Article
Curtis, V. A., Bullmore, E. T., Brammer, M. J., Wright, I. C., Williams, S. C. R., Morris, R. G., Sharma, T. S., … McGuire, P. K. (January 01, 1998). Attenuated Frontal Activation During a Verbal Fluency Task in Patients With Schizophrenia. The American Journal of Psychiatry, 155, 8, 1056.
The purpose of the article was to research on the behavior of cerebral blood oxygenation on subjects who have schizophrenia in a verbal fluency activity. There were two hypotheses formulated by the researchers. The first hypothesis was that schizophrenic patients would exhibit abnormally connected responses between temporal and frontal regions. The second hypothesis was that during word generation, schizophrenic patients would show minimal prefrontal activation. The results of the study have proven the hypothesis since there was a significance response to patients with schizophrenia as compared to the control group of the experiment. The schizophrenic subjects demonstrated a relatively low response in the left dorsal prefrontal cortex but had a higher response in the medial parietal cortex (Curtis et al., 1998, p.5). From the results, the major findings were that during word generation, patients with schizophrenia displayed an attenuated response in frontal regions (Curtis, et al., 1998, p.6).There was a more significant response in the medial parietal cortex as a result of word generation.
The research design used in this study is predominantly experimental. The authors use different patients who have schizophrenia and those who do not have the defect are picked from Bethlehem Royal Hospital. The subjects were required to perform two tasks. One of the tasks required the subjects to generate words starting with the word “rest.” After that, there was the construction of generic brain activation maps utilizing sinusoidal regression and nonparametric hypothesis testing. The authors performed an analysis to identify the difference between the specific responses of the subjects. The authors provided an explanation for the response attributed to the subjects. The researchers determined that there is a suppression in the neural activity of the temporal cortex during vocalisation. The suppression is affected by inputs from frontal areas which are responsible for generating speech; hence, the regions responsible for speech perception may be informed that the acoustic signals are of self-origin. In the experiment done by the researchers, there was a lack of temporal suppression due to the requirement to covert the articulatory response, which could not be achieved in the experiment.
In the experiment, non-schizophrenic patients are used as control subjects. Precisely, the subjects are exposed to identical conditions and the difference in the behaviour of the subjects is noted. Schizophrenic patients have a positive correlation in the regional cerebral blood, while the control subjects have a negative correlation. However, the study did not establish the difference between schizophrenic subjects and control subjects in terms of frontal blood flow in a verbal fluency activity. In this experiment, all the subjects are treated equally. Additionally, descriptive psychology is mentioned where there are scales of assessment for both negative and positive symptoms are used in the experiment. Descriptive psychopathology was applied during the day of scanning for the results.
An alternative explanation that can be given for the findings of the article is that patients with schizophrenia demonstrated an attenuated power of response in frontal regions because of the greater activation which may be found in others parts of the anterior cingulate gyrus; which is related to the compensatory response that is often required in the maintenance of a typical task, and a pattern is suggested for any activity which may be deemed to be disorganized in association with psychotic conditions.
References
Curtis, V. A., Bullmore, E. T., Brammer, M. J., Wright, I. C., Williams, S. C. R., Morris, R. G., Sharma, T. S., … McGuire, P. K. (January 01, 1998). Attenuated Frontal Activation During a Verbal Fluency Task in Patients With Schizophrenia. The American Journal of Psychiatry, 155, 8, 1056.