Automatic Assessment of Cognitive Tests for Differentiating Mild Cognitive Impairment: A Proof of Concept Study of the Digit Span Task.

BACKGROUND: Current conventional cognitive assessments are limited in their efficiency and sensitivity, often relying on a single score such as the total correct items. Typically, multiple features of response go uncaptured. OBJECTIVES: We aim to explore a new set of automatically derived features from the Digit Span (DS) task that address some of the drawbacks in the conventional scoring and are also useful for distinguishing subjects with Mild Cognitive Impairment (MCI) from those with intact cognition. METHODS: Audio-recordings of the DS tests administered to 85 subjects (22 MCI and 63 healthy controls, mean age 90.2 years) were transcribed using an Automatic Speech Recognition (ASR) system. Next, five correctness measures were generated from Levenshtein distance analysis of responses: number correct, incorrect, deleted, inserted, and substituted words compared to the test item. These per-item features were aggregated across all test items for both Forward Digit Span (FDS) and Backward Digit Span (BDS) tasks using summary statistical functions, constructing a global feature vector representing the detailed assessment of each subject's response. A support vector machine classifier distinguished MCI from cognitively intact participants. RESULTS: Conventional DS scores did not differentiate MCI participants from controls. The automated multi-feature DS-derived metric achieved 73% on AUC-ROC of the SVM classifier, independent of additional clinical features (77% when combined with demographic features of subjects); well above chance, 50%. CONCLUSION: Our analysis verifies the effectiveness of introduced measures, solely derived from the DS task, in the context of differentiating subjects with MCI from those with intact cognition.

Evaluation of a Patient-Collected Audio Audit and Feedback Quality Improvement Program on Clinician Attention to Patient Life Context and Health Care Costs in the Veterans Affairs Health Care System.

Importance: Evidence-based care plans can fail when they do not consider relevant patient life circumstances, termed contextual factors, such as a loss of social support or financial hardship. Preventing these contextual errors can reduce obstacles to effective care. Objective: To evaluate the effectiveness of a quality improvement program in which clinicians receive ongoing feedback on their attention to patient contextual factors. Design, Setting, and Participants: In this quality improvement study, patients at 6 Department of Veterans Affairs outpatient facilities audio recorded their primary care visits from May 2017 to May 2019. Encounters were analyzed using the Content Coding for Contextualization of Care (4C) method. A feedback intervention based on the 4C coded analysis was introduced using a stepped wedge design. In the 4C coding schema, clues that patients are struggling with contextual factors are termed contextual red flags (eg, sudden loss of control of a chronic condition), and a positive outcome is prospectively defined for each encounter as a quantifiable improvement of the contextual red flag. Data analysis was performed from May to October 2019. Interventions: Clinicians received feedback at 2 intensity levels on their attention to patient contextual factors and on predefined patient outcomes at 4 to 6 months. Main Outcomes and Measures: Contextual error rates, patient outcomes, and hospitalization rates and costs were measured. Results: The patients (mean age, 62.0 years; 92% male) recorded 4496 encounters with 666 clinicians. At baseline, clinicians addressed 413 of 618 contextual factors in their care plans (67%). After either standard or enhanced feedback, they addressed 1707 of 2367 contextual factors (72%), a significant difference (odds ratio, 1.3; 95% CI, 1.1-1.6; P = .01). In a mixed-effects logistic regression model, contextualized care planning was associated with a greater likelihood of improved outcomes (adjusted odds ratio, 2.5; 95% CI, 1.5-4.1; P < .001). In a budget analysis, estimated savings from avoided hospitalizations were $25.2 million (95% CI, $23.9-$26.6 million), at a cost of $337 242 for the intervention. Conclusions and Relevance: These findings suggest that patient-collected audio recordings of the medical encounter with feedback may enhance clinician attention to contextual factors, improve outcomes, and reduce hospitalizations. In addition, the intervention is associated with substantial cost savings.

Spontaneous trigger words associated with confirmed out-of-hospital cardiac arrest: a descriptive pilot study of emergency calls.

BACKGROUND: According to the International Liaison Committee on Resuscitation (ILCOR), the trigger words used by callers that are associated with cardiac arrest constitute a scientific knowledge gap. This study was designed to find hypothetical trigger words in emergency calls in order to improve the specificity of out-of-hospital cardiac arrest recognition. METHODS: In this descriptive pilot study conducted in a Finnish hospital district, linguistic contents of 80 emergency calls of dispatcher-suspected or EMS-encountered out-of-hospital cardiac arrests between January 1, 2017 and May 31, 2017 were analysed. Spontaneous trigger words used by callers were transcribed and grouped into 36 categories. The association between the spontaneous trigger words and confirmed true cardiac arrests was tested with logistic regression. RESULTS: Of the suspected cardiac arrests, 51 (64%) were confirmed as true cardiac arrests when ambulance personnel met the patient. A total of 291 spontaneous trigger words were analysed. 'Is not breathing' (n = 9 [18%] in the true cardiac arrest group vs n = 1 [3%] in the non-cardiac arrest group, odds ratio [OR] 6.00, 95% confidence interval [CI] 0.72-50.0), 'the patient is blue' (n = 9 [18%] vs n = 1 [3%], OR 6.00, 95% CI 0.72-50.0), 'collapsed or fallen down' (n = 12 [24%] vs n = 2 [7%], OR 4.15, 95% CI 0.86-20.1) and 'is wheezing' (n = 17 [33%] vs n = 5 [17%], OR 2.40, 95% CI 0.78-7.40) were frequently used to describe true cardiac arrest. 'Is snoring' was associated with a false suspicion of cardiac arrest (n = 1 [2%] vs n = 6 [21%], OR 0.08, 95% CI 0.009-0.67). CONCLUSIONS: In our pilot study, no trigger word was associated with confirmed cardiac arrest. 'Is wheezing' was a frequently used spontaneous trigger word among later confirmed cardiac arrest victims.

Automatic recording of individual oestrus vocalisation in group-housed dairy cattle: development of a cattle call monitor.

Oestrus detection remains a problem in the dairy cattle industry. Therefore, automatic detection systems have been developed to detect specific behavioural changes at oestrus. Vocal behaviour has not been considered in such automatic oestrus detection systems in cattle, though the vocalisation rate is known to increase during oestrus. The main challenge in using vocalisation to detect oestrus is correctly identifying the calling individual when animals are moving freely in large groups, as oestrus needs to be detected at an individual level. Therefore, we aimed to automate vocalisation recording and caller identification in group-housed dairy cows. This paper first presents the details of such a system and then presents the results of a pilot study validating its functionality, in which the automatic detection of calls from individual heifers was compared to video-based assessment of these calls by a trained human observer, a technique that has, until now, been considered the 'gold standard'. We developed a collar-based cattle call monitor (CCM) with structure-borne and airborne sound microphones and a recording unit and developed a postprocessing algorithm to identify the caller by matching the information from both microphones. Five group-housed heifers, each in the perioestrus or oestrus period, were equipped with a CCM prototype for 5 days. The recorded audio data were subsequently analysed and compared with audiovisual recordings. Overall, 1404 vocalisations from the focus heifers and 721 vocalisations from group mates were obtained. Vocalisations during collar changes or malfunctions of the CCM were omitted from the evaluation. The results showed that the CCM had a sensitivity of 87% and a specificity of 94%. The negative and positive predictive values were 80% and 96%, respectively. These results show that the detection of individual vocalisations and the correct identification of callers are possible, even in freely moving group-housed cattle. The results are promising for the future use of vocalisation in automatic oestrus detection systems.

Development of a measurement system for complex oral information transfer in medical consultations.

BACKGROUND: Information exchange between physician and patient is crucial to achieve patient involvement, shared decision making and treatment adherence. No reliable method exists for measuring how much information physicians provide in a complex, unscripted medical conversation, nor how much of this information patients recall. This study aims to fill this gap by developing a measurement system designed to compare complex orally provided information to patient recall. METHODS: The development of the complex information transfer measurement system required nine methodological steps. Core activities were data collection, definition of information units and the first draft of a codebook, refinement through independent coding and consensus, and reliability testing. Videotapes of physician-patient consultations based on a standardized scenario and post-consultation interviews with patients constituted the data. The codebook was developed from verbatim transcriptions of the videotapes. Inter-rater reliability was calculated using a random selection of 10% of the statements in the transcriptions. RESULTS: Thirtyfour transcriptions of visits and interviews were collected. We developed a set of rules for defining a single unit of information, defined detailed criteria for exclusion and inclusion of relevant units of information, and outlined systematic counting procedures. In the refinement phase, we established a system for comparing the information provided by the physician with what the patient recalled. While linguistic and conceptual issues arose during the process, coders still achieved good inter-rater reliability, with intra-class correlation for patient recall: 0.723, and for doctors: 0.761. A full codebook is available as an appendix. CONCLUSIONS: A measurement system specifically aimed at quantifying complex unscripted information exchange may be a useful addition to the tools for evaluating the results of health communication training and randomized controlled trials.

The short-term effects of recorded ocean sound with and without alpha frequency binaural beats on tinnitus perception.

BACKGROUND: The dichotic presentation of two auditory stimuli with a small frequency difference in each ear produces the perception of a third, fused auditory image called a binaural beat. Neural activity has been found to synchronize with these perceived beats. It is for this reason that binaural beats are often used in an attempt to induce certain psychological states that are associated with particular cortical rhythms. The aim of this proof-of-concept study was to explore the short-term effects of a binaural beat on tinnitus, to ascertain if further trials are justified. METHOD: Twenty adults with constant tinnitus and symmetrical hearing underwent audiological assessment and psychophysical measures of tinnitus. Participants were presented with two auditory stimuli: ocean waves with and without alpha frequency (8 Hz) binaural beats. Arousal and tinnitus perception were measured prior to and following each sound stimuli using the Perceived Arousal Scale and tinnitus rating scales. RESULTS: Small improvements in tinnitus rating scores occurred with sound. Some individuals showed more improvement with the binaural beats than ocean waves alone. CONCLUSION: The addition of binaural beats at 8 Hz to an ocean sound showed no significant group benefits above the ocean sound alone.

Benefits of a Home Treatment Program Using Guided Imagery Relaxation Based on Audio Recordings for People With Fibromyalgia.

Despite the plethora of treatments available for patients with fibromyalgia, there is insufficient evidence to date as to what the ideal treatment approach is. This study sought to determine the effectiveness of a home program of audio-recorded guided imagery relaxation on people with fibromyalgia. This experimental 8-week longitudinal trial design was undertaken with 60 people diagnosed with fibromyalgia who were randomly assigned to either a guided imagery intervention group or a control group. Pain at tender points, anxiety, self-efficacy, quality of sleep, quality of life, and the impact of the fibromyalgia were determined at baseline, at 4 weeks, and at 8 weeks. After the guided imagery intervention, we found significant differences regarding trait anxiety, sleep quality, and tenderness at some of the tender points. There is a need, therefore, to develop and evaluate interventions that may enhance the quality of life of those affected by this disorder.

Computational Analysis of Neonatal Mouse Ultrasonic Vocalization.

Neonatal vocalization is structurally altered in mouse models of autism spectrum disorder (ASD). Our published data showed that pup vocalization, under conditions of maternal separation, contains sequences whose alterations in a genetic mouse model of ASD impair social communication between pups and mothers. We describe details of a method which reveals the statistical structure of call sequences that are functionally critical for optimal maternal care. Entropy analysis determines the degree of non-random call sequencing. A Markov model determines the actual call sequences used by pups. Sparse partial least squares discriminant analysis (sPLS-DA) identifies call sequences that differentiate groups and reveals the degrees of individual variability in call sequences between groups. These three sets of analyses can be used to identify the otherwise hidden call structure that is altered in mouse models of developmental neuropsychiatric disorders, including not only autism but also schizophrenia. © 2018 by John Wiley & Sons, Inc.

The Most Common Feedback Themes in Communication Skills Training in an Internal Medicine Residency Program: Lessons from the Resident Audio-Recording Project.

Individualized structured feedback is an integral part of a resident's learning in communication skills. However, it is not clear what feedback residents receive for their communication skills development in real patient care. We will identify the most common feedback topics given to residents regarding communication skills during Internal Medicine residency training. We analyzed Resident Audio-recording Project feedback data from 2008 to 2013 by using a content analysis approach. Using open coding and an iterative categorization process, we identified 15 emerging themes for both positive and negative feedback. The most recurrent feedback topics were Patient education, Thoroughness, Organization, Questioning strategy, and Management. The residents were guided to improve their communication skills regarding Patient education, Thoroughness, Management, and Holistic exploration of patient's problem. Thoroughness and Communication intelligibility were newly identified themes that were rarely discussed in existing frameworks. Assessment rubrics serve as a lens through which we assess the adequacy of the residents' communication skills. Rather than sticking to a specific rubric, we chose to let the rubric evolve through our experience.

The Role of Primary Care Providers in Encouraging Older Patients to Change Their Lifestyle Behaviors.

OBJECTIVES: This study sought to identify older patients' perceptions of primary care providers' influence on their likelihood of improving diet and physical activity. METHODS: 104 adults ages 65 and older were interviewed immediately following a routine primary care visit about their plans and motivations for behavior change and how their clinic visit would influence their likelihood of making lifestyle changes. All interviews were recorded, transcribed and analyzed using a constant comparison approach. RESULTS: Participants reported that their providers influence their health behaviors by developing strong relationships, addressing concerns and encouraging change, and providing concrete instruction. When providers did not discuss diet or physical activity, or mentioned these topics only briefly, participants often perceived the message that they should continue their current behaviors. CONCLUSIONS: Whether and how diet and physical activity are discussed in primary care influences the likelihood that older adults will make changes in these behaviors. CLINICAL IMPLICATIONS: These findings highlight the need for a patient-centered counseling approach and caution providers to think twice before omitting discussion of the need for lifestyle change.

Pediatrician-Parent Conversations About Human Papillomavirus Vaccination: An Analysis of Audio Recordings.

PURPOSE: We sought to establish which human papillomavirus (HPV) vaccine communication approaches by pediatricians were associated with same-day HPV vaccination of 11- to 12-year-olds by evaluating audio recordings of visits. METHODS: Verilogue, a market research company maintaining a panel of primary care pediatricians, provided audio recordings and transcriptions of well-child visits for 11- to 12-year-old patients from January through June 2013. Seventy-five transcripts from 19 pediatricians were coded for use of presumptive language (i.e., words conveying assumption of vaccine delivery), offer of delay, recommendation strength, and information provision. Using logistic regression, we evaluated the association between pediatrician communication approaches and agreement to same-day HPV vaccination. Generalized estimating equations accounted for clustering of patients within pediatricians. RESULTS: Same-day agreement to HPV vaccination occurred in 29% of encounters. Pediatricians in the sample often provided parents with inconsistent, mixed messages and sometimes offered information about HPV or HPV vaccination that was inaccurate. Pediatricians used presumptive language in only 11 of 75 encounters; when used, presumptive language was associated with higher odds of accepting HPV vaccine (73% vs. 22%; odds ratio = 8.96; 95% confidence interval = 2.32-34.70). Pediatricians offered or recommended delay in most encounters (65%). HPV vaccine acceptance occurred far more often when pediatricians did not mention delaying vaccination (82% vs. 6%; odds ratio = 80.84; 95% confidence interval = 15.72-415.67). Same-day vaccination was not associated with strength of recommendation or pediatrician reference to vaccinating their own children. CONCLUSIONS: Our findings highlight the need to develop and evaluate physician-focused trainings on using presumptive language for same-day HPV vaccination.

Standardized Direct Observation Assessment Tool: Using a Training Video.

BACKGROUND: We developed a DVD training tool to educate physicians evaluating emergency residents on accurate Standardized Direct Observation Assessment Tool (SDOT) application. OBJECTIVE: Our goal was to assess whether this training video improved attendings' and senior residents' SDOT use. METHODS: Participants voluntarily completed SDOT evaluations based on a scripted "test" video. A DVD with "positive" and "negative" scenarios of proper SDOT use was viewed. It included education on appropriate recording of 26 behaviors. The test scenario was viewed again and follow-up SDOTs submitted. Performances by attendings and residents on the pre- and post-test SDOTs were compared. RESULTS: Twenty-six attendings and 26 senior residents participated. Prior SDOT experience was noted for 8 attendings and 11 residents. For 20 anchors, participants recorded observed behaviors with statistically significant difference on one each of the pretest (no. 20; p = 0.034) and post-test (no. 14; p = 0.041) SDOTs. On global competency assessments, pretest medical knowledge (p = 0.016) differed significantly between groups. The training intervention changed one anchor (no. 5; p = 0.035) and one global assessment (systems-based practice; p = 0.031) more negatively for residents. Recording SDOTs with exact agreement occurred 48.73% for attendings pretest and 54.41% post-test; resident scores were 45.86% and 49.55%, respectively. DVD exposure slightly raised attending scores (p = 0.289) and significantly lowered resident scores (p = 0.046). CONCLUSIONS: Exposure to an independently developed SDOT training video tended to raise attending scores, though without significance, while at the same time lowered senior resident scores statistically significantly. Emergency attendings' and senior residents' SDOT scoring rarely differed with significance; about half of anchor behaviors were recorded with exact agreement. This suggests senior residents, with appropriate education, may participate in SDOT assessment.

Expanding the first link in the chain of survival - Experiences from dispatcher referral of callers to AED locations.

INTRODUCTION: Early use of automated external defibrillators (AED) increases survival in cases of out-of-hospital cardiac arrest (OHCA). Dispatchers play important roles in identifying OHCA, dispatching ambulances and providing callers with telephone-assisted cardiopulmonary resuscitation. Guidelines recommend that AED registries be linked to dispatch centres as tools to refer callers to nearby AED. AIM: The aim of this study was to investigate to what extent dispatchers, when provided with a tool to display AED locations and accessibility, referred callers to nearby AED. METHODS: An application providing real-time visualization of AED locations and accessibility was implemented at four dispatch centres in Sweden. Dispatchers were instructed to refer callers to nearby AED when OHCA was suspected. Such cases were prospectively collected, and geographic information systems were used to identify those located ≤100m from an AED. Audio recordings of emergency calls were assessed to evaluate the AED referral rate. RESULTS: Between February and August 2014, 3009 suspected OHCA calls were received. In 6.6% of those calls (200/3009), an AED was ≤100m from the suspected OHCA. The AED was accessible and the caller was not alone on scene in 24% (47/200) of these cases. In two of those 47 cases (4.3%), the dispatcher referred the caller to the AED. CONCLUSION: Despite a tool for dispatchers to refer callers to a nearby AED, referral was rare. Only a minority of the suspected OHCA cases occurred ≤100m from an AED. We identified AED accessibility and callers being alone on scene as obstacles for AED referral.

Provider Recommendations in the Face of Scientific Uncertainty: An Analysis of Audio-Recorded Discussions about Vitamin D.

BACKGROUND: Little is known about how providers communicate recommendations when scientific uncertainty exists. OBJECTIVES: To compare provider recommendations to those in the scientific literature, with a focus on whether uncertainty was communicated. DESIGN: Qualitative (inductive systematic content analysis) and quantitative analysis of previously collected audio-recorded provider-patient office visits. PARTICIPANTS: Sixty-one providers and a socio-economically diverse convenience sample of 603 of their patients from outpatient community- and academic-based primary care, integrative medicine, and complementary and alternative medicine provider offices in Southern California. MAIN MEASURES: Comparison of provider information-giving about vitamin D to professional guidelines and scientific information for which conflicting recommendations or insufficient scientific evidence exists; certainty with which information was conveyed. RESULTS: Ninety-two (15.3 %) of 603 visit discussions touched upon issues related to vitamin D testing, management and benefits. Vitamin D deficiency screening was discussed with 23 (25 %) patients, the definition of vitamin D deficiency with 21 (22.8 %), the optimal range for vitamin D levels with 26 (28.3 %), vitamin D supplementation dosing with 50 (54.3 %), and benefits of supplementation with 46 (50 %). For each of the professional guidelines/scientific information examined, providers conveyed information that deviated from professional guidelines and the existing scientific evidence. Of 166 statements made about vitamin D in this study, providers conveyed 160 (96.4 %) with certainty, without mention of any equivocal or contradictory evidence in the scientific literature. No uncertainty was mentioned when vitamin D dosing was discussed, even when recommended dosing was higher than guideline recommendations. CONCLUSIONS AND RELEVANCE: Providers convey the vast majority of information and recommendations about vitamin D with certainty, even though the scientific literature contains inconsistent recommendations and declarations of inadequate evidence. Not communicating uncertainty blurs the contrast between evidence-based recommendations and those without evidence. Providers should explore best practices for involving patients in decision-making by acknowledging the uncertainty behind their recommendations.

Digital Audio Recording of Initial Patient Visits to an Ocular Oncology Clinic: A Pilot Study.

It is challenging for patients to receive a new diagnosis of a life-threatening ocular tumor when visiting an ocular oncology clinic for the first time. Audio recording of patient-physician interactions has been shown to be an effective memory aid and stress-reducing technique for patients with various types of nonophthalmic cancer. This study evaluated a protocol for digitally recording the initial conversation between the ocular oncologist and the patient. Twenty patients were enrolled in the study, and 13 patients (65%) returned the survey. All of the patients who returned the survey reported being "very satisfied" with the audio recording, indicating that patients with a newly diagnosed ocular tumor were highly satisfied with the audio recording of their conversations with the ocular oncologist. Although larger studies are needed to confirm this conclusion, the initial results are encouraging.

Spying on small wildlife sounds using affordable collar-mounted miniature microphones: an innovative method to record individual daylong vocalisations in chipmunks.

Technological advances can greatly benefit the scientific community by making new areas of research accessible. The study of animal vocal communication, in particular, can gain new insights and knowledge from technological improvements in recording equipment. Our comprehension of the acoustic signals emitted by animals would be greatly improved if we could continuously track the daily natural emissions of individuals in the wild, especially in the context of integrating individual variation into evolutionary ecology research questions. We show here how this can be accomplished using an operational tiny audio recorder that can easily be fitted as an on-board acoustic data-logger on small free-ranging animals. The high-quality 24 h acoustic recording logged on the spy microphone device allowed us to very efficiently collect daylong chipmunk vocalisations, giving us much more detailed data than the classical use of a directional microphone over an entire field season. The recordings also allowed us to monitor individual activity patterns and record incredibly long resting heart rates, and to identify self-scratching events and even whining from pre-emerging pups in their maternal burrow.

Breath-by-breath detection of apneic events for OSA severity estimation using non-contact audio recordings.

Obstructive sleep apnea (OSA) is a prevalent sleep disorder, characterized by recurrent episodes of upper airway obstructions during sleep. We hypothesize that breath-by-breath audio analysis of the respiratory cycle (i.e., inspiration and expiration phases) during sleep can reliably estimate the apnea hypopnea index (AHI), a measure of OSA severity. The AHI is calculated as the average number of apnea (A)/hypopnea (H) events per hour of sleep. Audio signals recordings of 186 adults referred to OSA diagnosis were acquired in-laboratory and at-home conditions during polysomnography and WatchPat study, respectively. A/H events were automatically segmented and classified using a binary random forest classifier. Total accuracy rate of 86.3% and an agreement of κ=42.98% were achieved in A/H event detection. Correlation of r=0.87 (r=0.74), diagnostic agreement of 76% (81.7%), and average absolute difference AHI error of 7.4 (7.8) (events/hour) were achieved in in-laboratory (at-home) conditions, respectively. Here we provide evidence that A/H events can be reliably detected at their exact time locations during sleep using non-contact audio approach. This study highlights the potential of this approach to reliably evaluate AHI in at home conditions.

Out-of-hospital cardiac arrest phone detection: those who most need chest compressions are the most difficult to recognize.

UNLABELLED: Dispatcher-assisted cardiopulmonary resuscitation increases the likelihood of survival and thus is highly recommended. However, the detection rate of out-of-hospital cardiac arrest (OHCA) is very different from one system to another, and early recognition of cardiac arrest in the dispatch centre remains challenging. The aim of this study was to assess the provision of dispatcher-assisted cardiopulmonary resuscitation in the main French dispatch centre. METHODS: In the Paris Fire Brigade, each patient over 15 years of age who presented an OHCA from 15 to 31 May 2012 was prospectively included. Field data and tape recordings of emergency calls were studied by three experienced physicians, to assess the rate (and delay) of OHCA recognition and chest compression initiation, and identify the causes of unrecognized OHCA. RESULTS: Among 82 consecutive calls for detectable cardiac arrest, the dispatcher recognized 50/82 (61%). The median times from call to OHCA recognition and from call to chest compression initiation were, respectively, 2 min 23s (1 min 51 s to 3 min 7s) and 3 min 37s (2 min 57 s to 5 min). The main causes of non-recognition of OHCA were the absence or incomplete assessment of breathing and the presence of agonal breathing. No cardiac arrest was missed when the dispatcher followed the local dispatch algorithm; this included the gesture of putting the hand on the abdomen and measuring the breathing frequency. Hospital admission with a beating heart was paradoxically 18% for detected cardiac arrest and 47% for undetected cardiac arrest (p=0.007). This paradox could be explained by the relation between agonal breathing and, on the one hand, good prognosis of OHCA and, on the other hand, difficulties in recognizing OHCA. CONCLUSION: The improvement of cardiac arrest recognition in the dispatch centre seemed mandatory, as the cardiac arrests of better immediate prognosis were not well detected. The measurement of OHCA recognition and CPR initiation by phone should be encouraged in dispatch centres as a key to initiating corrective measures.

In vivo recording of single-unit activity during singing in zebra finches.

The zebra finch is an important model for investigating the neural mechanisms that underlie vocal production and learning. Previous anatomical and gene expression studies have identified an interconnected set of brain areas in this organism that are important for singing. To advance our understanding of how these various brain areas act together to learn and produce a highly stereotyped song, it is necessary to record the activity of individual neurons during singing. Here, we present a protocol for recording single-unit activity in freely moving zebra finches during singing using a miniature, motorized microdrive. It includes procedures for both the microdrive implant surgery and the electrophysiological recordings. There are several advantages of this technique: (1) high-impedance electrodes can be used in the microdrive to obtain well-isolated single units; (2) a motorized microdrive is used to remotely control the electrode position, allowing neurons to be isolated without handling the bird, and (3) a lateral positioner is used to move electrodes into fresh tissue before each penetration, allowing recordings from well-isolated neurons over the course of several weeks. We also describe the application of the antidromic stimulation and the spike collision test to identify neurons based on the axonal projection patterns.