Commission Error Rates Research Articles

S58. COMPARISON OF FACE EMOTIONAL RECOGNITION DEFICITS IN REMITTED SCHIZOPHRENIA AND BIPOLAR I DISORDER

BackgroundSchizophrenia and Bipolar I disorder patients lack the ability to identify emotional expressions, which is characterized by poor social and professional functions. Facial affect recognition is a complex function that includes cortical and limbic connections, providing an essential source of information during face-to-face communication. In this study, the Facial Labeling Task, which can evaluate Koreans’ ability to recognize emotions using facial expressions, is used to compare defects in face emotional recognition in patients with remitted schizophrenia patients, euthymic bipolar I disorder patients, and normal controls.MethodsThree groups were included in this study: remitted patients with schizophrenia (n=75), patients in euthymic states of bipolar I disorder (n=70), and healthy controls (n=59) who were matched on age, sex, years of education. Facial Labeling Task was used to examine face emotional recognition defects the standardized happy, fearful, disgust, anger, sad, contempt, surprise and neutral faces from actors (4 males, 4 females) were used (emotional intensity 100%). Accuracy (commission error rates), correct response times of each trial were calculated. All subjects had to satisfy the inclusion criteria(absence of substance abuse, head trauma, mental retardation) and subjects with above mild level of psychiatric symptoms [BPRS(Brief Psychiatric Rating Scale) >31, K-MADRS(Korean version Montgomery-Asberg Depression Scale) Score >9, YMRS(Young Mania Rating Scale Korean version) Score >7] were excluded. All of patients group had to be in remitted state at least 3 months. All of subjects in normal control group were interviewed before the test using Structured Clinical Interview for DSM-IV Axis-1 Disorder to rule out psychiatric history. We used Korean version-Wechsler Adult Intelligence Scale. Psychomotor performance was examined using Finger Tapping Test.ResultsThere were no differences on demographic data between three groups. Although psychopathologies in all groups were within the criteria, there were group differences. The scoring of BPRS, YMRS, MADRS were higher in schizophrenia patients. Intelligence was low in schizophrenia and Bipolar I disorder patients. There was no difference among the group in the psychomotor speed. Two patients groups were significantly higher error rates for sadness (p < 0.01), anger (p < 0.001),, and neutral (p < 0.01). Schizophrenia group showed significantly higher error rates for contempt to normal controls (p < 0.05). Happy and neutral face had significantly more delayed correct response times in two patient groups than in the healthy controls (p < 0.05).DiscussionThese finds suggest that the patients with schizophrenia and bipolar I disorder have a defects in the perception and response of specific emotions in the remitted states, and schizophrenia is more emotionally impaired than bipolar disease. Therefore, it is thought that a defects in facial recognition should be considered in the process of assessing and treating patients with bipolar I disorder as well as those with schizophrenia.

The Landsat Burned Area algorithm and products for the conterminous United States

Complete and accurate burned area map data are needed to document spatial and temporal patterns of fires, to quantify their drivers, and to assess the impacts on human and natural systems. In this study, we developed the Landsat Burned Area (BA) algorithm, an update from the Landsat Burned Area Essential Climate Variable (BAECV) algorithm. Here, we present the BA algorithm and products, changes relative to the BAECV algorithm and products, and updated validation metrics. We also present spatial and temporal patterns of burned area across the conterminous U.S., how burned area varies in relation to the number of operational Landsat sensors, and a comparison with other burned area datasets, including the BAECV, Monitoring Trends in Burn Severity (MTBS), GeoMAC, and Moderate Resolution Imaging Spectroradiometer (MODIS) MCD64A1.006 data. The BA algorithm identifies burned areas in analysis ready data (ARD) time-series of Landsat imagery from 1984 through 2018 using machine learning, thresholding, and image segmentation. Validation with reference data from high-resolution commercial satellite imagery resulted in omission and commission error rates averaging 19% and 41%, respectively. In comparison, validation with Landsat reference data had omission and commission error rates averaging 40% and 28%, respectively when burned areas in cultivated crops and pasture/hay land-cover types were excluded. Both validation tests documented lower commission error rates relative to the BAECV products. The amount of burned area detected varies not only in response to climate but also with the number of operational sensors and scenes collected. The combined amount of burned area detected by multiple sensors was larger than from any individual sensor, but there was no significant difference between individual sensors. Therefore, we used BA products from individual sensors to assess trends over time and all available sensors to compare with other existing BA products. From 1984 through 2018, annual burned area averaged 30,000 km2, ranged between 14,000 km2 in 1991 and 46,500 km2 in 2012, and increased over time at a rate of 356 km2/year. Compared to existing burned area products, the new Landsat BA products identified 29% more burned area than the BAECV products (1984–2015), 183% more than the MTBS/GeoMAC products (1984–2018), and 56% more than the MCD64A1.006 products (2003–2018). The products had similar patterns of year-to-year variability; the R2 values of linear regressions between annual burned area were >0.70 with the BAECV products and the MTBS/GeoMAC products, but somewhat lower for the MCD64A1.006 product (R2 = 0.66). The BA products are routinely produced as new Landsat data are collected and provide a unique data source to monitor and assess the spatial and temporal patterns and the impacts of fire.

Exploring Implementor Error during Remotely Conducted School-Based Functional Analysis Telehealth Training Package

In schools, special education teachers and paraprofessionals are expected to support the completion of functional behavior assessment procedures in the development of a behavior support plan. Often times, school-personnel are limited in their training and resources, particularly in situations where experimental procedures are necessary. This exploratory study aimed to assess the remote delivery of a comprehensive functional analysis (FA) training package via telehealth to school personnel and examine the nature of implementor error through rate of omission and commission errors within and across FA conditions. Paraprofessionals and a special education teacher were trained over telehealth using telepresence robots to implement functional analyses in the schools. Three functional analyses were then conducted. Information regarding procedural integrity, acceptability, and rates of omission and commission errors during each FA condition are presented, along with implications for research and practice.

Reduced Nogo-P3 in adults with developmental coordination disorder (DCD)

Nogo-N2 is associated with the premotor cognitive process that precedes motor response (e.g., conflict monitoring), whereas Nogo-P3 is related to the inhibition of the actual motor response. We examined the influence of motor clumsiness of developmental coordination disorder (DCD) on components of the event-related potential in a Go/Nogo task. Participants were healthy adults (N = 81) that were classified into control and DCD groups based on the Movement Assessment Battery for Children Second Edition. We manipulated the difficulty in stopping a response by varying the frequency of Nogo stimuli in a response task into rare (20%) and frequent (80%) conditions, and Nogo-N2 and Nogo-P3 were calculated from electroencephalograms (EEGs) during the Go/Nogo tasks. The commission error rate in the rare condition was significantly higher in the DCD group than in the control group, indicating that motor clumsiness decreases task performance. There were no differences in Nogo-N2 between DCD and control groups. However, Nogo-P3 in the rare condition was reduced in the DCD group compared to the control group. These results suggest that the influence of motor clumsiness is limited to the cognitive process after the initiation of the actual motor response.

Acute alcohol intoxication and expectations reshape the spatiotemporal functional architecture of executive control

While the deleterious effects of acute ethyl alcohol intoxication on executive control are well-established, the underlying spatiotemporal brain mechanisms remain largely unresolved. In addition, since the effects of alcohol are noticeable to participants, isolating the effects of the substance from those related to expectations represents a major challenge. We addressed these issues using a double-blind, randomized, parallel, placebo-controlled experimental design comparing the behavioral and electrical neuroimaging acute effects of 0.6 vs 0.02 ​g/kg alcohol intake recorded in 65 healthy adults during an inhibitory control Go/NoGo task. Topographic ERP analyses of covariance with self-reported dose expectations allowed to dissociate their neurophysiological effects from those of the substance.While alcohol intoxication increased response time variability and post-error slowing, bayesian analyses indicated that it did not modify commission error rates. Functionally, alcohol induced topographic ERP modulations over the periods of the stimulus-locked N2 and P3 components, arising from pre-supplementary motor and anterior cingulate areas. In contrast, alcohol decreased the strength of the response-locked anterior cingulate error-related component but not its topography. This pattern indicates that alcohol had a locally specific influence within the executive control network, but disrupted performance monitoring processes via global strength-based mechanisms.We further revealed that alcohol-related expectations induced temporally specific functional modulations of the early N2 stimulus-locked medio-lateral prefrontal activity, a processing phase preceding those influenced by the actual alcohol intake.Our collective findings thus not only reveal the mechanisms underlying alcohol-induced impairments in impulse control and error processing, but also dissociate substance- from expectations- related functional effects.

Attention-related modulation of frontal midline theta oscillations in cingulate cortex during a spatial cueing Go/NoGo task

Recently frontal midline theta (FMθ, 4–8 Hz) oscillations have been consistently reported and proposed as the potential neural mechanism for response inhibition, a core component of human executive functions. However, it remains unclear to what extent the increase of FMθ power during response inhibition tasks is influenced by other non-inhibitory cognitive processes that are usually required for the tasks. In this study, we examined attention-related effects on FMθ during response inhibition by revisiting the EEG data from healthy young adults (N = 30) while performing a spatial cueing Go/NoGo task (Hong et al., 2017). Such an experimental design enabled us to manipulate selective attention that was voluntarily deployed to the stimuli triggering response inhibition. Although commission error rates were low for the NoGo trials, response preparation and prepotent motor activities were qualified by observing significant contingent negative variation (CNV) and lateralized readiness potential (LRP) in both the Go and the NoGo trials. We observed an increase of FMθ power in both attended and ignored conditions of the NoGo trials compared with the Go trials, while FMθ power was significantly smaller in the ignored condition than in the attended condition. Furthermore, source localization analysis suggested cingulate cortex as the main origin for FMθ in the NoGo trials, and FMθ power differences between the attended and ignored conditions were localized in cingulate gyrus. We further provided evidence for attention-dependent FMθ generation by correlating theta source density with ERP signatures of attention (N1), response preparation (CNV), and motor activity (LRP). Overall, our findings suggest that during the Go/NoGo task, the increase of FMθ power was not purely driven by response inhibition, and part of FMθ generators in cingulate gyrus was significantly modulated by attention-related processing (possibly conflict monitoring).

Automating offshore infrastructure extractions using synthetic aperture radar & Google Earth Engine

Although Land Use and Land Cover (LULC) change is primarily focused on the types, rates, causes, and consequences of land change, increased anthropogenic development on the ocean's surface, such as offshore oil extraction, offshore wind energy, aquaculture, and coral reef conversion to military outposts, suggest that LULC change not only pertains to historically terrestrial space, but also new lands created on top of ocean surfaces. Therefore, similar human disturbance analyses are necessary for these transformed marine environments, but the lack of accurate, accessible, and up-to-date location information about these spatially dispersed changes significantly limits examination of their environmental impacts. Subsequently these dynamic changes across the oceans are poorly documented. Here, we developed a cloud-native geoprocessing algorithm to automatically detect and extract offshore oil platforms in the Gulf of Mexico using synthetic aperture radar and Google Earth Engine. Cross-validated results indicate our top model identified offshore infrastructure with a probability of detection of 98.70%, an overall accuracy of 96.09%, a commission error rate of 2.68%, and an omission error rate of 1.30%. Its generalizability was tested across wind farms in waters of China and the United Kingdom, which resulted in an overall accuracy of 97.00%, a commission error rate of 2.07%, and omission error rate of 0.97%. These generalization capabilities indicate our model can be potentially used to map global offshore infrastructure. Such increased ocean transparency could allow for improved marine environmental management by bringing objectivity, scalability, and accessibility.

The Validity of a Frustration Paradigm to Assess the Effect of Frustration on Cognitive Control in School-Age Children

Irritability refers to a proneness for anger, and is a symptom of internalizing and externalizing psychopathology. Since irritability is associated with significant cross-sectional and longitudinal impairments, research on the behavioral and neural correlates of pediatric irritability in populations at risk for significant irritability is of paramount importance. Irritability can be assessed in the laboratory using behavioral paradigms that elicit frustration. Few behavioral frustration paradigms have been designed to measure the effects of frustration on cognitive control. Therefore, the goal of the present study was to validate a behavioral frustration paradigm for use in school-age children which addressed some of the limitations of prior research. Participants included children, ages 8–12 years, who were either typically developing (TD; n = 38) or diagnosed with attention-deficit/hyperactivity disorder (ADHD; n = 67), which provided a sample of children with a range of baseline irritability. All participants completed the Frustration Go/No-Go (GNG) task, and self-reported irritability was assessed using the Affective Reactivity Index. Results showed that across participants, self-reported frustration, commission error rate, and tau all increased with the addition of frustration, with similar effect sizes in ADHD and TD groups. Further, self-reported irritability, moreso than ADHD symptoms, predicted changes in self-reported frustration during the task. Together, these results support the construct validity of the Frustration GNG task as a means of assessing the effect of frustration on cognitive control. Clinical applications and future directions are discussed.

Associations between self-reported impulsivity and a latent variable of impulsive action constructed from three laboratory tasks

Previous research on relationships between self-reported impulsivity and behavioral impulsivity has been limited because behavioral impulsivity was assessed using individual tasks. To alleviate the task-impurity problem and the low reliability of laboratory tasks assessing impulsivity, the present study examined the correlations between a latent variable constructed from the performances of three laboratory tasks assessing impulsive action and each dimension of self-reported impulsivity. University students in Japan ( N = 176) responded to the UPPS-P Impulsive Behavior Scale assessing five dimensions of self-reported impulsivity that included the following: negative urgency, lack of premeditation, lack of perseverance, sensation seeking, and positive urgency. They also conducted laboratory tasks for assessing impulsive action: the go/no-go task, stop signal task, and Conners continuous performance test 3rd edition (CCPT). Results indicated weak correlations between each dimension of self-reported impulsivity and the latent variable named impulsive action constructed from the performances of three laboratory tasks (mean r = .10) and with the performances of individual laboratory tasks (mean r = .03). The latent variable of impulsive action and the commission error rate in the CCPT were significantly correlated with sensation seeking. However, this association disappeared after controlling for the influence of gender. These findings suggested that measures of self-reported and behavioral impulsivity might assess different constructs.

Effects of Interviewer Support on Maltreated and At-Risk Children’s Memory and Suggestibility

The present study examined the effects of interviewer support on the memory and suggestibility of children (N = 71), all of whom were involved in child maltreatment investigations. This was accomplished by questioning 3- to 12-year olds (66% African American) about a game played individually with an experimenter at the end of the maltreatment investigation, so that the results did not affect any evaluations or legal proceedings. After the game, the children were interviewed in a warm and engaging high support manner or in a relatively formal and withdrawn low support fashion--the latter, likely considered by some as “neutral” in child forensic interviews. Typical age effects emerged overall; for example, with the preschool (compared to school-aged) children providing fewer correct units of information in free recall and making more errors to specific and misleading questions. However, findings also varied in relation to interviewer support and type of question. To specific questions, older (but not younger) children in the low (compared to high) interviewer support condition made more omission errors, possibly due to the interviewer’s low support resulting in a “no bias” for older children in answering these questions. To misleading questions, younger (but not older) children in the high (compared to low) support condition made significantly more commission errors. The elevated commission error rate in the high support group appeared to be driven by a small number of 3- and 4-year-olds who had a “yes-bias” when answering misleading questions. Implications for children’s accuracy in maltreatment investigations and for children’s psychological and physical security are discussed.

Commission errors with forced response lag.

It is often necessary to retrieve intentions once a certain cue occurs in the environment. However, such prospective memory (PM) tasks can also be erroneously recalled even though they are no longer relevant and may result in commission errors. According to the dual mechanism account, commission errors occur because the intention is spontaneously retrieved, and there is a subsequent failure to suppress the associated action, resulting in erroneous instant execution. In three experiments, we tested whether failed response suppression is a prerequisite for commission errors. We set up a response lag condition in which participants had to delay their response to ongoing task trials for 1 s (Experiment 1) or 2 s (Experiments 2 and 3) and a pause condition in which the delay occurred between ongoing task trials. In both conditions, participants learned about a PM task and were then told that the PM task was cancelled. In addition, a control group with response lag executed the PM task and was subsequently told the task was finished. Later, all participants encountered several irrelevant PM cues. If failed response suppression is a prerequisite for commission errors, commission error rates should be non-existent in the response lag conditions, because participants had designated time to suppress the PM action. However, commission errors occurred at an equal rate in all lag and pause conditions. Due to this contradiction to the dual mechanism account, we suggest that the process for commission error occurrence should be reconsidered. Because commission errors appear not to be caused by failed response suppression, we discuss the idea that erroneous intentions might be formed when encountering the former PM cue and persist over delays between formation and execution.

Response control correlates of anomalous basal ganglia morphology in boys, but not girls, with attention-deficit/hyperactivity disorder

Anomalous basal ganglia morphology may contribute to deficient motor response control in children with attention-deficit/hyperactivity disorder (ADHD). This study expands upon recent evidence of sex differences in subcortical morphology and motor response control deficits among children with ADHD to examine basal ganglia volume and shape in relation to motor response control. Participants included 8–12 year-old children with ADHD (n = 52, 21 girls) and typically developing (TD) controls (n = 45, 19 girls). High resolution T1-weighted 3D MPRAGE images covering the whole brain were acquired for all participants on a 3 T scanner. Participants performed two computer-based go/no-go tasks that differed in the extent to which working memory was necessary to guide response selection. Shape-based morphometric analyses were performed in addition to traditional volumetric comparisons and correlations with measures of motor response control were examined. Boys with ADHD consistently demonstrated increased commission error rate and response variability, regardless of task demands, suggesting broad response control deficits. In contrast, response control deficits among girls with ADHD varied depending on task demands and performance measures. Volumetric reductions and inward deformation (compression) on the dorsal surface of the globus pallidus and within subregions of the putamen receiving projections from limbic, executive and motor cortices were observed in boys, but not girls, with ADHD relative to TD children. Mediation analyses revealed that putamen and globus pallidus volumes mediated the relationship between diagnosis and commission error rate. Furthermore, reduced volumes of these structures and localized inward deformation within executive and motor circuits correlated with poorer response control, particularly under conditions of increased cognitive load. These findings suggest that anomalous basal ganglia morphology is related to impaired motor response control among boys with ADHD.

Evaluating Unmanned Aerial Vehicle Images for Estimating Forest Canopy Fuels in a Ponderosa Pine Stand

Forests in the Southwestern United States are becoming increasingly susceptible to large wildfires. As a result, forest managers are conducting forest fuel reduction treatments for which spatial fuels and structure information are necessary. However, this information currently has coarse spatial resolution and variable accuracy. This study tested the feasibility of using unmanned aerial vehicle (UAV) imagery to estimate forest canopy fuels and structure in a southwestern ponderosa pine stand. UAV-based multispectral images and Structure-from-Motion point clouds were used to estimate canopy cover, canopy height, tree density, canopy base height, and canopy bulk density. Estimates were validated with field data from 57 plots and aerial photography from the U.S. Department of Agriculture National Agriculture Imaging Program. Results indicate that UAV imagery can be used to accurately estimate forest canopy cover (correlation coefficient (R2) = 0.82, root mean square error (RMSE) = 8.9%). Tree density estimates correctly detected 74% of field-mapped trees with a 16% commission error rate. Individual tree height estimates were strongly correlated with field measurements (R2 = 0.71, RMSE = 1.83 m), whereas canopy base height estimates had a weaker correlation (R2 = 0.34, RMSE = 2.52 m). Estimates of canopy bulk density were not correlated to field measurements. UAV-derived inputs resulted in drastically different estimates of potential crown fire behavior when compared with coarse resolution LANDFIRE data. Methods from this study provide additional data to supplement, or potentially substitute, traditional estimates of canopy fuel.

The Implications of Field Worker Characteristics and Landscape Heterogeneity for Classification Correctness and the Completeness of Topographical Mapping

The quality of spatial data may vary spatially. If mapping (interpretation of orthophotos) is done during fieldwork, this variation in quality may occur as a result of differences in the complexity of the landscape, differences in the characteristics of individual field workers, and differences in their perception of the landscape. In this study, we explored the interaction between the characteristics of these workers, including their gender and years of experience (as a proxy for their mapping skills), and landscape heterogeneity. There was no significant difference between male and female workers. Although field workers with more years of experience generally had higher mapping quality, the relationship was not statistically significant. We found differences in the rates of misclassification, omission, and commission errors between workers in different landscape types. We conclude that the error rates due to misclassification, omission, and commission were the lowest in more diverse landscapes (high number of different land use types) with a relatively high amount of buildings, whereas the error rates were the highest in mainly forested landscapes with larger and more complex shaped patches.

Short-Term Impact of tDCS Over the Right Inferior Frontal Cortex on Impulsive Responses in a Go/No-go Task.

Inhibitory control, a process deeply studied in laboratory settings, refers to the ability to inhibit an action once it has been initiated. A common way to process data in such tasks is to take the mean response time (RT) and error rate per participant. However, such an analysis ignores the strong dependency between spontaneous RT variations and error rate. Conditional accuracy function (CAF) is of particular interest, as by plotting the probability of a response to be correct as a function of its latency, it provides a means for studying the strength of impulsive responses associated with a higher frequency of fast response errors. This procedure was applied to a recent set of data in which the right inferior frontal gyrus (rIFG) was modulated using transcranial direct current stimulation (tDCS). Healthy participants (n = 40) were presented with a "Go/No-go" task (click on letter M, not on letter W, session 1). Then, one subgroup (n = 20) was randomly assigned to one 20-minutes neuromodulation session with tDCS (anodal electrode, rIFG; cathodal electrode, neck); and the other group (n = 20) to a condition with sham (placebo) tDCS. All participants were finally confronted to the same "Go/No-go" task (session 2). The rate of commission errors (click on W) and speed of response to Go trials were similar between sessions 1 and 2 in both neuromodulation groups. However, CAF showed that active tDCS over rIFG leads to a reduction of the drop in accuracy for fast responses (suggesting less impulsivity and greater inhibitory efficiency), this effect being only visible for the first experimental block following tDCS stimulation. Overall, the present data indicate that boosting the rIFG may be useful to enhance inhibitory skills, but that CAF could be of the greatest relevance to monitor the temporal dynamics of the neuromodulation effect.

Archaeological application of airborne LiDAR to examine social changes in the Ceibal region of the Maya lowlands

Although the application of LiDAR has made significant contributions to archaeology, LiDAR only provides a synchronic view of the current topography. An important challenge for researchers is to extract diachronic information over typically extensive LiDAR-surveyed areas in an efficient manner. By applying an architectural chronology obtained from intensive excavations at the site center and by complementing it with surface collection and test excavations in peripheral zones, we analyze LiDAR data over an area of 470 km2 to trace social changes through time in the Ceibal region, Guatemala, of the Maya lowlands. We refine estimates of structure counts and populations by applying commission and omission error rates calculated from the results of ground-truthing. Although the results of our study need to be tested and refined with additional research in the future, they provide an initial understanding of social processes over a wide area. Ceibal appears to have served as the only ceremonial complex in the region during the transition to sedentism at the beginning of the Middle Preclassic period (c. 1000 BC). As a more sedentary way of life was accepted during the late part of the Middle Preclassic period and the initial Late Preclassic period (600–300 BC), more ceremonial assemblages were constructed outside the Ceibal center, possibly symbolizing the local groups’ claim to surrounding agricultural lands. From the middle Late Preclassic to the initial Early Classic period (300 BC-AD 300), a significant number of pyramidal complexes were probably built. Their high concentration in the Ceibal center probably reflects increasing political centralization. After a demographic decline during the rest of the Early Classic period, the population in the Ceibal region reached the highest level during the Late and Terminal Classic periods, when dynastic rule was well established (AD 600–950).

Mapping forest change using stacked generalization: An ensemble approach

The ever-increasing volume and accessibility of remote sensing data has spawned many alternative approaches for mapping important environmental features and processes. For example, there are several viable but highly varied strategies for using time series of Landsat imagery to detect changes in forest cover. Performance among algorithms varies across complex natural systems, and it is reasonable to ask if aggregating the strengths of an ensemble of classifiers might result in increased overall accuracy. Relatively simple rules have been used in the past to aggregate classifications among remotely sensed maps (e.g. using majority predictions), and in other fields, empirical models have been used to create situationally specific algorithm weights. The latter process, called “stacked generalization” (or “stacking”), typically uses a parametric model for the fusion of algorithm outputs. We tested the performance of several leading forest disturbance detection algorithms against ensembles of the outputs of those same algorithms based upon stacking using both parametric and Random Forests-based fusion rules. Stacking using a Random Forests model cut omission and commission error rates in half in many cases in relation to individual change detection algorithms, and cut error rates by one quarter compared to more conventional parametric stacking. Stacking also offers two auxiliary benefits: alignment of outputs to the precise definitions built into a particular set of empirical calibration data; and, outputs which may be adjusted such that map class totals match independent estimates of change in each year. In general, ensemble predictions improve when new inputs are added that are both informative and uncorrelated with existing ensemble components. As increased use of cloud-based computing makes ensemble mapping methods more accessible, the most useful new algorithms may be those that specialize in providing spectral, temporal, or thematic information not already available through members of existing ensembles.

Response Inhibition Deficits and Altered Motor Network Connectivity in the Chronic Phase of Pediatric Traumatic Brain Injury.

Poor response inhibition is a hallmark of pediatric traumatic brain injury (TBI). We assessed motor response inhibition by measuring commission error rates on Simple (minimized cognitive demands) and Motivation (monetary reward) Go/No-Go tasks, comparing 17 children with chronic TBI (>1 year post-injury) and 14 matched, uninjured peers. Using resting state functional magnetic resonance imaging (fMRI), we examined between-group differences in whole-brain intrinsic connectivity of the motor network as derived from the averaged time course of bilateral primary motor cortex seeds, to identify regions of interest (ROIs) for brain-behavior correlations. Independent sample t tests compared Go/No-Go performance and connectivity at the ROI level. Pearson correlations examined relationships between intrinsic connectivity at the ROI level and Go/No-Go performance. Adolescents with TBI showed poorer performance on Simple and Motivation Go/No-Go tasks compared with controls. In whole-brain contrasts, adolescents with TBI showed significantly reduced functional connectivity between the motor network and voxels within the left caudate. Furthermore, in ROI analyses, the group with TBI had significantly lower connectivity between the motor network and left caudate and numerically lower connectivity between the motor network and right caudate. In adolescents with TBI, lower motor network to left caudate connectivity correlated with poorer Simple task performance; lower motor network to right caudate connectivity correlated with poorer Simple and Motivation task performance. No significant brain-behavior relationships existed among controls. These results are consistent with previous pediatric TBI literature and suggest that disrupted intrinsic connectivity of a corticostriatal motor network may contribute to response inhibition deficits.

Critical dynamics of endogenous fluctuations predict cognitive flexibility in the Go/NoGo task

Fluctuations with power-law scaling and long-range temporal correlations (LRTCs) are characteristic to human psychophysical performance. Systems operating in a critical state exhibit such LRTCs, but phenomenologically similar fluctuations and LRTCs may also be caused by slow decay of the system’s memory without the system being critical. Theoretically, criticality endows the system with the greatest representational capacity and flexibility in state transitions. Without criticality, however, slowly decaying system memory would predict inflexibility. We addressed these contrasting predictions of the ‘criticality’ and ‘long-memory’ candidate mechanisms of human behavioral LRTCs by using a Go/NoGo task wherein the commission errors constitute a measure of cognitive flexibility. Response time (RT) fluctuations in this task exhibited power-law frequency scaling, autocorrelations, and LRTCs. We show here that the LRTC scaling exponents, quantifying the strength of long-range correlations, were negatively correlated with the commission error rates. Strong LRTCs hence parallel optimal cognitive flexibility and, in line with the criticality hypothesis, indicate a functionally advantageous state. This conclusion was corroborated by a positive correlation between the LRTC scaling exponents and executive functions measured with the Rey-Osterrieth Complex Figure test. Our results hence support the notion that LRTCs arise from critical dynamics that is functionally significant for human cognitive performance.

Network-targeted cerebellar transcranial magnetic stimulation improves attentional control

Developing non-invasive brain stimulation interventions to improve attentional control is extremely relevant to a variety of neurological and psychiatric populations, yet few studies have identified reliable biomarkers that can be readily modified to improve attentional control. One potential biomarker of attention is functional connectivity in the core cortical network supporting attention - the dorsal attention network (DAN). We used a network-targeted cerebellar transcranial magnetic stimulation (TMS) procedure, intended to enhance cortical functional connectivity in the DAN. Specifically, in healthy young adults we administered intermittent theta burst TMS (iTBS) to the midline cerebellar node of the DAN and, as a control, the right cerebellar node of the default mode network (DMN). These cerebellar targets were localized using individual resting-state fMRI scans. Participants completed assessments of both sustained (gradual onset continuous performance task, gradCPT) and transient attentional control (attentional blink) immediately before and after stimulation, in two sessions (cerebellar DAN and DMN). Following cerebellar DAN stimulation, participants had significantly fewer attentional lapses (lower commission error rates) on the gradCPT. In contrast, stimulation to the cerebellar DMN did not affect gradCPT performance. Further, in the DAN condition, individuals with worse baseline gradCPT performance showed the greatest enhancement in gradCPT performance. These results suggest that temporarily increasing functional connectivity in the DAN via network-targeted cerebellar stimulation can enhance sustained attention, particularly in those with poor baseline performance. With regard to transient attention, TMS stimulation improved attentional blink performance across both stimulation sites, suggesting increasing functional connectivity in both networks can enhance this aspect of attention. These findings have important implications for intervention applications of TMS and theoretical models of functional connectivity.