Kerry Kilborn

On Harnessing the Electroencephalogram for the Musical Braincap

The braincap, as described in 3001: The Final Odyssey, the concluding edition of Arthur C. Clarke’s science fiction classic, is the ultimate humancomputer interface: it connects the brain to a system that is able to read thoughts and upload new information. The wearer can in minutes acquire new skills that would otherwise take years to master. Currently, however, a system that uploads information into the brain cannot exist outside the realm of science fiction, although machines that can read signals from the brain are becoming present-day reality. Furthermore, we should soon be able to control all sorts of devices by our thoughts alone. In 1998, a paper presented at the 9th European Congress of Clinical Neurophysiology already reported impressive advances in research on an electroencephalogram-based system to control a prosthetic hand (Guger and Pfurtscheller 1998). More recently, scientists at Brown University reported the development of a brain-computer interface for a system whereby a monkey controlled a cursor on a computer screen (Turner 2002). At first, the monkey used a joystick to move the cursor. After a while, the joystick was disconnected, and the monkey, who had not realized this, continued moving the cursor by means of tiny electrical signals emanating from an electrode implanted on the monkey’s motor cortex (the main brain area for motor control). We are interested in developing thoughtcontrolled musical devices, and to this end we are currently working on the design of a musical braincap. We are developing technology to interface the brain with music systems and compositional techniques suitable for thought control. This article focuses on extracting and harnessing tiny electrical brain signals from electroencephalograms (EEGs) that can be captured with electrodes on the scalp. We present three experiments whose results provide the basis for building systems to automatically detect information in the electroencephalogram associated with musical mental activities. Then, we describe how these results are currently being embedded in the design of the musical braincap. Before we present the experiments, we briefly introduce the growing field of BrainComputer Interfaces (BCI), followed by an introduction to the EEG and the signal processing techniques we employed to harness it. Before we continue, it is necessary to clarify the meaning of the expression ‘‘thought control.’’ In Eduardo Reck Miranda,* Ken Sharman,† Kerry Kilborn,‡ and Alexander Duncan§ *Computer Music Research—Neuroscience of Music Group, School of Computing, Communications, and Electronics, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, United Kingdom eduardo.miranda@plymouth.ac.uk † Instituto Tecnologico de Informatica Universidad Politecnica de Valencia, Camino de Vera s/n, 46071 Valencia, Spain ken@iti.upv.es ‡ Department of Psychology University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, United Kingdom k.kilborn@psy.gla.ac.uk § The Sun Centre Prades, 48160 St. Martin de Boubaux, France alex@thesuncentre.net On Harnessing the Electroencephalogram for the Musical Braincap

Minimal Information for Neural Electromagnetic Ontologies (MINEMO): A standards-compliant method for analysis and integration of event-related potentials (ERP) data

We present MINEMO (Minimal Information for Neural ElectroMagnetic Ontologies), a checklist for the description of event-related potentials (ERP) studies. MINEMO extends MINI (Minimal Information for Neuroscience Investigations)to the ERP domain. Checklist terms are explicated in NEMO, a formal ontology that is designed to support ERP data sharing and integration. MINEMO is also linked to an ERP database and web application (the NEMO portal). Users upload their data and enter MINEMO information through the portal. The database then stores these entries in RDF (Resource Description Framework), along with summary metrics, i.e., spatial and temporal metadata. Together these spatial, temporal, and functional metadata provide a complete description of ERP data and the context in which these data were acquired. The RDF files then serve as inputs to ontology-based labeling and meta-analysis. Our ultimate goal is to represent ERPs using a rich semantic structure, so results can be queried at multiple levels, to stimulate novel hypotheses and to promote a high-level, integrative account of ERP results across diverse study methods and paradigms.

Multiscale permutation entropy analysis of the EEG in early stage alzheimer's patients

Alzheimers Disease (AD) is a neurodegenerative disorder associated with a progressive loss of cognitive function. Early identification of AD, when symptoms are mild, can be difficult. Therefore, the development of clinically useful measures are necessary to improve diagnosis of the disease and to allow for early clinical intervention, as well as to aid in drug development. The aim of this study is to analyse the electroencephalography (EEG) of patients with mild AD while they were engaged in a memory task, and to contrast these results with those from cognitively healthy control subjects. We introduce a novel application of the Multiscale Permutation Entropy (MPE) analysis to the EEG signal of patients and controls during task execution, which allows us to compare the complexity of the underlying brain signals at multiple temporal scales. These complexity results are then correlated with cognitive behavioral measures to evaluate the correspondence between complexity and cognitive performance.

Source localization of event-related potential effects differentiates between vascular dementia and Alzheimer's disease

Background: VaD and AD have different underlying pathogenic mechanisms, and may produce distinct signatures in brain activity that could aid in differential diagnosis. We investigate possible differential markers based on source localization of electrophysiological correlates of memory processing in VaD and AD. Methods: Advances in high resolution whole head EEG recordings, together with accurate conductivity models of head tissues, mean that reasonably accurate distributed source models can now be established. We used 128-channel EEG to measure amplitudes, latencies and topographies of the N2, P4, and P7 in AD and VaD patients and controls during an episodic memory task (all groups N = 8). We then used source localization methods (GeoSource; LAURA) to determine the cortical generators for the best performing ERP diagnostic markers. Results: The posterior N2 is prominent in controls and AD, but attenuated in VaD. This N2 effect localizes to the central occipital cortex in AD and controls, but not in VaD. The prefrontal P4 is prominent in controls, and evident in VaD, but attenuated in AD. The P4 localizes in all groups to the medial temporal region, but with varying intensity and timing. The right parietal P7 effect is prominent in controls, but attenuated in AD and VaD. The P7 localizes to prefrontal cortex in controls, but involves only right posterior cortex in VaD, and central posterior cortex in AD. Conclusions: Source localization analysis shows that scalp ERP differences between AD and VaD can be unambiguously attributed to different underlying generators within the brain. We hypothesize that these effects reflect disease-specific neuropathology, and offer new functional biomarkers to aid in differential diagnosis of AD and VaD.

Involvement of the anterior cingulate cortex in time-based prospective memory task monitoring: An EEG analysis of brain sources using Independent Component and Measure Projection Analysis.

Objective Time-based prospective memory (PM), remembering to do something at a particular moment in the future, is considered to depend upon self-initiated strategic monitoring, involving a retrieval mode (sustained maintenance of the intention) plus target checking (intermittent time checks). The present experiment was designed to explore what brain regions and brain activity are associated with these components of strategic monitoring in time-based PM tasks. Method 24 participants were asked to reset a clock every four minutes, while performing a foreground ongoing word categorisation task. EEG activity was recorded and data were decomposed into source-resolved activity using Independent Component Analysis. Common brain regions across participants, associated with retrieval mode and target checking, were found using Measure Projection Analysis. Results Participants decreased their performance on the ongoing task when concurrently performed with the time-based PM task, reflecting an active retrieval mode that relied on withdrawal of limited resources from the ongoing task. Brain activity, with its source in or near the anterior cingulate cortex (ACC), showed changes associated with an active retrieval mode including greater negative ERP deflections, decreased theta synchronization, and increased alpha suppression for events locked to the ongoing task while maintaining a time-based intention. Activity in the ACC was also associated with time-checks and found consistently across participants; however, we did not find an association with time perception processing per se. Conclusion The involvement of the ACC in both aspects of time-based PM monitoring may be related to different functions that have been attributed to it: strategic control of attention during the retrieval mode (distributing attentional resources between the ongoing task and the time-based task) and anticipatory/decision making processing associated with clock-checks.

Multiscale permutation statistical complexity measure analysis of EEG in patients with mild Alzheimer's disease

isotropic sampling and were acquired in just less than 7 minutes. In each subject we measured age adjusted global brain stiffness (entire brain excluding cerebellum), in 8 regions and a summary ROI that included the frontal and temporal lobes but excluded the sensory/motor strip (labeled FT). Results: Group-wise difference in global stiffness demonstrated decreased brain stiffness in FTD (2.59 kPa) compared with NC (2.77 kPa) (p1⁄40.007). Regional differences were most prominent in the frontal lobes (p1⁄40.001) and the temporal lobes (p1⁄40.005). Stiffness did not differ by group in the parietal or occipital lobes or the preand post-central gyri. Based on these results, a summary ROI composed of the frontal and temporal lobes but excluding the sensory/motor areas was generated which obtains complete separation between the two groups. Figure 1 shows a boxplot of stiffness. Conclusions: It has been previously reported that global brain stiffness is decreased in subjects with AD [1]. We now report a specific pattern of fronto-temporal stiffness reduction in FTD, expanding the diagnostic utility of this novel biomarker of neurodegenerative disease. References: [1] Murphy et al. JMRI 2011. 34(3): 494.

FIRST LANGUAGE ACQUISITION: THE ESSENTIAL READINGS

FIRST LANGUAGE ACQUISITION: THE ESSENTIAL READINGS. Barbara Lust and Claire Foley (Eds.) . Oxford: Blackwell, 2004. Pp. xi + 442.

Cognitive penetrability of syntactic priming in Broca's aphasia.

78.95 cloth,

Dialogue despite difficulties: a study of communication between aphasic and unimpaired speakers

38.95 paper. The goal of understanding the processes and mechanisms by which a child acquires a first language (L1) is an ambitious one. The rapid progress in the field of L1 acquisition over the last 50 years or so, combined with the practical challenge posed by an increasingly multidisciplinary literature, presents a daunting picture to established scholars as well as newcomers. This volume, edited by Lust and Foley, is an outstanding collection of foundational readings in the philosophy and science of language acquisition. Anyone who wishes to understand the state of the field today—or has ambitions of contributing to its advancement tomorrow—will find this book a vital resource.