Tricuspid valve disease prevalence and the impact of tricuspid valve surgery on cardiovascular events and hospital resource use in medicare beneficiaries.

BACKGROUND: Tricuspid valve disease (TVD) is presumed common, however, little is known about its prevalence or the impact of tricuspid valve surgery (TVS) on healthcare resource use. METHODS: To describe the prevalence of TVD and assess the impact of TVS on resource utilization, Medicare Fee-For-Service beneficiaries from 2011 -2019 were assessed for the prevalence of non-rheumatic TVD. Hospital costs and rates of all-cause, cardiovascular (CV), and heart failure (HF) hospitalizations were compared in the 3 months pre TVS to acute (0-3 months) and chronic (3 -12 months) post TVS periods. RESULTS: Among 80.3 million beneficiaries from 2011 - 2019 Q1, over 700,000 (0.9%) had non-rheumatic TVD with 1.4% undergoing TVS. Thirty-day and 1 year mortality after TVS was 5.5% to15.5%. Compared with pre-surgery, CV and HF hospitalizations decreased from 0.12 to 0.08 per patient-month (P <.001), and 0.06 to 0.04 (P <.001) acutely. All-cause hospitalizations increased from 0.18 per patient-month to 0.23 per patient-month acutely post-surgery (P <.001), before decreasing to 0.09 per patient-month chronically (P <.001). Hospital costs increased from $2,174 per patient-month to $4,171 per patient-month acutely (P < .001), before falling to $1,441 per patient-month (P < .001) chronically. Lower costs for HF and CV hospitalization in both acute (P = .028 and P < .001, respectively) and chronic (P < .001 for both) periods were observed. CONCLUSIONS: TVS is associated with reduced CV and HF hospitalizations and associated hospital costs. Future work should determine whether transcatheter tricuspid valve repair offers similar or additional benefits.

Risk-taking bias in human decision-making is encoded via a right-left brain push-pull system.

A person's decisions vary even when options stay the same, like when a gambler changes bets despite constant odds of winning. Internal bias (e.g., emotion) contributes to this variability and is shaped by past outcomes, yet its neurobiology during decision-making is not well understood. To map neural circuits encoding bias, we administered a gambling task to 10 participants implanted with intracerebral depth electrodes in cortical and subcortical structures. We predicted the variability in betting behavior within and across patients by individual bias, which is estimated through a dynamical model of choice. Our analysis further revealed that high-frequency activity increased in the right hemisphere when participants were biased toward risky bets, while it increased in the left hemisphere when participants were biased away from risky bets. Our findings provide electrophysiological evidence that risk-taking bias is a lateralized push-pull neural system governing counterintuitive and highly variable decision-making in humans.

Use of Flash Continuous Glucose Monitoring Is Associated With A1C Reduction in People With Type 2 Diabetes Treated With Basal Insulin or Noninsulin Therapy.

BACKGROUND: Glycemic control is suboptimal in many individuals with type 2 diabetes. Although use of flash continuous glucose monitoring (CGM) has demonstrated A1C reductions in patients with type 2 diabetes treated with a multiple daily injection or insulin pump therapy regimen, the glycemic benefit of this technology in patients with type 2 diabetes using nonintensive treatment regimens has not been well studied. METHODS: This retrospective, observational study used the IBM Explorys database to assess changes in A1C after flash CGM prescription in a large population with suboptimally controlled type 2 diabetes treated with nonintensive therapy. Inclusion criteria were diagnosis of type 2 diabetes, age <65 years, treatment with basal insulin or noninsulin therapy, naive to any CGM, baseline A1C ≥8%, and a prescription for the FreeStyle Libre flash CGM system during the period between October 2017 and February 2020. Patients served as their own control subject. RESULTS: A total of 1,034 adults with type 2 diabetes (mean age 51.6 ± 9.2 years, 50.9% male, baseline A1C 10.1 ± 1.7%) were assessed. More patients received noninsulin treatments (n = 728) than basal insulin therapy (n = 306). We observed a significant reduction in A1C within the full cohort: from 10.1 ± 1.7 to 8.6 ± 1.8%; Δ -1.5 ± 2.2% (P <0.001). The largest reductions were seen in patients with a baseline A1C ≥12.0% (n = 181, A1C reduction -3.7%, P <0.001). Significant reductions were seen in both treatment groups (basal insulin -1.1%, noninsulin -1.6%, both P <0.001). CONCLUSION: Prescription of the flash CGM system was associated with significant reductions in A1C in patients with type 2 diabetes treated with basal insulin or noninsulin therapy. These findings provide evidence for expanding access to flash CGM within the broader population of people with type 2 diabetes.

Reinstatement of distributed cortical oscillations occurs with precise spatiotemporal dynamics during successful memory retrieval.

Reinstatement of neural activity is hypothesized to underlie our ability to mentally travel back in time to recover the context of a previous experience. We used intracranial recordings to directly examine the precise spatiotemporal extent of neural reinstatement as 32 participants with electrodes placed for seizure monitoring performed a paired-associates episodic verbal memory task. By cueing recall, we were able to compare reinstatement during correct and incorrect trials, and found that successful retrieval occurs with reinstatement of a gradually changing neural signal present during encoding. We examined reinstatement in individual frequency bands and individual electrodes and found that neural reinstatement was largely mediated by temporal lobe theta and high-gamma frequencies. Leveraging the high temporal precision afforded by intracranial recordings, our data demonstrate that high-gamma activity associated with reinstatement preceded theta activity during encoding, but during retrieval this difference in timing between frequency bands was absent. Our results build upon previous studies to provide direct evidence that successful retrieval involves the reinstatement of a temporal context, and that such reinstatement occurs with precise spatiotemporal dynamics.

Clinical and Radiographic results of a Retrograde Nail - Washer Combination Versus Lateral Locked Plating for Distal Femur Fractures.

OBJECTIVES: The objective of this study was to report outcomes of the Retrograde Femoral Nail-Advanced with Lateral Attachment Washer (RFNA-LAW) (Synthes; Paoli, PA) compared to laterally locked plates (LLP) when treating AO/OTA type 33 distal femoral fractures. METHODS: Design: Retrospective chart review. SETTING: Single, academic, Level-1 Trauma Center. PATIENT SELECTION CRITERIA: All adult patients who had fixation of an AO/OTA type 33 distal femoral fracture with the RFNA-LAW combination or LLP from 2018-2023 with follow-up to union or a minimum of one year. immediately post-operatively and at final follow-up. OUTCOME MEASURES AND COMPARISONS: The main outcome measure was union. Secondary outcomes included implant failure, infection, and alignment immediately post-operatively and at final follow-up. Patients were followed for a minimum of 1-year or to skeletal healing. RESULTS: Forty-eight patients (19 female) with a mean age of 56 years (range 19-94 years) were in the RFNA-LAW group. Fifty-three patients (29 female) with a mean age of 66 years (24-91 years) were in the LLP group. There were no significant differences when comparing Body Mass Index, diabetes, smoking status, mechanism of injury, or fracture classification between groups (p>0.05). There was no difference in immediate, post-operative alignment (p = 0.49). When comparing aLDFA measurements at final follow-up, there was significantly more malalignment in the LLP group (p = 0.005). There were 8 implant failures (15%) in the LLP group compared to 1 in the RFNA-LAW group (2%) (p = 0.02). There were 14 reoperations (26%) in the LLP group compared to 4 (8%) in the RFNA-LAW group (p = 0.02). CONCLUSIONS: The Retrograde Nail Advanced - Lateral Attachment Washer combination demonstrated a high union rate when treating complex fractures of the distal femur. When compared to lateral locked plating, this implant combination demonstrated significantly lower rates of nonunion and reoperation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effectiveness of Flat-Panel Fluoroscopy in Direct Anterior Total Hip Arthroplasty: A Comparison to Image Intensifier Fluoroscopy With Radiopaque Grid.

Introduction: The use of traditional, image intensifier fluoroscopy with a radiopaque grid during direct anterior total hip arthroplasty (DA THA) has demonstrated reduced variability in component positioning and operative time compared to fluoroscopy without a grid. A disadvantage of image intensifier fluoroscopy is spatial distortion, particularly compared to flat-panel fluoroscopy systems. The purpose of this study is to determine whether flat-panel fluoroscopy decreases variability in component positioning during DA THA compared to the use of traditional grid fluoroscopy. Methods: We retrospectively reviewed 70 consecutive DA THAs between February 2020 and February 2021: 36 using flat-panel fluoroscopy, and 34 using traditional fluoroscopy with a grid. Radiographs were independently reviewed by 2 authors to identify components exceeding goal parameters: cup abduction of 40 ± 10 degrees, as well as offset and limb lengths within 10 mm of the contralateral side. Binary values for goal parameter achievement were assigned for each THA. Results: No significant difference was observed in the number of hips that met goals for cup abduction (100% vs 97%, P = 1.00), hip offset (88% vs 88%, P = 1.00), limb length (91% vs 94% [ ±10 mm], P = .669, 65% vs 72% [±5 mm], P = .498), or for the number of hips that met all 3 component goals (79% vs 80%, P = 1.00). No significant difference in operative time was noted between the 2 groups (110.2 minutes vs 100.9, P = .76). Conclusions: We demonstrated no significant difference in component positioning in DA THAs utilizing flat-panel fluoroscopy as compared to using traditional fluoroscopy with a grid.

Chiropractic Manipulation Causing Anterior-Posterior Compression Type Pelvic Ring Injury: A Case Report.

CASE: We present a case of an anteroposterior compression (APC) type pelvic ring injury that occurred after chiropractic manipulation in a patient with a history of quadriplegia. Emergent surgical stabilization was undertaken, and he had an excellent outcome with no complications at 3.5-year follow-up. CONCLUSION: APC type pelvic ring injuries usually occur to high-energy mechanisms. We describe a case of a patient with quadriplegia and osteopenia that suffered a pelvic ring injury because of a unique mechanism. Practitioners performing pelvic manipulation should be aware of this type of injury in at-risk patients.

Positive Correlation Between Social Media Utilization by Orthopaedic Journals and Impact Factor.

INTRODUCTION: Social media use has exploded in popularity over the past decade with over 1.5 billion users on Facebook and 320 million users on Twitter. The aim of this study was to analyze the use of social media by orthopaedic journals and determine whether a relationship exists between social media followers and journal impact factor. METHODS: The Clarivate Analytics Impact Factor tool was used to identify all orthopaedic journals with a 2022 impact factor of greater than 1.5. We then conducted a query on Instagram, Twitter, LinkedIn, and Facebook to determine which programs had pages on each platform. RESULTS: Seventeen journals were included across all orthopaedic subspecialties. Of the 17 journals, 14 (82.4%) had a Facebook page, eight (47%) had an Instagram page, 15 (88.2%) had a Twitter account, and 8 (47%) had a LinkedIn profile. When compiling the number of followers by social media platform, Twitter had the most (177,543), followed by Facebook (149,388), Instagram (81,739), and LinkedIn (77,459). We found a significant correlation between the number of social media followers and journal impact factor (Pearson correlation coefficient [PCC] = 0.67; P = 0.003). When analyzing each social media platform independently, we found a significant correlation between the number of Facebook and Twitter followers and journal impact factor (PCC = 0.54; P = 0.02 and PCC = 0.80; P < 0.001, respectively). DISCUSSION: We have shown a notable association between the number of social media followers and a journal's impact factor. With the increasing shift toward online distribution, orthopaedic journals may use our data when evaluating their social media strategy to maintain and potentially increase their exposure and potentially their impact factor.

Periprosthetic distal femur fractures treated by retrograde intramedullary nails with a 10-degree distal bend achieve significantly better post-operative radiographic alignment when compared to conventional retrograde nails.

INTRODUCTION: Periprosthetic distal femur fractures (PPDFFs) are a common complication after total knee arthroplasty (TKA). In the setting of well-fixed TKA components, treatment options include retrograde intramedullary nailing (rIMN) or lateral locked plating. Treatment with rIMN has historically been associated with potential for extension deformity when using conventional nails. We hypothesized that the PPDFFs treated with an intramedullary nail with a specifically designed 10-degree distal bend for periprosthetic fractures would result in improved post-operative sagittal alignment compared to conventional intramedullary nails. MATERIALS AND METHODS: The study was conducted at a level-1 trauma center over a 12-year period (2010 - 2022). Patients over the age of 18 who sustained a PPDFF treated with rIMN were identified. The primary outcomes of the study were post-operative coronal and sagittal alignment determined by reviewing post-operative radiographs. RESULTS: A total of 50 patients were included. Twenty-three patients were treated with a rIMN with a 10° distal bend. Twenty-seven patients were treated with a rIMN with distal bend of 5° The mean aPDFA for the 10° distal bend group was 81.7° compared to 92.8° in the 5° distal bend group (p<0.001). There were 3/23 (13%) significant sagittal plane deformities the 10° distal bend group compared to 11/27 (41%) in the 5° distal bend group (p = 0.03). There was one patient with a post-operative extension deformity in the 10° distal bend group compared to 11 patients in the 5° distal bend group (p = 0.02). CONCLUSION: Retrograde intramedullary nailing of PPDFF with a 10° distal bend results in significantly better alignment in the sagittal plane when compared to a conventional 5° nail. The use of a 5° nail resulted in an extension deformity significantly more frequently. We therefore recommend the utilization of a rIMN with a 10° distal bend when treating PPDFFs. SUMMARY: Periprosthetic distal femur fractures are a common complication following total knee arthroplasty. While several studies report on the use of retrograde intramedullary nails in the treatment of periprosthetic distal femur fractures, there are limited reports of the use of a novel retrograde intramedullary nail with a 10° distal bend in the treatment of these injuries. Herein we present a radiographic study comparing coronal and sagittal postoperative alignment following treatment with retrograde intramedullary nails with a 10° distal bend versus conventional retrograde nails with a 5° distal bend.

Risk Factors for Revision Surgery Following Revision Total Knee Arthroplasty Using a Hinged Knee Prosthesis for Septic and Aseptic Indications.

INTRODUCTION: The use of hinged knee replacements (HKRs) for limb salvage is a popular option for revision total knee arthroplasty (RTKA). Although recent literature focuses on the outcomes of HKR for septic and aseptic RTKAs, little is reported on the risk factors of returning to the operating room. The purpose of this study was to evaluate risk factors of revision surgery and revision after receiving HKR for septic versus aseptic etiology. METHODS: A multicenter, retrospective review was conducted on consecutive patients who received HKR from January 2010 to February 2020 with a minimum follow-up of 2 years. Patients were separated into two groups: septic and aseptic RTKAs. Demographic, comorbidity, perioperative, postoperative, and survivorship data were collected and compared between groups. Cox hazard regression was used to identify risk factors associated with revision surgery and revision. RESULTS: One-hundred fifty patients were included. Eighty-five patients received HKR because of prior infection, and 65 received HKR for aseptic revision. A larger proportion of septic RTKA returned to the OR versus aseptic RTKA (46% vs 25%, P = 0.01). Survival curves revealed superior revision surgery-free survival favoring the aseptic group ( P = 0.002). Regression analysis revealed that HKR with concomitant flap reconstruction was associated with a three-fold increased risk of revision surgery ( P < 0.0001). DISCUSSION: HKR implantation for aseptic revision is more reliable with a lower revision surgery rate. Concomitant flap reconstruction increased the risk of revision surgery, regardless of indication for RTKA using HKR. Although surgeons must educate patients about these risk factors, HKR remains a successful treatment option for RTKA when indicated. LEVEL OF EVIDENCE: prognostic, level III evidence.

Flash CGM associated with event reduction in nonintensive diabetes therapy.

OBJECTIVES: We evaluated the effects of acquiring a flash continuous glucose monitoring (CGM) system in the population with type 2 diabetes (T2D) treated with basal or noninsulin therapy. STUDY DESIGN: This was a retrospective database analysis of the IBM MarketScan Commercial Claims and Medicare Supplemental databases that assessed rates of acute diabetes-related events (ADEs) and all-cause inpatient hospitalizations (ACHs) in a large population with T2D treated with basal insulin therapy or noninsulin medications. ADE and ACH rates 6 months prior to and 6 months post CGM acquisition were compared. METHODS: Inclusion criteria for analysis were diagnosis of T2D; age 18 years or older; treatment with long-acting, neutral protamine Hagedorn, or premixed insulin or noninsulin therapy; naïve to CGM; and acquisition of their flash CGM system between October 2017 and March 2019. Patients served as their own controls. Event rates were compared using weighted Cox regression with Andersen-Gill extension for repeat events. RESULTS: A cohort of 10,282 adults with T2D (mean [SD] age, 53.1 [9.6] years; 51.9% male) who met inclusion criteria were assessed. ADE rates decreased from 0.076 to 0.052 events per patient-year (HR, 0.68; 95% CI, 0.58-0.80; P < .001). ACH rates decreased from 0.177 to 0.151 events per patient-year (HR, 0.85; 95% CI, 0.77-0.94; P = .002). CONCLUSIONS: Acquisition of the flash CGM system was associated with significant reductions in outpatient and inpatient ADEs and ACHs. These findings provide compelling evidence that use of flash CGM in patients with T2D treated with basal insulin therapy or noninsulin therapy improves clinical outcomes and potentially reduces costs.

Flash CGM Is Associated With Reduced Diabetes Events and Hospitalizations in Insulin-Treated Type 2 Diabetes.

PURPOSE: Suboptimal glycemic control among individuals with diabetes is a leading cause of hospitalizations and emergency department utilization. Use of flash continuous glucose monitoring (flash CGM) improves glycemic control in type 1 and type 2 diabetes, which may result in lower risk for acute and chronic complications that require emergency services and/or hospitalizations. METHODS: In this retrospective, real-world study, we analyzed IBM MarketScan Commercial Claims and Medicare Supplemental databases to assess the impact of flash CGM on diabetes-related events and hospitalizations in a cohort of 2463 individuals with type 2 diabetes who were on short- or rapid-acting insulin therapy. Outcomes were changes in acute diabetes-related events (ADE) and all-cause inpatient hospitalizations (ACH), occurring during the first 6 months after acquiring the flash CGM system compared with event rates during the 6 months prior to system acquisition. ICD-10 codes were used to identify ADE for hypoglycemia, hypoglycemic coma, hyperglycemia, diabetic ketoacidosis, and hyperosmolarity. RESULTS: ADE rates decreased from 0.180 to 0.072 events/patient-year (hazard ratio [HR]: 0.39 [0.30, 0.51]; P < 0.001) and ACH rates decreased from 0.420 to 0.283 events/patient-year (HR: 0.68 [0.59 0.78]; P < 0.001). ADE reduction occurred regardless of age or gender. CONCLUSIONS: Acquisition of the flash CGM system was associated with reductions in ADE and ACH. These findings provide support for the use of flash CGM in type 2 diabetes patients treated with short- or rapid-acting insulin therapy to improve clinical outcomes and potentially reduce costs.

The influences and neural correlates of past and present during gambling in humans.

During financial decision-making tasks, humans often make "rational" decisions, where they maximize expected reward. However, this rationality may compete with a bias that reflects past outcomes. That is, if one just lost money or won money, this may impact future decisions. It is unclear how past outcomes influence future decisions in humans, and how neural circuits encode present and past information. In this study, six human subjects performed a financial decision-making task while we recorded local field potentials from multiple brain structures. We constructed a model for each subject characterizing bets on each trial as a function of present and past information. The models suggest that some patients are more influenced by previous trial outcomes (i.e., previous return and risk) than others who stick to more fixed decision strategies. In addition, past return and present risk modulated with the activity in the cuneus; while present return and past risk modulated with the activity in the superior temporal gyrus and the angular gyrus, respectively. Our findings suggest that these structures play a role in decision-making beyond their classical functions by incorporating predictions and risks in humans' decision strategy, and provide new insight into how humans link their internal biases to decisions.

The role of nonmotor brain regions during human motor control.

Neural prostheses have generally relied on signals from cortical motor regions to control reaching movements of a robotic arm. However, little work has been done in exploring the involvement of nonmotor cortical and associative regions during motor tasks. In this study, we identify regions which may encode direction during planning and movement of a center-out motor task. Local field potentials were collected using stereoelectroencephalography (SEEG) from nine epilepsy patients implanted with multiple depth electrodes for clinical purposes. Spectral analysis of the recorded data was performed using nonparametric statistical techniques to identify regions that may encode direction of movements during the motor task. The analysis revealed several nonmotor regions; including the right insular cortex, right temporal pole, right superior parietal lobule, and the right lingual gyrus, that encode directionality before and after movement onset. We observed that each of these regions encode direction in different frequency bands. This preliminary study suggests that nonmotor regions may be useful in assisting in neural prosthetic control.

The Role of Associative Cortices and Hippocampus during Movement Perturbations.

Although motor control has been extensively studied, most research involving neural recordings has focused on primary motor cortex, pre-motor cortex, supplementary motor area, and cerebellum. These regions are involved during normal movements, however, associative cortices and hippocampus are also likely involved during perturbed movements as one must detect the unexpected disturbance, inhibit the previous motor plan, and create a new plan to compensate. Minimal data is available on these brain regions during such "robust" movements. Here, epileptic patients implanted with intracerebral electrodes performed reaching movements while experiencing occasional unexpected force perturbations allowing study of the fronto-parietal, limbic and hippocampal network at unprecedented high spatial, and temporal scales. Areas including orbitofrontal cortex (OFC) and hippocampus showed increased activation during perturbed trials. These results, coupled with a visual novelty control task, suggest the hippocampal MTL-P300 novelty response is modality independent, and that the OFC is involved in modifying motor plans during robust movement.

Lucky Rhythms in Orbitofrontal Cortex Bias Gambling Decisions in Humans.

It is well established that emotions influence our decisions, yet the neural basis of this biasing effect is not well understood. Here we directly recorded local field potentials from the OrbitoFrontal Cortex (OFC) in five human subjects performing a financial decision-making task. We observed a striking increase in gamma-band (36-50 Hz) oscillatory activity that reflected subjects' decisions to make riskier choices. Additionally, these gamma rhythms were linked back to mismatched expectations or "luck" occurring in past trials. Specifically, when a subject expected to win but lost, the trial was defined as "unlucky" and when the subject expected to lose but won, the trial was defined as "lucky". Finally, a fading memory model of luck correlated to an objective measure of emotion, heart rate variability. Our findings suggest OFC may play a pivotal role in processing a subject's internal (emotional) state during financial decision-making, a particularly interesting result in light of the more recent "cognitive map" theory of OFC function.

A look at the strength of micro and macro EEG analysis for distinguishing insomnia within an HIV cohort.

HIV patients are often plagued by sleep disorders and suffer from sleep deprivation. However, there remains a wide gap in our understanding of the relationship between HIV status, poor sleep, overall function and future outcomes; particularly in the case of HIV patients otherwise well controlled on cART (combined anti-retroviral therapy). In this study, we compared two groups: 16 non-HIV subjects (seronegative controls) and 12 seropositive HIV patients with undetectable viral loads. We looked at sleep behavioral (macro-sleep) features and sleep spectral (micro-sleep) features obtained from human-scored overnight EEG recordings to study whether the scored EEG data can be used to distinguish between controls and HIV subjects. Specifically, the macro-sleep features were defined by sleep stages and included sleep transitions, percentage of time spent in each sleep stage, and duration of time spent in each sleep stage. The micro-sleep features were obtained from the power spectrum of the EEG signals by computing the total power across all channels and frequencies, as well as the average power in each sleep stage and across different frequency bands. While the macro features do not distinguish between the two groups, there is a significant difference and a high classification accuracy for the scoring-independent micro features. This spectral separation is interesting because evidence suggests a relationship between sleep complaints and cognitive dysfunction in HIV patients stable on cART. Furthermore, there are currently no biomarkers that predict the early development of cognitive decline in HIV patients. Thus, a micro-sleep architectural approach could serve as a biomarker to identify HIV patients vulnerable to cognitive decline, providing an avenue to explore the utility of early intervention.

To Score or Not to Score? A look at the distinguishing power of micro EEG analysis on an annotated sample of PSG studies conducted in an HIV cohort.

In this study, we used the Pittsburgh Sleep Quality Index to divide the subjects into two groups, good sleepers and bad sleepers. We computed sleep behavioral (macro-sleep architectural) features and sleep spectral (micro-sleep architectural) features in order to observe if the annotated EEG data can be used to distinguish between good and bad sleepers in a more quantitative manner. Specifically, the macro-sleep features were defined by sleep stages and included sleep transitions, percentage of time spent in each sleep stage, and duration of time spent in each sleep stage. The micro-sleep features were obtained from the power spectrum of the EEG signals by computing the total power across all channels and all frequencies, as well as the average power in each sleep stage and across different frequency bands. We found that while the scoring-independent micro features are significantly different between the two groups, the macro features are not able to significantly distinguish the two groups. The fact that the macro features computed from the scoring files cannot pick up the expected difference in the EEG signals raises the question as to whether human scoring of EEG signals is practical in assessing sleep quality.

High frequency activity correlates of robust movement in humans.

The neural circuitry underlying fast robust human motor control is not well understood. In this study we record neural activity from multiple stereotactic encephalograph (SEEG) depth electrodes in a human subject while he/she performs a center-out reaching task holding a robotic manipulandum that occasionally introduces an interfering force field. Collecting neural data from humans during motor tasks is rare, and SEEG provides an unusual opportunity to examine neural correlates of movement at a millisecond time scale in multiple brain regions. Time-frequency analysis shows that high frequency activity (50-150 Hz) increases significantly in the left precuneus and left hippocampus when the subject is compensating for a perturbation to their movement. These increases in activity occur with different durations indicating differing roles in the motor control process.

Oscillations in human orbitofrontal cortex during even chance gambling.

Evaluating value and risk as well as comparing expected and actual outcomes is the crux of decision making and reinforcement based learning. In this study, we record from stereotactic electroencephalograph depth electrodes in a human subject in numerous areas in the brain. We focus on the lateral and medial orbitofrontal cortex while they perform a gambling task involving betting on a high card. Preliminary time-frequency analysis shows modulations in the 5-15 Hz band that is well synced to the different events of the task. These oscillations increase in both high betting scenarios as well as in losing scenarios though their effects cannot be decoupled. However, the activity between lateral and medial orbitofrontal cortex is a lot more homogenous than previously seen. Additionally, the timing of some of these oscillations occurs before even a response in the visual cortex. This evidence hints that these areas encode priors that influence our decision in future statistically ambiguous scenarios.