Using the concepts of time-delayed feedback control in biofeedback systems in children with ADD: a preliminary study (Q2204514)

The study is concerned with biofeedback systems with time-delayed feedback control applied to problems in biofeedback systems in children with ADD. Two categories of control are considered; the first one involves time-delayed feedback control while the second one uses a fixed reference control. The parameterized model of reaction time (RT) is developed \(Y(t)= Ar+\ln(At+K_0)\), \(A =\alpha \ln(t) \alpha=(1-u(t))\) where \(Y(t)\) is the RT signal, \(r\) -- random number in \([0,1]\), \(u(t)\) -- control signal (which changes RTs) while \(A, K_0\), and \(\alpha\) are the parameters of the model. The optimization task is to keep \(Y(t)\) close to the reference, \(\text{ref}(t)\) in terms of minimization of \([Y(t)-\text{ref}(t)]^2\). The performance is investigated in cases of (i) no feedback, (ii) fixed reference, (iii) variable reference. The detailed experimental protocol is presented and the ensuing experimental results along with their analysis are provided. The advantages of the use of variable reference are outlined.