Category: Arts & Neuroscience; Measurement
Objective : First, the present study investigated the relationship between cognitive demand and two performance measures that measure outcome and response time. Second, it investigated the utility of functional Near InfraRed Spectroscopy (fNIR) a brain imaging device to measure the hemodynamic response in the prefrontal cortex during the performance measures as a biomarker of cognitive effort.
Design : The present study uses a cognitive paradigm that includes new category learning tasks that consist of three rules from the Categorization Program. Participants are required to identify three logical rules with increased complexity that categorize objects varying in color and shape. Speed and accuracy measures were obtained as well as physiological responses to stimuli recorded in real-time using the fNIRs equipment.
Setting : The present study took place at the Center of Applied Neuroscience, University of Cyprus in two specially designed and equipped rooms.
Participants (or Animals, Specimens, Cadavers) : The participants were a group of 28 undergraduate psychology students with age range 19-27 years. The sample was consisted from 24 women and 4 men.
Interventions : Interventions: Not applicable.
Main Outcome Measure(s) : We used two performance measures: 1. Outcome: percent of correct responses over the categorization questions presented 2. Response time: the time between the onset of the presented stimulus and the time of the response – regardless of whether it was correct.
Results : Correlating the cognitive demand that is inferred by analyzing the fNIR data with the reaction time data shows that the reaction time decreases when the cognitive demand increases.
Faster processing is associated with better hemodynamic response in the prefrontal regions. fNIRS seems to be a sensitive biomarker of cognitive effort and its utility should be explored in clinical populations such as patients suspected of concussion and MCI.