Other Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

Comparison Of Functional Network Connectivity For Passive-Listening And Active-Response Narrative Comprehension In Adolescents, Yingying Wang, Scott K. Holland

Center for Brain, Biology, and Behavior: Faculty Publications

Comprehension of narrative stories plays an important role in the development of language skills. In this study, we compared brain activity elicited by a passive-listening version and an active-response (AR) version of a narrative comprehension task by using independent component (IC) analysis on functional magnetic resonance imaging data from 21 adolescents (ages 14–18 years). Furthermore, we explored differences in functional network connectivity engaged by two versions of the task and investigated the relationship between the online response time and the strength of connectivity between each pair of ICs. Despite similar brain region involvements in auditory, temporoparietal, and frontoparietal language networks …

The Helminthological Society Of Washington 2013 Anniversary Award: Larry S. Roberts, Sherman S. Hendrix

Center for Brain, Biology, and Behavior: Faculty Publications

Dr. Roberts was born in the great state of Texas, and much of his early life is murky, but snakes are often mentioned. Larry received his Bachelor’s degree at Southern Methodist University; his Master of Science at the University of Illinois; and his Doctorate in the Department of Pathobiology at the Johns Hopkins School of Hygiene and Public Health. Larry’s doctoral research, published in Experimental Parasitology, documented the early development and crowding effect of the tapeworm, Hymenolepis diminuta, in the rat small intestine. His publication on this subject opened the door to the golden age of cestode physiology and biochemistry …

Can Helmet Design Reduce The Risk Of Concussion In Football?, Steven Rowson, Stefan M. Duma, Richard M. Greenwald, Jonathan Beckwith, Jeffrey J. Chu, Kevin M. Guskiewicz, Jason P. Mihalik, Joe Crisco, Bethany J. Wilcox, Thomas W. Mcallister, Arthur C. Maerlender, Steven P. Broglio, Brock Schnebel, Scott Anderson, P. Gunnar Brolinson

Center for Brain, Biology, and Behavior: Faculty Publications

Of all sports, football accounts for the highest incidence of concussion in the US due to the large number of athletes participating and the nature of the sport. While there is general agreement that concussion incidence can be reduced through rule changes and teaching proper tackling technique, there remains debate as to whether helmet design may also reduce the incidence of concussion. A retrospective analysis was performed of head impact data collected from 1833 collegiate football players who were instrumented with helmet-mounted accelerometer arrays for games and practices. Data were collected between 2005 and 2010 from 8 collegiate football teams: …

Winning And Losing: Differences In Reward And Punishment Sensitivity Between Smokers And Nonsmokers, Laura E. Martin, Lisa S. Cox, William M. Brooks, Cary R. Savage

Center for Brain, Biology, and Behavior: Faculty Publications

Background: Smokers show increased brain activation in reward processing regions in response to smoking-related cues, yet few studies have examined secondary rewards not associated with smoking (i.e., money). Inconsistencies exist in the studies that do examine secondary rewards with some studies showing increased brain activation in reward processing brain regions, while others show decreased activation or no difference in activation between smokers and nonsmokers. Aims: The goal of the current study is to see if smokers process the evaluation and delivery of equally salient real world rewards similarly or differently than nonsmokers. Methods: The current study employed functional magnetic resonance …

The Impact Of Interface Design During An Initial High-Technology Aac Experience: A Collective Case Study Of People With Aphasia, Aimee R. Dietz, Kristy S.E. Weissling, Julie Griffith, Miechelle L. Mckelvey, Devan Macke

Department of Special Education and Communication Disorders: Faculty Publications

The purpose of this collective case study was to describe the communication behaviors of five people with chronic aphasia when they retold personal narratives to an unfamiliar communication partner using four variants of a visual scene display (VSD) interface. The results revealed that spoken language comprised roughly 70% of expressive modality units; variable patterns of use for other modalities emerged. Although inconsistent across participants, several people with aphasia experienced no trouble sources during the retells using VSDs with personally relevant photographs and text boxes. Overall, participants perceived the personally relevant photographs and the text as helpful during the retells. These …

Sex Differences In White Matter Development During Adolescence: A Dti Study, Yingying Wang, Chris Adamson, Weihong Yuan, Mekibib Altaye, Anna W. Byars, Scott K. Holland

Center for Brain, Biology, and Behavior: Faculty Publications

Adolescence is a complex transitional period in human development, composing physical maturation, cognitive and social behavioral changes. The objective of this study is to investigate sex differences in white matter development and the associations between intelligence and white matter microstructure in the adolescent brain using diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS). In a cohort of 16 typically-developing adolescents aged 13 to 17 years, longitudinal DTI data were recorded from each subject at two time points that were one year apart. We used TBSS to analyze the diffusion indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity …

Combined Erp/Fmri Evidence For Early Word Recognition Effects In The Posterior Inferior Temporal Gyrus, Joseph Dien, Eric S. Brian, Dennis L. Molfese, Brian T. Gold

Center for Brain, Biology, and Behavior: Faculty Publications

Two brain regions with established roles in reading are the posterior middle temporal gyrus and the posterior fusiform gyrus. Lesion studies have also suggested that the region located between them, the posterior inferior temporal gyrus (pITG), plays a central role in word recognition. However, these lesion results could reflect disconnection effects since neuroimaging studies have not reported consistent lexicality effects in pITG. Here we tested whether these reported pITG lesion effects are due to disconnection effects or not using parallel ERP/fMRI studies. We predicted that the Recognition Potential (RP), a left-lateralized ERP negativity that peaks at about 200–250 ms, might …

Concordance Of Meg And Fmri Patterns In Adolescents During Verb Generation, Yingying Wang, Scott K. Holland, Jennifer Vannest

Center for Brain, Biology, and Behavior: Faculty Publications

In this study we focused on direct comparison between the spatial distributions of activation detected by functional magnetic resonance imaging (fMRI) and localization of sources detected by magnetoencephalography (MEG) during identical language tasks. We examined the spatial concordance between MEG and fMRI results in 16 adolescents performing a three-phase verb generation task that involves repeating the auditorily presented concrete noun and generating verbs either overtly or covertly in response to the auditorily presented noun. MEG analysis was completed using a synthetic aperture magnetometry (SAM) technique, while the fMRI data were analyzed using the general linear model approach with random-effects. To …

A One-Hour Sleep Restriction Impacts Brain Processing In Young Children Across Tasks: Evidence From Event-Related Potentials, Dennis Molfese, Anna Ivanenko, Alexandra P.F. Key, Adrienne Roman, Victoria J. Molfese, Louise M. O'Brien, David Gozal, Srinivas Kota, Caitlin M. Hudac

Center for Brain, Biology, and Behavior: Faculty Publications

The effect of mild sleep restriction on cognitive functioning in young children is unclear, yet sleep loss may impact children's abilities to attend to tasks with high processing demands. In a preliminary investigation, six children (6.6 - 8.3 years of age) with normal sleep patterns performed three tasks: attention (“Oddball”), speech perception (conconant-vowel syllables) and executive function (Directional Stroop). Event-related potentials (ERP) responses were recorded before (Control) and following one-week of 1-hour per day of sleep restriction. Brain activity across all tasks following Sleep Restriction differed from activity during Control Sleep, indicating that minor sleep restriction impacts children's neurocognitive functioning.

Normative Topographic Erp Analyses Of Speed Of Speech Processing And Grammar Before And After Grammatical Treatment, Paul J. Yoder, Dennis Molfese, Micah M. Murray, Alexandra P.F. Key

Center for Brain, Biology, and Behavior: Faculty Publications

Typically developing (TD) preschoolers and age-matched preschoolers with specific language impairment (SLI) received event-related potentials (ERPs) to four monosyllabic speech sounds prior to treatment and, in the SLI group, after 6 months of grammatical treatment. Before treatment, the TD group processed speech sounds faster than the SLI group. The SLI group increased the speed of their speech processing after treatment. Post-treatment speed of speech processing predicted later impairment in comprehending phrase elaboration in the SLI group. During the treatment phase, change in speed of speech processing predicted growth rate of grammar in the SLI group.

Sleep Hygiene And Problem Behaviors In Snoring And Non- Snoring School-Age Children, Lisa A. Witcher, David Gozal, Dennis L. Molfese, Scott M. Salathe, Karen Spruyt, Valerie Mclaughlin Crabtree

Center for Brain, Biology, and Behavior: Faculty Publications

Objectives—The effects of sleep-disordered breathing, sleep restriction, dyssomnias, and parasomnias on daytime behavior in children have been previously assessed. However, the potential relationship(s) between sleep hygiene and children’s daytime behavior remain to be explored. The primary goal of this study was to investigate the relationship between sleep hygiene and problematic behaviors in non-snoring and habitually snoring children.

Methods—Parents of 100 5- to 8-year-old children who were reported to snore “frequently” to “almost always,” and of 71 age-, gender-, and ethnicity-matched children who were reported to never snore participated in this study. As part of a larger, ongoing study, …

Flowcell Systems For Single Molecule Detection, John G. K. Williams, Gregory R. Bashford, Jiyan Chen, Dan Draney, Nara Narayanan, Bambi L. Reynolds, Pamela Sheaff

Biomedical Imaging and Biosignal Analysis Laboratory

The present invention provides compounds, methods and systems for sequencing nucleic acid using single molecule detection. Using labeled NPs that exhibit charge-switching behavior, single-molecule DNA sequencing in a microchannel sorting system is realized. In operation, sequencing products are detected enabling real-time sequencing as successive detectable moieties flow through a detection channel. By electrically sorting charged molecules, the cleaved product molecules are detected in isolation without interference from unincorporated NPs and without illuminating the polymerase-DNA complex.

Two-Dimensional Blood Flow Velocity Estimation Using Apparent Speckle Pattern Angle Dependence On Scan Velocity, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An algorithm which measures the lateral component of blood flow velocity was developed in our previous studies based on the increase in speckle size due to relative motion between moving scatterers and spatial rate of scanner A-line acquisition (scan velocity). In this paper, the apparent dominant angle of the speckle pattern in a straight vessel was investigated and a new method of two-dimensional blood flow velocity estimation is introduced. Different scan velocities were used for data acquisition from blood flow traveling at an angle relative to the ultrasound beam. The apparent angle of the speckle pattern changes with different scan …

Monitoring Cerebral Hemodynamics With Transcranial Doppler Ultrasound During Cognitive And Exercise Testing In Adults Following Unilateral Stroke, Brian P. Watt, Judith M. Burnfield, Edward J. Truemper, Thad W. Buster, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An observational study was performed as a preliminary investigation into the use of transcranial Doppler ultrasound (TCD) for recording cerebral hemodynamic changes during multiple tasks. TCD is a method of measuring cerebral blood flow (CBF) using ultrasound transducers in contact with the surface of the head. Using the maximum flow envelope of the Doppler spectrum returning from the middle cerebral artery (MCA), standard clinical flow indices can be calculated and displayed in real time providing information concerning perturbations in CBF and their potential cause. These indices as well as flow velocity measurements have been recognized as useful in measuring changes …

Cognitive Effects Of One Season Of Head Impacts In A Cohort Of Collegiate Contact Sport Athletes, Thomas W. Mcallister,, Laura A. Flashman, Arthur C. Maerlender, Richard M. Greenwald, Jonathan G. Beckwith, Tor D. Tosteson, Joe Crisco, Per Gunner Brolinson, Stefan Duma, Ann-Christine Duhaime, M. R. Grove, John H. Turco

Center for Brain, Biology, and Behavior: Faculty Publications

Objective: To determine whether exposure to repetitive head impacts over a single season negatively affects cognitive performance in collegiate contact sport athletes.

Methods: This is a prospective cohort study at 3 Division I National Collegiate Athletic Association athletic programs. Participants were 214 Division I college varsity football and ice hockey players who wore instrumented helmets that recorded the acceleration-time history of the head following impact, and 45 noncontact sport athletes. All athletes were assessed prior to and shortly after the season with a cognitive screening battery (ImPACT) and a subgroup of athletes also were assessed with 7 measures from a …

Initial Mlu Predicts The Relative Efficacy Of Two Grammatical Treatments In Preschoolers With Specific Language Impairments, Paul J. Yoder, Dennis L. Molfese, Elizabeth Gardner

Center for Brain, Biology, and Behavior: Faculty Publications

Purpose—We sought to confirm predictions based on past findings that pre-treatment mean length of utterance (MLU) would predict which of two grammatical treatments would best facilitate generalized and maintained grammatical development in preschoolers with specific language impairment (SLI).

Method—The participants were 57 preschoolers with specific language impairment (SLI). A randomized group experiment was used. The two grammatical treatments were Broad Target Recasts (BTR) and Milieu Language Teaching (MLT). MLU was assessed at Time 1 in two conversational language samples. Growth rate of productive grammar was quantified using growth curve modeling on the Index of Productive Syntax (IPSyn) from …

Interictal Magnetoencephalographic Findings Related With Surgical Outcomes In Lesional And Nonlesional Neocortical Epilepsy, Rui Zhang, Ting Wu, Yingying Wang, Hongyi Liu, Yuanjie Zou, Wen Liu, Jing Xiang, Chaoyong Xiao, Lu Yang, Zhen Fu

Center for Brain, Biology, and Behavior: Faculty Publications

Purpose: To investigate whether interictal magnetoencephalography (MEG) concordant with other techniques can predict surgical outcome in patients with lesional and nonlesional refractory neocortical epilepsy (NE).

Methods: 23 Patients with lesional NE and 20 patients with nonlesional NE were studied. MEG was recorded for all patients with a 275 channel whole-head system. Synthetic aperture magnetometry (SAM) with excess kurtosis (g2) and conventional Equivalent Current Dipole (ECD) were used for MEG data analysis. 27 Patients underwent long-term extraoperative intracranial video electroencephalography (iVEEG) monitoring. Surgical outcomes were assessed based on more than 1-year of post-surgical follow-up using Engel classification system.

Results: As we …

Neuromagnetic Measures Of Word Processing In Bilinguals And Monolinguals, Yingying Wang, Jing Xiang, Jennifer Vannest, Tom Holroyd, Daria Narmoneva, Paul Horn, Yinhong Liu, Douglas Rose, Ton Degrauw, Scott Holland

Center for Brain, Biology, and Behavior: Faculty Publications

Objective: This study aimed to use magnetoencephalography (MEG) to examine the question of whether Mandarin-English bilingual speakers recruit the same cortical areas or develop distinct language-specific networks without overlaps for word processing.

Methods: Eight healthy Mandarin-English bilingual adults and eight healthy English monolingual adults were scanned while single-word paradigms were audio-visually presented.

Results: Our results showed significantly stronger beta-band power suppression in the right inferior parietal lobe (IPL) covering the supramarginal gyrus (BA 40) and angular gyrus (BA 39) for bilinguals when processing Mandarin versus English. Moreover, there were no significant differences between bilinguals and monolinguals in the left inferior …

Sleep Assessments In Healthy School-Aged Children Using Actigraphy: Concordance With Polysomnography, Karen Spruyt, David Gozal, Ehab Dayyat, Adrienne Roman, Dennis L. Molfese

Center for Brain, Biology, and Behavior: Faculty Publications

Actigraphic recordings (ACT) are widely used in school children as a less intrusive and more extended approach to evaluation of sleep problems. However, critical assessment of the validity and reliability of ACT against overnight polysomnography (NPSG) are unavailable. Thus, we explored the degree of concordance between NPSG and ACT in school-aged children to delineate potential ACT boundaries when interpreting pediatric sleep. Non-dominant wrist ACT was simultaneously recorded with NPSG in 149 healthy school-aged children (4.1 to 8.8 years old, 41.7% boys and 80.4% Caucasian) recruited from the community. Analyses were limited to the Actiware (MiniMitter-64) calculated parameters originating from 1-min …

Sleep Duration, Sleep Regularity, Body Weight, And Metabolic Homeostasis In School-Aged Children, Karen Spruyt, Dennis L. Molfese, David Gozal

Center for Brain, Biology, and Behavior: Faculty Publications

OBJECTIVE: The goal was to explore the effects of duration and regularity of sleep schedules on BMI and the impact on metabolic regulation in children.

METHODS: Sleep patterns of 308 community-recruited children 4 to 10 years of age were assessed with wrist actigraphs for 1 week in a cross-sectional study, along with BMI assessment. Fasting morning plasma levels of glucose, insulin, lipids, and high-sensitivity C-reactive protein also were measured for a subsample.

RESULTS: Children slept 8 hours per night, on average, regardless of their weight categorization. A nonlinear trend between sleep and weight emerged. For obese children, …

Sleep Estimates In Children: Parental Versus Actigraphic Assessments, Ehab A. Dayyat, Karen Spruyt, Dennis L. Molfese, David Gozal

Center for Brain, Biology, and Behavior: Faculty Publications

Background: In the context of increasing awareness about the need for assessment of sleep duration in community and clinical settings, the use of questionnaire-based tools may be fraught with reporter bias. Conversely, actigraphy provides objective assessments of sleep patterns. In this study, we aimed to determine the potential discrepancies between parentally-based sleep logs and concurrent actigraphic recordings in children over a one-week period.

Methods: We studied 327 children aged 3–10 years, and included otherwise healthy, nonsnoring children from the community who were reported by their parents to be nonsnorers and had normal polysomnography, habitually-snoring children from the community …

Minimal Information For Neural Electromagnetic Ontologies (Minemo): A Standards-Compliant Method For Analysis And Integration Of Event-Related Potentials (Erp) Data, Gwen Frishkoff, Jason Sydes, Kurt Mueller, Tim Curran, John F. Connolly, Kerry Kilborn, Dennis L. Molfese, Charles Perfetti, Allen D. Malony

Center for Brain, Biology, and Behavior: Faculty Publications

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 …

Lateral Blood Flow Velocity Estimation Based On Ultrasound Speckle Size Change With Scan Velocity, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional (Doppler-based) blood flow velocity measurement methods using ultrasound are capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. In addition, these methods require repeated pulse-echo interrogation at the same spatial location. A new method has been introduced which estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to blood reflectors (typically red blood cells) stretches (i.e., is smeared) if the …

Charge Switch Nucleotides, John G. K. Williams, Gregory R. Bashford, Jiyan Chen, Dan Draney, Nara Narayanan, Bambi L. Reynolds, Pamela Sheaff

Biomedical Imaging and Biosignal Analysis Laboratory

The present invention provides compounds, methods and systems for sequencing nucleic acid using single molecule detection. Using labeled NPs that exhibit charge-switching behavior, single-molecule DNA sequencing in a microchannel sorting system is realized. In operation, sequencing products are detected enabling real-time sequencing as successive detectable moieties flow through a detection channel. By electrically sorting charged molecules, the cleaved product molecules are detected in isolation Without interference from unincorporated NPs and Without illuminating the polymerase-DNA complex.

Charge Switch Nucleotides, John G. K. Williams, Gregory R. Bashford, Jiyan Chen, Dan Draney, Nara Narayanan, Bambi Reynolds, Pamela Sheaff

Biomedical Imaging and Biosignal Analysis Laboratory

The present invention provides compounds, methods and systems for sequencing nucleic acid using single molecule detection. Using labeled NPs that exhibit charged-switching behavior, single-molecule DNA sequencing in a microchannel sorting system is realized. In operation, sequencing products are detected enabling real-time sequencing as successive detectable moieties flow through a detection channel. By electrically sorting charged molecules, the cleaved product molecules are detected in isolation Without interference from unincorporated NPs and Without illuminating the polymerase-DNA complex.

Sleep-Disordered Breathing Affects Auditory Processing In 5–7 Year-Old Children: Evidence From Brain Recordings, Alexandra P.F. Key, Dennis L. Molfese, Louise O’Brien, David Gozal

Center for Brain, Biology, and Behavior: Faculty Publications

Poor sleep in children is associated with lower neurocognitive functioning and increased maladaptive behaviors. The current study examined the impact of snoring (the most common manifestation of sleep-disordered breathing) on cognitive and brain functioning in a sample of 35 asymptomatic children ages 5–7 years identified in the community as having habitual snoring (SDB). All participants completed polysomnographic, neurocognitive (NEPSY) and psychophysiological (ERPs to speech sounds) assessments. The results indicated that sub-clinical levels of SDB may not necessarily lead to reduced performance on standardized behavioral measures of attention and memory. However, brain indices of speech perception and discrimination (N1/P2) are sensitive …

Frequency And Spatial Characteristics Of Highfrequency Neuromagnetic Signals In Childhood Epilepsy, Jing Xiang, Yang Liu, Yingying Wang, Elijah G. Kirtman, Cincinnati Children’S Hospital Medical Center Kotecha, Yangmei Chen, Xiaolin Huo, Hisako Fujiwara, Nat Hemasilpin, Ki Lee, Francesco T. Mangano, James Leach, Blaise Jones, Ton Degrauw, Douglas Rose

Center for Brain, Biology, and Behavior: Faculty Publications

Purpose. Invasive intracranial recordings have suggested that high-frequency oscillation is involved in epileptogenesis and is highly localized to epileptogenic zones. The aim of the present study is to characterize the frequency and spatial patterns of high-frequency brain signals in childhood epilepsy using a non-invasive technology. Methods. Thirty children with clinically diagnosed epilepsy were studied using a whole head magnetoencephalography (MEG) system. MEG data were digitized at 4 000 Hz. The frequency and spatial characteristics of high-frequency neuromagnetic signals were analyzed using continuous wavelet transform and beamformer. Threedimensional magnetic resonance imaging (MRI) was obtained for each patient to localize magnetic sources. …

Resolving The Lateral Component Of Blood Flow Velocity Based On Ultrasound Speckle Size Change With Scan Direction And Speed, Tiantian Xu, Greg R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional blood flow velocity measurement using ultrasound is capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these Doppler-based methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. In addition, these methods require repeated pulse-echo interrogation at the same spatial location. In this paper, we introduce a method which estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to the blood reflectors (typically red blood cells) stretches (i.e., is “smeared”) if …

Further Progress On Lateral Flow Estimation Using Speckle Size Variation With Scan Direction, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional blood flow velocity measurement using ultrasound is capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these Doppler-based methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. In addition, these methods require repeated pulse-echo interrogation at the same spatial location. In this paper, we report additional data on a new method recently introduced. This method estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to the blood reflectors (typically red …

Single Molecule Diffusion Coefficient Estimation By Image Analysis Of Simulated Ccd Images To Aid High-Throughput Screening, Pengfei Song, Lloyd M. Davis, Greg Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Extension of one-dimensional signal analysis to two-dimensional image analysis could accelerate conventional methods of high-throughput screening in the discovery of new pharmaceutical agents. This work describes a first step taken towards this goal – the evaluation of image-analysis based estimation strategies of the diffusion coefficient of a single molecule transported within a microfabricated flowcell. A computer simulation of single-molecule imaging by a charge-coupled device (CCD) camera is used to determine if it is possible to distinguish three different types of molecules with different diffusion coefficients. The Gaussian fitting algorithm finds the variance of the transverse trajectory, which increases linearly with …