Showing papers by "Peter C. M. Molenaar published in 2009"

The New Person-Specific Paradigm in Psychology

Abstract: Most research methodology in the behavioral sciences employs interindividual analyses, which provide information about the state of affairs of the population. However, as shown by classical mathematical-statistical theorems (the ergodic theorems), such analyses do not provide information for, and cannot be applied at, the level of the individual, except on rare occasions when the processes of interest meet certain stringent conditions. When psychological processes violate these conditions, the interindividual analyses that are now standardly applied have to be replaced by analysis of intraindividual variation in order to obtain valid results. Two illustrations involving analysis of intraindividual variation of personality and emotional processes are given.

Molecular Architecture of the Human Sinus Node: Insights Into the Function of the Cardiac Pacemaker

Abstract: BACKGROUND: Although we know much about the molecular makeup of the sinus node (SN) in small mammals, little is known about it in humans. The aims of the present study were to investigate the expression of ion channels in the human SN and to use the data to predict electrical activity. METHODS AND RESULTS: Quantitative polymerase chain reaction, in situ hybridization, and immunofluorescence were used to analyze 6 human tissue samples. Messenger RNA (mRNA) for 120 ion channels (and some related proteins) was measured in the SN, a novel paranodal area, and the right atrium (RA). The results showed, for example, that in the SN compared with the RA, there was a lower expression of Na(v)1.5, K(v)4.3, K(v)1.5, ERG, K(ir)2.1, K(ir)6.2, RyR2, SERCA2a, Cx40, and Cx43 mRNAs but a higher expression of Ca(v)1.3, Ca(v)3.1, HCN1, and HCN4 mRNAs. The expression pattern of many ion channels in the paranodal area was intermediate between that of the SN and RA; however, compared with the SN and RA, the paranodal area showed greater expression of K(v)4.2, K(ir)6.1, TASK1, SK2, and MiRP2. Expression of ion channel proteins was in agreement with expression of the corresponding mRNAs. The levels of mRNA in the SN, as a percentage of those in the RA, were used to estimate conductances of key ionic currents as a percentage of those in a mathematical model of human atrial action potential. The resulting SN model successfully produced pacemaking. CONCLUSIONS: Ion channels show a complex and heterogeneous pattern of expression in the SN, paranodal area, and RA in humans, and the expression pattern is appropriate to explain pacemaking.

Dynamic process methodology in the social and developmental sciences

Abstract: The Unbearable Dynamicity of Psychological Processes: Highlights of the Psychodynamic Theories.- Reviving Person-Centered Inquiry in Psychology: Why it's Erstwhile Dormancy?.- How Methodology Became a Toolbox-And How it Escapes from that Box.- The Two Disciplines of Scientific Psychology, or: The Disunity of Psychology as a Working Hypothesis.- The Experimental Methodology of Constructive Microgenesis.- The Schema Approach: A Dynamic View on Remembering.- Against Reification! Praxeological Methodology and its Benefits.- Grasping the Dynamic Nature of Intersubjectivity.- Idiographic Data Analysis: Quantitative Methods-From Simple to Advanced.- Depicting the Dynamics of Living the Life: The Trajectory Equifinality Model.- Analysis of Intensive Categorical Longitudinal Data.- Advances in Dynamic Factor Analysis of Psychological Processes.- Hidden Markov Models for Individual Time Series.- Multilevel Simultaneous Component Analysis for Studying Intra-Individual Variability and Inter-Individual Differences.- Idiographic Microgenesis: Re-Visiting the Experimental Tradition of Aktualgenese.- Dynamic Methods for Research in Education.- Social Dynamics in Complex Family Contexts and its Study.- Dynamics of Life-Course Transitions: A Methodological Reflection.- Dynamic Methodology in Infancy Research.- Dynamics of Psychotherapy Processes.- Dramatic Life Courses: Migrants in the Making.- Innovative Moments and Change Processes in Psychotherapy: An Exercise in New Methodology.- Techno Parties, Soccer Riots, and Breakdance: Actionistic Orientations as a Principle of Adolescence.- Dynamic Processes and the Anthropology of Emotions in the Life Course and Aging: Late-Life Love Sentiments and Household Dynamics in Tuareg Psycho-Biographies.- Synthetic Phenomena and Dynamic Methodologies.- Developmental Science: Integrating Knowledge About Dynamic Processes in Human Development.- Cognitive and Interactive Patterning: Processes of Creating Meaning.

Analyzing Developmental Processes on an Individual Level Using Nonstationary Time Series Modeling.

Abstract: Individuals change over time, often in complex ways. Generally, studies of change over time have combined individuals into groups for analysis, which is inappropriate in most, if not all, studies of development. The authors explain how to identify appropriate levels of analysis (individual vs. group) and demonstrate how to estimate changes in developmental processes over time using a multivariate nonstationary time series model. They apply this model to describe the changing relationships between a biological son and father and a stepson and stepfather at the individual level. The authors also explain how to use an extended Kalman filter with iteration and smoothing estimator to capture how dynamics change over time. Finally, they suggest further applications of the multivariate nonstationary time series model and detail the next steps in the development of statistical models used to analyze individual-level data.

Issues in Intraindividual Variability: Individual Differences in Equilibria and Dynamics Over Multiple Time Scales

Abstract: This article addresses three issues germane to experimental design and statistical analysis of intraindividual variability such as the articles contained within this special section. First, the time scale of the measurement of a process can have profound effects on the outcome of analyses of the resulting time series. Measurement in time poses special problems in the design of experiments: the time scale of the measurements must be appropriate for the time scale of the process. Second, deterministic and stochastic models should be fit at the individual level and only at a second level should individual differences in parameters be modeled. Third, one must consider the possibility that nomothetic relations may be exposed by the invariance of covariance between latent variables rather than within a factor analytic measurement model.

The Recoverability of P-technique Factor Analysis

Abstract: It seems that just when we are about to lay P-technique factor analysis finally to rest as obsolete because of newer, more sophisticated multivariate time-series models using latent variables-dynamic factor models-it rears its head to inform us that an obituary may be premature. We present the results of some simulations demonstrating that even though it does not explicitly model lagged information, P-technique's ability to recover the parameters of underlying dynamic processes involving lagged relations among the manifest variables is apparently robust and accurate. An empirical example is presented using 103 days of affective mood self-ratings from a young pregnant woman. Implications of the simulation and empirical findings are briefly discussed.

P2 purinergic receptor mRNA in rat and human sinoatrial node and other heart regions

Abstract: It is known that adenosine 5′-triphosphate (ATP) is a cotransmitter in the heart. Additionally, ATP is released from ischemic and hypoxic myocytes. Therefore, cardiac-derived sources of ATP have the potential to modify cardiac function. ATP activates P2X1–7 and P2Y1–14 receptors; however, the presence of P2X and P2Y receptor subtypes in strategic cardiac locations such as the sinoatrial node has not been determined. An understanding of P2X and P2Y receptor localization would facilitate investigation of purine receptor function in the heart. Therefore, we used quantitative PCR and in situ hybridization to measure the expression of mRNA of all known purine receptors in rat left ventricle, right atrium and sinoatrial node (SAN), and human right atrium and SAN. Expression of mRNA for all the cloned P2 receptors was observed in the ventricles, atria, and SAN of the rat. However, their abundance varied in different regions of the heart. P2X5 was the most abundant of the P2X receptors in all three regions of the rat heart. In rat left ventricle, P2Y1, P2Y2, and P2Y14 mRNA levels were highest for P2Y receptors, while in right atrium and SAN, P2Y2 and P2Y14 levels were highest, respectively. We extended these studies to investigate P2X4 receptor mRNA in heart from rats with coronary artery ligation-induced heart failure. P2X4 receptor mRNA was upregulated by 93% in SAN (P < 0.05), while a trend towards an increase was also observed in the right atrium and left ventricle (not significant). Thus, P2X4-mediated effects might be modulated in heart failure. mRNA for P2X4–7 and P2Y1,2,4,6,12–14, but not P2X2,3 and P2Y11, was detected in human right atrium and SAN. In addition, mRNA for P2X1 was detected in human SAN but not human right atrium. In human right atrium and SAN, P2X4 and P2X7 mRNA was the highest for P2X receptors. P2Y1 and P2Y2 mRNA were the most abundant for P2Y receptors in the right atrium, while P2Y1, P2Y2, and P2Y14 were the most abundant P2Y receptor subtypes in human SAN. This study shows a widespread distribution of P2 receptor mRNA in rat heart tissues but a more restricted presence and distribution of P2 receptor mRNA in human atrium and SAN. This study provides further direction for the elucidation of P2 receptor modulation of heart rate and contractility.

The effect of plasma from muscle-specific tyrosine kinase myasthenia patients on regenerating endplates.

Abstract: Muscle-specific tyrosine kinase (MuSK) is essential for clustering of acetylcholine receptors (AChRs) at embryogenesis and likely also important for maintaining synaptic structure in adult muscle. In 5 to 7% of myasthenia gravis (MG) cases, the patients’ blood contains antibodies to MuSK. To investigate the effect of MuSK-MG antibody on synapse regeneration, notexin was used to induce damage to the flexor digitorum brevis muscle. We administered aliquots of MuSK-MG patients’ plasma to the flexor digitorum brevis twice daily for a period up to 21 days, and muscles were investigated ex vivo in contraction experiments. AChR levels were measured with 125I-α-bungarotoxin, and endplates were studied with quantitative immunohistochemistry. In normal muscles and in 14-day regenerated muscles, MuSK plasma caused impairment of nerve stimulus-induced contraction in the presence of 0.35 and 0.5 mmol/L Ca2+ with or without 100 to 400 nmol/L tubocurarine. Endplate size was decreased in regenerated muscles relative to controls; however, we did not observe such differences in muscle not treated with notexin. MuSK plasma had no effect on the amount and turnover rate of AChRs. Our results suggest that anti-MuSK antibodies influence the activity of MuSK molecules without reducing their number, thereby diminishing the size of the endplate and affecting the functioning of AChRs.

Advances in Dynamic Factor Analysis of Psychological Processes

Abstract: The currently dominant, myopic approach to statistical analysis in psychology is based on analysis of inter-individual variation. Differences between subjects drawn from a population of subjects provide the information to make inferences about states of affairs at the population level. For instance, the factor structure of a personality test is determined by drawing a random sample of subjects from the population of interest, estimating the item correlation matrix by pooling across the scores of sampled subjects, and generalizing the results of the ensuing factor analysis to the population of subjects.

AChR deficiency due to ε-subunit mutations: two common mutations in the Netherlands

Abstract: Congenital myasthenic syndromes are a clinically and genetically heterogeneous group of hereditary disorders affecting neuromuscular transmission. We have identified mutations within the acetylcholine receptor (AChR) e-subunit gene underlying congenital myasthenic syndromes in nine patients (seven kinships) of Dutch origin. Previously reported mutations e1369delG and eR311Q were found to be common; e1369delG was present on at least one allele in seven of the nine patients, and eR311Q in six. Phenotypes ranged from relatively mild ptosis and external ophthalmoplegia to generalized myasthenia. The common occurrence of eR311Q and e1369delG suggests a possible founder for each of these mutations originating in North Western Europe, possibly in Holland. Knowledge of the ethnic or geographic origin within Europe of AChR deficiency patients can help in targeting genetic screening and it may be possible to provide a rapid genetic diagnosis for patients of Dutch origin by screening first for eR311Q and e1369delG.

Commentary on “Idiographic Filters for Psychological Constructs”

Abstract: This is a very interesting and important proposal for an alternative definition of measurement equivalence. In what follows, I will consider operational and conceptual aspects of the proposal. Defi...