Localization Task Research Articles

Pilot Data for a New Headphone-Based Assessment of Absolute Localization in the Assessment of Auditory Processing Disorder (APD)

Background/Objectives: Localization deficit is often said to be a symptom of Auditory Processing Disorder (APD). However, no clinically viable assessment of localization ability has been developed to date. The current study presents pilot data for a new assessment of absolute auditory localization using headphones. Methods: Speech phrases encoded with non-individualized head-related transfer functions (HRTF) using real-time digital processing were presented to two cohorts of participants with normal hearing. Variations in the simulated environment (anechoic and reverberant) and signal to noise ratio (SNR) were made to assess each of these factors’ influences on localization performance. Experiment 1 assessed 30 young adults aged 21–33 years old and Experiment 2 assessed 28 young adults aged 21–29 years old. All participants had hearing thresholds better than 20 dB HL. Results: Participants performed the localization task with a moderate degree of accuracy (Experiment 1: Mean RMS error = 25.9°; Experiment 2: Mean RMS error 27.2°). Front–back errors (FBEs) were evident, contributing to an average RMS error that was notably elevated when compared to similar free-field tasks. There was no statistically significant influence from the simulated environment or SNR on performance. Conclusions: An exploration of test viability in the pediatric and APD-positive populations is warranted alongside further correction for FBEs; however, the potential for future clinical implementation of this measure of absolute auditory localization is encouraging.

Acoustic Emission Partial Discharge Localization in Oil Based on Artificial Bee Colony

This study explores the application of an artificial bee colony (ABC) to locate partial discharge (PD) in a test tank based on acoustic emission (AE) approach. Data from a previous AE PD experimental study, which includes the coordinates of 3 AE sensors and the time difference of arrival (TDOA), were used to construct the nonlinear localization equations. It is known that localization algorithms are among the factors that can affect PD localization accuracy, and the ongoing research in this area underscores the need for further advancements in this topic. Therefore, the ABC was proposed to estimate the PD location through a colony of 120 bees, evenly divided into 60 employed and 60 onlooker bees. The employed bees explored the bounded search space, and onlooker bees refined PD locations found by the employed bees through local search. Scout bees were set out whenever a bee exceeded the limit of abandonment to discover possible PD locations in new areas of the search space. After 500 iterations, the optimal solution was the estimated PD location produced by ABC. Comparisons with the genetic algorithm (GA), particle swarm optimization (PSO) and bat algorithm (BA) revealed that the distance error, maximum deviation and computation time for AE PD localization based on ABC are the lowest. The study concludes that the ABC is more suitable for the multi-variable PD localization task than the GA, PSO, and BA due to its effective balance between local search by onlooker bees and global exploration by scout bees.

An Attentional Graph Neural Network-Based Fault Point Positioning Model for Low-Voltage Distribution Networks

With the rapid development of the smart grid, the fast and accurate fault location of low-voltage distribution networks has become the key to ensuring the stability and reliability of the power supply. This paper aims to explore and construct a fault location model of low-voltage distribution network based on an attention diagram neural network. First, this paper analyzes the current situation and challenges of fault location in low-voltage distribution network, and points out that traditional methods have limitations when processing large-scale and high-dimensional power system data. Subsequently, a graph neural network (GNN) is introduced for processing graph-structured network data, and combined with attention mechanisms. Thus, an innovative attention-graph neural network model (named as A-GNN) is proposed for the purpose. The model can make full use of the topology structure and node feature information in the power grid, and dynamically adjust the information aggregation weight between different nodes through the attention mechanism. This is expected to achieve efficient and accurate fault location. In the experimental part, we trained and tested the A-GNN model based on the real low-voltage distribution network dataset, and compared it with several prediction models. The experimental results show that the A-GNN model has higher accuracy and recall rate in fault location tasks, especially in complex fault scenarios.

Behavioral adaptations after unilateral whisker denervation.

The rodent whisker system provides an excellent model to study experience dependent plasticity in neural morphology, circuitry, and behavior. Rodents use bilateral whisker sensation to gather information about their environment. Unilateral whisker denervation disrupts whisker circuitry but its impact on task specific behavior is largely unknown. Adult mice with unilateral whisker denervation display a preference to using the intact whisker set to inspect objects, but do not have altered open field navigation. An object localization task requiring only the intact whisker set did not detect any change in performance, but gap crossing was impaired after unilateral whisker denervation. Finally, chronic whisker denervation led to increased anxiety-like behavior which was rescued by training on the gap cross task. These findings indicate that mice use behavioral strategies to adapt to life with only one set of intact whiskers.

Changes in thoracic erector spinae regional activation during postural adjustments and functional reaching tasks after spinal cord injury.

Many individuals with incomplete spinal cord injury (SCI) exhibit reduced volitional control of trunk muscles, such as impaired voluntary contractions of the erector spinae (ES), due to damage to the neural pathways regulating sensorimotor function. Studies using conventional bipolar electromyography (EMG) showed alterations in the overall, or global, activation of the trunk muscles in people with SCI. However, how activation varied across specific regions within the ES, referred to as regional activation, remains unknown. The aim of the study was to investigate the regional distribution of the ES activity below the level of injury in individuals with incomplete SCI during postural tasks and multidirectional reaching tasks using high-density EMG. Twenty-one individuals with incomplete SCI and age-matched controls were recruited. The EMG amplitude of the thoracic ES and displacement of the arm, trunk, and center of pressure were recorded during the tasks. Activation was more in the lower region of the ES in individuals with SCI compared with the controls during the postural tasks. Additionally, activation was limited to a small area of the ES during the reaching tasks. The EMG amplitude was greater during reaching forward than returning to the upright posture in the controls; however, this phase-dependent difference in the EMG amplitude was not present in individuals with SCI. Our findings demonstrate changes in regional activation of the thoracic ES during postural and reaching tasks, likely reflecting injury-induced changes in selective neural control to activate residual muscle fibers of the ES for postural control and function after SCI.

Action toward sound sources enhances auditory spatial confidence: on the metacognitive consequences of reaching to sounds

Each perceptual process is accompanied with an evaluation regarding the reliability of what we are perceiving. The close connection between confidence in perceptual judgments and planning of actions has been documented in studies investigating visual perception. Here, we extend this investigation to auditory perception by focusing on spatial hearing, in which the interpretation of auditory cues can often present uncertainties. We asked if confidence in perceived sound position changes when we interact with the sound source by planning a sound-directed motor action (reaching) vs. a verbal response (naming). We tested 30 participants in a sound localization task in which they were both asked to localize sound sources by reaching them or by naming the labels above them in a within-participants experimental design. Participants performed the task with binaural hearing and with one ear plugged to increase errors and reduce confidence. Results showed that sound localization performance did not differ between reaching and naming, and yet participants felt more confident and required less time to complete the trial when reaching to the sources compared to naming them, regardless of the listening condition. Moreover, we found that during monaural listening the coherence between performance and confidence was reduced in each trial, irrespective of response type, suggesting increased difficulties in metacognitive monitoring. These findings suggest that, even in the case of spatial hearing, motor action planning plays a role in the formulation of confidence judgments, alongside sensory inputs and decision-making processes and stress the importance of including metacognitive measurements into spatial hearing research.

Sequence learning following maternal immune activation.

Maternal immune activation (MIA) is a risk factor for schizophrenia. Since memory for sequence and stimulus order are disrupted in individuals with schizophrenia, we tested whether MIA animals showed deficits in a sequence learning and object-place recency memory task. In experiment one, control and MIA-challenged rats were required to nose poke five ports in a cued sequence. The sequences were presented randomly except for one structured sequence that was repetitive and initiated from the same port. Both groups were more accurate on the structured sequence and learned the task at similar rates. When a new structured sequence was presented, control animals were able to respond flexibly and take advantage of the structure, whereas the performance of MIA animals was similar for random and structured sequences. Experiment two tested MIA and control rats were evaluated in a Temporal Ordering for Spatial Locations task (TOSL). Control animals had a significant preference for the object in the least-recent location, indicating a novelty preference, while MIA animals did not, although the between-group difference failed to reach significance. Exploration patterns changed differentially over time, possibly because of variation in habituation processes. As a result, MIA animals were significantly less likely to explore the object at the least-recent location during the second half of the exploration session, compared to control animals. Collectively these studies indicate that while MIA animals are unimpaired in simple sequence learning, they display changes in behaviour compared to controls. Differences may result from habituation rate or inflexibility when responding to change.

A piezoelectric coded-excitation scanning acoustic transducer for Lamb wave inspections

Abstract Several techniques for Guided Wave (GW) inspections have already been developed. Most of them rely on extensive sensor deployment and damage localization algorithms characterized by significant computational costs. However, there is a growing demand for simpler, more autonomous, and more affordable systems across various fields. In particular, the implementation of wireless, battery-powered systems with a reduced number of sensor nodes and simpler processing would greatly facilitate the transition of this inspection technology on the field. Following this direction, this work presents the design of a novel piezoelectric transducer composed of four different patches, i.e. with only four input/output channels, to scan a given area. The peculiar piezo-load distributions allow the association of different spectral binary sequences for each 6∘ discrete angular step. By evaluating the distance-of-flights (DoFs) of detected peaks, the range coordinates for multiple defects are identified. Meanwhile, the angular information is extracted by demodulating binary sequences of peaks with comparable DoFs across several frequency bands. Since the transducer is designed as an encoder, it is referred to as coded-excitation scanning acoustic transducer (CESAT). More specifically, the Gray code is used to generate spectral patterns to reduce the uncertainty between two adjacent angular steps. A new quantization procedure for the optimal generation of the piezo distributions is also proposed. Ad hoc signal processing algorithms, suitable for embedded applications, were developed to extract multi-target range and angle information. The processing is based on the frequency decomposition of the recorded signal using an FIR filter bank and on dispersion compensation procedures for pulse ‘re-compression’. The transducer encoder behavior is validated through a finite element analysis. Finally, numerical simulations were performed to assess the effectiveness of the CESAT and associated signal processing in multi-defect detection and localization tasks.

OLODN: An efficient lightweight people detection method for occlusion and crowding scenarios

AbstractAddressing the real‐time object detection problem for devices with limited computing resources in densely populated and occluded scenarios, a novel occlusion‐aware lightweight object detection network (OLODN) is proposed. This network integrates innovative components to significantly enhance detection efficiency while maintaining high accuracy. Firstly, OLODN employs FasterNet blocks and reparameterised generalised‐FPN to reduce computational complexity and preserve feature extraction and fusion capabilities. Secondly, a reinforced coordination attention mechanism is designed to strengthen the network's ability to capture occlusion boundary information. Additionally, a spatial pyramid pooling feature concatenation module is introduced to integrate multi‐scale features and enhance the algorithm's robustness to occlusions. Lastly, OLODN adopts a task‐aligned one‐stage object detection strategy, optimising the anchor alignment of classification and localisation tasks, effectively improving detection accuracy under occluded conditions. Experiments demonstrate the superiority of the proposed method. On the WiderPerson dataset, OLODN achieved a recall rate of 68.0%, which is 2.8% higher than YOLOv11's 65.2%, while running at 35.3 frames per second (f/s) on CPU and 76.6 f/s on GPU, faster than YOLOv11's 34.1 f/s and 74.5 f/s by 1.2 f/s and 2.1 f/s, respectively.

Effects of kinesio taping on lower limb biomechanical characteristics during dynamic postural control tasks in individuals with chronic ankle instability.

Previous studies have demonstrated significant biomechanical differences between individuals with chronic ankle instability (CAI) and healthy controls during the Y-balance test. This study aimed to examine the effects of kinesio taping (KT) on lower limb biomechanical characteristics during the Y-balance anterior reach task in individuals with CAI. A total of 30 participants were recruited, comprising 15 individuals with CAI and 15 healthy controls. All participants were randomly assigned three taping conditions: no taping (NT), placebo taping (PT), and KT, followed by the Y-balance anterior reach task. Each condition was separated by one-week intervals. Kinematic and kinetic data of the lower limbs during the movement phase were collected using the Vicon motion capture system (Vicon, T40, 200 Hz) and two Kistler force platforms (Kistler, 1000 Hz). KT significantly improved the Y-balance anterior reach distance (P = 0.003) and peak ankle eversion angle (P = 0.019) compared to NT. Additionally, KT resulted in increased peak knee flexion angle (P = 0.002, P = 0.011) and peak ankle dorsiflexion angle (P <0.001, P = 0.005) relative to both NT and PT. KT also significantly reduced mediolateral center of pressure (COP) displacement (P = 0.001) and average velocity of mediolateral COP displacement (P = 0.033) in comparison to NT. Furthermore, KT decreased mediolateral center of gravity displacement (P = 0.002, P = 0.003) relative to both NT and PT. KT significantly improved abnormal ankle posture by promoting greater ankle dorsiflexion and eversion angles. Additionally, KT reduced mediolateral COP displacement and average velocity to improve postural stability. These changes may contribute to reduced risk of ankle sprains. Therefore, KT may serve as an effective tool for managing recurrent ankle sprains in individuals with CAI.

Therapeutic Intervention for Trunk Control Impairments in Central Nervous System Disorders: A Comprehensive Review of Methods and Efficacy.

Trunk control involves multiple brain regions related to motor control systems. Therefore, patients with central nervous system (CNS) disorders frequently exhibit impaired trunk control, decreasing their activities of daily living (ADL). Although some therapeutic interventions for trunk impairments have been effective, their general effects on CNS disorders remain unclear. This review aimed to clarify this issue in patients with stroke, cerebellar ataxia, and Parkinson's disease (PD), representing trunk control impairment by lesions in the cortical and corticospinal systems, cerebellum, and basal ganglia, respectively. Using online databases, we searched for randomized controlled trials that investigated the effects of therapeutic interventions for trunk impairments in patients with stroke, cerebellar ataxia, and PD, reported in English from 2013 to 2023. Overall, 50 articles were reviewed. Core-stability exercise (CSE), which activates the trunk muscles, specifically in the lumbar and pelvic areas, through postural adjustment tasks, is effective in patients with stroke, cerebellar ataxia, and PD. Weight-shifting exercise, unstable surface training, training with transcutaneous electrical stimulation, and noninvasive brain stimulation have been effective in patients following stroke. The combination of CSE with task-oriented training based on daily activities has been effective in patients with cerebellar ataxia. Perceptual training, repetitive trans-spinal magnetic stimulation, and aquatic training effectively improved alignment and balance function in patients with PD. This review provides evidence-based strategies to improve trunk control, ADL, and quality of life for patients with trunk control impairments caused by CNS disorders.

SFML: A personalized, efficient, and privacy-preserving collaborative traffic classification architecture based on split learning and mutual learning

Traffic classification is essential for network management and optimization, enhancing user experience, network performance, and security. However, evolving technologies and complex network environments pose challenges. Recently, researchers have turned to machine learning for traffic classification due to its ability to automatically extract and distinguish traffic features, outperforming traditional methods in handling complex patterns and environmental changes while maintaining high accuracy. Federated learning, a distributed learning approach, enables model training without revealing original data, making it appealing for traffic classification to safeguard user privacy and data security. However, applying it to this task poses two challenges. Firstly, common client devices like routers and switches have limited computing resources, which can hinder efficient training and increase time costs. Secondly, real-world applications often demand personalized models and tasks for clients, posing further complexities. To address these issues, we propose Split Federated Mutual Learning (SFML), an innovative federated learning architecture designed for traffic classification that combines split learning and mutual learning. In SFML, each client maintains two models: a privacy model for the local task and a public model for the global task. These two models learn from each other through knowledge distillation. Furthermore, by leveraging split learning, we offload most of the computational tasks to the server, significantly reducing the computational burden on the client. Experimental results demonstrate that SFML outperforms typical training architectures in terms of convergence speed, model performance, and privacy protection. Not only does SFML improve training efficiency, but it also satisfies the personalized needs of clients and reduces their computational workload and communication overhead, providing users with a superior network experience.

Non-dominant hand contractions do not facilitate performance under pressure in common desktop tasks.

Non-dominant hand contractions (NDHCs) have been shown to help expert motor skills in high-pressure scenarios that induce performance anxiety. Most studies of NHDCs under pressure have examined benefits in overlearned specialist movements (e.g., sporting skills), while few have considered if NDHCs can aid common movements with population-wide expertise (e.g., typing). Accordingly, across three experiments, we explored if NDHCs could protect or facilitate performance under time and/or evaluation pressure in a cursor positioning task (Experiments 1 & 2) and a typing task (Experiment 3). Despite varying the nature of the task, pressure manipulation, and design, and successfully manipulating state anxiety in each experiment, we found no evidence that NDHCs assist performance under pressure in these tasks. For the pressure × contraction condition interaction, the largest inclusion Bayes Factor was .40 for task response time and .62 for task error (Experiment 1), indicating evidence in favour of a null result. Our results, along with other recent studies in this area, cast doubt on the benefits of NDHCs under pressure outside sporting tasks and underline the need for a better mechanistic account of the phenomenon.

Overcoming boundary conditions for object location memory destabilization in male rats involves dopamine D1 receptor activation.

Consolidated long-term memories can undergo strength or content modification via protein synthesis-dependent reconsolidation. This is the process by which a reminder cue initiates reactivation of the memory trace, triggering destabilization. Older and more strongly encoded spatial memories can resist destabilization due to biological boundary conditions. The present study investigated the role of dopamine (DA) at D1 receptors (D1Rs) in object location memory destabilization and overcoming boundary conditions for older ("remote"; tested with a 48-h rather than a 24-h delay between sample and reactivation) memory destabilization. Using male rats in a modified object location task, we found that administering the D1R antagonist SCH23390 (0.1mg/kg, i.p.) prior to reactivation blocked destabilization of recently encoded memories, as well as novelty-induced destabilization of remote memories. Using remote parameters, systemically administered D1R agonist SKF38393 (5mg/kg, i.p.) induced destabilization of remote object location memories in the absence of salient novelty. Intra-dorsal hippocampus administration of SCH23390 (2μg/μL) also blocked destabilization of remote object location memories when a salient novel cue was present. These results are consistent with previous findings implicating DA in memory destabilization as well as demonstrate a role for D1-receptor activation in the destabilization of boundary condition protected-object location memories.

Impaired visual attention and numerical processing in children with anisometropic amblyopia and after visual acuity recovery

Amblyopia affects more than visual acuity. To compare the performances of visual selective attention and numerical processing in children with anisometropic amblyopia and children with normal vision, and investigate whether performance would be improved after visual acuity recovery, we performed 3 visual attention tasks (identifying number location task, numerical comparison task, and specific number comparison task) in children with anisometropic amblyopia, children who had recovered from anisometropic amblyopia, and children with normal vision in 6–8 and 9–11 years groups. The numerical processing ability, visual selective attention, and numerical distance effect were assessed by their reaction time of different tasks. The amblyopia group showed significantly worse visual selective attention than control group. However, the recovered amblyopic group showed worse visual selective attention compared to control group only in 9–11 years group. Children aged 6–8 had a greater numerical distance effect than 9–11 in control group, while there were no significant differences between different age groups in amblyopia and recovered amblyopic children. These findings suggest children with anisometropic amblyopia have not only defective visual selective attention but also different age-related patterns of numerical distance effect. Moreover, the improvement of visual selective attention after early stage of visual acuity recovery is better at younger age.

DESERTION AND THE FIGHT AGAINST IT IN THE TERRITORY OF THE MARI TERRITORY IN 1919–1920 (based on the materials of the State Archive of the Republic of Mari El)

Desertion, as an element of the Russian army’s disintegration at the beginning of the 20th century, was finally formed during the First World War. Lack of motivation, depressed morale and abandoned battlefield positions became the main reasons for Russia’s military and political failures at the final stage of the war. That is why, in the conditions of the Civil War outbreak in Russia, an important task for the new Soviet government was to strengthen discipline and revive the combat capability of the army. The fight against desertion was the key to preserve and establish the Soviet power on the ground, including in the Mari Territory. The purpose of the study is to study desertion as a phenomenon of the Civil War period in Russia in 1919–1920 in the Mari Territory, as well as to identify the main forms and methods of combating it. Materials and methods. The research used general scientific and special historical methods and approaches. When working with archival materials on the topic of desertion in the Mari Territory, a collection of documents that had not previously appeared in scientific circulation was formed. Research results. The authority responsible for the search and capture of deserters was the Central Commission for Combating Desertion. The Mari Territory in this matter fell under the jurisdiction of governorate commissions for combating desertion, located in the cities of Kazan and Vyatka. To carry out local tasks in each uyezd of the Mari Territory its own commission for combating desertion was formed under the uyezd military commissariat. They actively cooperated and carried out joint work with both the military commissariat and the uyezd commission for combating counterrevolution. Village councils were also supposed to provide active assistance.The Soviet government toughened penalties for desertion, but also used soft methods to combat this phenomenon. The study conclusions. During the Russian Civil War, six forms of combating desertion operated in the Mari Territory, all of them functioned together and formed a single integrated system to eradicate and prevent this kind of crime.

A detailed inquiry of the differences between headphones and loudspeakers influences on dynamic postural task performance.

We examined the impact of auditory stimuli and their methods on a dynamic balance task performance. Twenty-four young adults wore an HTC Vive headset and dodged a virtual ball to the right or left based on its color (blue to the left, red to the right, and vice versa). We manipulated the environment by introducing congruent (auditory stimuli from the correct direction) or incongruent (auditory stimuli played randomly from either side) and comparing a multimodal (visual and congruent auditory stimuli) to unimodal (visual or auditory stimuli) presentation. We tested four apparatuses: loudspeakers, headphones, passthrough, (wearing headphones while auditory stimuli come from loudspeakers) and room simulation (externalization via headphones). We quantified reaction time (RT) and accuracy (choosing the correct direction to dodge) from the head movement. We hypothesized that the weight of the headset will slow RT, and that externalization of the auditory stimuli will make it more usable when no visual cues are provided. Interestingly, both hypotheses were refuted. In silent conditions, RT was faster with headphones compared to loudspeakers, but this difference disappeared when auditory stimuli were introduced. Participants used congruent auditory stimuli to improve accuracy but disregarded incongruent auditory stimuli across all apparatuses except for room simulation. In conclusion, this study confirmed that healthy young adults can use congruent auditory stimuli to enhance accuracy and disregard incongruent auditory stimuli such that accuracy is not harmed. RT was either faster or the same with headphones compared to loudspeakers. Notably, this specific room simulation did not enhance performance.

Auditory and Visual Thalamocortical Connectivity Alterations in Unmedicated People with Schizophrenia: An Individualized Sensory Thalamic Localization and Resting-State Functional Connectivity Study.

Converging evidence from clinical neuroimaging and animal models has strongly implicated dysfunction of thalamocortical circuits in the pathophysiology of schizophrenia. Preclinical models of genetic risk for schizophrenia have shown reduced synaptic transmission from auditory thalamus to primary auditory cortex, which may represent a correlate of auditory disturbances such as hallucinations. Human neuroimaging studies, however, have found a generalized increase in resting state functional connectivity (RSFC) between whole thalamus and sensorimotor cortex in people with schizophrenia (PSZ). We aimed to more directly translate preclinical findings by specifically localizing auditory and visual thalamic nuclei in unmedicated PSZ and measuring RSFC to primary sensory cortices. In this case-control study, 82 unmedicated PSZ and 55 matched healthy controls (HC) completed RSFC functional magnetic resonance imaging (fMRI). Auditory and visual thalamic nuclei were localized for 55 unmedicated PSZ and 46 HC who additionally completed a sensory thalamic nuclei localizer fMRI task (N = 101). Using localized nuclei as RSFC seeds we assessed group differences in auditory and visual thalamocortical connectivity and associations with positive symptom severity. Auditory thalamocortical connectivity was not significantly different between PSZ and HC, but hyperconnectivity was associated with greater positive symptom severity in bilateral superior temporal gyrus. Visual thalamocortical connectivity was significantly greater in PSZ relative to HC in secondary and higher-order visual cortex, but not predictive of positive symptom severity. These results indicate that visual thalamocortical hyperconnectivity is a generalized marker of schizophrenia, while hyperconnectivity in auditory thalamocortical circuits relates more specifically to positive symptom severity.

A Case Study on EEG Signal Correlation Towards Potential Epileptic Foci Triangulation.

The precise localization of epileptic foci with the help of EEG or iEEG signals is still a clinical challenge with current methodology, especially if the foci are not close to individual electrodes. On the research side, dipole reconstruction for focus localization is a topic of recent and current developments. Relatively low numbers of recording electrodes cause ill-posed and ill-conditioned problems in the inversion of lead-field matrices to calculate the focus location. Estimations instead of tissue conductivity measurements further deteriorate the precision of location tasks. In addition, time-resolved phase shifts are used to describe connectivity. We hypothesize that correlations over runtime approaches might be feasible to predict seizure foci with adequate precision. In a case study on EEG correlation in a healthy subject, we found repetitive periods of alternating high correlation in the short (20 ms) and long (300 ms) range. During these periods, a numerical determination of proportions of predominant latency and, newly established here, directionality is possible, which supports the identification of loops that, according to current opinion, manifest themselves in epileptic seizures. In the future, this latency and directionality analysis could support focus localization via dipole reconstruction using new triangulation calculations.

Front-back asymmetries in endogenous auditory spatial attention.

Research on endogenous auditory spatial attention typically uses headphones or sounds in the frontal hemispace, which undersamples panoramic spatial hearing. Crossmodal attention studies also show that visual information impacts spatial hearing and attention. Given the overlap between vision and audition in frontal space, we tested the hypothesis that the distribution of endogenous auditory spatial attention would differ when attending to the front versus back hemispace. Participants performed a non-spatial discrimination task where most sounds were presented at a standard location, but occasionally shifted to other locations. Auditory spatial attention cueing and gradient effects across locations were measured in five experiments. Accuracy was greatest at standard versus shift locations, and was comparable when attending to the front or back. Reaction time measures of cueing and gradient effects were larger when attending to the front versus back midline, a finding that was evident when the range of spatial locations was 180° or 360°. When participants were blindfolded, the front/back differences were still present. Sound localization and divided attention tasks showed that the front/back differences were attentional, rather than perceptual, in nature. Collectively, the findings reveal that the impact of endogenous auditory spatial attention depends on where attention is being focused.