Comparison of changes in oxygenated hemoglobin during the tree-drawing task between patients with schizophrenia and healthy controls

Abstract

BackgroundTree-drawing test is used as a projective psychological test that expresses the abnormal internal experience in patients with schizophrenia (SZ). Despite the widely accepted view that the cognitive function is involved in characteristic tree-drawing in patients with SZ, no study has psychophysiologically examined it. The present study aimed to investigate the involvement of cognitive function during tree-drawing in patients with SZ. For that purpose, we evaluated the brain function in patients with SZ during a tree-drawing task by using near-infrared spectroscopy (NIRS) and compared them with those in healthy controls.Patients and methodsThe subjects were 28 healthy controls and 28 patients with SZ. Changes in the oxygenated hemoglobin ([oxy-Hb]) concentration in both the groups during the task of drawing a tree imagined freely (free-drawing task) and the task of copying an illustration of a tree (copying task) were measured by using NIRS.ResultsBecause of the difference between the task conditions, [oxy-Hb] levels in controls during the free-drawing task were higher than that during the copying task at the bilateral frontal pole regions and left inferior frontal region. Because of the difference between the groups, [oxy-Hb] levels at the left middle frontal region, bilateral inferior frontal regions, bilateral inferior parietal regions, and left superior temporal region during the free-drawing task in patients were lower than that in controls.Conclusion[oxy-Hb] during the tree-drawing task in patients with SZ was lower than that in healthy controls. Our results suggest that brain dysfunction in patients with SZ might be associated with their tree-drawing.

Application of Near-Infrared Spectroscopy for Evidence-Based Psychotherapy

“…It has been suggested that this may occur because of a compensatory mechanism; when a task is demanding with high difficulty, increased efforts are required, leading to excessive brain activity (Tsujimoto et al, 2013). The compensatory mechanism has been also indicated in patients with schizophrenia (Koike et al, 2011;Nakano et al, 2018), bipolar disorder (Ono et al, 2017), and ecstasy polydrug users (Roberts and Montgomery, 2015) when tasks are demanding or symptoms are severe. Nevertheless, it has been suggested that this phenomenon can be distinguished by the lack of associated behavioral differences (Roberts and Montgomery, 2015).…”

Application of functional near-infrared spectroscopy in the healthcare industry: A review

“…The analysis of HbO signals showed that the activation in SZ patients during a tree-drawing task was lower than that in healthy persons. 219…”

The Tree Drawing Test in Evolution: An Explorative Longitudinal Study in Alzheimer’s Disease

“…33 Although mainly developed for the study of pediatric age, TDT has been also widely studied in adult psychiatric patients, both schizophrenics and depressed. [34][35][36][37][38][39][40] Trees drawn by schizophrenic patients are generally of small size, the trunk is a single line or narrow and is open at the base, and the branches are single lines or open at the end reflecting the fact that these patients tend to be socially withdrawn with a reduced ability in reality testing. 35 Furthermore, in schizophrenics the involvement of the left middle frontal region, bilateral inferior frontal and parietal regions, and the left superior temporal region while drawing an imagined tree has been shown by means of near-infrared cerebral spectroscopy thus supposing attention, working memory and executive functions as the main cognitive functions involved.…”