Dynamiken deklarativer Gedächtnisleistungen vom Säuglings- zum Kleinkindalter

Deferred imitations assess declarative memory in infants. Many cross-sectional and a few longitudinal studies revealed that, with development, infants learn faster,and retain more target actions over longer retention intervals. Longitudinal stabilities are modest and increase through the second year. To date, there are only few multivariate deferred imitation studies pointing to interactions between declarative memory, language and self-development. However, as these studies applied variable-centered data analysis approaches, the individual stance was not taken into account.Therefore, the present dissertation focuses on the explanation of inter-individual differences of deferred imitation through the second year. In the multivariate, longitudinal Frankfurt Memory Study (FRAMES), declarative memory (deferred imitation), non-declarative memory (train task), as well as cognitive, language, motor, social, emotional and body self-awareness development (Developmental Test for 6-month- to 6-year-olds, ET6-6) were assessed on three measurement occasions (12-, 18- and 24-month-olds). From a psychometric perspective, sound tests for the assessment of deferred imitation in the respective age groups were developed (Paper 1 & 2). Reliability analyses (Paper 3) indicated relatively high short-term-stability for the deferred imitation test (12-month-olds). The co-development of declarative and nondeclarative memory in 12- and 18-month-olds provided evidence for discriminative validity (Paper 4). Longitudinally, deferred imitation performance tremendously increased throughout the second year, and performance was moderately stable between 12 and 18 months and stability increased between 18 and 24 months. Using a person-centered analysis approach (relative difference scores; cluster analysis), developmental subgroups were extracted out of the total sample. These groups differed in terms of mean growth and stability. However, between the first and second measurement occasion, the groups did not differ with respect to motor, cognitive and language development (Paper 5). Using the data of three measurement occasions, subgroups were extracted showing significant differences with respect to language, motor and body self-awareness development (Paper 6). The results are discussed against the background of infancy development theories.Seit den Studien zur Imitation von Gesichtsgesten von Meltzoff und Moore (1977) gilt Imitationslernen als bedeutender Lernmechanismus bei Säuglingen. Mit fortschreitender Entwicklung, spätestens ab dem 6. Lebensmonat, werden zudem verzögerte Imitationen beobachtet. Zur Messung dieser Fähigkeit werden Säuglingen neuartige Objekte und dazugehörige Handlungen präsentiert und nach einer Verzögerungsphase (Stunden, Tage, Wochen) wird das handlungsbezogene Verhalten der Säuglinge beobachtet. Querschnittstudien zur Verzögerten Imitation haben gezeigt, dass Säuglinge und Kleinkinder mit zunehmendem Alter mehr Items enkodieren, die Lerngeschwindigkeit zunimmt sowie das Retentionsintervall ansteigt. In den bisher vorliegenden Längsschnittstudien zeigten sich ansteigende Leistungen des deklarativen Gedächtnisses im Entwicklungsverlauf sowie moderate Stabilitäten. Die wenigen multivariaten Längs- sowie Querschnittstudien deuten darauf hin, dass sowohl Sprache als auch das Selbst als wichtige Korrelate deklarativer Gedächtnisleistungen in Frage kommen. Die vorliegende Arbeit widmet sich daher im Rahmen eines multivariaten Längsschnittdesigns der Frage nach inter-individuellen Differenzen intra-individueller Veränderungen der Verzögerten Imitation im Verlauf des zweiten Lebensjahres. Im ersten Teil der Arbeit werden die Entwicklung und die testtheoretischen Grundlagen der Messinstrumente zur Erfassung der Verzögerten Imitation für den Altersbereich von 12, 18 und 24 Monaten beschrieben. Im zweiten Teil der Arbeit werden Ergebnisse einer Längsschnittstudie (N = 92) mit drei Messzeitpunkten (12, 18 und 24 Monate alte Kinder) beschrieben. Die Ergebnisse zeigen, dass die Leistungen des deklarativen Gedächtnisses im Laufe des zweiten Lebensjahres in beachtlicher Weise anstiegen. So erinnerten Kinder im Alter von 12 Monaten M = 4 (SD = 1.55) von 7 Teilhandlungen, im Alter von 18 Monaten M = 6.9 (SD = 1,85) von 12 Teilhandlungen. Die Zweijährigen erinnerten schließlich M = 17.82 (SD = 3.81) von 29 Teilhandlungen. Hierbei fanden sich keine Geschlechtsunterschiede. Dieser Leistungszuwachs repliziert die Befunde aus bisherigen Quer- sowie Längsschnittstudien. Im Hinblick auf die interindividuellen Stabilitäten der Leistungen zeigte sich, dass diese zwischen 12 und 18 Monaten relativ niedrig waren und zwischen dem 18. und 24. Lebensmonat leicht anstiegen. Um die niedrigen Stabilitäten im Rahmen eines differentiellen Ansatzes weiter erklären zu können erfolgten gruppenbasierte Analysen. Durch personenzentrierte Verfahren wurden zwei Gruppen extrahiert, welche differentielle Wachstumskurven sowie relativ hohe Stabilitäten zeigten. Diese beiden Gruppen unterschieden sich im Alter von 18 Monaten in den Entwicklungsdimension Sprach- sowie motorische Entwicklung als auch in der Dimension Körperbewusstsein signifikant voneinander. Diese Befunde stehen im Einklang mit Theorien zur Rolle des Selbst bei der Entwicklung deklarativer, insbesondere episodischer Erinnerung sowie mit empirischen Ergebnissen zur Rolle der Sprache beim Aufbau deklarativer Erinnerungen

Differences between Old and Young Adults’ Ability to Recognize Human Faces Underlie Processing of Horizontal Information

Recent psychophysical research supports the notion that horizontal information of a face is primarily important for facial identity processes. Even though this has been demonstrated to be valid for young adults, the concept of horizontal information as primary informative source has not yet been applied to older adults’ ability to correctly identify faces. In the current paper, the role different filtering methods might play in an identity processing task is examined for young and old adults, both taken from student populations. Contrary to most findings in the field of developmental face perception, only a near-significant age effect is apparent in upright and un-manipulated presentation of stimuli, whereas a bigger difference between age groups can be observed for a condition which removes all but horizontal information of a face. It is concluded that a critical feature of human face perception, the preferential processing of horizontal information, is less efficient past the age of 60 and is involved in recognition processes that undergo age-related decline usually found in the literature

Infants in Control: Rapid Anticipation of Action Outcomes in a Gaze-Contingent Paradigm

Infants' poor motor abilities limit their interaction with their environment and render studying infant cognition notoriously difficult. Exceptions are eye movements, which reach high accuracy early, but generally do not allow manipulation of the physical environment. In this study, real-time eye tracking is used to put 6- and 8-month-old infants in direct control of their visual surroundings to study the fundamental problem of discovery of agency, i.e. the ability to infer that certain sensory events are caused by one's own actions. We demonstrate that infants quickly learn to perform eye movements to trigger the appearance of new stimuli and that they anticipate the consequences of their actions in as few as 3 trials. Our findings show that infants can rapidly discover new ways of controlling their environment. We suggest that gaze-contingent paradigms offer effective new ways for studying many aspects of infant learning and cognition in an interactive fashion and provide new opportunities for behavioral training and treatment in infants

Developmental trend towards exact imitation in the second year of life: Evidence from a longitudinal study

Findings from previous cross-sectional studies showed that while toddlers around their first birthday imitate selectively, that is, they systematically omit some kinds of target action steps or they copy only the goal, but not the means of the modeled actions, older toddlers imitate more exactly. The aim of the present article is to provide longitudinal evidence for this developmental trend and to investigate how imitation of different kinds of target action steps contributes to inter-individual differences in overall imitation performance. The present analysis of longitudinal deferred imitation data contrasted toddlers’ imitation of functional and relevant (FURE) versus arbitrary and irrelevant (ARIR) target action steps at the ages of 18 and 24 months. The results show that the difference between the imitation rates of these two kinds of target action steps decreased with age, supporting the developmental trend from selective towards more exact imitation. In addition, findings of the present analyses point to the prominent role of toddlers’ imitation of arbitrary and irrelevant target action steps in shaping inter-individual variability of overall deferred imitation performance

Infants’ Visual Processing of Faces and Objects: Age-Related Changes in Interest, and Stability of Individual Differences

Longitudinal measures of infant visual processing of faces and objects were collected from a sample of healthy infants (N=40) every month from 6 to 9 months of age. Infants performed two habituation tasks each month, one with novel female faces as stimuli, and another with novel complex objects. Different individual faces and objects served as habituation (i.e., visual learning) and dishabituation (i.e., novelty response) stimuli. Measures included overall looking time to the habituation stimuli, slope of habituation, and recovery to the dishabituation stimuli. Infants were more interested in faces than objects, but this was contextualized by task order. The order effect suggests a “habituation of habituation ” effect. Infants showed an age-related decrease in interest in objects, but no decrease in interest in faces. This contradicts claims that infants shift around 6-7 months from interest in faces to interest in objects. The results showed modest between-month stability of interest in faces, but little stability in any other behavioral measures. This implies that habituation is driven more by unexplained subject x session x stimulus variance than by “infant IQ.

An own-age bias in recognizing faces with horizontal information

Horizontal information, as a result of a selective filtering process, are essential in younger adults’ (YA) ability to recognize human faces. Obermeyer, Kolling, Schaich, and Knopf (2012) recently reported impaired recognition of faces with horizontal information in older adults (OA) suggesting age-variant processing. Two yet unconsidered factors (stimulus age and exposure duration) that may have influenced previous results, were investigated in this study. Forty-seven YA (18-35yrs) and 49 OA (62-83yrs) were tested in a 2x2x2x2 mixed design with the between-subjects factors age group (YA vs OA) and stimulus age (young faces vs older faces) and the within-subjects factors filter (filtered (HF) faces vs unfiltered faces (UF)) and exposure duration (0.8s vs 8s). Subjects were presented morph videos between pairs of faces: A starting face gradually merged into either the previously encoded target face or a control face. As expected, results showed an increase in recognition sensitivity (d’) with longer exposure duration in YA with both younger and older HF faces. OA however were unable to recognize filtered young faces not even with increased exposure duration. Furthermore, only elderly participants showed more accurate recognition with faces of their own age relative to other-age faces (own-age bias, OAB). For YA no OAB was observed. Filtered face recognition was significantly correlated with unfiltered recognition in YA but not in OA. It is concluded, that processing of horizontal information changes at a higher age. Presenting filtered or unfiltered faces both targets convergent face-specific processing only in YA but not in OA

'THIS ISN'T ME!': the role of age-related self- and user images for robot acceptance by elders

Although companion-type robots are already commercially available, little interest has been taken in identifying reasons for inter-individual differences in their acceptance. Elders’ age-related perceptions of both their own self (self-image) and of the general older robot user (user image) could play a relevant role in this context. Since little is known to date about elders’ companion-type robot user image, it is one aim of this study to investigate its age-related facets, concentrating on possibly stigmatizing perceptions of elder robot users. The study also addresses the association between elders’ age-related self-image and robot acceptance: Is the association independent of the user image or not? To investigate these research questions, N = 28 adults aged 63 years and older were introduced to the companion-type robot Pleo. Afterwards, several markers of robot acceptance were assessed. Actual and ideal self- and subjective robot user image were assessed by a study-specific semantic differential on the stereotype dimensions of warmth and competence. Results show that participants tended to stigmatize elder robot users. The self-images were not directly related to robot acceptance, but affected it in the context of the user image. A higher fit between self- and user image was associated with higher perceived usefulness, social acceptance, and intention to use the robot. To conclude, elders’ subjective interpretations of new technologies play a relevant role for their acceptance. Together with elders’ individual self-images, they need to be considered in both robot development and implementation. Future research should consider that associations between user characteristics and robot acceptance by elders can be complex and easily overlooked

2-Year-Olds Learning From 2D Media With and Without Parental Support : Comparing Two Forms of Joint Media Engagement With Passive Viewing and Learning From 3D

The study investigates to what degree two different joint media engagement (JME) strategies affect childrens learning from two-dimensional (2D)-media. More specifically, we expected an instructed JME strategy to be more effective than a spontaneous, non-instructed, JME strategy. Thirty-five 2-year old children saw a short video on a tablet demonstrating memory tasks together with a parent. The parents were randomized into two groups: One group (N = 17) was instructed to help their child by describing the actions they saw on the video while the other group (N = 18) received no specific instruction besides "do as you usually do." The parents in the instructed group used significantly more words and verbs when supporting their child but both groups of children did equally well on the memory test. In a second step, we compared the performance of the two JME groups with an opportunistic comparison group (N = 95) tested with half of the memory tasks live and half of the tasks on 2D without any JME support. Results showed that the JME intervention groups received significantly higher recall scores than the no JME 2D comparison group. In contrast, the three-dimensional (3D) comparison group outperformed both JME groups. In sum, our findings suggest that JME as implemented here is more effective in promoting learning than a no JME 2D demonstration but less so than the standard 3D presentation of the tasks.Funding Agencies|Swedish Research CouncilSwedish Research CouncilEuropean Commission [2016-01033]; Swedish Research Council for Health, Working Life and WelfareSwedish Research CouncilSwedish Research Council for Health Working Life &amp; Welfare (Forte) [2016-00048]</p

Results of Experiment 1.

<p>(A) Average click counts of 6-month-olds and 8-month-olds. (B) Average fixation durations on image area and button area. (C) Average reaction time as a function of click number (error bars indicate s.e.m.). Only the first 15 clicks were plotted, since only a minority of infants performed 16 or more clicks. Infants' average reaction time after their first click is 277 ms, but becomes much faster by the third click. A linear curve (y = −7.53*x+218.77, ) and an inverse curve (y = 123.5/x+158.35, ) were fitted to infants' average reaction times.</p