Pop vs rock: A comparison study of managing sessions in the recording studio and the influences of genre

This study examined the recording session management approaches of two music producers, Phil Harding and Greg Haver, to ascertain if and how their different approaches impact the outcomes of music production projects. Semi-structured interviews were conducted with each producer to gain insight into their approaches generally, and also, as a point of comparison, their work on the educational Gus Dudgeon Foundation/Joint Audio Media Education Support (GDF/JAMES) summer recording sessions specifically. Thematic analyses of the interviews revealed that the producers’ respective approaches are influenced by the genres in which each predominantly works. Harding, a pop producer, is very systematic. Haver, who is better known for his work in rock, uses an organic approach. Consequently, there were some clear differences in their decision making and organizational strategies at the GDF/JAMES sessions. The producers used different criteria to choose a project/artist. Each used distinctive approaches in pre-production (i.e. work on song arrangements and other technical musical decisions), production (recording) and mixing. Still, both produced pop recordings that largely conform to pop norms. Both recordings have similar pop arrangements and meet commercial standards. Findings provide new understanding of session management techniques that can benefit both music production education and practitioners.

Evaluation and resolution of many challenges of neural spike-sorting: a new sorter

We evaluate existing spike sorters and present a new one that resolves many sorting challenges. The new sorter, called "full binary pursuit" or FBP, comprises multiple steps. First, it thresholds and clusters to identify the waveforms of all unique neurons in the recording. Second, it uses greedy binary pursuit to optimally assign all the spike events in the original voltages to separable neurons. Third, it resolves spike events that are described more accurately as the superposition of spikes from two other neurons. Fourth, it resolves situations where the recorded neurons drift in amplitude or across electrode contacts during a long recording session. Comparison with other sorters on ground-truth datasets reveals many of the failure modes of spike sorting. We examine overall spike sorter performance in ground-truth datasets and suggest post-sorting analyses that can improve the veracity of neural analyses by minimizing the intrusion of failure modes into analysis and interpretation of neural data. Our analysis reveals the tradeoff between the number of channels a sorter can process, speed of sorting, and some of the failure modes of spike sorting. FBP works best on data from 32 channels or fewer. It trades speed and number of channels for avoidance of specific failure modes that would be challenges for some use cases. We conclude that all spike sorting algorithms studied have advantages and shortcomings, and the appropriate use of a spike sorter requires a detailed assessment of the data being sorted and the experimental goals for analyses.

Ensemble interaction in indeterminate music

Examining ensemble interaction in the music of experimental composer Christian Wolff, this chapter uses as a case study a professional recording session undertaken by the ensemble Apartment House of <em>Exercises</em> (1973–2013), a series of pieces for (mostly) unspecified instrumentation and numbers of players. Wolff’s skeletal notation is deliberately under-determined, acting like something of a puzzle to be solved. Consequently, the players must negotiate a way of working with the notation and with each other, making decisions prior to, and during, the moment of performance. Drawing on interviews and observational studies, the chapter identifies three different forms of interaction in the musicians’ playing as they engaged with Wolff’s notation: working responsively, independently, and emergently. The chapter offers a view of ensemble interaction that is characterized by cooperation, but also uncertainty, surprise, or even complete breakdown.

Interrater and Intrarater Reliability of Electrical Impedance Myography: A Comparison between Large and Small Handheld Electrode Arrays

The objective of this study was to evaluate the interrater and intrarater reliability of electrical impedance myography (EIM) using handheld sensors of different sizes. Electrical impedance myography of the biceps brachii muscle of twenty healthy individuals was performed by two raters using both large and small sensors. The procedures were also repeated 5 to 8 days after the first recording session. The repeatability of the resistance, reactance, and phase angle at two different current frequencies (50 and 100 kHz) was assessed by the intraclass correlation coefficient (ICC). The ICCs of the large sensor were higher than those of the small sensor for both the intrarater and interrater reliabilities. High-frequency current tended to improve the ICC for the small sensor. These results indicate reasonable repeatability of the handheld electrode arrays for EIM measurements. The findings suggest that electrode array should be selected appropriately according to the size of the tested muscle.

Guidelines for the Measurement of Rein Tension in Equestrian Sport

Rein tension is relatively easy to measure, and the resulting data are useful for evaluating the interaction between horse and rider. To date, there have been a number of studies using different transducers, calibration methods and analytical techniques. The purpose of this paper is to make recommendations regarding the collection, analysis and reporting of rein tension data. The goal is to assist users in selecting appropriate equipment, choosing verified methods of calibration, data collection and analysis, and reporting their results consistently to facilitate comparisons between different studies. Sensors should have a suitable range and resolution together with a fast enough dynamic response, according to the gait, speed and type of riding for which they will be used. An appropriate calibration procedure is necessary before each recording session. A recording frequency of 50 Hz is adequate for most rein tension studies. The data may be analyzed using time-series methods or by extracting and analyzing discrete variables chosen in accordance with the study objectives. Consistent reporting facilitates comparisons between studies.

EEG-Based Focus Estimation Using Neurable's Enten Headphones and Analytics Platform

We introduce Neurable's research on focus using our recently developed Enten EEG headphones. First we quantify Enten's performance on standard EEG protocols, including eyes-closed alpha rhythms, auditory evoked response and the P300 event-related potential paradigm. We show that Enten's performance is on-par with established industry-standard hardware. We then introduce a series of experimental tasks designed to mimic how focus might be maintained or disrupted in a real-world office setting. We show that (A) these tasks induce behavioral changes that reflect underlying changes in focus levels and (B) our proprietary algorithm detects these changes across a large number of sessions without needing to adjust the model per participant or recording session. Through manipulation of our experimental protocol, we show that our algorithm is not dependent on gross EMG artifacts and it is driven by changes in EEG. Finally, we evaluated the model's performance on the same subject across several days, and show that performance remained consistent over time. Our model correctly captured 80% ± 4.1% of distractions present in our experiments with statistical significance. This indicates that our model generalizes across subjects, time points, and conditions. Our findings are based on EEG data collected from 132 participants across 337 sessions and 45 different experiments.

Consistent population activity on the scale of minutes in the mouse hippocampus

Neurons in the hippocampus fire in consistent sequence over the timescale of seconds during the delay period of some memory experiments. For longer timescales, firing of hippocampal neurons also changes slowly over minutes within experimental sessions. It was thought that these slow dynamics are caused by stochastic drift or a continuous change in the representation of the episode, rather than consistent sequences unfolding over minutes. This paper studies the consistency of contextual drift in three chronic calcium imaging recordings from the hippocampus CA1 region in mice. Computational measures of consistency show reliable sequences within experimental trials at the scale of seconds as one would expect from time cells or place cells during the trial, as well as across experimental trials on the scale of minutes within a recording session. Consistent sequences in the hippocampus are observed over a wide range of time scales, from seconds to minutes. Hippocampal activity could reflect a scale-invariant spatiotemporal context as suggested by theories of memory from cognitive psychology.

Evaluation and resolution of many challenges of neural spike-sorting: a new sorter

We evaluate existing spike sorters and present a new one that resolves many sorting challenges. The new sorter, called “full binary pursuit” or FBP, comprises multiple steps. First, it thresholds and clusters to identify the waveforms of all unique neurons in the recording. Second, it uses greedy binary pursuit to optimally recognize the spike events in the original voltages. Third, it resolves spike events that are described more accurately as the superposition of spikes from two other neurons. Fourth, it resolves situations where the recorded neurons drift in amplitude or across electrode contacts during a long recording session. Comparison with other sorters on real and simulated ground-truth datasets reveals many of the failure modes of spike sorters. We suggest a set of post-sorting analyses that can improve the veracity of neural recordings by minimizing the intrusion of those failure modes into analysis and interpretation of neural data.

Reliability of the Soleus H-Reflex in Different Sitting Postures

The Soleus (SOL) Hoffmann reflex (H-reflex) is commonly recorded in sitting position. However, the reliability of recording is unknown. We assessed the reliability of SOL H-reflex amplitude measurements across multiple traces and sessions during erect, slumped, and slouched sitting postures using the generalizability theory. Five traces of the SOL H-reflex maximum amplitude (Hmax) were recorded from 10 healthy participants during erect, slumped, and slouched sitting postures in two sessions. A decision study analysis was then conducted to calculate the reliability coefficients of the Hmax for five traces and two sessions and to mathematically calculate the coefficients for seven and ten traces, and one and three sessions in the three sitting postures. For five traces and two sessions, the results showed reliability coefficients between 0.970 and 0.971, 0.980 and 0.979, and equal to 0.943 for erect, slumped, and slouched sitting, respectively. Averaging five traces of the Hmax in a single recording session was sufficient to obtain acceptable reliability in the three sitting postures (reliability range, 0.892–0.988). It was concluded that the SOL Hmax can be recorded during erect, slumped, and slouched sitting postures with adequate reliability.

Head-direction coding in the hippocampal formation of birds

Birds strongly rely on spatial memory and navigation. However, it is unknown how space is represented in the avian brain. Here we used tetrodes to record neurons from the hippocampal formation (HPF) of Japanese quails – a migratory ground-dwelling species – while the quails roamed a 1×1-meter arena (>2,100 neurons from 21 birds). Whereas spatially-modulated cells (place-cells, border-cells, etc.) were generally not encountered, the firing-rate of 12% of the neurons was unimodally and significantly modulated by the head-azimuth – i.e. these were head-direction cells (HD cells, n=260). Typically, HD cells were maximally active at one preferred-direction and minimally at the opposite null-direction, with preferred-directions spanning all 360°. The HD tuning was relatively broad (mean= 130°), independent of the animal’s position and speed, and was stable during the recording-session. These findings support the existence of an allocentric head-direction representation in the quail HPF, and provide the first demonstration of head-direction cells in birds.