Parallel Encoding of Speech in Human Frontal and Temporal Lobes.

Models of speech perception are centered around a hierarchy in which auditory representations in the thalamus propagate to primary auditory cortex, then to the lateral temporal cortex, and finally through dorsal and ventral pathways to sites in the frontal lobe. However, evidence for short latency speech responses and low-level spectrotemporal representations in frontal cortex raises the question of whether speech-evoked activity in frontal cortex strictly reflects downstream processing from lateral temporal cortex or whether there are direct parallel pathways from the thalamus or primary auditory cortex to the frontal lobe that supplement the traditional hierarchical architecture. Here, we used high-density direct cortical recordings, high-resolution diffusion tractography, and hemodynamic functional connectivity to evaluate for evidence of direct parallel inputs to frontal cortex from low-level areas. We found that neural populations in the frontal lobe show speech-evoked responses that are synchronous or occur earlier than responses in the lateral temporal cortex. These short latency frontal lobe neural populations encode spectrotemporal speech content indistinguishable from spectrotemporal encoding patterns observed in the lateral temporal lobe, suggesting parallel auditory speech representations reaching temporal and frontal cortex simultaneously. This is further supported by white matter tractography and functional connectivity patterns that connect the auditory nucleus of the thalamus (medial geniculate body) and the primary auditory cortex to the frontal lobe. Together, these results support the existence of a robust pathway of parallel inputs from low-level auditory areas to frontal lobe targets and illustrate long-range parallel architecture that works alongside the classical hierarchical speech network model.

Trends of Self-Inflicted Firearm Injuries at a Rural Level 1 Trauma Center.

Firearm injuries are a major public health concern with much focus on injuries due to violent crimes in urban areas. Less focus has been on self-inflicted injuries and rural settings. This study included 201 patients, of which 124 (61.7%) were accidental and 77 (38.3%) were intentional self-inflicted gunshot wounds (GSWs) sustained over 6 years at a rural level 1 trauma center. Injury severity scores (P < .001), hospital days (P < .001), and mortality (P < .001) were significantly higher among intentional self-inflicted GSWs. Injuries to the head were the most common injury among patients with intentional self-inflicted GSWs (P < .001).Accidental and intentional self-inflicted GSWs make up a large portion of firearm injuries seen at our rural level 1 trauma center, and defining these injuries can facilitate the need for targeted gun safety and injury prevention efforts.

Outcome of Seatbelt Education and Safety Program Among Teenagers.

Despite the effectiveness of seatbelts, concerns persist about compliance, especially among teenagers. Survey data from a local high school and registry data from a level 1 trauma center were used to observe seatbelt and motor vehicle accident trends. The survey data was analyzed to gauge student's sentiments on seatbelt education. The trauma center data was analyzed to identify characteristics and trends among teenage motor vehicle accidents. Social media was the most common strategy selected for seatbelt safety awareness. Random seatbelt checks performed over 4 months revealed seatbelt compliance rates of 90%, 93.55%, and 96.94% after education intervention. Trauma center data showed that lack of seatbelt usage resulted in greater morbidity. These findings emphasize the need for targeted interventions. This study provides insights into creating effective education campaigns that can be used to enhance safety belt compliance and potentially reduce injury.

Effects of Trauma Center Consolidation on Adult Trauma at a Rural Level 1 Trauma Center.

OBJECTIVE: The aim was to determine the impact of consolidation of two rural level 1 trauma centers on adult trauma patients presenting to the remaining level 1 trauma center. To our knowledge, a study assessing the impact of trauma center consolidation on adult trauma patients had yet to be performed. METHODS: A single institution, retrospective study was conducted at a rural level 1 trauma center. Adult trauma patients who presented to our center from January 2017 to January 2022 were included. The cohorts spanned 33 months pre- and post-consolidation. Multiple demographic and outcome measures were gathered. Data were analyzed using the student's t-test and Chi-squared testing. RESULTS: There was a 33% increase in overall trauma activations and 9% increase in transfers from outside facilities post-consolidation. The post-consolidation group was significantly older, had higher mean injury severity score, and decreased hospital-free days. The post-consolidation group also saw an increase in ICU admission and surgical intervention. While there were no significant differences in ICU-free days or ventilator days, patients in the post-consolidation group with the highest level of activation who required both surgical intervention and ICU admission experienced decreased mortality. CONCLUSION: The consolidation of trauma services to a single level 1 trauma center in a rural Appalachian health system led to higher trauma volume and acuity, but most importantly decreased mortality for the most severely injured trauma patients.

Encoding of melody in the human auditory cortex.

Melody is a core component of music in which discrete pitches are serially arranged to convey emotion and meaning. Perception varies along several pitch-based dimensions: (i) the absolute pitch of notes, (ii) the difference in pitch between successive notes, and (iii) the statistical expectation of each note given prior context. How the brain represents these dimensions and whether their encoding is specialized for music remains unknown. We recorded high-density neurophysiological activity directly from the human auditory cortex while participants listened to Western musical phrases. Pitch, pitch-change, and expectation were selectively encoded at different cortical sites, indicating a spatial map for representing distinct melodic dimensions. The same participants listened to spoken English, and we compared responses to music and speech. Cortical sites selective for music encoded expectation, while sites that encoded pitch and pitch-change in music used the same neural code to represent equivalent properties of speech. Findings reveal how the perception of melody recruits both music-specific and general-purpose sound representations.

Large-scale single-neuron speech sound encoding across the depth of human cortex.

Understanding the neural basis of speech perception requires that we study the human brain both at the scale of the fundamental computational unit of neurons and in their organization across the depth of cortex. Here we used high-density Neuropixels arrays1-3 to record from 685 neurons across cortical layers at nine sites in a high-level auditory region that is critical for speech, the superior temporal gyrus4,5, while participants listened to spoken sentences. Single neurons encoded a wide range of speech sound cues, including features of consonants and vowels, relative vocal pitch, onsets, amplitude envelope and sequence statistics. Neurons at each cross-laminar recording exhibited dominant tuning to a primary speech feature while also containing a substantial proportion of neurons that encoded other features contributing to heterogeneous selectivity. Spatially, neurons at similar cortical depths tended to encode similar speech features. Activity across all cortical layers was predictive of high-frequency field potentials (electrocorticography), providing a neuronal origin for macroelectrode recordings from the cortical surface. Together, these results establish single-neuron tuning across the cortical laminae as an important dimension of speech encoding in human superior temporal gyrus.

Encoding of melody in the human auditory cortex.

Melody is a core component of music in which discrete pitches are serially arranged to convey emotion and meaning. Perception of melody varies along several pitch-based dimensions: (1) the absolute pitch of notes, (2) the difference in pitch between successive notes, and (3) the higher-order statistical expectation of each note conditioned on its prior context. While humans readily perceive melody, how these dimensions are collectively represented in the brain and whether their encoding is specialized for music remains unknown. Here, we recorded high-density neurophysiological activity directly from the surface of human auditory cortex while Western participants listened to Western musical phrases. Pitch, pitch-change, and expectation were selectively encoded at different cortical sites, indicating a spatial code for representing distinct dimensions of melody. The same participants listened to spoken English, and we compared evoked responses to music and speech. Cortical sites selective for music were systematically driven by the encoding of expectation. In contrast, sites that encoded pitch and pitch-change used the same neural code to represent equivalent properties of speech. These findings reveal the multidimensional nature of melody encoding, consisting of both music-specific and domain-general sound representations in auditory cortex. Teaser: The human brain contains both general-purpose and music-specific neural populations for processing distinct attributes of melody.

Interictal epileptiform discharges contribute to word-finding difficulty in epilepsy through multiple cognitive mechanisms.

OBJECTIVE: Cognitive impairment often impacts quality of life in epilepsy even if seizures are controlled. Word-finding difficulty is particularly prevalent and often attributed to etiological (static, baseline) circuit alterations. We sought to determine whether interictal discharges convey significant superimposed contributions to word-finding difficulty in patients, and if so, through which cognitive mechanism(s). METHODS: Twenty-three patients undergoing intracranial monitoring for drug-resistant epilepsy participated in multiple tasks involving word production (auditory naming, short-term verbal free recall, repetition) to probe word-finding difficulty across different cognitive domains. We compared behavioral performance between trials with versus without interictal discharges across six major brain areas and adjusted for intersubject differences using mixed-effects models. We also evaluated for subjective word-finding difficulties through retrospective chart review. RESULTS: Subjective word-finding difficulty was reported by the majority (79%) of studied patients preoperatively. During intracranial recordings, interictal epileptiform discharges (IEDs) in the medial temporal lobe were associated with long-term lexicosemantic memory impairments as indexed by auditory naming (p = .009), in addition to their established impact on short-term verbal memory as indexed by free recall (p = .004). Interictal discharges involving the lateral temporal cortex and lateral frontal cortex were associated with delayed reaction time in the auditory naming task (p = .016 and p = .018), as well as phonological working memory impairments as indexed by repetition reaction time (p = .002). Effects of IEDs across anatomical regions were strongly dependent on their precise timing within the task. SIGNIFICANCE: IEDs appear to act through multiple cognitive mechanisms to form a convergent basis for the debilitating clinical word-finding difficulty reported by patients with epilepsy. This was particularly notable for medial temporal spikes, which are quite common in adult focal epilepsy. In parallel with the treatment of seizures, the modulation of interictal discharges through emerging pharmacological means and neurostimulation approaches may be an opportunity to help address devastating memory and language impairments in epilepsy.

Transcutaneous Auricular Vagus Nerve Stimulation Modulates Performance but Not Pupil Size During Nonnative Speech Category Learning.

PURPOSE: Subthreshold transcutaneous auricular vagus nerve stimulation (taVNS) synchronized with behavioral training can selectively enhance nonnative speech category learning in adults. Prior work has demonstrated that behavioral performance increases when taVNS is paired with easier-to-learn Mandarin tone categories in native English listeners, relative to when taVNS is paired with harder-to-learn Mandarin tone categories or without taVNS. Mechanistically, this temporally precise plasticity has been attributed to noradrenergic modulation. However, prior work did not specifically utilize methodologies that indexed noradrenergic modulation and, therefore, was unable to explicitly test this hypothesis. Our goal for this study was to use pupillometry to gain mechanistic insights into taVNS behavioral effects. METHOD: Thirty-eight participants learned to categorize Mandarin tones while pupillometry was recorded. In a double-blinded design, participants were divided into two taVNS groups that, as in the prior study, differed according to whether taVNS was paired with easier-to-learn tones or harder-to-learn tones. Learning performance and pupillary responses were measured using linear mixed-effects models. RESULTS: We found that taVNS did not have any tone-specific or group behavioral or pupillary effects. However, in an exploratory analysis, we observed that taVNS did lead to faster rates of learning on trials paired with stimulation, particularly for those who were stimulated at lower amplitudes. CONCLUSIONS: Our results suggest that pupillary responses may not be a reliable marker of locus coeruleus-norepinephrine system activity in humans. However, future research should systematically examine the effects of stimulation amplitude on both behavior and pupillary responses. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24036666.

Impact of Trauma Resuscitation Emergency Care Nurse Deployment in Trauma Activations in a Rural Trauma Center.

BACKGROUND: Although the role of a dedicated trauma nurse has been implemented in an urban setting, it has not been studied in the rural trauma setting. We instituted a trauma resuscitation emergency care (TREC) nurse role to respond to trauma activations at our rural trauma center. OBJECTIVE: This study aims to determine the impact of TREC nurse deployment on the timeliness of resuscitation interventions in trauma activations. METHODS: This pre- and postintervention study at a rural Level I trauma center compared the time to resuscitation interventions before (August 2018 to July 2019) and after (August 2019 to July 2020) deploying TREC nurses to trauma activations. RESULTS: A total of 2,593 participants were studied, of which 1,153 (44%) were in the pre-TREC group and 1,440 (56%) in the post-TREC group. After TREC deployment, the median (interquartile range [IQR]) emergency department times within the first hour decreased from 45 (31.23-53) to 35 (16-51) min ( p = .013). The median (IQR) time to the operating room within the first hour decreased from 46 (37-52) to 29 (12-46) min ( p = .001), and within the first 2 hr, decreased from 59 (43.8-86) to 48 (23-72) min ( p = .014). CONCLUSION: Our study found that TREC nurse deployment improved resuscitation intervention timeliness during the first 2 hr (early phase) of trauma activations.

Apraxia of speech with phonological alexia and agraphia following resection of the left middle precentral gyrus: illustrative case.

BACKGROUND: Apraxia of speech is a disorder of speech-motor planning in which articulation is effortful and error-prone despite normal strength of the articulators. Phonological alexia and agraphia are disorders of reading and writing disproportionately affecting unfamiliar words. These disorders are almost always accompanied by aphasia. OBSERVATIONS: A 36-year-old woman underwent resection of a grade IV astrocytoma based in the left middle precentral gyrus, including a cortical site associated with speech arrest during electrocortical stimulation mapping. Following surgery, she exhibited moderate apraxia of speech and difficulty with reading and spelling, both of which improved but persisted 6 months after surgery. A battery of speech and language assessments was administered, revealing preserved comprehension, naming, cognition, and orofacial praxis, with largely isolated deficits in speech-motor planning and the spelling and reading of nonwords. LESSONS: This case describes a specific constellation of speech-motor and written language symptoms-apraxia of speech, phonological agraphia, and phonological alexia in the absence of aphasia-which the authors theorize may be attributable to disruption of a single process of "motor-phonological sequencing." The middle precentral gyrus may play an important role in the planning of motorically complex phonological sequences for production, independent of output modality.

Poor Outcomes of Patients From Delayed Care After Ground Level Falls.

BACKGROUND: Ground level falls are a common cause of morbidity and mortality in trauma patients. Delayed presentation in many conditions has been proven to lead to worsened outcomes. Currently, there are limited data on outcomes of those who have a delayed presentation after a ground level fall. MATERIALS AND METHODS: This study was a retrospective analysis of the Trauma Registry at our center. Any adult patient who presented after a ground level fall was grouped based on their time to presentation post-injury: less than or greater than 24 h. Age, gender, hospital length of stay (LOS), intensive care unit (ICU) LOS, mechanical ventilation days, Injury Severity Score, and mortality were patient characteristics gathered. A Student's t-test and Chi-squared testing were utilized to determine the presence of significant differences between the groups. Significance was set at P < .05. RESULTS: Two hundred of 4018 patients had delayed presentation. Those with delayed presentation were more likely to be male (P = .028), younger in age (71 vs 74 years old, P < .01), had greater hospital LOS (6 vs. 5, P < .01), ICU LOS (5 vs. 3, P < .01), and mechanical ventilation days (13 vs. 5 days, P < .01). They also had higher ISS (8 vs. 7, P < .01), and mortality was significantly higher in those who presented after 24 h (P = .034). CONCLUSION: Patients with delayed presentation after a ground level fall have worsened Injury Severity Scores and outcomes to include hospital and ICU LOS, ventilator days, and overall mortality.

Impact of Non-Automobile Rollover Accidents on Patient Outcomes at an Appalachian Level I Trauma Center.

The objective of this study was to evaluate outcomes of patients involved in rollover accidents in non-automobile vehicles in a rural level I trauma center. This was a retrospective study including a total of 127 patients over 5 years who were admitted to our level I trauma center following rollover accidents in either of the following: ATV, lawnmower, or tractor. Patients were significantly older in the tractor and lawnmower rollover groups, and patients less than 65 years old were significantly more likely to sustain an injury in a rollover accident when compared to those greater than 65. Patients with extremity fractures secondary to tractor rollovers were more likely to be older, and patients who sustained spinal injuries secondary to tractor rollovers were more likely to be younger. Non-automobile rollovers have the potential to cause traumatic injuries; however, there does not appear to be 1 vehicle type that is more prone to injury.

Experimental Study of the Adsorption and Decomposition of Sarin on Dry Copper(II) Oxide.

Organophosphonates were originally developed as insecticides but were quickly identified as highly toxic acetylcholinesterase inhibitors, leading to their exploitation as chemical warfare agents (CWA). To develop next generation filtration technologies, there must be a fundamental understanding of the molecular interactions occurring with toxic chemicals, such as CWAs. In this paper, we investigate the interaction between dry CuO nanoparticles and sarin (GB), using infrared (IR) spectroscopy in an effort to build an atomic understanding. We show sarin strongly interacts with CuO and then quickly degrades, primarily through the cleavage of the P-F bond, creating a bridging species on the CuO surface with the assistance of lattice oxygen. Upon heating, the decomposition product isopropyl methyl phosphonic acid (IMPA) does not continue to decompose but desorbs from the surface. These observations are further elaborated through theoretical models of sarin on dry CuO (111).

Impact of All-Terrain Vehicle Accidents on Pediatric Patient Outcomes at an Appalachian Children's Hospital.

Introduction The use of all-terrain vehicles (ATVs) has become increasingly popular as an outdoor recreational activity among people living in the United States, particularly in areas such as the southeast. There are significant risks involved with riding ATVs, especially in the pediatric population, due to lack of training and experience. The purpose of this study was to evaluate the outcomes of pediatric patients involved in ATV-associated accidents. Methods This study is a retrospective review of 98 pediatric patients ages 15 years and younger involved in ATV accidents who were admitted to a pediatric hospital between January 2015 and December 2020. Outcomes, including types of injuries sustained, length of hospital stay, length of ICU stay, and injury severity score (ISS) were analyzed between age groups (0-5, 6-10, and 11-15). Results The mean hospital stay across all age groups was 1.7 ± 1.9 days, mean ICU stay was 3.8 ± 4.0 days, and mean injury severity score (ISS) was 5.9 ±4.8. The 11-15-year-old age group had a significantly longer hospital stay and higher ISS scores compared to both of the younger age groups (0-5 and 6-10 years old). There was no difference in ICU days between the age groups. Orthopedic injuries were the most common type of injury, occurring in 55% of all patients, followed by head injuries in 29% of patients, and spinal fractures in 2% of patients. The most common orthopedic fracture in the 11-15-year-old group was tibia/fibula, while humerus fractures were the most common type of fracture in the 0-5 and 6-10 year age groups. Orthopedic procedures were required in 35% of all included patients. There was no statistically significant difference in types of injuries and types of fractures sustained between each group. Chest injuries, including pneumothorax, lung contusions, and rib fractures, occurred most often in the older age group 11-15 years (n=65). Those who experienced chest injuries had a higher ISS, although it was not statistically significant (p=0.06) compared to those who did not have chest injuries. There was no difference in hospital or ICU length of stay in patients with chest injuries. Conclusions The results of this study demonstrate the outcomes of pediatric patients admitted for ATV accidents at a rural Appalachian pediatric hospital and provide an overview of the most common injuries involved in this trauma mechanism. Pediatric patients aged 11-15 years of age involved in ATV accidents are at risk for longer hospital length of stay and higher ISS compared to younger age groups. Additionally, patients ages 11-15 were more susceptible to chest injuries following ATV accidents. The results of this study will be used to develop a standardized trauma protocol for the management of this specific trauma mechanism in the pediatric population based on common injury patterns among each age group.

Spectroscopic studies of methyl paraoxon decomposition over mesoporous Ce-doped titanias for toxic chemical filtration.

The ever-constant threat of chemical warfare agents (CWA) motivates the design of materials to provide better protection to warfighters and civilians. Cerium and titanium oxide are known to react with organophosphorus compounds such Sarin and Soman. To study the decomposition of methyl paraoxon (CWA simulant) on such materials, we synthesized ordered mesoporous metal oxides (MMO) TiO2, CexTi1-xO2 (x = 0.005, 0.5, 0.10, 0.15) and CeO2. We fully characterized TiO2 and Ce-doped TiO2 and found phase-pure oxides with cylindrical hexagonally packed pores and high surface areas (176-252 m2/g). Methyl paraoxon decomposition was tracked through UV/Vis and found Ce0.15Ti0.85O2 to decompose the most methyl paraoxon, but CeO2 to be the most reactive when normalized to surface area. The surface area normalized rate constant (kSA) for CeO2 was 3-4.6 times larger than that of TiO2 and the CexTi1-xO2 series. While TiO2 and CexTi1-xO2 for 0.05 ≤ x ≤ 0.10 displayed no significant differences in the kinetics, the mostly amorphous Ce0.15Ti0.85O2 displayed a slight increase in reactivity. Our findings indicate that the nature of the cation, Ce4+ vs Ti4+, is less important to methyl paraoxon reactivity on these MMOs compared to other factors such as crystal structure type.

High-density single-unit human cortical recordings using the Neuropixels probe.

The action potential is a fundamental unit of neural computation. Even though significant advances have been made in recording large numbers of individual neurons in animal models, translation of these methodologies to humans has been limited because of clinical constraints and electrode reliability. Here, we present a reliable method for intraoperative recording of dozens of neurons in humans using the Neuropixels probe, yielding up to ∼100 simultaneously recorded single units. Most single units were active within 1 min of reaching target depth. The motion of the electrode array had a strong inverse correlation with yield, identifying a major challenge and opportunity to further increase the probe utility. Cell pairs active close in time were spatially closer in most recordings, demonstrating the power to resolve complex cortical dynamics. Altogether, this approach provides access to population single-unit activity across the depth of human neocortex at scales previously only accessible in animal models.

Controlled Substance Use and Clinical Outcomes of Elderly Patients After a Fall.

Controlled substance use, particularly among the rising elderly population, places these patients at a much higher risk of falls, injuries, and hospitalization. This study examines the association between preinjury controlled substance prescription and clinical outcomes of older adults after a ground-level fall. A total of 5,930 patients were included. Their home medication list was analyzed to record active opioids, benzodiazepines, narcotics, or other substances defined as controlled according to the Drug Enforcement Agency. Almost half (45%) of the patients were taking controlled substances. Sixty-seven percent of those were females. Total hospital days, Injury Severity Score (ISS), and mortality outcomes were not significantly different between groups. However, intensive care unit (ICU) days, days on mechanical ventilation (MV), and discharge destination were significantly different for patients taking controlled substances versus those not taking controlled substances. Patients taking controlled substances were more likely to be discharged to short- and long-term care facilities versus patients not taking controlled substances (P≤0.001).

Human intracranial recordings reveal distinct cortical activity patterns during invasive and non-invasive vagus nerve stimulation.

Vagus nerve stimulation (VNS) is being used increasingly to treat a wide array of diseases and disorders. This growth is driven in part by the putative ability to stimulate the nerve non-invasively. Despite decades of use and a rapidly expanding application space, we lack a complete understanding of the acute effects of VNS on human cortical neurophysiology. Here, we investigated cortical responses to sub-perceptual threshold cervical implanted (iVNS) and transcutaneous auricular (taVNS) vagus nerve stimulation using intracranial neurophysiological recordings in human epilepsy patients. To understand the areas that are modulated by VNS and how they differ depending on invasiveness and stimulation parameters, we compared VNS-evoked neural activity across a range of stimulation modalities, frequencies, and amplitudes. Using comparable stimulation parameters, both iVNS and taVNS caused subtle changes in low-frequency power across broad cortical networks, which were not the same across modalities and were highly variable across participants. However, within at least some individuals, it may be possible to elicit similar responses across modalities using distinct sets of stimulation parameters. These results demonstrate that both invasive and non-invasive VNS cause evoked changes in activity across a set of highly distributed cortical networks that are relevant to a diverse array of clinical, rehabilitative, and enhancement applications.