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PubMed1986

The effects of adenosine, ATP and ADP on ventricular automaticity induced by a local injury in the isolated right ventricle of the rat.

The effects of adenosine, adenosine triphosphate (ATP) and adenosine diphosphate (ADP) on ventricular automaticity induced by a local injury have been studied in the isolated right ventricle of the rat. Adenosine in low concentrations (10(-10)--10(-8) M) increased ventricular automaticity but in high concentrations (10(-5)--10(-4) M) decreased it. ATP and ADP decreased consistently ventricular automaticity, ATP being more effective than ADP. Theophylline in a concentration (5 X 10(-4) M) devoid of effect on ventricular automaticity antagonized both the excitatory and the inhibitory effects of adenosine. A high calcium solution (5.4 mM calcium) also prevented both the excitatory and the inhibitory effects of adenosine. The results suggest that adenosine in low concentrations might contribute to ventricular dysrhythmias, and that ATP and ADP as well as high concentrations of adenosine might have antidysrhythmic effects. The effects of adenosine appear to be mediated through calcium-dependent theophylline-sensitive receptors: the high affinity receptor operating the excitatory effect and the low affinity adenosine receptor operating the adenosine inhibitory effect on ventricular automaticity.

Adenosine↗
PubMed1984

Selectivity of alinidine, a bradycardic agent, for SA nodal automaticity versus other cardiac activities in isolated, blood-perfused dog-heart preparations.

Selectivity of alinidine for SA nodal automaticity vs. other cardiac activities was investigated using isolated, blood-perfused SA node, AV node and papillary muscle preparations of the dog. The drug was administered intra-arterially. In SA node preparations alinidine (1 microgram-1 mg) produced a dose-dependent decrease of sinus rate down to about 74% of the basal value at 1 mg, but no atrial standstill. In AV node preparations alinidine, injected into the posterior septal artery (PSA) which supplies the AV node, prolonged AV conduction time up to about 124% of the basal value but only in large doses (30 micrograms-1 mg). In the same preparations, when injected into the anterior septal artery, which supplies structures from the His bundle down to the ventricular septum (the intraventricular conduction system), alinidine in large doses (300 micrograms-1 mg) also prolonged AV conduction time nearly to the same extent as when injected into the PSA. In both cases neither second- nor third-degree AV block occurred. In paced papillary muscle preparations alinidine reduced the force of contraction down to about 64% of the basal value but in large doses (100 micrograms-1 mg). In spontaneously beating papillary muscle preparations alinidine reduced the rate of ventricular automaticity down to about 78% of the basal value but in large doses (100 micrograms-1 mg). Alinidine (100 micrograms-1 mg) produced a transient increase in blood flow in these preparations but not in SA node preparations. The cardiac effects of alinidine were longer-lasting than its vascular effect and the reduction of sinus rate was particularly long-lasting. The order of selectivity of alinidine determined from the above results is as follows: SA nodal automaticity much greater than ventricular automaticity greater than intraventricular conduction divided by AV nodal conduction divided by cardiac muscle contraction divided by coronary blood flow. Such a cardiovascular profile of alinidine is different from that of AQ-A 39, another bradycardic agent, which is nearly equi-effective on both SA nodal and ventricular automaticity.

Animals↗
PubMed1995

Automaticity in fusional vergence therapy.

BACKGROUND: Fusional vergence therapy is typically performed under conditions that permit the patient to direct considerable attention and effort to the visual task. Unless visual function is sufficiently automatic as to require minimal attention and effort, attention directed toward visual function may detract from that available for cognitive processing. This report describes a method to develop greater automaticity of fusional vengence through the use of concurrent demands. METHODS: A retrospective pilot study of patient records was performed to assess the use of a concurrent motor demand (bouncing on a rebounder) to develop automaticity of fusional vergence. RESULTS: In most cases, patients who achieved adequate fusional vergence without the concurrent motor demand demonstrated a decrease in fusional vergence ranges when the motor demand was added, and then improved with practice so that vergence ranges while bouncing on the rebounder approached those achieved while seated. This pattern was obtained in 75 percent of the base-out and 57.1 percent of the base-in protocols. Some patients who showed a decrement in performance with introduction of the concurrent demand failed to improve with practice; this pattern was observed in 28.6 percent of the base-in protocols, but in none of the base-out protocols. Some patients showed no decrease in performance when the concurrent distracting task was introduced (observed in 25 percent of the base-out protocols and 14.3 percent of the base-in protocols). CONCLUSIONS: In most cases, maximum automaticity is not achieved when fusional vergence is trained under conditions that permit the patient to devote full attention to the vergence task. Introducing concurrent distractors may be desirable to automate performance and enable the patient to maintain fusional vergence even while attention is directed to the concurrent task. Heightened automaticity may reduce the effort and attention that must be directed toward binocular function, and hence maximize attentional capacity available for information-processing, comprehension, and performance on the task at hand.

Adolescent↗
PubMed1994

Nuclear morphometry in automatic biopsy and radical prostatectomy specimens of prostatic carcinoma. A comparison.

Nuclear shape analysis performed upon prostatectomy specimens of prostatic carcinoma distinguished individual patients with good and poor prognoses. In order to be useful for prognosis assessment preoperatively, nuclear morphometry must be measured on needle biopsy specimens. We compared nuclear morphometry on automatic biopsy and radical prostatectomy specimens in 20 patients with prostatic carcinoma. Nuclear size was smaller (paired Student t test, P < .0001) in biopsy specimens (perimeter 17.0 +/- SD 4.9 microns, area 29.9 +/- 6.6 microns2) than in prostatectomy specimens (perimeter 24.6 +/- 4.4 microns, area 48.2 +/- 8.7 microns2). Nuclear shape was more abnormal in automatic biopsy specimens (nuclear roundness factor 82.0 +/- 18.8, ellipticity 90.5 +/- 27.7) than in surgical specimens (nuclear roundness factor 43.5 +/- 8.8, ellipticity 54.0 +/- 14.7) (P < .0001). Study of specimens obtained by automatic biopsy preoperatively and automatic biopsy of the prostatectomy specimens at various steps of processing revealed that nuclear swelling and rounding occurred after 2-24 hours of formalin fixation. Automatic prostate biopsies may more accurately reflect true nuclear morphometry and should be studied for preoperative prognosis prediction in patients with clinically localized prostatic carcinoma.

Biopsy↗
PubMed1993

[The modulation of anomalous automatism in ischemic Purkinje fibers by a specific subclass of alpha 1-adrenoblockers].

In the present study, the authors used two specific blockers of alpha 1-adrenergic receptor subtypes (chloroethyclonidine and WB-4101) to determine the mechanisms responsible for automatic rhythm occurring during simulated ischemia and reperfusion of isolated canine Purkinje fibers. In the control situation, all fibers showed membrane potentials greater than -90 mV and normal automatic rhythm. During simulated ischemia, the membrane potential depolarized to the -60 mV range. Abnormal automaticity was seen in 20% of fibers untreated with phenylephrine and in 50% of those supervised with 10(-7) M phenylephrine. The incidence of abnormal automaticity was reduced to 0% with WB-4101 and increased to 90% with chloroethylclonidine. Moreover, the ischemic fibers were significantly more hyperpolarized during superfusion with WB-4101 than with chloroethylclonidine. It is concluded that automatic arrhythmias induced by alpha 1-adrenergic stimulation during simulated ischemia may be attributed to a specific alpha 1-adrenergic receptor subtype that is blocked by WB-4101.

Action Potentials↗
PubMed1994

Automatic SNOMED coding.

Medical coding has become an important new industry that has originated from the field of medical informatics. Automatic coding of specimens has emerged as a way of relieving hospitals from the cost of paying professional coders and for achieving uniform coding for all specimens. Unfortunately, automatic coding, like manual coding, has numerous pitfalls. Further, the coding algorithms employed by manufacturers of automatic coders are typically proprietary. We have developed a method for automatic coding of pathology reports. Using this public domain autocoder, we have previously demonstrated that automatic SNOMED coding was superior to manual coding in several measurable categories, including the overall number of codes generated and the number of distinct code entities provided. In this report, we describe an algorithm that executes this strategy in the M-Technology environment.

Algorithms↗
PubMedDate not supplied

Automatic 3D intersubject registration of MR volumetric data in standardized Talairach space.

OBJECTIVE: In both diagnostic and research applications, the interpretation of MR images of the human brain is facilitated when different data sets can be compared by visual inspection of equivalent anatomical planes. Quantitative analysis with predefined atlas templates often requires the initial alignment of atlas and image planes. Unfortunately, the axial planes acquired during separate scanning sessions are often different in their relative position and orientation, and these slices are not coplanar with those in the atlas. We have developed a completely automatic method to register a given volumetric data set with Talairach stereotaxic coordinate system. MATERIALS AND METHODS: The registration method is based on multi-scale, three-dimensional (3D) cross-correlation with an average (n > 300) MR brain image volume aligned with the Talariach stereotaxic space. Once the data set is re-sampled by the transformation recovered by the algorithm, atlas slices can be directly superimposed on the corresponding slices of the re-sampled volume. the use of such a standardized space also allows the direct comparison, voxel to voxel, of two or more data sets brought into stereotaxic space. RESULTS: With use of a two-tailed Student t test for paired samples, there was no significant difference in the transformation parameters recovered by the automatic algorithm when compared with two manual landmark-based methods (p > 0.1 for all parameters except y-scale, where p > 0.05). Using root-mean-square difference between normalized voxel intensities as an unbiased measure of registration, we show that when estimated and averaged over 60 volumetric MR images in standard space, this measure was 30% lower for the automatic technique than the manual method, indicating better registrations. Likewise, the automatic method showed a 57% reduction in standard deviation, implying a more stable technique. The algorithm is able to recover the transformation even when data are missing from the top or bottom of the volume. CONCLUSION: We present a fully automatic registration method to map volumetric data into stereotaxic space that yields results comparable with those of manually based techniques. The method requires no manual identification of points or contours and therefore does not suffer the drawbacks involved in user intervention such as reproducibility and interobserver variability.

Algorithms↗
PubMed1998

Automatic detection of stable and unstable chromosome aberrations visualized by three-color imaging after fluorescence in situ hybridization with a painting and a pancentromeric DNA probe.

Two-color fluorescence in situ hybridization (FISH) in combination with digital image analysis was used to develop an automatic system for the detection and classification of chromosome aberrations. Algorithms were developed for the automatic thresholding of the three digitized images: an FITC image representing specific painted chromosomes, a TRITC image representing the centromeres of all chromosomes, and a DAPI image representing all the counterstained chromosomes. A further algorithm was developed for the automatic classification of the different types of chromosome aberrations, such as translocations, dicentrics, and fragments. For this study, a dataset of 252 metaphases were digitized and analyzed automatically as well as manually. Of these metaphases, 81.3% could be correctly classified by the algorithm. The error rate was reduced to 9.3% by automatically excluding the detected clusters and artifacts. The average analysis time per metaphase was 34.5 s without any user intervention.

Adenocarcinoma↗
PubMed2003

"Automatism" and the emergence of dynamic psychiatry.

This article is about the clash of two explanatory paradigms, each attempting to account for the same data of human experience. In the first half of the nineteenth century, physiologists investigated reflex actions and applied a recently coined word, "automatism," to describe actions which, although seeming to arise from higher centers, actually result from automatic reaction to sensory stimuli. Experiments with spinal reflexes led to the investigation of the reflex action of the brain or "cerebral automatisms." Reflex actions of this kind were used to explain everything from acting compulsively to composing symphonies. Physiological explanations of phenomena of this kind seemed insufficient to some and, in the 1880s, Frederic Myers and Pierre Janet developed psychological frameworks for understanding these phenomena, positing hidden centers of intelligence at work in the individual, outside ordinary awareness, which produce what came to be called "psychological automatisms." Their attempts to unify this psychological framework with the existing physiological one failed. Nevertheless, their work played a crucial role in paving the way for what Ellenberger called dynamic psychiatry, which accepts the reality of an unconscious dynamic of the psyche.

Automatism↗
PubMed2001

Semantic priming in Alzheimer's dementia: evidence for dissociation of automatic and attentional processes.

The nature of the semantic memory deficit in dementia of the Alzheimer's type (DAT) was investigated in a semantic priming task which was designed to assess both automatic and attention-induced priming effects. Ten DAT patients and 10 age-matched control subjects completed a word naming semantic priming task in which both relatedness proportion (RP) and stimulus-onset asynchrony (SOA) were varied. A clear dissociation between automatic and attentional priming effects in both groups was demonstrated; however, the DAT subjects' pattern of priming deviated significantly from that of the normal controls. The DAT patients failed to produce any priming under conditions which encouraged automatic semantic processing and produced facilitation only when the RP was high. In addition, the DAT group produced hyperpriming, with significantly larger facilitation effects than the control group. These results suggest an impairment of automatic spreading activation in DAT and have implications for theories of semantic memory impairment in DAT as well as models of normal priming.

Aged↗
PubMed1995

Automaticity and the anxiety disorders.

Experimental psychopathologists have increasingly relied upon the concepts and methods of cognitive psychology in their attempts to elucidate information-processing biases associated with anxiety disorders. Many of these biases presumably constitute instances of automatic, not strategic, processing. But research has shown that attributes of automaticity (i.e. capacity-free, unconsious, involuntary) do not all apply to selective processing of threat associated with anxiety. Experimental and clinical findings suggest that biases are automatic in the sense of being involuntary (and sometimes unconscious), but not in the sense of being capacity-free. Implications of involuntary automatic processing of threat for behavior therapy are discussed.

Anxiety Disorders↗
PubMed2006

Electrode manipulation automatism during temporal lobe seizures.

OBJECTIVE: To describe clinical characteristics and lateralizing value of peri-ictal electrode manipulation automatism (EMA) in patients with temporal lobe epilepsy (TLE) and compare our data with ictal manual automatisms described in the literature. METHODS: Two-hundred and five videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed and EMA (tugging, scratching or adjusting the electrodes and cables) were monitored. RESULTS: Twenty-eight (51%) patients showed EMA during 47 (23%) seizures. Ictal start was noted in 22 seizures and in 19/22 cases EMA finished before the end of seizure. Ictal EMAs were always associated with automotor seizure components. During 25 seizures, exclusively postictal EMAs were observed. Electrode manipulation was presented during 24/112 left-sided and 23/93 right-sided seizures (p = 0.742). Peri-ictal EMA was unilateral (completed by one hand) in 24/47 seizures (10 ictal, 14 postictal); it was done by the hand ipsilateral to the seizure onset zone in 17/24 and by contralateral hand in 7/24 cases (p = 0.064). We observed concomitant contralateral dystonic posturing during 3/10 seizures with unilateral ictal EMA. Unilateral hand automatism, temporally independent from the EMA appeared in 30 (64%) of the 47 seizures. CONCLUSION: Peri-ictal EMA is a frequent phenomenon but shows no lateralizing value in TLE. The mechanism of EMA is in many ways dissimilar from that of earlier described manual automatisms.

Adolescent↗
PubMedDate not supplied

Functional analysis of aberrant behavior maintained by automatic reinforcement: assessments of specific sensory reinforcers.

The purpose of this study was to develop a systematic functional assessment package for aberrant behaviors maintained by nonsocial (automatic) reinforcement. The assessment package included four components: (1) functional analysis, (2) antecedent assessment of specific automatic reinforcement sources, (3) stimulus preference assessment, and (4) treatment evaluation. Functional analysis data indicated automatic reinforcement functions of the stereotypy exhibited by a 10-year-old male and the self-injury (SIB) exhibited by a 30-year-old male. Antecedent assessments of sensory classes indicated that auditory stimulation and tactile stimulation were associated with stereotypy and SIB, respectively. A multiple-stimulus-without-replacement procedure was conducted with each participant to identify the most- and least-preferred stimuli within the identified sensory classes. In an attempt to validate the assessment package for each participant, a DRO procedure was implemented using a reversal design with a multielement component. DRO procedures using stimuli within the targeted sensory classes were successful in eliminating the aberrant behaviors of both participants. The results are discussed in the context of improving the methodology for assessing and treating automatically reinforced behaviors.

Adult↗
PubMed2001

Spontaneous prejudice in context: variability in automatically activated attitudes.

The goal of the research reported in this article was to examine whether automatic group attitudes and stereotypes, commonly thought to be fixed responses to a social category cue, are sensitive to changes in the situational context. Two experiments demonstrated such variability of automatic responses due to changes in the stimulus context. In Study 1 White participants' implicit attitudes toward Blacks varied as a result of exposure to either a positive (a family barbecue) or a negative (a gang incident) stereotypic situation. Study 2 demonstrated similar context effects under clearly automatic processing conditions. Here, the use of different background pictures (church interior vs. street corner) for Black and White face primes affected participants' racial attitudes as measured by a sequential priming task. Implications for the concept of automaticity in social cognition are discussed.

Adolescent↗
PubMed1997

Recollective and automatic uses of memory.

Three cued-recall experiments examined the effects of learning conditions and set size on recollective and automatic uses of memory. Words were studied under different conditions and had either small or large preexisting associative sets. Results based on the process-dissociation procedure showed that learning conditions and set size influenced recollective uses of memory, whereas only set size influenced automatic uses. Other results indicated that process-dissociation and direct-indirect test procedures produce similar results. The findings suggest that the relative contributions of recently acquired information and preexisting information depend on how memory is being used. Recollective uses of memory are affected by the nature of recent study and by what such study activates in long-term memory. In contrast, automatic uses of memory are more affected by what the test cue automatically activates than by what has been learned during recent study.

Automatism↗
PubMed2005

Conceptualizing control in social cognition: how executive functioning modulates the expression of automatic stereotyping.

Two studies investigated the role of executive control in moderating the relationship between automatic stereotype activation and behavioral responses. Race bias in weapon identification was used to measure stereotyping, and a process dissociation procedure was used to measure automatic and controlled components of performance. In Experiment 1, the controlled component was shown to correlate with general attention control and race-specific motivations to control prejudice. Across multiple measures, automatic race bias was more likely to be expressed as behavioral discrimination among individuals with poor executive control. Experiment 2 found the same relationship between automatic and controlled components of behavior when predicting impressions of a Black individual. Executive control is discussed in the context of other control strategies in influential dual-process models of stereotyping.

Attitude↗
PubMed2006

From automatic antigay prejudice to behavior: the moderating role of conscious beliefs about gender and behavioral control.

Two experiments tested whether the relation between automatic prejudice and discriminatory behavior is moderated by 2 conscious processes: conscious egalitarian beliefs and behavioral control. The authors predicted that, when both conscious processes are deactivated, automatic prejudice would elicit discriminatory behavior. When either of the 2 processes is activated, behavioral bias would be eliminated. The authors assessed participants' automatic attitudes toward gay men, conscious beliefs about gender, behavioral control, and interactions with gay confederates. In Experiment 1, men's beliefs about gender were heterogeneous, whereas women's beliefs were mostly egalitarian; men's responses supported the predictions, but women's responses did not. In Experiment 2, the authors recruited a sample with greater diversity in gender-related beliefs. Results showed that, for both sexes, automatic prejudice produced biased behavior in the absence of conscious egalitarian beliefs and behavioral control. The presence of either conscious process eliminated behavioral bias.

Adult↗
PubMed2006

Automaticity: a theoretical and conceptual analysis.

Several theoretical views of automaticity are discussed. Most of these suggest that automaticity should be diagnosed by looking at the presence of features such as unintentional, uncontrolled/uncontrollable, goal independent, autonomous, purely stimulus driven, unconscious, efficient, and fast. Contemporary views further suggest that these features should be investigated separately. The authors examine whether features of automaticity can be disentangled on a conceptual level, because only then is the separate investigation of them worth the effort. They conclude that the conceptual analysis of features is to a large extent feasible. Not all researchers agree with this position, however. The authors show that assumptions of overlap among features are determined by the other researchers' views of automaticity and by the models they endorse for information processing in general.

Automatism↗