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Augmenting Attention with Brain–Computer Interfaces
Published in Chang S. Nam, Anton Nijholt, Fabien Lotte, Brain–Computer Interfaces Handbook, 2018
Mehdi Ordikhani-Seyedlar, Mikhail A. Lebedev
In our daily life, we constantly receive multiple sensory inputs from the external world; the amount of incoming sensory information is huge. The only way for the brain can process this information stream and generate proper behavioral responses is to filter out irrelevant incoming signals and leave only the important ones. As a result of such attentional filtering, only a tiny amount of the initial sensory information reaches higher-order areas of the brain (Posner 1994, 2012). The signals that are filtered out are still represented by neural modulations, especially at the early processing stages, but they are usually not perceived consciously. On the other hand, the relevant signals are selected by the brain attentional mechanism, and they enter the conscious processing stage. Such attentional selection is governed by a network of interconnected brain areas. One of these areas, the prefrontal cortex (PFC) has a particularly important role in the mechanisms of selective attention. PFC is activated during attentional tasks, and lesions to this area lead to attentional deficits (Ferrier 1876). Posner’s laboratory has conducted a series of studies to identify the brain areas involved in attention (Fan et al. 2005; Petersen & Posner 2012; Posner & Rothbart 2007). These studies have demonstrated that multiple brain areas govern attention, and the same areas are also engaged in oculomotor control. In addition to PFC, the attentional brain network includes parietal cortical areas, the frontal eye field (FEF), subcortical nuclei, and, importantly, the superior colliculus.
Understanding cognition and how it changes with aging, brain disease, and lifestyle choices
Published in Journal of the Royal Society of New Zealand, 2021
The impact of brain disease on cognition varies depending on the location and nature of the disease-related disruption. Focal lesion research has been particularly instrumental in determining the specific cognitive functions of different brain structures, as associated cognitive impairment can be more directly linked to discrete regions of damage, whereas drawing links associated with diffuse (i.e. non-focal) damage is less straightforward. Although the extent of naturally occurring brain lesions varies considerably across patients, by recruiting a number of patients who all have brain damage involving a particular region of interest, and comparing them against control groups, the function of a particular brain region can be determined. For example, the role of the human frontal eye field in saccadic eye movement control has been elucidated through this methodology. Building on findings from research in macaque monkeys, human patient research revealed the importance of the frontal eye field in voluntary eye movement control, including generation of volitional saccades and strategic control over both reflexive saccades and disengagement from fixation (Henik et al. 1994; Rafal et al. 2000; Machado and Rafal 2004a, 2004b). The importance of this frontal region in strategic eye movement control has been corroborated through a combination of magnetic and electrical brain stimulation studies, with the latter demonstrating some promise with respect to therapeutic benefits (Ro et al. 1997; Kanai et al. 2012; Chen et al. 2018).