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At least 415 records · Page 23Linked to original sources
PubMed2003

Intimate partner violence and substance use: a longitudinal day-to-day examination.

The likelihood of male-to-female physical aggression on days of male partners' substance use, during a 15-month period, was examined. Participants were from married or cohabiting partner violent men entering a drug abuse treatment program (N=149). Compared to days of no drug or alcohol use, the likelihood of male-to-female physical aggression was significantly higher on days of substance use, after controlling for male partners' antisocial personality (ASP) disorder and couples' global relationship distress. Of the psychoactive substances examined, the use of alcohol and cocaine was associated with significant increases in the daily likelihood of male-to-female physical aggression; cannabis and opiates were not significantly associated with an increased likelihood of male partner violence.

Adult↗
PubMed2005

Subjective reactions to cocaine and marijuana are associated with abuse and dependence.

Subjective effects of marijuana and cocaine use are associated with amount of drug use and potentially with risk of abuse and dependence. We used Latent Class Analyses (LCA) to examine subjective responses to two categories of drugs and link these to abuse and dependence. In 1992, subjective responses were queried of 2506 marijuana and 661 cocaine lifetime users who were members of the Vietnam Era Twin Registry. LCA was used to identify classes of subjective effects. Multinomial logistic regression models were computed to test for an association between classes and marijuana and cocaine abuse or dependence. The best LCA solution for marijuana identified 6 distinct classes characterized as positive, relaxed, reactive, adverse, low and very reactive. The best LCA solution for cocaine identified 5 distinct classes characterized as positive, alert, adverse, low and very reactive. Marijuana abuse and dependence were significantly associated with each latent class. Cocaine abuse was associated with the reactive class (OR=3.9; 95% CI: 1.6-9.5). Cocaine dependence was associated with reactive (OR=15.3; 95% CI: 7.1-32.6), adverse (OR=9.7; 95% CI: 4.5-21.0) and very reactive (OR=18.7; 95% CI: 5.6-62.6) classes. We found evidence for both qualitative and quantitative subjective effect profiles. Subjective effects, both positive and adverse are associated with lifetime risk for marijuana and cocaine dependence.

Adult↗
PubMed2006

Utility of the theory of reasoned action and theory of planned behavior for predicting Chinese adolescent smoking.

One third of smokers worldwide live in China. Identifying predictors of smoking is important for prevention program development. This study explored whether the Theory of Reasoned Action (TRA) and Theory of Planned Behavior (TPB) predict adolescent smoking in China. Data were obtained from 14,434 middle and high school students (48.6% boys, 51.4% girls) in seven geographically varied cities in China. TRA and TPB were tested by multilevel mediation modeling, and compared by multilevel analyses and likelihood ratio tests. Perceived behavioral control was tested as a main effect in TPB and a moderation effect in TRA. The mediation effects of smoking intention were supported in both models (p<0.001). TPB accounted for significantly more variance than TRA (p<0.001). Perceived behavioral control significantly interacted with attitudes and social norms in TRA (p<0.001). Therefore, TRA and TPB are applicable to China to predict adolescent smoking. TPB is superior to TRA for the prediction and TRA can better predict smoking among students with lower than higher perceived behavioral control.

Adolescent↗
PubMed2005

A Turing test of a timing theory.

A quantitative theory of timing or conditioning can be evaluated with a Turing test in which the behavioral results of an experiment can be compared with the predicted results from the theory. An example is described based upon an experiment in which 12 rats were trained on three fixed-interval schedules of reinforcement, and a simulation of the predicted results from a packet theory of timing. An objective classification rule was used to determine whether a sample from the data or a sample from the theory was more similar to another sample from the theory. With an ideal theory, the expected probability of a correct classification would be 0.5. The observed probability of a correct classification was 0.6, which was slightly, but reliably, greater than 0.5. A Turing test provides a graded metric for the evaluation of a quantitative theory.

Animals↗
PubMed2006

Linking obsessional beliefs to OCD symptoms in older and younger adults.

There are many open questions about the phenomenology of obsessive-compulsive disorder (OCD) in the elderly, and theories about the development of OCD have rarely been applied to older populations. The current study uses structural equation models to evaluate the relationship between obsessional beliefs and OCD symptoms across young and older adult age groups in a large community sample (aged 18-93; N=335), and to examine whether subjective concerns about cognitive decline partially mediate this relationship. Results support partial mediation, and follow-up analyses suggest that the pattern of relationships among subjective cognitive concerns, obsessional beliefs and OCD symptoms is invariant for younger and older adults, but older adults report relatively greater levels of subjective cognitive concerns.

Adolescent↗
PubMed2006

Ergonomic considerations in work-related upper extremity disorders.

Correctly applied, an ergonomics approach can reduce the likelihood of work-induced disorders and can assist in accommodating individuals who have work-related disorders, but it cannot eliminate disorders that have been mistakenly attributed to work by social processes. A contextual model of work-related upper extremity disorders is proposed that explicitly acknowledges that factors extrinsic to work can shape perceptions of upper extremity disorders and influence the process of somatic interpretation and health outcomes. Experiences in the United Kingdom of ergonomic regulations associated with computer use and the media coverage of work-related upper extremity disorders are used to illustrate this model.

Arm Injuries↗
PubMed2005

The scrambling theorem: a simple proof of the logical possibility of spectrum inversion.

The possibility of spectrum inversion has been debated since it was raised by and is still discussed because of its implications for functionalist theories of conscious experience (e.g., Palmer, 1999). This paper provides a mathematical formulation of the question of spectrum inversion and proves that such inversions, and indeed bijective scramblings of color in general, are logically possible. Symmetries in the structure of color space are, for purposes of the proof, irrelevant. The proof entails that conscious experiences are not identical with functional relations. It leaves open the empirical possibility that functional relations might, at least in part, be causally responsible for generating conscious experiences. Functionalists can propose causal accounts that meet the normal standards for scientific theories, including numerical precision and novel prediction; they cannot, however, claim that, because functional relationships and conscious experiences are identical, any attempt to construct such causal theories entails a category error.

Consciousness↗
PubMed2006

A neural plasticity perspective on the schizophrenic condition.

Imbalanced plasticity of neural networks in the brain is proposed to underlie deficits in the integration of efferent and afferent processes in schizophrenia. These deficits affect the priming of the behavior implementing systems by prior knowledge, and thus impair both controlled regulation and automatic activation of mental and motor processes. The sense of self as a distinct entity can consequently be undermined. In predominantly reality-distorting patients, hypo-plasticity of neural connectivity may cause the emergence of highly focused but inflexible patterns of activation in their representation and response systems. This may lead to dominance of prepotent patterns of activity in these systems and a relative inability of higher control systems to bias lower level activity towards congruence with the ongoing cognitive and motor context. By contrast, predominantly disorganized patients are characterized by hyper-plastic connectivity. This leads to a weakening of prepotent response tendencies but also, as in reality-distorting patients, to less effective top-down contextual constraining.

Ego↗
PubMed2006

Measure of experimental pain using Rasch analysis.

Most common instruments used to assess the painfulness of nociceptive stimuli and the perception of such stimuli are ordinal. This property limits arithmetical operations and statistical procedures that can be applied on their numbers. The Rasch methodology provides mathematical procedures for transforming scores on an ordinal scale into measures on an interval scale. The present paper aims at presenting the basics of this methodology by applying it to the measurement of experimentally induced pain. Six blocks of seven CO(2) laser heat stimuli varying in intensity were delivered on the hand of 100 healthy subjects. They rated their pain perception on a three-level verbal rating scale (not painful, slightly painful, painful). One member of the family of Rasch models, the many-facet model, was applied to the analysis of these ratings. The analysis provided linear measures of the painfulness for each intensity of stimulation, of the pain perception of each subject and of the painfulness of each successive block. All these measures are located on a single pain perception continuum. Advantages and disadvantages of this methodology will be discussed in terms of subsequent possible mathematical analyses, statistical tests and implications for experimental and clinical investigations.

Adult↗
PubMed2006

Modelling suicide risk in later life.

Affective disorder is generally regarded as the prominent risk factor for suicide in the old age population. Despite the large number of empirical studies available in the literature, there is no attempt in modelling the dynamics of an individual's level of suicide risk theoretically yet. In particular, a dynamic model which can simulate the time evolution of an individual's level of risk for suicide and provide quantitative estimates of the probability of suicide risk is still lacking. In the present study we apply the contingent claims analysis of credit risk modelling in the field of quantitative finance to derive a theoretical stochastic model for estimation of the probability of suicide risk in later life in terms of a signalling index of affective disorder. Our model is based upon the hypothesis that the current state of affective disorder of a patient can be represented by a signalling index and exhibits stochastic movement and that a threshold of affective disorder, which signifies the occurrence of suicide, exists. According to the numerical results, the implications of our model are consistent with the clinical findings. Hence, we believe that such a dynamic model will be essential to the design of effective suicide prevention strategies in the target population of older adults, especially in the primary care setting.

Aged↗
PubMed2006

A mathematical framework for probabilistic choice based on information theory and psychophysics.

Risky decision-making (e.g. reward dependency) has been associated with substance abuse, psychopathy and pathological gambling; conversely, marked sensitivity to risk and uncertainty have been observed in anxiety disorder patients. In economic decision theory, probability and uncertainty have been dissociated. Frank Knight defined uncertainty as loss of information on the probability distribution of outcomes for choices (i.e., unpredictability), which is referred to as Knightian uncertainty (also as ambiguity). However, even when the probability distribution of outcomes is known, there are different degrees of predictability. In information theory, this type of degrees of uncertainty/unpredictability has been parametrized by introducing Shannon entropy. In the present paper, we show: (i) a mathematical framework combining Shannon entropy in information theory and Weber's law in psychophysics is capable of parametrizing subject's level of both aversion to probabilistic uncertainty (exaggerated in anxiety disorder patients) and reward dependency (enhanced in drug addicts and pathological gamblers), and (ii) this framework has an analogue in thermodynamics, therefore this can readily be utilized in studies in the nascent fields of neuroeconomics and econophysics as well. Future study directions for elucidating maladaptive personality characteristics in neuropsychiatric patients by using the present framework are discussed.

Anxiety Disorders↗
PubMed2006

A probabilistic model of gaze imitation and shared attention.

An important component of language acquisition and cognitive learning is gaze imitation. Infants as young as one year of age can follow the gaze of an adult to determine the object the adult is focusing on. The ability to follow gaze is a precursor to shared attention, wherein two or more agents simultaneously focus their attention on a single object in the environment. Shared attention is a necessary skill for many complex, natural forms of learning, including learning based on imitation. This paper presents a probabilistic model of gaze imitation and shared attention that is inspired by Meltzoff and Moore's AIM model for imitation in infants. Our model combines a probabilistic algorithm for estimating gaze vectors with bottom-up saliency maps of visual scenes to produce maximum a posteriori (MAP) estimates of objects being looked at by an observed instructor. We test our model using a robotic system involving a pan-tilt camera head and show that combining saliency maps with gaze estimates leads to greater accuracy than using gaze alone. We additionally show that the system can learn instructor-specific probability distributions over objects, leading to increasing gaze accuracy over successive interactions with the instructor. Our results provide further support for probabilistic models of imitation and suggest new ways of implementing robotic systems that can interact with humans over an extended period of time.

Attention↗
PubMed2006

Anterior cingulate activity modulates nonlinear decision weight function of uncertain prospects.

Prospect theory developed by Kahneman and Tversky has been among the most influential psychological models and explains many nonnormative decision-making phenomena, e.g. why people play the lottery or bet on long-shots. A Certainty Equivalent procedure was used during functional magnetic resonance imaging to identify the neural substrates that are important for nonlinear transformation of probabilities to decision weights. Differential activation in the anterior cingulate cortex during high versus low probability prospects correlated (r = 0.84, P < 0.01) with the degree of the nonlinearity of the transformation of probabilities to decision weights, which indicates that risk-seeking behavior for low probability prospects and risk-averse decision-making for mid to high probability prospects may be due to a lack of controlled processing by the anterior cingulate cortex.

Adult↗
PubMed2005

Temporal and probabilistic discounting of rewards in children and adolescents: effects of age and ADHD symptoms.

This study investigated whether age and ADHD symptoms affected choice preferences in children and adolescents when they chose between (1) small immediate rewards and larger delayed rewards and (2) small certain rewards and larger probabilistic uncertain rewards. A temporal discounting (TD) task and a probabilistic discounting (PD) task were used to measure the degree to which the subjective value of a large reward decreased as one had to wait longer for it (TD), and as the probability of obtaining it decreased (PD). Rewards used were small amounts of money. In the TD task, the large reward (10 cents) was delayed by between 0 and 30s, and the immediate reward varied in magnitude (0-10 cents). In the PD task, receipt of the large reward (10 cents) varied in likelihood, with probabilities of 0, 0.25, 0.5, 0.75, and 1.0 used, and the certain reward varied in magnitude (0-10 cents). Age and diagnostic group did not affect the degree of PD of rewards: All participants made choices so that total gains were maximized. As predicted, young children, aged 6-11 years (n = 25) demonstrated steeper TD of rewards than adolescents, aged 12-17 years (n = 21). This effect remained significant even when choosing the immediate reward did not shorten overall task duration. This, together with the lack of interaction between TD task version and age, suggests that steeper discounting in young children is driven by reward immediacy and not by delay aversion. Contrary to our predictions, participants with ADHD (n = 22) did not demonstrate steeper TD of rewards than controls (n = 24). These results raise the possibility that strong preferences for small immediate rewards in ADHD, as found in previous research, depend on factors such as total maximum gain and the use of fixed versus varied delay durations. The decrease in TD as observed in adolescents compared to children may be related to developmental changes in the (dorsolateral) prefrontal cortex. Future research needs to investigate these possibilities.

Adolescent↗
PubMedDate not supplied

Access in health services research: the battle of the frameworks.

BACKGROUND: Access is an important concept in the study of the organization, financing and delivery of healthcare services. It is also an important political symbol and policy goal. PURPOSE: This article reviews the major theoretical frameworks that have been used to support the study of access and measure the degree to which healthcare systems have met standards of access. METHOD: The article uses a critical review of the major works of the leading theorists in the field of access studies. DISCUSSION: Theories of access accept that it is a dynamic process where there is the potential for individuals and families to learn and modify their behavior. That learning and adaptation is less often explored in empirical research of access to health care. CONCLUSION: Researchers should consider the more dynamic aspects of access as they attempt to understand how to improve the health care delivery system. Access models can be used to direct the formulation of better health policy if they reflect real world processes.

Community Health Planning↗
PubMed2005

Illusory volumes in human stereo perception.

Any complete theory of human stereopsis must model not only how the correspondences between locations in the two views are determined and the depths are recovered from their disparity, but also how the ambiguity arising from such factors as noise, periodicity, and large regions of constant intensity are resolved and missing data are interpolated. In investigating this process of recovering surface structure from sparse disparity information, using stereo pairs with sparse identifiable features, we made an observation that contradicts all extant models. It suggests the inadequacy of retinotopic representation in modeling surface perception in this stage. We also suggest a possible alternative theory, which is a minimization of the modulus of Gaussian curvature.

Depth Perception↗
PubMed2001

Interpretations for anxiety symptoms in social phobia.

This study explored the ways in which people interpret visible physical symptoms of anxiety. A group of participants with social phobia (SP) and a nonclinical control (NCC) group completed either the Actor version or the Observer version of the Symptom Interpretation Scale (SIS), designed for the purposes of this study. The SIS asks participants to rate the extent to which each of eight interpretations is a likely explanation for a number of visible symptoms of anxiety. On the Actor version of the SIS, participants are asked to judge how their own anxiety symptoms are interpreted by others. On the Observer version of the SIS, participants are asked how they typically interpret anxiety symptoms that they notice in others. When participants were asked about anxiety symptoms that they themselves exhibit, people with social phobia were more likely than nonclinical controls to think that others interpreted these symptoms as being indicative of intense anxiety or a psychiatric condition and were less likely to think that others interpreted these symptoms as being indicative of a normal physical state. Data also suggested that people with social phobia have a more flexible cognitive style when asked to interpret anxiety symptoms exhibited by others than when asked about how others view their own anxiety symptoms. These findings are discussed in the context of recent psychological models of social anxiety and social phobia.

Adult↗