Scott Makeig - Independent Researcher (original) (raw)

Papers by Scott Makeig

Journal of the Acoustical Society of America, Nov 1, 1982

Trends in Neurosciences, Aug 1, 2002

Techniques & Applications Diverse human disorders, including the majority of neurodegenerative di... more Techniques & Applications Diverse human disorders, including the majority of neurodegenerative diseases, are thought to arise from the misfolding and aggregation of protein. We have recently described a novel technology to amplify cyclically misfolded proteins in vitro. This procedure, named protein misfolding cyclic amplification (PMCA), is conceptually analogous to DNA amplification by PCR and has tremendous implications for research and diagnosis. The PMCA concept has been proved on the amplification of prions implicated in the pathogenesis of transmissible spongiform encephalopathies. In this article we describe the rational behind PMCA and some of the many potential applications of this novel technology.

Journal of the Acoustical Society of America, May 1, 1986

of stimuli from two independent ER-2 insert earphones, each providing a flat eardrum-pressure fre... more of stimuli from two independent ER-2 insert earphones, each providing a flat eardrum-pressure frequency response to 12 kHz. The complete microphone exhibits a typical noise spectrum level of -20 dB SPL at 1 kHz decreasing to --26 dB at 5 kHz, 8 to 10 dB below that of a single Knowles EA-1954 microphone and 5 to 10 dB below the apparent noise level of good young ears based on the estimate ofKillion [ J. Acoust. Soc. Am. 59, 424-433 (1976) ]. 8:45 C2. Synchronization of spontaneous otoacousfic emissions and driven Umit-cycle oscillators. Glenis R. Long (

Clinical Neurophysiology, Sep 1, 1993

Transient and steady-state auditory evoked fields (AEFs) to brief tone pips were recorded over th... more Transient and steady-state auditory evoked fields (AEFs) to brief tone pips were recorded over the left hemisphere at 7 different stimulus rates (0.125-39 Hz) using a 37-channel biomagnetometer. Previous observations of transient auditory gamma band response (GBR) activity were replicated. Similar rate characteristics and equivalent dipole locations supported the suggestion that the steady-state response (SSR) at about 40 Hz represents the summation of successive overlapping (10 Hz) middle latency responses (MLRs). On the other hand, differences in equivalent dipole locations and habituation effects suggest that the magnetically recorded GBR is a separate phenomenon which occurs primarily at low stimulus rates and is unrelated to either the magnetically recorded MRL or SSR.

Investigative Ophthalmology & Visual Science, Apr 30, 2014

Journal of the Acoustical Society of America, Dec 1, 1986

obtained for: ( 1 ) left monaural stimulation; (2) right monaural stimulation; and (3) binaural s... more obtained for: ( 1 ) left monaural stimulation; (2) right monaural stimulation; and (3) binaural stimulation. Individual binaural interaction waveforms were derived as described above. A shift of the major component of the binaural interaction between the adult and infant was observed. The largest BIC occurs in the adult at the time of P30 and N40 with a 41% interaction at P30 and a 21% interaction at N40. The morphology of the infant middle latency potentials differs significantly from the adult form by the narrowness of an N13 component and the lack of a clearly defined P30. N40 does not occur in the infant. The major interaction in the infant occurs at the time of N20, showing an interaction of 45%. This difference probably reflects changes in the middle latency components between adults and infants, with the adult showing a predominant P30-N40 component. [Work supported in part by the National Institutes of Health and the National Foundation March of Dimes. ] 9:45 W6. The use of paired clicks to examine forward masking in auditory brainstem responses.

Pornography consumption is highly prevalent, particularly among young adult males. For some indiv... more Pornography consumption is highly prevalent, particularly among young adult males. For some individuals, problematic pornography use (PPU) is a reason for seeking treatment. Despite the pervasiveness of pornography, PPU appears under-investigated, including with respect to the underlying neural mechanisms. Using functional magnetic resonance imaging (fMRI), we examined ventral striatal responses to erotic and monetary stimuli, disentangling cue-related 'wanting' from reward-related 'liking' among 28 heterosexual males seeking treatment for PPU and 24 heterosexual males without PPU. Subjects engaged in an incentive delay task in the scanner, in which they received erotic or monetary rewards preceded by predictive cues. BOLD responses to erotic and monetary cues were analyzed and examined with respect to self-reported data on sexual activity collected over the 2 preceding months. Men with and without PPU differed in their striatal responses to cues predicting erotic pictures, but not in their responses to erotic pictures. PPU subjects when compared to control subjects showed increased activation of ventral striatum specifically for cues predicting erotic pictures but not for cues predicting monetary gains. Relative sensitivity to cues predicting erotic pictures versus monetary gains was significantly related to the increased behavioral motivation to view erotic images (suggestive of higher 'wanting'), severity of PPU, amount of pornography use per week and number of weekly masturbations. Our findings suggest that, similar to what is observed in substance and gambling addictions, the neural and behavioral mechanisms associated with the anticipatory processing of cues specifically predicting erotic rewards relate importantly to clinically relevant features of PPU. These findings suggest that PPU may represent a behavioral addiction and that interventions helpful in targeting behavioral and substance addictions warrant consideration for adaptation and use in helping men with PPU.

Biological Psychiatry, 2015

Psychiatry is a young, still developing science that must, against sharp opposition, gradually ac... more Psychiatry is a young, still developing science that must, against sharp opposition, gradually achieve the position it deserves according to its scientific and practical importance. There is no doubt that it will achieve this position-for it has at its disposal the same weapons which have served the other branches of medicine so well: clinical observation, the microscope and experimentation" (1).

Mobile Brain/Body Imaging: A Decade of Emergence

Frontiers in Human Neuroscience, 2018

The neuroscientific study of human navigation has been con-strained by the prerequisite of tradit... more The neuroscientific study of human navigation has been con-strained by the prerequisite of traditional brain imaging studies that re-quire participants to remain stationary. Such imaging approaches neglect a central component that characterizes navigation -the multisensory ex-perience of self-movement. Navigation by active movement through space combines multisensory perception with internally generated self-motion cues. We investigated the spatial micro genesis during free ambulatory exploration of interactive sparse virtual environments using motion cap-ture synchronized to high resolution electroencephalographic (EEG) data as well psychometric and self-report measures. In such environments, map-like allocentric representations must be constructed out of transient, egocentric first-person perspective 3-D spatial information. Considering individual differences of spatial learning ability, we studied if changes in exploration behavior coincide with spatial learning of an environment...

EEG Research Methodology and Brainwave Entrainment

2003 Special Issue Complex independent component analysis of frequency-domain electroencephalographic data

Independent component analysis (ICA) has proven useful for modeling brain and electroencephalogra... more Independent component analysis (ICA) has proven useful for modeling brain and electroencephalographic (EEG) data. Here, we present a new, generalized method to better capture the dynamics of brain signals than previous ICA algorithms. We regard EEG sources as eliciting spatio-temporal activity patterns, corresponding to, e.g. trajectories of activation propagating across cortex. This leads to a model of convolutive signal superposition, in contrast with the commonly used instantaneous mixing model. In the frequency-domain, convolutive mixing is equivalent to multiplicative mixing of complex signal sources within distinct spectral bands. We decompose the recorded spectral- domain signals into independent components by a complex infomax ICA algorithm. First results from a visual attention EEG experiment exhibit: (1) sources of spatio-temporal dynamics in the data, (2) links to subject behavior, (3) sources with a limited spectral extent, and (4) a higher degree of independence compare...

Analysis of neuronal source dynamics and connectivity during seizure using adaptive vector autoregressive models, sparse bayesian learning, independent component analysis, and electrocorticography

Frontiers in Human Neuroscience, 2011

Mobile Brain-Body Imaging of ASD Participants During Natural Movement

ABSTRACT Background: Motor dysfunction (e.g., abnormalities of gait, balance, muscle tone, head a... more ABSTRACT Background: Motor dysfunction (e.g., abnormalities of gait, balance, muscle tone, head and eye movement and coordination) is a prominent feature in autism that may be a contributing factor in cognitive and social impairments. Isolating specific underlying mechanisms that lead to a variety of motor impairments (e.g., timing, anticipation) would inform effective intervention that may in turn improve not only motor competence but also behavioral problems that are affected by motor dysfunction. We are currently conducting a first quantitative study of motor function in ASD that relates motor dysfunction to both underlying brain structure and function as well as to behavioral. Central to this study is the ground-breaking mobile brain/body imaging (MoBI) system (Makeig et al., 2009). This novel system uses a combination of cameras and LED emitters for motion capture with simultaneous collection of high-density scalp EEG to quantify the accuracy, coordination, and timing of motor functions and to allow modeling of cortical network function during specific phases of motor operations. Development of analytic methods is critical to the success of this work. Objectives: The goals of the experiment presented here were 1) to test the feasibility of integrating EEG with motor activity collected during a task in which the participant moved freely around a large room, and 2) to determine the most appropriate analytic methods for these novel multi-modal datasets. Methods: We recorded 128-channel EEG and 66-sensor motion-capture data from boys between the ages of 13-17 (ASD and typically developing controls). The task, embedded in a simple video game, required participants to walk across a large room in order to reach a cartoon ‘alien’ projected on a wall. On STRAIGHT trials, the participant could reach the alien by walking straight across the room; on TURN trials the alien would move to one of the adjacent walls requiring the participant to change direction. Motion-capture data was used to determine the point at which the participant began a turn to follow the alien. EEG data were decomposed using Independent Components Analysis, and activity of individual Independent Components (ICs) was time-locked to the turning time point identified from the motion-capture data. For each IC of interest, we performed time-frequency analyses, and estimated the cortical solution; we also modeled causal relationships between pairs of ICs. Results: We successfully separated cortical EEG activity from movement-generated artifact. After integrating motion and EEG data, we found the markers best related to task behavior, and used these markers to identify EEG networks associated with that behavior. We identified ICs from two categories: those whose activity was associated with leg/foot movement, and those whose activity was associated with, but more importantly preceded the act of turning. Cortical source modeling indicated that these components were located in brain areas consistent with the motor network. Conclusions: This pilot work established the feasibility of recording and analyzing EEG activity from freely-moving participants. Modeling causal relationships between the various EEG networks revealed interactions that will allow us to differentiate between motor planning and execution.

PsycEXTRA Dataset

Objective. In neuroscience, time-frequency analysis has been used to get insight into brain rhyth... more Objective. In neuroscience, time-frequency analysis has been used to get insight into brain rhythms from brain recordings. In event-related protocols, one applies it to investigate how the brain responds to a stimulation repeated over many trials. In this framework, three measures have been considered: the amplitude of the transform for each single trial averaged across trials, avgAMP; inter-trial phase coherence, ITC; and the power of the evoked potential transform, POWavg. These three measures are sensitive to different aspects of event-related responses, ITC and POWavg sharing a common sensitivity to phase resetting phenomena. Methods. In the present manuscript, we further investigated the connection between ITC and POWavg using theoretical calculations, a simulation study and analysis of experimental data. Results. We derived exact expressions for the relationship between POWavg and ITC in the particular case of the S-transform of an oscillatory signal. In the more general case, we showed that POWavg and ITC are connected through a relationship that roughly reads POWavg ≈ avgAMP 2 × ITC 2 . This result was confirmed on simulations. We finally compared the theoretical prediction with results from real data. Conclusion. We showed that POWavg and ITC are related through an approximate, simple relationship that also involves avgAMP. Significance. The presented relationship between POWavg, ITC, and avgAMP confirms previous empirical evidence and provides a novel perspective to investigate evoked brain rhythms. It may provide a significant refinement to the neuroscientific toolbox for studying evoked oscillations.

Mapping ERP Features on the Cortical Surface through a Spatiotemporal Modality

Removal of eye activity artifacts form visual event-related potential in normal and clinical subject

Objectives: Electrical potentials produced by blinks and eye movements,present serious problems,f... more Objectives: Electrical potentials produced by blinks and eye movements,present serious problems,for electroencephalographic (EEG) and event-related potential (ERP) data interpretation and analysis, particularly for analysis of data from some clinical populations. Often, all epochs contaminated by large eye artifacts are rejected as unusable, though this may prove unacceptable when blinks and eye movements occur frequently. Methods: Frontal channels are often used as reference signals to regress out eye artifacts, but inevitably portions of relevant EEG signals also appearing in EOG channels are thereby eliminated or mixed,into other scalp channels. A generally applicable adaptive method,for removing,artifacts from EEG records based on blind source separation by independent,component,analysis (ICA) (Neural Computation 7 (1995) 1129; Neural Computation 10(8) (1998) 2103; Neural Computation 11(2) (1999) 606) overcomes,these limitations. Results: Results on EEG data collected from 28 no...

The Quarterly Review of Biology, 2000