In order to relate regional activity in the human brain to the different components of discrimination tasks, we compared regional cerebral blood flow, measured with positron emission tomography, under four conditions: successive orientation discrimination, orientation identification, detection and passive viewing. By adding successive discrimination and passive viewing at a second, lower rate we were able to investigate the main effects and interaction between task and presentation rate. Four occipital regions--the posterior calcarine region bilaterally, the right lingual gyrus and the right interior occipital cortex--displayed a main effect of presentation rate. Two regions--a right posterolateral occipital region and a right posterior fusiform region--displayed a significant main effect of task. The involvement of this posterior fusiform region in successive discrimination was also revealed by the subtraction of detection from successive discrimination, as was that of the right middle fusiform gyrus. Finally, a more anterior right middle fusiform region was differentially active in successive discrimination compared to identification, suggesting that activity in this region is related to the temporal comparison of orientation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1460-9568.1997.tb01395.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Background: Existing work suggested that AD pathology can affect the direction and intensity of information signaling in functional brain regions. The present study evaluates the time-delayed effective connectivity of normal controls (NC) and patients with mild cognitive impairment (MCI) under motion-detection tasks and explores identification of possible anomalies and deviated patterns in effective connectivity associated with AD pathology.
Method: Our research focuses on task-based EEG (64-channel), where participants were asked to perform a motion direction discrimination task.
Biomarkers.
Alzheimers Dement
December 2024
Michigan Alzheimer's Disease Research Center, Ann Arbor, MI, USA.
Background: Patients with cognitive impairment are likely to suffer from weakening of functional connectivity between certain brain regions, which may often be accompanied by increased connectivity between some other regions, the latter of which may reflect the compensatory mechanisms of the brain. In this EEG-based study, we investigate the differences in functional connectivity between persons with normal cognition (NC) and MCI patients in motion detection tasks.
Method: Our research focuses on task-based EEG (64-channel) acquired at Wayne State University, where participants with subjective cognitive complaints were asked to perform a motion direction discrimination task.
Biomarkers.
Alzheimers Dement
December 2024
Michigan Alzheimer's Disease Research Center, Ann Arbor, MI, USA.
Background: Changes in effective connectivity, which represents the directed connectivity or information flow from one brain region to the other, have been proposed to underlie mild cognitive impairment (MCI) and Alzheimer's disease (AD) pathology. The present study explores possible differences in brain effective connectivity between persons with normal cognition (NC) and patients with MCI.
Method: Our research focuses on task-based EEG (64-channel) acquired at Wayne State University, where participants were asked to perform a motion direction discrimination task.
Redox-stimulated catalytic DNA circuit for high-fidelity imaging of microRNA and in situ interpretation of the relevant regulatory pathway.
Biosens Bioelectron
December 2024
Department of Gastroenterology, Hubei Key Laboratory of Tumor Biological Behavior, Zhongnan Hospital of Wuhan University, Wuhan, 430072, PR China; Research Institute of Shenzhen, Wuhan University, Shenzhen, 518057, PR China. Electronic address:
Biomolecules play essential roles in regulating the orderly progression of biochemical reaction networks. DNA-based biocircuits supplement an attractive and ideal approach for the visual imaging of endogenous biomolecules, yet their sensing performance is commonly encumbered by the undesired signal leakage. To solve this issue, here we proposed a glutathione (GSH)-activated DNA circuit for achieving the spatio-selective microRNA imaging through the successive response of a GSH-specific activation procedure and a non-enzymatic catalytic signal amplification procedure.
View Article and Find Full Text PDFValue of serum pepsinogen ratio screening for early gastric cancer and precancerous lesions in Youcheng area.
World J Gastrointest Surg
December 2024
Health Management Center, Shengli Oilfield Central Hospital, Dongying 257000, Shandong Province, China.
Background: The 5-year survival rate of patients with advanced gastric cancer remains extremely low (< 15%), whereas the 5-year survival rate of patients with early gastric cancer (EGC) is > 90%. Consequently, strengthening the screening of patients with EGC and precancerous lesions (PCLs) is essential.
Aim: To identify the value of serum pepsinogen ratio (PGR) screening for EGC and PCLs in the Shengli Oilfield Central Hospital.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!