Toward a universal decoder of linguistic meaning from brain activation.

Prior work decoding linguistic meaning from imaging data has been largely limited to concrete nouns, using similar stimuli for training and testing, from a relatively small number of semantic categories. Here we present a new approach for building a brain decoding system in which words and sentences are represented as vectors in a semantic space constructed from massive text corpora. By efficiently sampling this space to select training stimuli shown to subjects, we maximize the ability to generalize to new meanings from limited imaging data. To validate this approach, we train the system on imaging data of individual concepts, and show it can decode semantic vector representations from imaging data of sentences about a wide variety of both concrete and abstract topics from two separate datasets. These decoded representations are sufficiently detailed to distinguish even semantically similar sentences, and to capture the similarity structure of meaning relationships between sentences.

A comparative evaluation of off-the-shelf distributed semantic representations for modelling behavioural data.

In this paper we carry out an extensive comparison of many off-the-shelf distributed semantic vectors representations of words, for the purpose of making predictions about behavioural results or human annotations of data. In doing this comparison we also provide a guide for how vector similarity computations can be used to make such predictions, and introduce many resources available both in terms of datasets and of vector representations. Finally, we discuss the shortcomings of this approach and future research directions that might address them.

A TASER conducted electrical weapon with cardiac biomonitoring capability: Proof of concept and initial human trial.

INTRODUCTION: Despite research demonstrating the overall safety of Conducted Electrical Weapons (CEWs), commonly known by the brand name TASER(®), concerns remain regarding cardiac safety. The addition of cardiac biomonitoring capability to a CEW could prove useful and even lifesaving in the rare event of a medical crisis by detecting and analyzing cardiac rhythms during the period immediately after CEW discharge. OBJECTIVE: To combine an electrocardiogram (ECG) device with a CEW to detect and store ECG signals while still allowing the CEW to perform its primary function of delivering an incapacitating electrical discharge. METHODS: This work was performed in three phases. In Phase 1 standard law enforcement issue CEW cartridges were modified to demonstrate transmission of ECG signals. In Phase 2, a miniaturized ECG recorder was combined with a standard issue CEW and tested. In Phase 3, a prototype CEW with on-board cardiac biomonitoring was tested on human volunteers to assess its ability to perform its primary function of electrical incapacitation. RESULTS: Bench testing demonstrated that slightly modified CEW cartridge wires transmitted simulated ECG signals produced by an ECG rhythm generator and from a human volunteer. Ultimately, a modified CEW incorporating ECG monitoring successfully delivered incapacitating current to human volunteers and successfully recorded ECG signals from subcutaneous CEW probes after firing. CONCLUSION: An ECG recording device was successfully incorporated into a standard issue CEW without impeding the functioning of the device. This serves as proof-of-concept that safety measures such as cardiac biomonitoring can be incorporated into CEWs and possibly other law enforcement devices.

Tuning out the noise: cognitive biases.

In my brief training as an emergency physician, I have experienced numerous distracting cognitive biases that have interfered with establishing proper diagnoses. Recognizing these potential barriers and appreciating them is essential to excellent patient care.

Cor triatriatum with single atrium presenting in adulthood.

We present the case of an asymptomatic 21-year-old woman referred because of an abnormal routine electrocardiogram. Transthoracic and transesophageal echocardiography revealed a complete absence of the atrial septum, a common atrium septated posteriorly from the pulmonary venous chamber, a partial atrioventricular canal, a cleft mitral valve and a persistent left superior vena cava draining into an enlarged coronary sinus. These findings were confirmed during surgical correction. Our patient presented with an unusual and fascinating combination of congenital malformations that remained well tolerated and undiscovered into adulthood.