A fNIRS investigation of switching and inhibition during the modified Stroop task in younger and older adults

fNIRS-based investigation of the Stroop task after TBI

“…Increased activity during the incongruent condition of the Stroop paradigm compared to the simpler color naming condition is commensurate with fMRI studies among normal controls, as tasks requiring increased attentional demand and/or inhibition of a prepotent response requires is associated with increased prefrontal cortex activity (MacLeod 1992;Banich et al 2000;Holtzer et al 2011). The spatial locations activated by the incongruent condition in this study are consistent with the regions involved during the Stroop incongruent task using fMRI, as the literature has demonstrated significant bilateral prefrontal cortex involvement (Ben-David et al 2011;Laguë-Beauvais et al 2013).…”

Shedding light on the effect of priority instructions during dual-task performance in younger and older adults: A fNIRS study

“…fNIRS is a non-invasive imaging technique that uses near infrared light in order to measure changes in oxy-and deoxy-hemoglobin in the brain. Many studies have shown its validity to assess changes in frontal lobe activation in sustained attention and inhibition tasks [e.g., in younger adults (e.g., Carter, Russell, & Helton, 2013;De Joux, Russell, & Helton, 2013;Ong, Russell, & Helton, 2013;Stevenson, Russell, & Helton, 2011)] and inhibition and switching in both younger and older adults (Lague-Beauvais et al, 2013). One contribution of the present study is to show that fNIRS can also be used to track neural correlates of dual-task performances in these populations.…”

“…Neurological correlates of attentional age differences are now known to be due to factors such as decreased synaptic density and brain atrophy (Hedden & Gabrieli, 2004;Goh, 2001;Nieto-Sampedro & Nieto-Diaz, 2005), reduced functional connectivity and weakened white matter integrity (Davis, Kragel, Madden, & Cabeza, 2012), diminished blood flow to the frontal lobes, decreased metabolic rate of oxygen compsumption (Drag & Bieliauskas, 2010), and decrease in neurotransmitter release and synapse efficiency (Goh, 2001;Bishop, Lu, & Yankner, 2010). However, recent studies suggest that not all executive control mechanisms are equally affected by age (Verhaeghen, 2011) and that the pattern of prefrontal engagement might depend on the mechanisms involved (Lague-Beauvais, Brunet, Gagnon, Lesage, & Bherer, 2013).…”

“…The current optical imaging study was designed to assess behavioral and neural age differences in dual-task performances as a function of priority instructions. Recent evidence shows that there are different patterns of prefrontal activation for tasks requiring different executive mechanisms [e.g., switching vs. inhibition (Lague-Beauvais et al, 2013;Turner & Spreng, 2012)] and that these mechanisms are not affected equally in normal aging. Thus, we hypothesized that when performing two tasks at the same time, different task priority instructions would lead to different patterns of prefrontal lobe activation and that this effect would differ among older and younger adults.…”

Imbalanced

“…Under such circumstances the cerebral cortex/fire chief must become involved by quickly inhibiting irrelevant afferent input and distracting cognitive processes, weighing the multiple inputs, and rapidly generating a coordinated response via the lower centers/dispatchers. Evidence suggests that the dorsolateral prefrontal cortex (DLPFC) is involved in executive functions, 15 and imaging studies show this area to be highly active during recovery from large perturbations 16 and in the compensation for ataxic gait following cerebellar injury. 17 Finally, the fire chief’s rapid planning is for naught if the trucks are slow and, similarly, there must be sufficient strength in key muscles to generate torque quickly enough for the perturbation to be successfully rejected.…”