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PubMed1988

Points and endpoints: a size/spacing constraint for dot grouping.

One-dimensional arrangements of dots immediately group into contours. It is reported that, when these contours participate in certain larger arrangements, there is an abrupt point at which the percept changes as a function of dot spacing (or density along the contour). Closely spaced arrangements give rise to subjective effects involving apparent brightness and depth, whereas sparsely spaced ones do not. The effects are most clear in configurations that involve endpoints and possible occlusions. For these configurations, densely dotted contours are perceptually equivalent to solid ones, but sparse ones are not. This change in percept occurs abruptly and consistently at a dot to space ratio of 1:5, when the dot density is normalized by dot size, and this point is called the size/spacing constraint. It holds only for dots of the order of 1 min visual angle in diameter when small to modest contrast values are used. The subjective effects are not present for dotted contours (or even for solid ones) that are smaller (less than 0.5 min), and differ for contours that are larger (greater than 10 min). To demonstrate the significance of size/spacing constraints for early vision, a framework for grouping consisting of processes at many different levels is outlined, and the requirements for the earliest one (orientation selection) are sketched in greater detail. The size/spacing constraint follows directly from one of these requirements--receptive field structure--and seems to indicate a switch from early orientation-selection processes to later ones.

Attention↗
PubMed2005

Improved postural control through repetition and consolidation.

Research regarding the optimal frequency of training in postural control rehabilitation has been sparse. Posturography with vibratory proprioceptive stimulation was performed with eyes open and closed on 36 healthy subjects divided into 3 groups. Each group was tested 5 times, though with different time-intervals; 20 minutes, 3 hours and 24 hours respectively. Two different adaptive processes seems to be involved in the formation of a new movement pattern when exposed to a postural disturbance, one fast adaptation active during each test occasion and a second adaptation active between the consecutive tests. As the same adaptation pattern was found regardless the repetition time interval, the results imply either that the consolidation process of the new motor memory is time-independent or that the stimulus was sufficiently strong to induce fast consolidation thus leaving the time-interval unimportant. The findings suggest that it is primarily the number of repetitions in the exercises that governs the outcome of training, whereas the time interval between the exercises is of less importance.

Adaptation, Psychological↗
PubMed1995

Interactions between location and task affect the spatial and directional firing of hippocampal neurons.

When rats forage for randomly dispersed food in a high walled cylinder the firing of their hippocampal "place" cells exhibits little dependence on the direction faced by the rat. On radial arm mazes and similar tasks, place cells are strongly directionally selective within their fields. These tasks differ in several respects, including the visual environment, configuration of the traversable space, motor behavior (e.g., linear and angular velocities), and behavioral context (e.g., presence of specific, consistent goal locations within the environment). The contributions of these factors to spatial and directional tuning of hippocampal neurons was systematically examined in rats performing several tasks in either an enriched or a sparse visual environment, and on different apparati. Place fields were more spatially and directionally selective on a radial maze than on an open, circular platform, regardless of the visual environment. On the platform, fields were more directional when the rat searched for food at fixed locations, in a stereotypic and directed manner, than when the food was scattered randomly. Thus, it seems that place fields are more directional when the animal is planning or following a route between points of special significance. This might be related to the spatial focus of the rat's attention (e.g., a particular reference point). Changing the behavioral task was also accompanied by a change in firing location in about one-third of the cells. Thus, hippocampal neuronal activity appears to encode a complex interaction between locations, their significance and the behaviors the rat is called upon to execute.

Animals↗
PubMed2001

Coding specificity in cortical microcircuits: a multiple-electrode analysis of primate prefrontal cortex.

Neurons with directional specificities are active in the prefrontal cortex (PFC) during tasks that require spatial working memory. Although the coordination of neuronal activity in PFC is thought to be maintained by a network of recurrent connections, direct physiological evidence regarding such networks is sparse. To gain insight into the functional organization of the working memory system in vivo, we recorded simultaneously from multiple neurons spaced 0.2-1 mm apart in monkeys performing an oculomotor delayed response task. We used cross-correlation analysis and characterized the effective connectivity between neurons in relation to their spatial and temporal response properties. The majority of narrow (<5 msec) cross-correlation peaks indicated common input and were most often observed between pairs of neurons within 0.3 mm of each other. Neurons recorded at these distances represented the full range of spatial locations, suggesting that the entire visual hemifield is represented in modules of corresponding dimensions. Nearby neurons could be activated in any epoch of the behavioral task (stimulus presentation, delay, response). The incidence and strength of cross-correlation, however, was highest among cells sharing similar spatial tuning and similar temporal profiles of activation across task epochs. The dependence of correlated discharge on the functional properties of neurons was observed both when we analyzed firing from the task period as well as from baseline fixation. Our results suggest that the coding specificity of individual neurons extends to the local circuits of which they are part.

Action Potentials↗
PubMed2005

Analysis of behavioral asymmetries in the elevated plus-maze and in the T-maze.

When studying functional asymmetries in normal laboratory rats, several behavioral tests have been applied and proven their utility, including turning in rotometers or open-fields, handedness in paw usage, T-maze alternation, and others. Here, we analyzed male Wistar rats in two tests, namely the elevated plus-maze and the T-maze. In these tests, behavioral asymmetries are rather likely to occur, since the animals have to show several types of turns towards the left or right when ambulating through these environments. In a first study using the plus-maze, we provide detailed data on (A) the types of turns which the animals showed when changing their direction within arms (i.e., 180 degrees turns), and (B) the types of turns when proceeding from one arm to an adjacent one (i.e., 90 degrees turns). With respect to asymmetry, we found moderate biases in favor of the right. On the 1st day of plus-maze testing, there was a trend for more rightward turns within arms. On the 2nd day of testing, there was a trend for turns towards the right when alternating between arms of the plus-maze. In a 2nd study, we asked for asymmetries in the plus-maze in animals, which had been treated acutely with the psychostimulatory amphetamine analogue 3,4-methylene-dioxymethamphetamine (MDMA). Psychostimulants drugs, especially amphetamine, have repeatedly been used before in work on functional asymmetry, since they can enhance or reveal asymmetries in normal rats. MDMA had dose-dependent effects on activity, which affected turns within arms, and turns between arms; however, there was only sparse evidence with respect to asymmetry. Interestingly, and if at all, asymmetry was in favor of the right. Finally, we present data for behavior in the T-maze, where we used a spontaneous test version, that is, the animals could explore the maze but had no task to solve. Asymmetries were measured as turns within the start arm (180 degrees), and as left- or rightward turns between arms (90 degrees ) at the T-point of the maze. In both measures, we again obtained evidence for asymmetries in favor of the right. This work supports previous studies showing that the T-maze is suitable to analyze behavioral asymmetries in rats. In addition, it provides new evidence with respect to the elevated plus-maze, indicating that this standard tool of anxiety research may also be useful in research on behavioral asymmetries and their underlying brain mechanisms. Behavioral biases in favor of the right, as shown here, have often been reported before, especially with Wistar rats. Such biases should be taken into account, since they can serve as an approach to study brain/behavior relationships, and since they may affect the outcome of physiological manipulations or behavioral trainings.

Analysis of Variance↗
PubMed1994

Neural ensemble coding in inferior temporal cortex.

1. Isolated, single-neuron extracellular potentials were recorded sequentially in area TE of the inferior temporal cortex (IT) of two macaque monkeys (n = 58 and n = 41 neurons). Data were obtained while the animals were performing a paired-associate task. The task utilized five stimuli and eight stimulus pairings (4 correct and 4 incorrect). Data were evaluated as average spike rate during experimental epochs of 100 or 400 ms. Single-unit and population characteristics were measured using a form of linear discriminant analysis and information theoretic measures. To evaluate the significance of covariance on population code measures, additional data consisting of simultaneous recordings from < or = 8 isolated neurons (n = 37) were obtained from a third macaque monkey that was passively viewing visual stimuli. 2. On average, 43% of IT neurons were activated by any of the stimuli used (60% if those inhibited also are included). Yet the neurons were rather unique in the relative magnitude of their responses to each stimulus in the test set. These results suggest that information may be represented in IT by the pattern of activity across neurons and that the representation is not sparsely coded. It is further suggested that the representation scheme may have similarities to DNA or computer codes wherein a coding element is not a local parametric descriptor. This is a departure from the V1 representation, which appears to be both local and parametric. It is also different from theories of IT representation that suggest a constructive basis set or "alphabet". From this view, determination of stimulus discrimination capacity in IT should be evaluated by measures of population activity patterns. 3. Evaluation of small groups of simultaneously recorded neurons obtained during a fixation task suggests that little information about visual stimuli is conveyed by covariance of activity in IT when a 100-ms time scale is used as in this study. This finding is consistent with a prior report, by Gochin et al., which used a 1-ms time scale and failed to find neural activity coherence or oscillations dependent on stimuli. 4. Population-stimulus-discrimination capacity measures were influenced by the number of neurons and to some extent the number and type of stimuli. 5. Information conveyed by individual neurons (mutual information) averaged 0.26 bits. The distribution of information values was unimodal and is therefore more consistent with a distributed than a local coding scheme.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Depth interpolation with sparse disparity cues.

The interpolation of stereoscopic depth given only sparse disparity information was investigated. The basic stimulus was a rectangle with zero disparity at one edge, and 20 or 30 min visual angle disparity at the other. The depth assigned to the ambiguous intervening locations was measured by means of a small briefly-flashed binocular comparison spot. For a stimulus consisting of a uniform rectangle presented on a background of random dots with zero disparity, interpolated depth was greater for a high mean contrast between rectangle and background than for a low mean contrast. Relative to a linear interpolation between the edges, a larger difference in edge disparity resulted in poorer depth interpolation. Depth interpolation based on rivalrous information was examined by filling the stimulus rectangle with narrow-band filtered noise which was uncorrelated between the two eyes. Four different passbands which were matched in apparent contrast were investigated. The results demonstrate that the rivalrous low-spatial-frequency content was resistant to interpolation; rivalrous high spatial frequencies did not interfere with depth interpolation. High-spatial-frequency stimuli yielded a percept similar to the uniform-field condition, whereas low-spatial-frequency stimuli lay in a depth plane near or even behind the background. In the latter case a transparent plane was perceived which was linearly interpolated between the two edges, and which floated above the rivalrous noise.

Attention↗
PubMed2003

Outcome after laparoscopic adjustable gastric banding - 8 years experience.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) has been our choice operation for morbid obesity since 1994. Despite a long list of publications about the LAGB during recent years, the evidence with regard to long-term weight loss after LAGB has been rather sparse. The outcome of the first 100 patients and the total number of 984 LAGB procedures were evaluated. METHODS: 984 consecutive patients (82.5% female) underwent LAGB. Initial body weight was 132.2 +/- 23.9 SD kg and body mass index (BMI) was 46.8 +/- 7.2 kg/m(2). Mean age was 37.9 (18-65). Retrogastric placement was performed in 577 patients up to June 1998. Thereafter, the pars flaccida to perigastric (two-step technique) was used in the following 407 patients. RESULTS: Mortality and conversion rates were 0. Follow-up of the first 100 patients has been 97% and ranges in the following years between 95% and 100% (mean 97.2%). Median follow-up of the first 100 patients who were available for follow-up was 98.9 months (8.24 years). Median follow-up of all patients was 55.5 months (range 99-1). Early complications were 1 gastric perforation after previous hiatal surgery and 1 gastric slippage (band was removed). All complications were seen during the first 100 procedures. Late complications of the first 100 cases included 17 slippages requiring reinterventions during the following years; total rate of slippage decreased later to 3.7%. Mean excess weight loss was 59.3% after 8 years, if patients with band loss are excluded. BMI dropped from 46.8 to 32.3 kg/m(2). 5 patients of the first 100 LAGB had the band removed, followed by weight gain; 3 of the 5 patients underwent laparoscopic Roux-en-Y gastric bypass (LRYGBP) with successful weight loss after the redo-surgery. 14 patients were switched to a "banded" LRYGBP and 2 patients to a LRYGBP during 2001-2002. The quality of life indices were still improved in 82% of the first 100 patients. The percentages of good and excellent results were at the highest level at 2 years after LAGB (92%). CONCLUSIONS: LAGB is safe, with a lower complication rate than other bariatric operations. Reoperations can be performed laparoscopically with low morbidity and short hospitalizations. The LAGB seems to be the basic bariatric procedure, which can be switched laparoscopically to combined bariatric procedures if treatment fails. After the learning curve of the surgeon, results are markedly improved. On the basis of 8 years long-term follow-up, it is an effective procedure.

Adult↗
PubMed2006

Typological effects on spelling development: a crosslinguistic study of Hebrew and Dutch.

This study investigates the role of phonological and morphological information in children's developing orthographies in two languages with different linguistic typologies: Hebrew, a Semitic language with a highly synthetic morphology, and Dutch, a Germanic language with a sparse morphology. 192 Israeli and 192 Belgian monolingual schoolchildren in grades 1-6 (aged 6;0-12;0) were administered respective dictation tasks in which homophonous segments were the targets. In each language, these phonologically distinct segments are neutralized phonetically but are nevertheless represented orthographically. In both languages the target segments in the test words differed along two dimensions: (1) their morphological function as part of a stem or root versus as part of an affix; and (2) their morphophonological recoverability. The spelling tests in both languages consisted of four conditions which differed in the number and type of cues for retrieving the correct spelling of homophonous graphemes. The cues were of two types: morphological cues, which offer spellers clues to the correct spelling through consistent orthography/morphology mapping regularities; and morphophonological cues, which offer spellers clues to the correct spelling through the manipulation of orthography/morphophonology conversion procedures. A central finding of this study is the differential treatment of morphological cues by Dutch and Hebrew spelling learners. When faced with neutralized segments with and without morphological function, Hebrew-speaking children find morphology an enormously helpful tool. Dutch-speaking children, in contrast, do not find morphology a good cue provider. The impact of typology on the interface between spoken and written language is invoked as an explanation of the main findings.

Belgium↗
PubMed2026

Disagreement-informed arbitration for gene regulatory network inference: A score-level meta-classifier and a diagnostic typology of inter-method conflict.

Gene regulatory network inference methods routinely disagree about individual edges, and practitioners resolve those conflicts by choosing one method or averaging them all. We ask whether the conflict can instead be arbitrated per edge. A gradient-boosted classifier is trained on the raw scores that ten inference methods-correlation-based, information-theoretic, sparse-regression and tree-ensemble, including GENIE3, GRNBoost2, CLR and ARACNe-assign to each candidate regulator-target pair, so that the weight given to each method varies from edge to edge. Across six single-cell perturbation screens spanning four cell types, arbitration improves on mean ensembling by +0.056 AUROC on Adamson and +0.083 on Shifrut under target-grouped cross-validation. The evaluation protocol turns out to matter more than the model. Edge-level cross-validation, standard in this literature, inflates apparent gains by 0.060 AUROC through target-gene leakage-comparable to the entire honest improvement. The effect is far larger for methods that represent genes implicitly: a supervised graph-attention link predictor trained on identical folds scores AUROC 0.930 under edge-level cross-validation, better than anything else we evaluate, and 0.533 once target genes are held out. Any method that parameterises genes is exposed, which covers most graph- and embedding-based approaches. A five-category typology of inter-method conflict localises where arbitration pays off, with the largest gains on edges where the methods disagree and the smallest where they already agree, while adding nothing as model input; we therefore report it as a diagnostic instrument rather than a modelling contribution. We also characterise what the ground truth measures: most perturbed genes in widely used screens are not transcription factors, and a mediation screen bounds how much of the perturbation response can be direct.

Ensemble methods↗
PubMed2000

Prefrontal dopamine is directly involved in the anxiogenic interoceptive cue of pentylenetetrazol but not in the interoceptive cue of chlordiazepoxide in the rat.

RATIONALE: The prefrontal cortical (PFC) dopamine (DA) system has been implicated in anxiety-related behavioral changes, but direct, unequivocal support for this idea is sparse. OBJECTIVES: The present aim was to study the functional significance of prefrontal DA using the pentylenetetrazol (PTZ) discrimination model of anxiety. A comparison was made with its role in the cue of the anxiolytic drug chlordiazepoxide (CDP). METHODS: Two groups of rats were trained to discriminate either PTZ (20 mg/kg, s.c.) or CDP (10 mg/kg, i.p.) from saline using an operant drug discrimination procedure. After prolonged training, half of each group was used to assess biochemical changes induced by both drugs in different sub areas of the PFC. For the remaining rats, discrimination training continued and generalization tests with PTZ and CDP were performed. Rats were then provided with bilateral guide cannulae aimed at the ventromedial (vm) PFC, and the effects of local infusions of DAergic drugs on discriminative performance were evaluated. RESULTS: CDP did not affect PFC DA activity, but PTZ increased the DOPAC/DA ratio in the vmPFC selectively. Generalization tests showed that the cues of PTZ and CDP were dose dependent. In PTZ-trained rats, infusions of the DA receptor antagonist cis-flupenthixol into the vmPFC blocked the PTZ cue dose dependently, whereas the agonist apomorphine partially generalized to this cue. In CDP-trained rats, neither drug antagonized or generalized to the CDP cue, showing that PFC DA is not critically involved in the CDP cue and that local pharmacological manipulations of PFC DA do not affect discriminative abilities per se. CONCLUSIONS: The DAergic innervation of the PFC is directly involved in the behavioral effects of PTZ suggesting a role for it in anxiety.

Animals↗
PubMed2003

Functional anatomy of pitch memory--an fMRI study with sparse temporal sampling.

Auditory functional magnetic resonance imaging tasks are challenging since the MR scanner noise can interfere with the auditory stimulation. To avoid this interference a sparse temporal sampling method with a long repetition time (TR = 17 s) was used to explore the functional anatomy of pitch memory. Eighteen right-handed subjects listened to a sequence of sine-wave tones (4.6 s total duration) and were asked to make a decision (depending on a visual prompt) whether the last or second to last tone was the same or different as the first tone. An alternating button press condition served as a control. Sets of 24 axial slices were acquired with a variable delay time (between 0 and 6 s) between the end of the auditory stimulation and the MR acquisition. Individual imaging time points were combined into three clusters (0-2, 3-4, and 5-6 s after the end of the auditory stimulation) for the analysis. The analysis showed a dynamic activation pattern over time which involved the superior temporal gyrus, supramarginal gyrus, posterior dorsolateral frontal regions, superior parietal regions, and dorsolateral cerebellar regions bilaterally as well as the left inferior frontal gyrus. By regressing the performance score in the pitch memory task with task-related MR signal changes, the supramarginal gyrus (left>right) and the dorsolateral cerebellum (lobules V and VI, left>right) were significantly correlated with good task performance. The SMG and the dorsolateral cerebellum may play a critical role in short-term storage of pitch information and the continuous pitch discrimination necessary for performing this pitch memory task.

Adolescent↗
PubMed2005

The influence of fear avoidance beliefs on disability and quality of life is sparse in Spanish low back pain patients.

STUDY DESIGN: Correlation between previously validated questionnaires. OBJECTIVES: To assess the influence of fear avoidance beliefs (FAB) on disability and quality of life in Spanish low back pain (LBP) patients. SUMMARY OF BACKGROUND DATA: FAB has shown to be a major determinant of disability in LBP patients in Northern European and Anglo-Saxon cultural environments. There are no data on its influence on Latin-Mediterranean patients. METHODS: The study was done in 12 primary care and 9 hospital services from seven different regions of Spain, with 209 patients who were in a potentially active working situation and visited the National Health Service for LBP. None was excluded and the sample was balanced for acute, subacute, and chronic patients. On their first visit and 14 days later, patients were given two independent Visual Analogue Scales (VAS) for LBP and leg pain, as well as the validated Spanish versions of the Fear Avoidance Beliefs (FABQ), Roland-Morris (RMQ), and SF-12 questionnaires. RESULTS: Correlations between LBP, leg pain, FABQ, disability, and quality of life were moderate on day 1 (r = 0.320-0.564) and stronger on day 15 (r = 0.457-0.637). All of them were statistically highly significant (P = 0.000). Regression models showed that LBP severity explains 33% of disability on day 1 and 20% on day 15, while FAB only explains 6% on day 1 and 2% on day 15. FAB does not explain mental quality of life. It explains only 5% of physical quality of life on day 1 and 4% on day 15. There was no interaction between FAB and chronicity, and FABQ values on day 1 did not predict disability or quality of life at day 15. CONCLUSIONS: As opposed to what has been shown in other cultural settings, FAB have virtually no clinical relevance in Spanish LBP patients who are treated in the National Health Service and who are in a potentially active working situation. The influence of FAB on disability is minimal and much less than that of pain severity, and their contribution to the patient's quality of life is irrelevant. Further studies should explore the potential value of FAB in other Latin-Mediterranean countries.

Adult↗
PubMed2006

Success factors for telehealth--a case study.

PURPOSE: To present the lessons learned from an evaluation of a comprehensive telehealth project regarding success factors and evaluation methodology for such projects. METHODS: A recent experience with the evaluation of new telehealth services in BC, Canada, is summarized. Two domains of clinical applications, as well as educational and administrative uses, and the project environment were evaluated. In order to contribute to the success of the project, the evaluation included formative and summative approaches employing qualitative and quantitative methods with data collection from telehealth events, participants and existing databases. The evaluation had to be carried out under severe budgetary and time constraints. We therefore deliberately chose a broad ranging exploratory approach within a framework provided, and generated questions to be answered on the basis of initial observations and participant driven interviews with progressively more focused and detailed data gathering, including perusal of a variety of existing data sources. A unique feature was an economic evaluation using static simulation models. RESULTS: The evaluation yielded rich and detailed data, which were able to explain a number of unanticipated findings. One clinical application domain was cancelled after 6 months, the other continues. The factors contributing to success include: Focus on chronic conditions which require visual information for proper management. Involvement of established teams in regular scheduled visits or in sessions scheduled well in advance. Problems arose with: Ad hoc applications, in particular under emergency conditions. Applications that disregard established referral patterns. Applications that support only part of a unit's services. The latter leads to the service mismatch dilemma (SMMD) with the end result that even those e-health services provided are not used. The problems encountered were compounded by issues arising from the manner in which the telehealth services had been introduced, in particular the lack of time for preparation and establishment of routine use. Educational applications had significant clinical benefits. Administrative applications generated savings which exceeded the substantial capital investment and made educational and clinical applications available at variable cost. CONCLUSION: Evaluation under severe constraints can yield rich information. The identified success factors, including provision of an overarching architecture and infrastructure, strong program management, thorough needs analysis and detailing applications to match the identified needs should improve the sustainability of e-health projects. Insights gained: Existing assumptions before the study was conducted: Evaluation has to proceed from identified questions according to a rigorous experimental design. Emergency and trauma services in remote regions can and should be supported via telehealth based on video-conferencing. Educational applications of telehealth directed at providers are beneficial for recruitment and retention of providers in remote areas. Insights gained by the study: An exploratory approach to evaluation using a multiplicity of methods can yield rich and detailed information even under severe constraints. Ad hoc and emergency clinical applications of telehealth can present problems unless they are based on thorough, detailed analyses of environment and need, conform to established practice patterns and rely on established trusting collaborative relationships. Less difficult applications should be introduced before attempting to support use under emergency conditions. Educational applications are of interest beyond the provider community to patients, family and community members, and have clinical value. In large, sparsely populated areas with difficult travel conditions administrative applications by themselves generate savings that compensate for the substantial capital investment for telehealth required for clinical applications.

British Columbia↗
PubMed2006

Emotional, behavioral, social, and academic outcomes in adolescents born with very low birth weight.

BACKGROUND: Very low birth weight survivors are at increased risk of developing emotional and behavioral problems and low social and academic competencies. Information on such problems in very low birth weight adolescents is still sparse. OBJECTIVES: Our purpose for this work was to study gender-specific emotional and behavioral problems and social and academic competencies in a cohort of very low birth weight adolescents in north Norway. METHODS: Families with very low birth weight adolescents aged 13 to 18 years, born between 1978 and 1989 (n = 162) were addressed by mail and asked to complete the Child Behavior Check List and the Youth Self-Report. Data were compared with 2 normative adolescent populations (Child Behavior Check List, n = 540; Youth Self-Report, n = 2522). Scores given by very low birth weight adolescents and their parents on identical items in Child Behavior Check List and Youth Self-Report (cross-informant syndrome constructs) were compared in pairs. To explore predictive effects, demographic and early medical characteristics were entered into a hierarchical multiple regression analysis. RESULTS: There were 156 eligible families, and 99 (63.5%) responded. All completed the Child Behavior Check List, and 82 (52.6%) completed the Youth Self-Report. Very low birth weight boys reported less externalizing and internalizing behaviors and thought and attention problems and higher activity score, whereas very low birth weight girls reported less externalizing behavior and less social, thought, and attention problems and higher activity score compared with normative adolescents. Very low birth weight parents, however, reported more social and attention problems and less social and school competence in boys and more internalizing behavior and social and attention problems and less school competence in girls compared with normative parents. They scored high proportions of both genders within the borderline/clinical range on all of the scales, except for externalizing behavior and social problems in girls. Female very low birth weight adolescents, in contrast to males, reported more problems than parents when compared in pairs, and externalizing problems in particular were not recognized by parents. CONCLUSIONS: From parents' point of view, significant proportions of very low birth weight adolescents experience more emotional and behavioral problems and less competence than normative adolescents. In contrast, very low birth weight adolescents state less problems and similar or higher competence than normative adolescents. Very low birth weight adolescent girls report more emotional and behavioral problems compared with their parents than very low birth weight adolescent boys do. Externalizing problems in very low birth weight adolescent girls are often not recognized by parents. To better understand these seemingly paradoxical findings and to develop adequate intervention programs, there is a need for prospective longitudinal studies.

Adolescent↗