The secular trend of intelligence test scores: The Danish experience for young men born between 1940 and 2000.

The present study investigated the Danish secular trend of intelligence test scores among young men born between 1940 and 2000, as well as the possible associations of birth cohort changes in family size, nutrition, education, and intelligence test score variability with the increasing secular trend. The study population included all men born from 1940 to 2000 who appeared before a draft board before 2020 (N = 1,556,770). At the mandatory draft board examination, the approximately 19-year-old men underwent a medical examination and an intelligence test. In the statistical analyses, the IQ mean and standard deviation (SD) were estimated separately for each of the included annual birth cohorts based on information from birth cohorts with available total intelligence test scores for all tested individuals (i.e. 1940-1958 and 1987-2000; the mean and SD were interpolated for the intermediate birth cohorts). Moreover, the possible associations with birth cohort changes in family size, height as a proxy for nutritional status, education, and IQ variability were investigated among those birth cohorts for whom a secular increase in intelligence test scores was found. The results showed that the estimated mean IQ score increased from a baseline set to 100 (SD: 15) among individuals born in 1940 to 108.9 (SD: 12.2) among individuals born in 1980, since when it has decreased. Focusing on the birth cohorts of 1940-1980, for whom a secular increase in intelligence test scores was found, birth cohort changes in family size, height, and education explained large proportions of the birth cohort variance in mean intelligence test scores, suggesting that these factors may be important contributors to the observed Flynn effect in Denmark.

Is There a Correlation Between the Number of Brain Cells and IQ?

Our access to a unique material of postmortem brains obtained from decades of data collection enabled a stereological analysis of the neuron numbers and correlation of results with individual premorbid intelligence quotient (IQ) data. In our sample of 50 brains from men, we find that IQ does not correlate with the number of brain cells in the human neocortex and was only weakly correlated to brain weight. Our stereological examination extended to measures of several other parameters that might be of relevance to intelligence, including numbers of cerebral glial cells (astrocytes, oligodendrocytes, and microglia) and the volume of key areas in the gray and white matter and of the cerebral ventricles, also showing near-zero nonsignificant correlations to IQ.

Assessment of cognitive ability at conscription for the Danish army: Is a single total score sufficient?

Børge Priens Prøve (BPP) was developed for the Danish Army by psychologist Børge Prien in the 1950s, as a test of general cognitive ability for use at conscription for the Danish armed forces. The final BPP (1957) had four subtests; a Raven-like matrix subtest, and three subtests measuring verbal, numerical, and visuospatial ability. The BPP is a speeded test counting the number of correct responses within 45 minutes. Thus, we consider the BPP as a measure of "cognitive efficiency" rather than a pure measure of cognitive ability. The BPP is still in use.Using techniques available in 1960, Rasch concluded that the matrices and numerical tests appeared to satisfy the requirements of the Rasch (Probabilistic models for some intelligence and attainment tests, Danish Institute for Educational Research, Copenhagen; 1960) model, while the verbal and visuospatial tests did not. Since then, there have been, to our knowledge, no published studies of the psychometric scaling properties of the BPP, partly because the practice of the Danish draft board has been to record only the total score. We examine these properties by analysis of data from two cohorts (n = 9,491), using the Leunbach (A probabilistic measurement model for assessing whether two tests measure the same personal factor. The Danish Institute of Educational, Copenhagen, Denmark; 1976) model to assess whether the sum of the four subtests provides a statistically sufficient measure of a common latent trait. Since we found only weak evidence against fit to the Leunbach model, we claim that this warrants the use of a summarized total BPP score. We examined whether BPP subscales suffered from differential test functioning (DTF) relative to samples. Weak, and for practical purposes too weak, DTF was suggested for one subscale.

Cognitive behavioural treatment for the chronic post-traumatic headache patient: a randomized controlled trial.

BACKGROUND: Chronic post-traumatic headache (CPTH) after mild head injury can be difficult to manage. Research is scarce and successful interventions are lacking.To evaluate the effect of a group-based Cognitive Behavioural Therapy (CBT) intervention in relation to headache, pain perception, psychological symptoms and quality of life in patients with CPTH. METHODS: Ninety patients with CPTH according to ICHD-2 criteria were enrolled from the Danish Headache Center into a randomized, controlled trial. Patients were randomly assigned to either a waiting list group or to a nine-week CBT group intervention. At baseline and after 26 weeks all patients completed the Rivermead Post Concussion Symptoms Questionnaire, SF-36, SCL-90-R and a headache diary. RESULTS: The CBT had no effect on headache and pressure pain thresholds and only a minor impact on the CPTH patients' quality of life, psychological distress, and the overall experience of symptoms. The waiting-list group experienced no change in headache but, opposed to the treatment group, a significant decrease in somatic and cognitive symptoms indicating a spontaneous remission over time. CONCLUSIONS: Our primarily negative findings confirm that management of patients with CPTH still remains a considerable challenge. Psychological group therapy with CBT might be effective in an earlier stage of CPTH and in less severely affected patients but our findings strongly underline the need for randomized controlled studies to test the efficacy of psychological therapy.

Adult cognitive ability and educational level in relation to concussions in childhood and adolescence: a population study of young men.

OBJECTIVE: To investigate the relationship of concussion(s) suffered through childhood and adolescence with completed level of school education and cognitive ability in young adulthood. METHODS: Educational level and scores on a test of cognitive ability were obtained for a cohort of 130,298 young men processed by the Danish draft board. Of these, 6146 had, at some age from birth onwards, been briefly admitted to hospital with a main discharge diagnosis of concussion. A further 402 had two such concussions and 48 had three or more. RESULTS: Educational level and cognitive ability test scores were negatively associated with the number of concussions and the age at concussion(s). Most markedly, compared to the 123,684 non-concussed men, those with two or more concussions had lower educational levels (OR = 0.48; 95% CI = 0.26-0.89), as also did those sustaining one concussion between the age of 13 up to the time of testing (OR = 0.47: 0.42-0.52). CONCLUSIONS: Since concussions do not generally have long-term effects, the results suggest that lower educational level is primarily a risk factor for sustaining a concussion at all ages, but in particular in adolescence more than in childhood and in the case of multiple concussions. It should, however, be recognized that, in some proportion of cases, the educational deficits have probably arisen as a consequence of the persistent symptoms of a lengthy post-concussional syndrome.

Conscious knowledge influences decision-making differently in substance abusers with and without co-morbid antisocial personality disorder.

Decision-making impairment, as measured by the Iowa Gambling Task (IGT), is a consistent finding among individuals with substance use disorder (SUD). We studied how this impairment is influenced by co-morbid antisocial personality disorder (ASPD) and conscious knowledge of the task. Three groups were investigated: SUD individuals without co-morbid ASPD (n = 30), SUD individuals with co-morbid ASPD (n = 16), and healthy controls (n = 17). Both SUD and SUD+ASPD participants had poor overall IGT performance. A block-by-block analysis revealed that SUD participants exhibited slow but steady improvement across the IGT, whereas SUD+ASPD participants exhibited initial normal improvement, but dropped off during the last 40 trials. Conscious knowledge of the task was significantly correlated to performance for controls and SUD participants, but not for SUD+ASPD participants. Our findings suggest that decision-making proceeds differently in SUD and SUD+ASPD individuals due to differences in acquisition and application of conscious knowledge.

Family matters: parental-acquired brain injury and child functioning.

OBJECTIVES: To relate illness related to and family factors to emotional and behavioural problems in school-age children (7-14 years old) of parents with acquired brain injury and their healthy spouses. PARTICIPANTS, MATERIALS/METHODS: Members of 35 families in which a parent had been diagnosed with acquired brain injury participated. Family and brain injury characteristics were reported by the ill and healthy parents. Children self-reported post-traumatic stress symptoms (PSS) using the Child Impact of Events revised (CRIES). Emotional and behavioural problems among the children were also identified by the parents using the Achenbach's Child Behaviour Checklist (CBCL). RESULTS: The family stress variables relating to the healthy spouse in all six comparisons were significant (p <= 0.05) or nearly so (p = 0.07) in each case showing higher scores for spouses to be associated with higher CRIES and CBCL total scores for the children. For the adjusted associations, we again found the family stress variables in the healthy spouse to be related to the risk of emotional and behavioral problems in the children. CONCLUSIONS: The present results suggest that in ABI families, the children's emotional functioning depends upon family factors and primarily on the level of parental stress in the healthy parent.

Cognitive impairment in the preclinical stage of dementia in FTD-3 CHMP2B mutation carriers: a longitudinal prospective study.

OBJECTIVE AND METHODS: A longitudinal study spanning over 8 years and including 17 asymptomatic individuals with CHMP2B mutations was conducted to assess the earliest neuropsychological changes in autosomal dominant neurodegenerative disease frontotemporal dementia (FTD) linked to chromosome 3 (FTD-3). Subjects were assessed with neuropsychological tests in 2002, 2005 and 2010. RESULTS: Cross-sectional analyses showed that the mutation carriers scored lower on tests of psychomotor speed, working memory, executive functions and verbal memory than a control group consisting of not-at-risk family members and spouses. Longitudinal analyses showed a gradual decline in psychomotor speed, working memory capacity and global executive measures in the group of non-demented mutation carriers that was not found in the control group. In contrast, there were no significant group differences in domain scores on memory or visuospatial functions. On an individual level the cognitive changes over time varied considerably. CONCLUSION: Subjects with CHMP2B mutation show cognitive changes dominated by executive dysfunctions, years before they fulfil diagnostic criteria of FTD. However, there is great heterogeneity in the individual cognitive trajectories.

Post-traumatic stress symptoms and psychological functioning in children of parents with acquired brain injury.

INTRODUCTION/OBJECTIVES: The effect of parental brain injury on children has been relatively little investigated. This study examines post-traumatic stress symptoms (PSS) and psychological functioning in children with a parent with an acquired brain injury. PARTICIPANTS, MATERIALS AND METHODS: The participants were 35 patients with acquired brain injury, their spouses and children aged 7-14 years recruited from out-patient brain injury rehabilitation units across Denmark. Children self-reported psychological functioning using the Becks Youth Inventory (BYI) and Child Impact of Events revised (CRIES) measuring PSS symptoms. Emotional and behavioural problems among the children were also identified by the parents using the Achenbach's Child Behaviour Checklist (CBCL). A matched control group, consisting of 20 children of parents suffering from diabetes, was recruited from the National Danish Diabetes Register. RESULTS: Post-traumatic stress symptoms above cut-off score (<30) were found (CRIES) in 46% of the children in the brain injury group compared to 10% in the diabetes group. The parents in the brain injury group reported more emotional and behavioural problems in their children when compared to published norms (CBCL). CONCLUSIONS: When parents have acquired brain injury, their children appear to be at a substantial risk for developing post-traumatic stress symptoms. These results indicate the need for a child-centred family support service to reduce the risk of children being traumatized by parental brain injury, with a special focus on the relational changes within the family.

The reliability and validity of the Danish Draft Board Cognitive Ability Test: Børge Prien's Prøve.

The Danish Draft Board has used the same test for assessing general cognitive ability, the Børge Prien's Prøve (BPP), for over 50 years during which time all men on reaching the age of 18 become liable for conscription. Data from the test has, over the decades, been used in numerous and wide-ranging research studies. Nonetheless, owing to the special circumstances of its administration, some psychometric properties, which are generally assessed for psychological tests, have not previously been investigated for the BPP. First, since the test is only used at the assessment phase, retesting with the BPP occurs only rarely and under exceptional circumstances. Therefore, its Test-Retest reliability has hitherto not been documented. Second, questions have often been raised as to whether the validity of the BPP is undermined by either a lack of motivation and under-performing among some of the men taking the test, being, as they are, compelled to do so, and/or by gradual obsolescence of the test over the decades of its use. We here present findings from three new studies to show that (a) the BPP has a satisfactory Test-Retest reliability, r=0.77, (b) BPP test scores are not positively associated with expressed attitude to being called upon to serve conscription and (c) the correlation between the BPP and a measure of educational level has remained stable (at about 0.5) through the last two decades. Taken together these three findings further support the continuing value of the BPP in research relating to cognitive ability.

Spanish, French, and British cross-cultural validation of the European Brain Injury Questionnaire.

OBJECTIVE: To explore the factor structure of the European Brain Injury Questionnaire and to assess the cross-cultural and construct validity of this questionnaire by using Rasch analysis. PARTICIPANTS: A total of 366 individuals with traumatic brain injury or stroke were recruited from 3 different countries: Spain (116 participants), the United Kingdom (110 participants), and France (140 participants). ANALYSES: We first performed a factor analysis and then applied Rasch analysis to the resulting factors to examine construct and cross-cultural validity. RESULTS: Three subscales labeled Depressive Mood, Cognitive Dysfunction, and Poor Social and Emotional Self-regulation were extracted using the factor analysis. In the Rasch analyses, 8 items were removed because of misfit and 7 items showed differential item functioning by country. CONCLUSION: Rasch analyses showed good fit to the model, unidimensionality, construct validity, and good reliability of the 3 European Brain Injury Questionnaire subscales. However, only the Depressive and Cognitive subscales showed cross-cultural validity.

The Danish draft board's intelligence test, Børge Priens Prøve: psychometric properties and research applications through 50 years.

For over 50 years the Danish draft board has used the same test, Børge Priens Prøve (BPP) for cognitive abilities, involving four paper-and-pencil subtests, to assess suitability for conscription. The potential availability of test scores has been an invaluable resource for research into factors relating to intelligence. In this article the circumstances of the original development of the test are briefly presented, followed by a description of the four subtests and the conditions of testing, scoring and result registration. Over forty studies are identified, including some unpublished, which have explored the psychometric properties of the BPP and have shown the relationships between intelligence as measured by the BPP and a wide range of biological, social and health-related factors.

Assessment of unilateral spatial neglect: scoring star cancellation performance from video recordings--method, reliability, benefits, and normative data.

Unilateral spatial neglect, a debilitating condition affecting awareness of one side of space, is commonly assessed using cancellation tasks in which patients cross out targets distributed over a sheet. Standard scores emphasize the left-right distribution of omissions. Here, the additional value of extracting temporal as well as spatial aspects of performance from video recordings was examined. Videos from 18 patients with left neglect and 19 healthy age-matched control participants were obtained. Interrater reliability of the video analysis was high. In addition to overall differences in target detection and bias, patients significantly differed from the control group in terms of the location of first cancellation, overall slowness, greater variability in speed, systematic slowing with time on task and as a function of target location, less coherent search organization, and a sharply increased tendency to recancel targets. Considering a subset of patients whose scores, by standard criteria, were at or near the normal range indicated that these additional variables indeed increased the sensitivity of the task as well as allowed the simultaneous assessment of spatial and nonspatial aspects of the disorder.

Alleviation of carer strain during the use of the NeuroPage device by people with acquired brain injury.

BACKGROUND: Previous studies have demonstrated the efficacy of a paging system, NeuroPage (Cambridgeshire Primary Care Trust Corporation, Fulbourn, Cambridgeshire, UK), in compensating for memory and planning dysfunctions in people with acquired brain injury (ABI; mainly stroke or traumatic brain injury). In this study, the degree to which this efficacy is accompanied by a reduced experience of strain among carers of patients with ABI was investigated. METHODS: Carers of 99 people with ABI completed a questionnaire concerning strain resulting from caring for the injured individual. The questionnaire was completed at the following three time points: before the use of NeuroPage, at the end of a 7-week period of use, and, for one subgroup, a further 7 weeks after withdrawal of NeuroPage. RESULTS: There were significant reductions in strain reported by carers following the 7-week period of NeuroPage use (Cohen's d = 0.3-0.4). This finding persisted when the carer was a spouse or a parent. The reduced strain among carers continued even after withdrawal of NeuroPage. CONCLUSION: The efficacy of the NeuroPage paging system for people with ABI appears to result in reduced strain for their carers.

The relationship between clients' cognitive functioning and the therapeutic working alliance in post-acute brain injury rehabilitation.

OBJECTIVE: To examine the impact of brain-injured patients' cognitive abilities on their working alliance (WA) with their therapist in post-acute rehabilitation. DESIGN: Cognitive tests were administered to brain-injured individuals at the beginning of post-acute, holistic brain-injury rehabilitation. Clients as well as their primary therapists rated their mutual WA at four time points throughout a 14-week rehabilitation programme. Subjects consisted of 86 clients as well as their primary therapists. Clients had suffered a traumatic brain injury (n = 27), a cerebrovascular accident (n = 49) or another neurological insult (n = 10). MEASURES: (1) Neuropsychological tests of attention, memory and higher cognitive functions; (2) the Working Alliance Inventory, client and therapist short form. RESULTS: Overall, the relationships between cognitive tests and WA ratings were weak. The tests of attention, memory and higher cortical functions were differentially related to clients' and therapists' view of their mutual WA at the different stages of their collaborative work. DISCUSSION AND CONCLUSION: Clients' cognitive profile affects clients' and therapists' view of their WA in different ways. The weakness of the correlations between cognitive tests and WA ratings may indicate that a good WA is achievable also with clients with severe cognitive difficulties.

Hearing loss in relation to educational attainment and cognitive abilities: a population study.

Severe hearing loss among children has often been found to be associated with educational disadvantage and lower-than-average performance on cognitive tests, but less is known about the much more widespread milder levels of hearing loss. In a cohort of 22 162 young Danish men appearing before the draft board, about 75% had normal hearing at 20 dB, and about 20% had mild hearing loss not worse than 25 dB in both ears for all tones less than 3000 Hz, and not worse than an average of 45 dB in both ears for all tones above 2000 Hz. The remaining 5% had more severe hearing loss. The proportions who had continued school education after age 16 years among the three groups were 51%, 42% and 34% respectively and their mean IQs were 101, 98 and 94. The evidence suggests that even mild hearing loss is associated with distinct educational and cognitive disadvantage which itself may result from difficulties in following classroom teaching.

Subjective outcome of brain injury rehabilitation in relation to the therapeutic working alliance, client compliance and awareness.

OBJECTIVE: To investigate the relationship between working alliance, compliance, awareness and subjective outcome of brain injury rehabilitation. Subjects were 86 patients who were clients in an holistic neuropsychological outpatient rehabilitation programme. They had suffered a traumatic brain injury (n = 27), a cerebrovascular accident (n = 49) or some other neurological insult (n = 10). MEASURES: The therapeutic alliance, clients' awareness and their compliance were rated four times during the 14-week rehabilitation programme. The therapeutic alliance was rated by both clients and therapist using the Working Alliance Inventory (WAI), awareness and compliance were rated by the therapists. Clients completed the European Brain Injury Questionnaire (EBIQ) at programme start and end. Clients and therapists rated the overall success of their collaboration at programme end. RESULTS: Clients' experience of a good emotional bond between themselves and therapists in mid-therapy was predictive for the reduction of clients' report of depressive symptoms on the EBIQ depression sub-scale (R = 0.68, n = 43, p < 0.001). Good compliance early in the programme was predictive of changes on the EBIQ. Improvement of awareness was related to the amplification of depressive symptoms (r = -0.27, n = 56, p < 0.05). CONCLUSIONS: Brain injury rehabilitation should be seen as a dynamic process that develops between clients and therapists. Future research should further investigate the relationship between process and outcome and how the therapeutic process can be optimized.

Patient compliance in brain injury rehabilitation in relation to awareness and cognitive and physical improvement.

UNLABELLED: The purpose of the present study was to investigate the relationship between patients' compliance and awareness and outcome of brain injury rehabilitation. Subjects were 98 patients who underwent a holistic neuropsychological outpatient rehabilitation programme. Patients had suffered a traumatic brain injury (n = 26), a cerebrovascular accident (n = 58), or another neurological insult (n = 14). MEASURES: Two staff members, a neuropsychologist and a physiotherapist, retrospectively and separately rated patients' awareness and their compliance. Outcome was measured with the d2 test of concentration, measures of oxygen uptake, strength endurance, running speed, and patients' and relatives' ratings of patients' cognitive, physical, and overall problems on the European Brain Injury Questionnaire (EBIQ). The discrepancy between patients' and relatives' ratings on the EBIQ was incorporated as a second measure of patients' awareness. RESULTS: The neuropsychologist's compliance ratings were significantly related to measures of insight, improvement of d2 performance accuracy and stability, improvement of oxygen uptake, and reduction of cognitive and overall problems as reported by the patients, while the physiotherapist's compliance ratings were related to measures of insight, improvement of d2 performance speed, improvement of oxygen uptake and strength endurance, and all three EBIQ patient scales. DISCUSSION: The results suggest a differential relationship between situation-specific compliance and outcome.

Working alliance and patient compliance in brain injury rehabilitation and their relation to psychosocial outcome.

Employment and physical activity at follow up of 98 patients who underwent a holistic neuropsychological outpatient rehabilitation programme were examined in relation to therapeutic process factors. The patients had suffered a traumatic brain injury (n = 26), a cerebrovascular accident (n = 58) or another neurological insult (n = 14). Two staff members, a neuropsychologist and a physiotherapist, retrospectively rated patients' compliance with the therapeutic regime and their working alliances. They completed the ratings separately, but had some degree of common knowledge about the patients. While the compliance ratings were closely associated, working alliance ratings differed between the raters. The working alliance ratings were predictive of employment, but not physical activity. Both compliance ratings predicted physical training, but only the neuropsychologist's compliance rating was associated with follow-up employment. Post-hoc analysis showed that high compliance ratings given by the physiotherapist were also a predictor of employment. Overall, there was a tendency for the neuropsychologist's ratings to be more closely associated with employment than the physiotherapist's ratings. These results indicate that employment and physical activity are differentially predictable from different process measures rated from different professional perspectives.