cerebellar hemisphere. Participants involved in the study were too small in number hence did not fairly represent the population. A study should be which will ensure that direct evidence is for the above. A number of participants also need to be increased to provide or give an accurate and more reliable result. Other methods should also be into increase on the credibility of the previous results (Balconi, 2013). References Balconi, M, (2013). Dorsolateral prefrontal cortex, working memory and episodic Memory processes: insight through transcranial magnetic stimulation techniques. Shanghai institute for biological sciences. Blumenfeld, R.S, & Ranganath, C, (2006). Dorsolateral prefrontal cortex promotes long-term memory formation through its role in working memory organization. University Maneti, R, Cotelli, M, Robertson, I.H, & Miniussi, C, (2012). Transcranial brain stimulation studies of episodic memory in young adults, elderly adults, and individuals with memory dysfunction: A review Neurosis, J.C, (2011). Putting the pieces together: The role of dorsolateral prefrontal cortex in relational memory encoding. Read More