ddc:100

The present study explored the concept of cognitive reserve by using a testing-the-limits paradigm (Kliegl et al., 1989). 140 young (M = 22.8 years, range = 20-30) and 140 older (M = 67.3 years, range = 57-75) adults were provided with extensive retest practice in the Digit Symbol Substitution Test (DSST) and a visual search task. Cognitive abilities (fluid reasoning, memory, attention) and personality dimensions (Big Five) served as predictors of retest improvement (i.e., cognitive reserve). Latent Growth Curve analyses demonstrated greater DSST improvement for the young group, but similar visual search improvement for both age groups, indicating age-independent cognitive reserve in visual search. Improvement rates for both tasks were weakly correlated, speaking rather for task-specific learning than for a general cognitive reserve. Cognitive reserve was rather independent from cognitive abilities and, with one exception, also from personality dimensions. Implications for cognitive reserve in general and DSST and visual search retest learning in particular are discussed.

Kognitive Reserve wird als individuelles Potential verstanden, um kognitive Herausforderungen zu meistern. Das Ziel der Studie bestand in einer Charakterisierung der Reserve bei Patienten mit unipolarer Depression im Vergleich zu gesunden Probanden. Das Ausmaß der Reserve wurde durch den Übungsgewinn in einem Testing-the-Limits Verfahren erhoben. Die Ergebnisse zeigten, dass Depression nicht zwangsläufig mit einer reduzierten Reserve assoziiert ist. Patienten mit kognitiven Defiziten in anderen Testverfahren weisen jedoch häufig auch eine verringerte Reserve auf. Das Ausmaß der Reserve bei Patienten ist dabei von Variablen der kognitiven Architektur und der Depressionsschwere, nicht aber von Persönlichkeit, Bildung und Lebensalter abhängig. Diskutiert wird u.a. ein Nutzen der kognitiven Reserve als Prädiktor von Therapieerfolg und Rückfallrisiko.

Es wurden 74 fremduntergebrachte Kinder und Jugendliche im Alter zwischen 10 und 18 Jahren sowie deren Pflegeeltern befragt. Es wurden unter anderem Informationen zu folgenden Punkten gesammelt: Grund der Fremdunterbringung, traumatische Vorkommnisse in der Herkunftsfamilie, vergangene und aktuelle Befindlichkeit und Belastung des Pflegekindes, grundsätzliches Vorkommen und Ausmaß der Symptome einer Posttraumatischen Belastungsstörung (PTBS). Dabei wurden eine Reihe von Instrumenten eingesetzt: Die Child Behavior Checklist (CBCL), Child Dissociative Checklist (CDC), Assessment Checklist for Children (ACC), die Familienklimaskalen (FKS), ressourcenorientierte Anfangsfragen für das Pflegekind, das Interview zu Belastungsstörungen für Kinder und Jugendliche (IBS-KJ), der Childhood Trauma Questionnaire (CTQ) und ein halbstandardisiertes exploratives Interview für Pflegeeltern (H-EIP). Es zeigte sich bezogen auf Forschungsaspekt 1 (Vorhersage der kindlichen PTBS-Belastung), dass die akutelle (internalisierende, externalisierende und dissoziative) Symptomatik sowie das Geschlecht einerseits und das Ausmaß kindlicher Traumatisierung in der Herkunftsfamilie sowie die Anzahl an Gründen für die Herausnahme andererseits als Prädiktoren zur Vorhersage der aktuellen PTBS bei Pflegekindern geeignet scheinen. Bezogen auf Forschungsaspekt 2 (Adaption der ACC für den deutschsprachigen Bereich) ergab sich, dass die Inhaltsvalidität der deutschen ACC gegeben sein dürfte. Die testtheoretischen Analysen sind für Skalen 2 bis 5 sowie Skalen 8 und 9a bzw. 9 und die Skalen NZ und SW als akzeptabel zu bezeichnen, so dass für diese Skalen eine vorläufig abschließende positive Beurteilung auf Basis der hier vorliegenden Daten erteilt werden konnte, die restlichen Skalen bedürfen erneuter Überprüfung an einer größeren Stichprobe. Die ersten Ergebnisse sprechen jedoch für eine klinische Nützlichkeit der ACC, Ökonomie und sonstige testtheoretische Kriterien (wie Reliabilität und Validität) konnten als zufriedenstellend beurteilt werden.

The focus of the current study is the individual and environmental attributes of inventiveness among children and adolescents. Research was conducted on the young inventors who were part of a nation-wide inventive ideation contest for children and adolescents in P. R. China. A total of 621 (303 boys, 318 girls, Mage = 13.9, SD = 2.5) 4th to 12th grade students from 112 schools all over China participated in the study. Among them, 38 (20 boys, 18 girls, Mage = 14.9, SD = 3.3) reported holding one or more patents. Independent t-test showed, compared to their lower-level counterparts, higher-level young inventors were more intrinsically motivated for inventive endeavours and were more open to new experiences. They also reported more encouragement and resources for invention from their schools. Logistic regression showed that school encouragement made the major contribution in discriminating these two groups. 2×3 MANONA revealed a significant main effect of gender and age group but no significant interaction between the two factors. Results of the univariate tests challenged the stereotyped view against the inventive ability of girls. Girls scored higher in Openness and lower in executive thinking style. The aesthetic appeal of their inventive products was also rated higher by experts. Albeit this superiority, girls, however, reported less encouragement from their parents to make inventions. Results of the cross-sectional study of the different age groups did not support a hypothesized growth of inventiveness from the lower to the higher grades. Instead, an uneven developmental pattern in inventiveness and the relevant domains were revealed, which was on the large part attributed to the influence of the educational environment. Taken together, the results of the current study highlight the important role the environmental factors play in fostering or hindering the development of inventiveness among children and adolescents.

Scham- und Schuldverarbeitung haben in verschiedenen Forschungsrichtungen eine hohe Relevanz, z.B. in den theologischen, soziologischen, aber auch in der psychologischen Forschung, sowie in der präventiven Diagnostik und Therapie einzelner Individuen. Sie leisten als „soziale Emotionen“ einen sehr wichtigen Beitrag zum emotionalen Erleben eines Individuums und zum Zusammenhalt vieler Individuen in einer Gesellschaft. Zwangserkrankungen mit Zwangsgedanken weisen im Vordergrund der Symptomatik oft-mals eine übermäßige Beschäftigung mit gesellschaftsorientierten und normorientierten Inhalten und Themen auf, die bei den Betroffenen ein Scham- und Schuldgefühl erzeugen. Die Frage, inwiefern Scham und Schuld von Zwangspatienten im Vergleich zu Gesunden unterschiedlich erlebt und verarbeitet werden stand im Vordergrund der Studie. Es wurden zwangserkrankte Patienten und gesunde Probanden (jeweils n=20; 50% weib-lich, Alter: 20-40 Jahre) mit neuropsychologischen und bildgebenden Verfahren im Hin-blick auf die Verarbeitung von Scham und Schuld untersucht. Neben Verfahren zur Stich-probenbeschreibung bestanden die erhobenen Verhaltensdaten aus Paper-Pencil-Fragebögen zu den Emotionen Scham und Schuld, sowie zu den Emotionen Angst und Aggression, der Selbstaufmerksamkeit und der eigenen Kontrollüberzeugung. Die Ergebnisse zeigen einen deutlichen Unterschied hinsichtlich der Verarbeitung von scham- und schuldbezogenen Inhalten bei Zwangspatienten im Vergleich zu Gesunden. Dies zeichnete sich in den Fragebögen ab, wobei Patienten ein intensiveres Erleben von Angst und Ärger beschrieben, eine signifikant höhere Selbstaufmerksamkeit im privaten und öffentlichen Bereich zeigten und signifikant seltener der Meinung waren, ihr Leben selbst kontrollieren und bestimmen zu können. Bezüglich der neuronalen Verarbeitung von Scham und Schuld zeigte sich bei beiden Emotionen vor allem eine generelle gesteigerte bilaterale frontale neuronale Aktivität bei den Patienten im Vergleich zur Kontrollgruppe. Diese Ergebnisse leisten einen Beitrag zur pathologischen Scham- und Schuldverarbeitung, die bislang noch nicht interdisziplinär neurofunktionell untersucht wurde, sowie einen Bei-trag zur Erklärung der Entstehung und Aufrechterhaltung von Zwangserkrankungen.

Die in der vorliegenden Arbeit untersuchten Pflegekinder haben in ihrer Vorgeschichte eine Vielzahl von traumatischen Ereignissen erlebt, die eine Fremdplatzierung notwendig machten. Die Traumaexposition von über 90% macht deutlich, dass fast jedes Pflegekind bereits mindestens ein traumatisches Ereignis erlebt hat. Das Risiko einer Traumatisierung liegt damit ungleich höher als in der Normalbevölkerung. Daher gehören Pflegekinder zu einer Hochrisikogruppe. Aufgrund des hohen Risikos, eine traumatische Situation zu erleben, erstaunt es, dass nur 5.4% nach den klassischen DSM-IV Kriterien und nur 13.5% nach den kinderspezifischen Kriterien von Scheeringa eine PTBS-Diagnose erhielten. Aufgrund methodischer Einschränkungen ist davon auszugehen, dass die PTBS-Belastung in der vorliegenden Stichprobe eher unterschätzt wird. Eine standardisierte Eingangsdiagnostik zu Beginn des Pflegeverhältnisses könnte hier Abhilfe schaffen. Zudem darf nicht übersehen werden, dass auch eine subklinische PTBS zu funktionalen Beeinträchtigungen führen kann.

In the following sections, English summaries of the three studies presented in this dissertation are given. For a detailed German synopsis of the present work, see chapter 8 (pp. 118 et seqq.). Research in the field of aging and dementia is a main concern as the population of elderly people is growing continuously due to increasing life expectancy and thus, an accumulative number of people who live well beyond 65 years of age run a risk of developing age-associated neurodegenerative disorders of cognitive function, such as Alzheimer’s disease (AD), emerging as a major health problem. The present work is based on growing evidence that deficits in visual selective attention occur early in the progression to AD (Foldi et al., 2002) and therefore might be present as the first non-memory deficits (Perry & Hodges, 1999) at the early prodromal stage of mild cognitive impairment (MCI; Petersen et al., 1999). The present dissertation was performed to contribute to the still ongoing debate as to whether certain aspects of visual selective attention are par-ticularly vulnerable or preserved, especially at the stage of MCI, and whether attentional func-tioning might be qualitatively and/ or quantitatively different from attentional performance at the AD stage on the one hand or normal functioning on the other hand. As theoretical basis, Bundesen’s theory of visual attention (TVA; Bundesen, 1990, 1998) was employed to assess several latent, mathematically independent and quantitative parameter es-timates which are derived from two highly comparable paradigms – computerized whole re-port and partial report of briefly presented visual letter arrays. Central conclusions arising out of TVA-based investigations (e.g., Bublak et al., 2005; Bublak, Redel, & Finke, 2006; Duncan et al., 1999; Duncan et al., 2003; Finke et al., 2006; Gerlach, Marstrand, Habekost, & Gade, 2005; Habekost & Bundesen, 2003; Habekost & Rostrup, 2006; Peers et al., 2005) point at four central strengths of this tool for attentional assessment – the quality criteria sensitivity, specificity, reliability and validity. Study 1: In AD, the amyloid cascade hypothesis (Hardy & Selkoe, 2002) assumes that rising plaque and tangle burden invokes loss of nerve cells through direct and indirect effects on synaptic, neuronal and neuritic function (see e.g. Cirrito et al., 2005), resulting in progressive intellectual decline. Thus, sensitive biomarkers loading functionally on the neural alterations invoked by AD from early on, might improve the possibility to identify at risk subjects in time, providing a chance for effective treatment (Shah et al., 2008). The first study (see chapter 4, pp. 31 et seqq.) examined whether cognitive parameters for estimating the capacity of visual attention might serve that purpose. Based on Bundesen’s (1990) TVA, visual information uptake was analyzed in 18 subjects with probable AD, 18 subjects with amnestic MCI, and 18 healthy elderly control subjects. Groups were matched for gender, age, and education. From a whole report task requiring ver-bal report of briefly presented letters, four parameters were derived, characterizing different aspects of visual processing capacity: perceptual threshold t0, iconic memory μ, processing speed C, and visual short-term memory (VSTM) storage capacity K. Comparison of these attentional parameters between groups revealed an elevation of the per-ceptual threshold already in MCI subjects, while processing speed and VSTM storage capacity showed a significant decline for AD patients, only. AD patients on medication with acetyl-choline esterase inhibitors had higher processing speed, but were still below the level of MCI patients. Perceptual threshold values were significantly correlated with disease duration, but not with cognitive measures. Conversely, speed and VSTM were significantly related to cog-nitive scores, but not to disease duration. In particular, VSTM storage was related to neurop-sychological tasks applying visual material (picture naming and visuo-construction), while speed showed an additional relationship also to measures of verbal memory. These results indicate a staged pattern of deficits affecting pre-attentive visual processing in MCI, and attentive processing in AD. They fit into the amyloid cascade hypothesis according to which the neuropathology of AD is characterized by a net accumulation and deposition of β-amyloid (Aβ) in the initial phase, giving rise to neuronal and neuritic dysfunction. Later, gradual neuronal loss and transmitter disturbances finally cause the increasing intellectual de-cline during further progression of the disease. A threshold elevation may thus be considered as a possible index of impaired neuronal functioning prior to cell death, while speed and VSTM deficits may be indicative already of a substantial loss of neuronal cell assemblies and a degeneration of neurotransmitter systems. Study 2: AD is the most frequent form of dementia which appears both as a familial and a sporadic va-riant. In the by far more frequent sporadic form, a genetic risk factor is also implicated, in that carriers of the apolipoprotein E ε4 allele (ApoE4) have a 3 to 15 times higher risk of develop-ing the disease, compared to non-carriers (Blennow, de Leon, & Zetterberg, 2006). Using an identical TVA-based partial report paradigm as in the present study, Finke et al. (2006) had found a close relationship between the severity of the underlying genetic pathology in another neurodegenerative, namely Huntington’s, disease and the direction and degree of spatial attentional weighting. Sensitive tools for assessing selective visual attention might serve as early cognitive markers in the course of AD and therefore enhance the identification rate of at-risk subjects at the MCI stage (Shah et al., 2008) as well as of subjects with underlying genetic risk (ApoE4). The second study (see chapter 5, pp. 60 et seqq.) aimed at examining whether attentional parameters of visuospatial and task-related selection are appropriate means for that purpose. Visual selective attention was investigated in 32 patients with amnestic MCI, 16 patients with probable AD, and 36 healthy elderly control subjects. Groups were matched for age, gender and educational level. In combination with Bundesen’s (1990) TVA, two mathematically in-dependent and quantitative parameter estimates were derived from a partial report of briefly presented letter arrays: top-down control of attentional selection, representing task-related at-tentional weighting for prioritizing relevant visual objects, and spatial distribution of atten-tional weights across the left and right visual hemifield. Compared to controls, MCI patients showed significantly reduced top-down controlled selec-tion which further deteriorated in AD subjects. Moreover, attentional weighting was signifi-cantly unbalanced across hemifields in MCI and tended to be more lateralized in AD. The ma-jority of patients was biased to the left. Across MCI and AD patients, ApoE4 carriers revealed a leftward spatial bias. The leftward bias was the more pronounced the younger the ApoE4-positive patients and the earlier disease onset. ApoE4-negative subjects showed balanced attentional weighting. These results indicate that impaired top-down control may be linked to early dysfunction of cortico-cortical networks connecting parietal and frontal lobes. Accompanying, an early inter-hemispheric asymmetry in temporo-parietal cortical interactions might cause a pathological spatial bias. As the inheritance of ApoE4 is associated with an interhemispheric imbalance in parietal cortical interactions, a pathological spatial bias may function as early cognitive marker for detecting subjects at risk for probable AD. Study 3: In the latter study, the TVA-based partial report paradigm proved to be a sensitive tool for ve-rifying that both, deficits in task-related selection and a pathological attentional imbalance, are already present at the early stage of amnestic MCI and increase further at the AD stage (see second study, chapter 5, pp. 60 et seqq.). It was hypothesized that these deficiencies in selective attention may result from an early disconnection syndrome and an interhemispheric imbalance in cortical interactions, respectively, in the fronto-parietal attention network, before gradual neuronal loss leads to further decline in selective attentional and intellectual functions at later stages. In the third study (see chapter 6, pp. 93 et seqq.), these hypotheses were tested by investigat-ing the relationship of both partial report parameters, top-down control α and especially the laterality index of attentional weighting wλ, to regional glucose metabolism measured by rest-ing-state positron emission tomography (PET) in a sample of 30 amnestic MCI or mild AD patients. Hypometabolism across all patients was slightly increased in the left hemisphere. Interestingly, the more reduced the metabolism in the left temporo-parietal junction (TPJ) the more pro-nounced was the top-down control deficit. Accordingly, hypometabolism in the left TPJ pre-dicted the magnitude of the spatial bias. Furthermore, relative hypometabolism in the left TPJ and left inferior parietal lobe (IPL) as compared to the right TPJ and right IPL, respectively, was correlated with direction and degree of spatial bias. Taken together, PET imaging results support the hypotheses that, one the one hand, early def-icits in task-related weighting may result from a fronto-parietal disconnection syndrome al-ready at the stage of MCI. On the other hand, very early AD seems to be also associated with an interhemispheric imbalance of metabolism, particularly in the temporo-parietal cortices, resulting in a correspondingly directed and distinctive visuo-spatial attentional bias. Conclusions and outlook: This dissertation intended to investigate the probable valuable contribution of the whole and partial report of briefly presented letter arrays based on Bundesen’s theory of visual attention (TVA; Bundesen, 1990, 1998; Bundesen, Habekost, & Kyllingsbaek, 2005) in assessing am-nestic MCI and AD patients in comparison to healthy elderly control subjects. The results of the three presented studies suggest a staging model of visual selective atten-tional impairments in MCI and AD. Deficits of pre-attentive processing (perceptual threshold t0), task-related (top-down control α) and spatial weighting (laterality index of attentional weighting wλ) were already detectable in MCI patients, while aspects of processing capacity (perceptual processing speed C and VSTM storage capacity K) were still intact. At a later stage of the disease, further deterioration of top-down control α and increasing lateralization of spatial weighting wλ accompanied impairments in perceptual processing speed C and VSTM storage capacity K. In conclusion, the TVA-based assessment of selective visual attention proved to be a sensitive diagnostic tool for revealing subtle deficits already at the stage of MCI which might exhibit the capability of an early cognitive marker for the identification of subjects at risk of AD. To address this question, this survey needs to be complemented by longitudinal studies.