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A common problem in brain imaging is how to most appropriately coregister anatomical and functional data sets into a common space. For surface-based recordings such as the event related optical signal (EROS), near-infrared spectroscopy (NIRS), event-related potentials (ERPs), and magnetoencephalography (MEG), alignment is typically done using either (1) a(More)
Neuroimaging data emphasize that older adults often show greater extent of brain activation than younger adults for similar objective levels of difficulty. A possible interpretation of this finding is that older adults need to recruit neuronal resources at lower loads than younger adults, leaving no resources for higher loads, and thus leading to(More)
The event-related optical signal (EROS) has been recently proposed as a method for studying noninvasively the time course of activity in localized cortical areas (G. Gratton and M. Fabiani, 1998, Psychonomic Bull. Rev. 5: 535-563). Previous data have shown that EROS has very good temporal resolution and can provide detailed surface activity maps. In the(More)
Brain aging is characterized by changes in both hemodynamic and neuronal responses, which may be influenced by the cardiorespiratory fitness of the individual. To investigate the relationship between neuronal and hemodynamic changes, we studied the brain activity elicited by visual stimulation (checkerboard reversals at different frequencies) in younger(More)
fMRI and ERP studies have shown that tasks comprising conflicting stimulus-response associations activate a variety of cortical regions. It remains unclear whether any of these areas are activated by all conflict tasks, or whether conflict resolution is a common property of a number of distinct anatomical regions. Several regions in frontal and parietal(More)
The brain's vasculature is likely to be subjected to the same age-related physiological and anatomical changes affecting the rest of the cardiovascular system. Since aerobic fitness is known to alleviate both cognitive and volumetric losses in the brain, it is important to investigate some of the possible mechanisms underlying these beneficial changes. Here(More)
Sound repetition typically reduces auditory N1 amplitudes, more so at higher rates. This has been attributed to refractoriness of N1 generators. However, evidence that N1 attenuation is delayed 300-400 ms after the first occurrence of a repeated sound suggests an alternative process, such as inhibition, that requires 300-400 ms to become fully operational.(More)
This article presents a new approach to designing brain–computer interfaces (BCIs) that explicitly accounts for both the uncertainty of neural signals and the important role of sensory feedback. This approach views a BCI as the means by which users communicate intent to an external device and models intent as a string in an ordered symbolic language. This(More)
Changes in attention allocation with complex task learning reflect processing automatization and more efficient control. We studied these changes using ERP and EEG spectral analyses in subjects playing Space Fortress, a complex video game comprising standard cognitive task components. We hypothesized that training would free up attentional resources for a(More)