Layered control architectures in robots and vertebrates

We revieiv recent research in robotics, neuroscience, evolutionary neurobiology, and ethology with the aim of highlighting some points of agreement and convergence. Specifically, we com pare Brooks' (1986) subsumption architecture for robot control with research in neuroscience demonstrating layered control systems in vertebrate brains, and with research in ethology that emphasizes the decomposition of control into multiple, intertwined behavior systems. From this perspective we then describe interesting parallels between the subsumption architecture and the natural layered behavior system that determines defense reactions in the rat. We then consider the action selection problem for robots and vertebrates and argue that, in addition to subsumption- like conflict resolution mechanisms, the vertebrate nervous system employs specialized selection mechanisms located in a group of central brain structures termed the basal ganglia. We suggest that similar specialized switching mechanisms might be employed in layered robot control archi tectures to provide effective and flexible action selection

Impact of a web-supported programme of Constraint Induced Therapy following stroke (LifeCIT)

Background: upper extremity (UE) movement is often compromised following a stroke. Constraint Induced Therapy (CIT) is an evidence-based intensive intervention (1) which involves people with stoke practicing activites with their affected hand whilst wearing a mitt on their other hand, but it relies on intensive therapy. A study trialling CIT in a community setting without a therapist present found key barriers to be lack of motivation to wear the mitt and comply with the exercise programme (2). A web supported CIT system (LifeCIT) for UE stroke rehabilitation was developed to address this barrier. Objective: to evaluate the impact of using LifeCIT for UE stroke rehabilitation compared to usual care in subacute/chronic stroke patients at home.Methods: subacute/chronic stroke patients were randomized into a three week intervention consisting of LifeCIT or control groups. UE impairment and function were assessed with the Motor activity log (MAL), Fugl-Meyer (FMA-UE) and Wolf Motor Function Test (WMFT) pre and post intervention and at a six month follow-up. Results: sixteen patients completed the trial. Between group differences, favouring the LifeCIT group in MAL (AOU and QOU) and WMFT (FAS) were identified post intervention (ANCOVA) and controlled for baseline clinical scores, Orpington score and Sub-acute/chronic. Mean improvement in the LifeCIT group MALfrom baseline to post treatment (1.02 AOU and QOU) and at six months (0.6 AOU and QOU) was above the minimally clinically important difference (MCID) for the MAL (MCID = 0.5) Improvement in the LifeCIT group WMFT (FAS) met MCID from baseline to post intervention (0.35) and at six months (0.3) FAS MCID=0.2 - 0.4. Interview data confirmed positive acceptance of LifeCIT. Conclusion: use of LifeCIT in the community improved UE function in subacute/chronic stroke patients following a three week intervention and at a six month follow-up, suggesting a larger scale study should be run. References(1) Wolf SL, Winstein CJ, Miller JP, Taub E, Uswatte G, Morris D et al. Effect of constraint-induced movement therapy on upper extremity function 3 to 9 months after stroke: the EXCITE randomized clinical trial. Journal of the American Medical Association 2006; 296(17):2095-2104.(2) Burns A, Burridge J.H., Pickering R.M. Does the use of a constraint mitten to encourage use of the hemiplegic upper limb improve arm function in adults with subacute stroke? Clin Rehabil 2007; 21:895-904.Supported by the National Institute for Health Research (NIHR) Research for Patient Benefit (RFPB) <br/