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PubMed1997

Automatic versus controlled semantic priming in schizophrenia.

Schizophrenic individuals (n = 31), including paranoid and nonparanoid diagnostic subgroups, and normal controls (n = 20) participated in a semantic priming experiment involving a single-choice lexical decision task. For the automatic priming blocks, a 260-ms stimulus onset asynchrony (SOA) was used; for the controlled priming blocks, 1,000-ms SOA was used. The paranoid subgroup showed significantly less priming than did the control group. The nonparanoid subgroup showed a decrease in priming compared with the control group that approached significance. There was an increased priming effect for the controlled compared with the automatic priming condition; this difference was not modulated by participant group. Nonsignificant semantic priming (equal to 0) occurred only for schizophrenic subgroups and only in automatic priming conditions.

Adult↗
PubMed1999

Alcohol effects on intentional behavior: dissociating controlled and automatic influences.

This research examined the effect of alcohol on intentional behavior using a process dissociation procedure to separate the influences of conscious controlled processes from those of unconscious automatic processes. In 2 identical experiments, 24 male social drinkers studied a list of words before they received either 0.56 g/kg alcohol, an alcohol placebo, or soda. Participants then performed a word stem completion test that provided estimates of controlled influences and of automatic influences on their responses. The results of the 2 experiments were consistent. Comparisons among the treatments showed that alcohol reduced conscious controlled processes and left automatic processes unchanged. The findings contribute to understanding how the drug may reduce cognitive control of intentional behavior and raise important questions concerning personal and environmental factors that might mediate these effects.

Adult↗
PubMed2000

Beyond behaviorism: on the automaticity of higher mental processes.

The first 100 years of experimental psychology were dominated by 2 major schools of thought: behaviorism and cognitive science. Here the authors consider the common philosophical commitment to determinism by both schools, and how the radical behaviorists' thesis of the determined nature of higher mental processes is being pursued today in social cognition research on automaticity. In harmony with "dual process" models in contemporary cognitive science, which equate determined processes with those that are automatic and which require no intervening conscious choice or guidance, as opposed to "controlled" processes which do, the social cognition research on the automaticity of higher mental processes provides compelling evidence for the determinism of those processes. This research has revealed that social interaction, evaluation and judgment, and the operation of internal goal structures can all proceed without the intervention of conscious acts of will and guidance of the process.

Animals↗
PubMed1999

Rapid estimation of the accuracy of automatic blood pressure measuring devices (READ).

We propose a rapid method for the evaluation of automatic blood pressure measurement devices (READ) in response to the claim to simplify the validation of those devices. The READ is based on numerous blood pressure (BP) measurements at rest and during a standardised postural challenge in a small number of subjects who exhibit a wide range of BPs. Automatic (AU) and mercury sphygmomanometric (MS) brachial BP were measured simultaneously in a blinded manner. An average of 30 measurements per patient were done in 10-min while in a supine position, followed by 30 min in head-up tilt and again supine for 10 min. Two Collin-8800 automated oscillometric devices were tested with the aid of the READ in 15 adults. The consistency of the MS standard was demonstrated by duplicate MS measurements showing minimal inter-observer differences consistent with class A of the British Hypertension Society (BHS) grading system. AU-to-MS differences of 447 measurements were mean systolic deltaBP = 1.1 +/- 11.4 mm Hg and mean diastolic deltaBP = -13.36 +/- 8.9 mm Hg, classifying into category D of the BHS. Both tested instruments, each subject, each phase of the tilt test (supine I, tilt, supine II) and each mode of measurement (at 5-min intervals or continuously) equally qualified as 'D'. We conclude that the READ permitted us to identify quickly and at low expense a grossly inaccurate automatic BP measuring device. Further studies will show whether the READ can be efficient as a pre-validation test, post-validation test, and for assessment of ambulatory BP measuring devices.

Adult↗
PubMed2001

Two novel procedures for automatic resolution of two-way data from coupled chromatography.

In order to deal with the problem of simultaneous qualitative and quantitative analysis of the complicated samples in analytical chemistry, two novel procedures for automatic resolution of two-way data from coupled chromatography were developed in this work. The first can be used to determine automatically the number of components involved in a certain peak cluster. The second method is an iterative resolution procedure named the stepwise key spectrum selection which has also been developed to resolve automatically the spectra and chromatographic profiles of every component in the peak cluster investigated. The results obtained from simulated and real data show that the proposed methods perform fairly well.

Journal Article↗
PubMed1997

Development of a two-stage procedure for the automatic recognition of dysfluencies in the speech of children who stutter: II. ANN recognition of repetitions and prolongations with supplied word segment markers.

This program of work is intended to develop automatic recognition procedures to locate and assess stuttered dysfluencies. This and the preceding article focus on developing and testing recognizers for repetitions and prolongations in stuttered speech. The automatic recognizers classify the speech in two stages: In the first the speech is segmented and in the second the segments are categorized. The units segmented are words. The current article describes results for an automatic recognizer intended to classify words as fluent or containing a repetition or prolongation in a text read by children who stutter that contained the three types of words alone. Word segmentations are supplied and the classifier is an artificial neural network (ANN). Classification performance was assessed on material that was not used for training. Correct performance occurred when the ANN placed a word into the same category as the human judge whose material was used to train the ANNs. The best ANN correctly classified 95% of fluent, and 78% of dysfluent words in the test material.

Adolescent↗
PubMed2000

Automatic image acquisition, calibration and montage assembly for biological X-ray microscopy.

We describe a system for the automatic acquisition and processing of digital images in a high-resolution X-ray microscope, including the formation of large-field high-resolution image montages. A computer-controlled sample positioning stage provides approximate coordinates for each high-resolution subimage. Individual subimages are corrected to compensate for time-varying, non-uniform illumination and CCD-related artefacts. They are then automatically assembled into a montage. The montage assembly algorithm is designed to use the overlap between each subimage and multiple neighbours to improve the performance of the registration step and the fidelity of the result. This is accomplished by explicit use of recorded stage positions, optimized ordering of subimage insertion, and registration of subimages to the developing montage. Using this procedure registration errors are below the resolution limit of the microscope (43 nm). The image produced is a seamless, large-field montage at full resolution, assembled automatically without human intervention. Beyond this, it is also an accurate X-ray transmission map that allows the quantitative measurement of anatomical and chemical features of the sample. Applying these tools to a biological problem, we have conducted the largest X-ray microscopical study to date.

Animals↗
PubMed2002

Frequent and prolonged asymptomatic episodes of paroxysmal atrial fibrillation revealed by automatic long-term event recorders in patients with a negative 24-hour Holter.

The presence, frequency, and duration of episodes of paroxysmal atrial fibrillation (PAF) is difficult to establish. This is caused by the limited duration of standard Holter recordings and to the unsatisfactory yield of patient-triggered event recorders, because of asymptomatic events and of an inconsistent use of the patient dependent triggering function. A prospective cohort of 65 consecutive patients with recurrent palpitations and a negative 24-hour ECG Holter was investigated by means of a cardiac event recorder bearing continuous automatic arrhythmia analysis and storage. Over a mean duration of 77 +/- 36 hours, episodes of PAF were diagnosed in 20 (31%) patients, who had a total of 37 episodes; mean duration of PAF episodes was 7 hours 50 minutes +/- 8/hours 45 minutes (minimum 45 minutes, maximum 28 hours). Eleven (55%) of these 20 patients were asymptomatic and would have remained undiagnosed without the automatic mode of the event recorder. Asymptomatic PAF episodes were longer than symptomatic ones (10 hours 30 minutes +/- 6 hours 30 minutes vs 4 hours 50 minutes +/- 4 hours, P < 0.05). In addition, episodes of sustained paroxysmal supraventricular tachycardia (PSVT) were diagnosed in 39 (57%) patients, of whom 34 (87%) were symptomatic. In this prospective cohort, a second standard 24-hour monitoring would have missed 44% of the patients with PAF or PSVT and a classical patient-triggered event recorder 13%. In patients still complaining of palpitations after one negative 24-hour Holter, numerous, prolonged, and often asymptomatic episodes of PAF can be revealed by long-term automatic event recorders. These devices should help clarify the clinical consequences of such episodes.

Atrial Fibrillation↗
PubMed2003

Automatic sensor algorithms expedite pacemaker follow-ups.

OBJECTIVE: Automatic algorithms can be used to optimize settings and reduce the duration of pacemaker (PM) clinical follow-up. METHODS: This study prospectively evaluated 87 patients (74.2 +/- 10.7 years old, 52% men) who received PM with the Autoslope algorithm. Patients randomized to the manual group (group M, n = 43) performed a walk test and used sensor-indicated rate histograms to adjust the sensor, while in the automatic group (group A, n = 44) the sensor was automatically adjusted by the Autoslope. The patients were followed for 6 months. Follow-up time required for device interrogation and optimal sensor set-up, and the number of sensor parameters reprogramming were recorded. Changes in the patients' activity level were also evaluated. RESULTS: Group A required significantly less follow-up time than group M (9.4 +/- 5.7 min vs 13.5 +/- 8.5 min, P = 0.0002). The average number of sensor parameters reprogrammed during visits was significantly lower in group A than M (0.6 +/- 0.9 vs 0.9 +/- 1.3, P = 0.048). Threshold was adjusted 34.4% of the time in the sensor evaluations in group M versus 12.9% in group A (P = 0.0004). Although more patients in group A reported being more active, the changes in patients' activity level did not lead to increasing sensor setup time or number of parameter reprogramming in either group. CONCLUSIONS: Auto sensor adjustment required less time during routine PM clinical follow-up by reducing steps needed for manual sensor threshold adjustment.

Aged↗
PubMed2001

Electrocardiographic analysis of ectopic atrial activity obscured by ventricular repolarization: P wave isolation using an automatic 62-lead QRST subtraction algorithm.

INTRODUCTION: Atrial activity on the surface ECG during premature beats and supraventricular arrhythmias frequently is obscured by the superimposed QRST complex of the previous cardiac cycle. This study examines the performance of a newly developed automatic QRST subtraction algorithm to isolate ectopic P waves from the preceding T-U wave. METHODS AND RESULTS: The 62-lead ECG recordings were obtained during (1) sinus rhythm and programmed right atrial stimulation in 12 patients (group A); and (2) sinus rhythm and atrial premature beats, atrial tachycardia, or paroxysmal atrial fibrillation in 5 patients (group B). Pacing in group A patients was conducted at a slow drive cycle length to generate an ectopic P wave not obscured by the previous QRST complex and by delivering single premature extrastimuli at progressively shorter coupling intervals to produce an ectopic P wave obscured by the upsloping (early T-U wave), peak (middle T-U wave), and downsloping component of the T-U wave (late T-U wave). All ectopic P waves in group B patients were concealed by the preceding T-U wave. Automatic QRST subtraction was attained using an adaptive template constructed from averaged QRST complexes (mean 83 +/- 25 complexes) obtained during sinus rhythm (groups A and B) or atrial overdrive pacing (group A). P wave integral maps subsequently were computed, visually compared, and mathematically correlated. A high correspondence in spatial map pattern was observed between integral maps of "nonobscured" and previously "obscured" paced P waves obtained in group A patients (mean r = 0.88 +/- 0.07) as well as between integral maps of two to three previously obscured P waves with the same atrial arrhythmia morphology obtained in group B patients (mean r = 0.94 +/- 0.05). Improved morphologic P wave replication in group A patients was acquired when concealment occurred in the early (mean r = 0.90 +/- 0.08) or late part of the T-U wave (mean r = 0.90 +/- 0.06) as opposed to the middle T-U wave (mean r = 0.85 +/- 0.07) (P = NS and P < 0.05 for early vs middle and late vs middle T-U wave, respectively). CONCLUSION: This novel automatic 62-lead QRST subtraction algorithm enables discrete isolation of T-U wave obscured ectopic atrial activity on the surface ECG while retaining the intricate spatial detail in P wave morphology. Future clinical application of the algorithm may enable improved ECG localization of focal triggers of paroxysmal atrial fibrillation, atrial tachycardia, and the atrial insertion of accessory pathways.

Adult↗
PubMed2001

Clinical validation of new pacing-sensing configurations for atrial automatic capture verification in pacemakers.

INTRODUCTION: This study evaluated an atrial automatic capture verification scheme based on atrial evoked response (AER). Atrial pacing was between Atip and Can (Atip-Can) using different coupling capacitances (CCs). Independent pairs of sensing electrodes between Aring and Vtip (Aring-Vtip) or between Aring and a separate indifferent electrode (Aring-Indiff) were used to reduce pacing-induced afterpotentials. METHODS AND RESULTS: A custom-made external pacing system was used to perform automatic step-up and step-down pacing (0.1 to 7.1 V at 0.5 msec, step size of 0.1 V) using different CCs (2 or 15 microF). Intracardiac signals from Aring-Indiff and Aring-Vtip were independently recorded and analyzed both in real time and off-line to detect AER. Every paced beat also was visually inspected and compared with surface ECG to verify the captures. With the intracardiac signals properly filtered, AER detection was based on the signal within a window of 12 to 65 msec after the stimulus. Data from 27 patients (4 chronic and 23 acute implantations; age 65.6+/-13.9 years) were analyzed. Bipolar atrial lead measurements using a standard pacing system analyzer were as follows (mean +/- SD): impedance 695+/-227 ohms, P wave amplitude 4.2+/-2.3 mV, slew rate 1.1+/-0.9 V/sec, and pacing threshold at 0.5 msec 1.0+/-0.5 V. The results with CC = 2 microF showed that of 9,500 atrial paced beats, correct capture verification rates were 99.8% (Aring-Indiff) and 99.4% (Aring-Vtip). Similar results were achieved with CC = 15 microF (99.7% and 99.5%, respectively). CONCLUSION: AER can be reliably detected using independent pacing (Atip-Can) and sensing (Aring-Vtip or Aring-Indiff) electrodes. Therefore, atrial automatic capture verification by AER detection is feasible.

Adult↗
PubMed2005

Automatic impedance monitoring and patient alert feature in implantable cardioverter defibrillators: being alert for the unexpected!

Recent advances in implantable cardioverter defibrillator (ICD) technology have enabled implementation of an automatic monitoring feature in ICDs that provides daily measurements of several technical parameters such as battery status, pacing, and high-voltage impedance. The system alerts the patient with an audible alarm to contact the physician in case the measured parameters are not within normal limits. Early detection of intermittent and potentially serious complications justifies routine use of this feature. This report describes a patient with an ICD who died suddenly due to ventricular fibrillation, which was not appropriately treated by the device. The cause of device malfunction was most likely an intermittent lead fracture that was not detected by the automatic impedance monitoring and alert feature of this device. Based on these data, potential benefits and theoretical pitfalls of automatic impedance monitoring and alert features are discussed.

Adult↗
PubMed2003

Automatic cardiac event recorders reveal paroxysmal atrial fibrillation after unexplained strokes or transient ischemic attacks.

BACKGROUND: The etiology of stroke or transitory ischemic attack (TIA) remains frequently unknown. While paroxysmal atrial fibrillation (PAF) is often suspected, its presence remains difficult to establish. Therefore, we investigated the occurrence of PAF episodes in such a population using a long-term automatic cardiac event recorder. METHODS: We prospectively investigated 60 consecutive subjects admitted in our university hospital for stroke (n=44) or TIA (n=16), adding long-term automatic cardiac event recorders, with a target duration of 4 days, to standard investigations, which included 12-lead ECGs and 24-hour Holter recordings. RESULTS: In 28 patients no etiology was found for their stroke or TIA. However, one or more than one PAF episode was found in 4 of them (14.3%) using the long-term automatic event recorder. In the 32 remaining patients, 8 presented with PAF, and this was considered as the cause of their stroke. In both groups, AF was paroxysmal. The PAF episodes' duration went from 1 to 96 hours (mean +/- standard deviation, 18 hours and 30 minutes+/-30 hours). CONCLUSIONS: Patients suffering PAF episodes after ischemic stroke or TIA were statistically less often recognized using the 24-hour Holter ECG recording alone than the R-Test Evolution alone.

Adult↗
PubMed2000

[Contrast media-enhanced 3D MR angiography of peripheral arteries using an automatic tracking technique at 1.0 Tesla].

PURPOSE: Assessment of the value of contrast-enhanced MR angiography (ceMRA) using an automatic tracking technique at 1.0 Tesla in comparison with digital subtraction angiography (DSA) of the pelvic and lower limb arteries. MATERIALS AND METHODS: In 15 patients with peripheral arterial occlusive disease a ceMRA (3D FLASH, TR/TE = 6.2/2.3 ms, Flip angle alpha = 30 degrees, Matrix 170 x 256) using a new automatic tracking technique was accomplished. The reference method was DSA. Twenty-one vessel segments of each patient were graded as normal, stenosed (> 50%) or occluded. Image material was evaluated independently by two radiologists. RESULTS: In comparison, the interobserver agreement showed a good (Cohen's kappa > 71%) concordance for 38% of the 21 vessel segments, a moderate (Cohen's kappa between 31%-70%) for 21% and a poor (Cohen's kappa < 30%) concordance for 38% of the 21 vessel segments. Regarding the MRA and DSA results, a good concordance was achieved for 62% of the 21 vessel segments, 14% showed a moderate concordance and 24% only a poor concordance. CONCLUSION: In patients with peripheral arterial occlusive disease ceMRA using an automatic tracking technique enables a reliable evaluation of pelvis and upper limb arteries at 1.0 Tesla. However, a reliable evaluation of lower limb arteries is not yet possible.

Aged↗
PubMed1998

[Cutting edges after automatic lamellar keratotomy].

BACKGROUND: In order to perform an automatic lamellar keratotomy microkeratomes are used, which differ from each other in several technical details. This study was done to examine, whether there are characteristics of the cutting edge, typical of each device, and whether there are some correlations between the cutting quality and technical parameters. METHODS: In Germany seven different keratomes are used today. We performed the procedure of automatic lamellar keratotomy by using each of them on 8 fresh enucleated pig eyes and we examined the corneal tissue by means of scanning electron microscopy. The cutting edges were judged by their smoothness and sharpness. RESULTS: A dominantly smooth cutting edge was found on the corneas cut by the MKM-System, the Universal Keratome and the BK-Microkeratome Set, while the Automatic Corneal Shaper, the Microtech-Mikrokeratom, the Rotor-Keratom and the Schwind-Mikrokeratom mostly produced a saw-toothed edge. CONCLUSIONS: The quality of the cutting edge may be influenced by the relationship of the speed of the pass and the rate of blade oscillation/rotation. Therefore it seems that a lower feed during one oscillation/rotation results in a more smooth pattern of the cutting edge.

Animals↗
PubMed2001

Automatic differentiation of melanoma from melanocytic nevi with multispectral digital dermoscopy: a feasibility study.

BACKGROUND: Differentiation of melanoma from melanocytic nevi is difficult even for skin cancer specialists. This motivates interest in computer-assisted analysis of lesion images. OBJECTIVE: Our purpose was to offer fully automatic differentiation of melanoma from dysplastic and other melanocytic nevi through multispectral digital dermoscopy. METHOD: At 4 clinical centers, images were taken of pigmented lesions suspected of being melanoma before biopsy. Ten gray-level (MelaFind) images of each lesion were acquired, each in a different portion of the visible and near-infrared spectrum. The images of 63 melanomas (33 invasive, 30 in situ) and 183 melanocytic nevi (of which 111 were dysplastic) were processed automatically through a computer expert system to separate melanomas from nevi. The expert system used either a linear or a nonlinear classifier. The "gold standard" for training and testing these classifiers was concordant diagnosis by two dermatopathologists. RESULTS: On resubstitution, 100% sensitivity was achieved at 85% specificity with a 13-parameter linear classifier and 100%/73% with a 12-parameter nonlinear classifier. Under leave-one-out cross-validation, the linear classifier gave 100%/84% (sensitivity/specificity), whereas the nonlinear classifier gave 95%/68%. Infrared image features were significant, as were features based on wavelet analysis. CONCLUSION: Automatic differentiation of invasive and in situ melanomas from melanocytic nevi is feasible, through multispectral digital dermoscopy.

Diagnosis, Differential↗
PubMed2003

Automatic life-long monitoring of individual insect behaviour now possible.

Automatic tracking and identification of individuals has the potential to revolutionize the study of insects, especially social insects, by opening up options for questions which could not be asked before. To achieve this we developed a reliable and cost-sensible RFID (Radio-Frequency Identification) based solution that automatically recognises a virtually unlimited number (18 x 10(18) possible ID numbers) of individual insects down to the size of bees and ants. The data are collected automatically for any desired time span (if interesting, up to the entire life of the individual), pre-processed and saved in a database for further analysis. The usage of database techniques allows parallel data processing with a virtually unlimited number of parameter connections. ID numbers can be linked to any simultaneously recorded parameters of interest, e.g. spatial and temporal information as shown here for a bumblebee colony.

Journal Article↗
PubMed2001

Coloring single stroop elements: reducing automaticity or slowing color processing?

Automaticity theory and the effect of coloring a single element were tested with all or only 1 element colored in Stroop tasks. The 312 participants in 5 experiments indicated stimulus presentation color by key press. Experiments 1 and 2 replicated those of D. Besner, J. A. Stoltz, and C. Boutilier (1997) with some changes, and revealed similar results: less Stroop interference with only 1 letter colored. Besner et al. (1997) interpreted the results as indicating that coloring a single letter eliminates automatic reading processes. The cause of that reduction in Stroop interference was investigated in Experiments 3, 4, and 5 using color words, bars, and rectangles. The effect of coloring 1 element was to increase color-naming time by the same amount for congruent and neutral, nonverbal stimuli, but not for incongruent stimuli. The results are interpreted in terms of automaticity theory, and a continuous flow approach to the Stroop effect is presented.

Attention↗