Information in a message can either be fully expressed (explicitly) or indirectly stated (implied) and understood by inference or association. Previous research suggested an age-related decline in performance of implicit compared to explicit information and that this relationship is moderated by prior knowledge. Whereas previous studies mainly obtained quantitative data of inferencing performance, the current study employed both quantitative and qualitative techniques to understand age-related differences in inferencing. Twenty younger and older participants evaluated whether a series of one-sentence statements were true or false based on specific two-sentence text passages. Text passages either resembled real warnings (taken from actual products) or were novel (the opposite of a warning found on an actual product). Statements either explicitly stated information from the text passage or required participants to go beyond information given in the text. Quantitative analysis showed that older adults accuracy compared to that of younger adults when evaluating real text passages, with explicit items being evaluated more accurately than implicit items. For novel text passages (generally lower accuracy scores), younger adults showed the same pattern as for real text passages, whereas older adults accuracy was low for both explicit and implicit statements. Qualitative analyses supported that participants correct answers generally reflected that the intended inference was drawn and that for incorrect answers the inference was not mentioned. The data also suggested that accuracy scores may underestimate the actual ability to infer. Both age groups mentioned most often that text-related factors (e.g., clarity) influenced their decision and brought outside information (e.g., education, experience, expectations) to the task regardless of text passage or statement type. Older adults more often referred to outside information than younger adults, particularly when evaluating novel text passages and their answer was wrong. This study substantiated that age-related differences in a task requiring inferencing may be explained by a combination of the factors of working memory (time and availability of information) and prior knowledge as well as a possible decline in inferencing ability. Prior knowledge is important for both age groups and especially so for older adults. Important implications for designers are to make information available and explicit.

It is often difficult for people to understand speech when there are other ongoing conversations in the background. This dissertation investigates how different background maskers interfere with our ability to comprehend speech and the reasons why older listeners have more difficulties than younger listeners in these tasks. An ecologically valid approach was applied: instead of words or short sentences, participants were presented with two fairly lengthy lectures simultaneously, and their task was to listen to the target lecture, and ignore the competing one. Afterwards, they answered questions regarding the target lecture. Experiment 1 found that both normal-hearing and hearing-impaired older adults performed poorer than younger adults when everyone was tested in identical listening situations. However, when the listening situation was individually adjusted to compensate for age-related differences in the ability to recognize individual words in noise, age-related difference in comprehension disappeared. Experiment 2 compared the masking effects of a single-talker competing lecture to a babble of 12 voices, and the signal-to-noise ratio (SNR) was manipulated so that the masker was either of similar volume as the target, or much louder. The results showed that the competing speech was much more distracting than babble. Moreover, increasing the masker level negatively affected speech comprehension only when the masker was babble; when it was a single-talker lecture, the performance plateaued as the SNR decreased from -2 to -12 dB. Experiment 3 compared the effects of semantic content and acoustic similarity on speech comprehension by comparing a normal speech masker with a time-reversed one (to examine the effect of semantic content) and a normal speech masker with an 8-band vocoded speech (to examine the effect of acoustic similarity). The results showed that both semantic content and acoustic similarity contributed to informational masking, but the latter seemed to play a bigger role than the former. Together, the results indicated that older adults’ speech comprehension difficulties with maskers were mainly due to declines in their hearing capacities rather than their cognitive functions. The acoustic similarity between the target and competing speech may be the main reason for informational masking, with semantic interference playing a secondary role.

It is often difficult for people to understand speech when there are other ongoing conversations in the background. This dissertation investigates how different background maskers interfere with our ability to comprehend speech and the reasons why older listeners have more difficulties than younger listeners in these tasks. An ecologically valid approach was applied: instead of words or short sentences, participants were presented with two fairly lengthy lectures simultaneously, and their task was to listen to the target lecture, and ignore the competing one. Afterwards, they answered questions regarding the target lecture. Experiment 1 found that both normal-hearing and hearing-impaired older adults performed poorer than younger adults when everyone was tested in identical listening situations. However, when the listening situation was individually adjusted to compensate for age-related differences in the ability to recognize individual words in noise, age-related difference in comprehension disappeared. Experiment 2 compared the masking effects of a single-talker competing lecture to a babble of 12 voices, and the signal-to-noise ratio (SNR) was manipulated so that the masker was either of similar volume as the target, or much louder. The results showed that the competing speech was much more distracting than babble. Moreover, increasing the masker level negatively affected speech comprehension only when the masker was babble; when it was a single-talker lecture, the performance plateaued as the SNR decreased from -2 to -12 dB. Experiment 3 compared the effects of semantic content and acoustic similarity on speech comprehension by comparing a normal speech masker with a time-reversed one (to examine the effect of semantic content) and a normal speech masker with an 8-band vocoded speech (to examine the effect of acoustic similarity). The results showed that both semantic content and acoustic similarity contributed to informational masking, but the latter seemed to play a bigger role than the former. Together, the results indicated that older adults’ speech comprehension difficulties with maskers were mainly due to declines in their hearing capacities rather than their cognitive functions. The acoustic similarity between the target and competing speech may be the main reason for informational masking, with semantic interference playing a secondary role.

This study is an investigation into the relationship between numeric cognition and aging. Specifically, older and younger adults engaged in an experimental protocol that allowed observation of number comparison accuracy and response time latencies associated with the SNARC effect, the distance effect, and number format. The experimental protocol featured a computerized magnitude comparison task wherein the participants were prompted to identify the larger of two numbers. Half of the trials featured whole numbers and half featured fractions. The number stimuli were consistently mapped such that half of all trials were at near distance (i.e., difference of 2) or far distance (i.e., difference of 4) and half of all trials had the larger numerosity on the left side of space and the other half with the larger numerosity on the right side of space. Older adults were significantly slower and less accurate than young adults. Both age groups were significantly slower and less accurate when comparing fractions as opposed to comparing whole numbers. The SNARC effect impaired accuracy in both age groups but did not significantly impact response times. The distance effect impacted both age cohorts in accuracy but differentially impacted older adult response times more than young adult response times. The results of this study support the model of numeric cognition as an automatic process when comparing whole numbers at a far distance and this process is not disrupted by the SNARC effect but is when comparing whole numbers at near distance. The results also indicate that fraction comparison is a controlled process even when the fraction stimuli are consistently mapped. Further investigation is necessary to understand the amount of cognitive resources necessitated by fraction processing and if training can improve fraction comparison.

Classic Hodgkin Lymphoma (cHL) has an annual incidence of 2.4 cases per 100 000 population in the UK, and is one of the most common malignancies diagnosed in young adults aged 15 to 34. The majority of younger patients have a good long-term outcome with between 80 and 90% disease-specific survival but cHL also affects older adults in whom the prognosis is significantly poorer. The role of tumour-associated macrophages (TAM) in cHL has gained much interest, with several studies reporting an association between high numbers of CD68-positive TAM and poor prognosis. There is also a question over the prognostic significance of Epstein-Barr Virus (EBV) infection which is implicated in up to 50% of cHL cases in developed countries. Published data suggests that EBV positivity in elderly patients may be associated with a poorer outcome, whereas in younger adults may be of prognostic benefit. Differences related to age are of interest particularly as an age-related decline in immunity has been linked with the development of certain subtypes of Non-Hodgkin Lymphoma in older patients. In a retrospective study, two separate cohorts of patients with cHL were examined with the aim of identifying: • Differences in the cellular composition of the tumour microenvironment in cHL which has arisen in young and elderly adult patients; • Differences in the cellular composition of the tumour microenvironment in cHL associated with or without EBV infection; • Factors within the tumour microenvironment which may influence prognosis and may be targeted for novel treatments. One group consisted of patients aged between 15 and 34 years at diagnosis and the other, of those aged 60 or over at presentation. Tissue obtained at the time of diagnosis was examined with regard to a number of factors related to the malignant cells and the surrounding microenvironment, including the number and phenotype of macrophages, the number of plasmacytoid dendritic cells and the number of malignant Hodgkin Reed-Sternberg (HRS) cells and non-malignant ‘background’ cells undergoing apoptosis. Comparisons were made between the two age groups, also taking into account the EBV-status of tumours, cHL subtype and gender. Results confirmed the current understanding that EBV-positive cHL is more common in older patients and has a strong, but not exclusive, association with the MCHL subtype. In addition, a strong link between young males and EBV-positive disease was shown. Macrophages were found to vary between the two age groups, in number and phenotype and there were clear differences associated with the presence or absence of EBV infection. While no definite link with outcome and macrophages was identified it was apparent that the implications of macrophages in the tumour microenvironment may differ between the two age groups. The number of apoptotic cells correlated closely with the number of macrophages and in the young the number of HRS cells was associated with prognosis. Investigation of the tumour microenvironment is complex and caution is needed in interpreting studies which do not differentiate between patients according to age, as tumour characteristics may have variable implications in different age groups. In this thesis a number of clinicopathological differences were identified between the two age groups. These point to the need for further larger studies to delineate how such age-related differences may or may not be associated with immune function and how this information could be translated into treatments to improve outcomes.

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Experimentelle und neurophysiologische Studien weisen auf eine Spezifität der Gesichterkognition hin. In der differentiellen Psychologie wird ein Schwerpunkt auf die Differenzierbarkeit sozio-kognitiver Leistungen von akademischen Fähigkeiten gelegt. Dabei werden bislang kaum Versuche unternommen, Messmodelle zu etablieren, die in neurokognitiven Modellen verankert sind. Basierend auf neuartigen Versuchen zur Etablierung solcher Modelle ist es das Ziel dieser Dissertation, die Robustheit dieser Modelle aus einer entwicklungspsychologischen Perspektive zu betrachten und diese zu erweitern. Zudem werden altersbedingte Leistungsunterschiede in der Gesichterkognition auf der Ebene latenter Faktoren ermittelt und die Hypothese altersbedingter kognitiver Dedifferenzierung mit modernen Methoden kritisch untersucht. Das Hauptziel ist die Erbringung entwicklungspsychologischer Evidenz für die Spezifität der Gesichterkognition. In einem ersten - primär methodologischen - Manuskript wird erstmalig in der Literatur die Implementierung von Funktionen der Beobachtungsgewichtung aus der nicht-parametrischen Regression für Strukturgleichungsanalysen vorgeschlagen. Diese Methode ergänzt Multigruppenanalysen bei der Untersuchung kognitiver Dedifferenzierung. Weitere vier Manuskripte adressieren Fragestellungen zur Gesichterkognition und zeigen: 1) Gesichterwahrnehmung, Gesichtergedächtnis und die Schnelligkeit der Gesichtererkennung sind separierbare Prozesse über die gesamte erwachsene Lebensspanne; 2) die Schnelligkeit der Gesichtererkennung kann nicht von der Schnelligkeit der Emotions- und Objekterkennung faktoriell getrennt werden; 3) Gesichterwahrnehmung und Gesichtergedächtnis können bis zum späten Alter von allgemeinen kognitiven Fähigkeiten getrennt werden, und 4) eine leichte Dedifferenzierung zwischen Objekt- und Gesichterkognition tritt auf der Ebene von Akkuratheitsmessungen auf. Implikationen sind in den Manuskripten ausführlich diskutiert und im Epilog zusammengefasst. / Cognitive-experimental and neuropsychological studies provided strong evidence for the specificity of face cognition. In individual differences research, face tasks are used within a broader variety of tasks, usually with the intention to measure some social skills. Contemporary individual differences research still focuses on the distinction between social-emotional vs. academic intelligence, rather than establishing measurement models with a solid basis in experimental and neuropsychological work. Building upon recent efforts to establish such measurement models this dissertation aimed to extend available models and assess their robustness across age. Furthermore, it investigates mean age differences for latent factors, critically looks at phenomena of dedifferentiation with novel and innovative analytic methods, and attempts to provide more evidence on the uniqueness and communalities of face cognition throughout adulthood. In a first primarily methodological manuscript, we propose for the first time in the literature an implementation of functions to weight observations used in nonparametric regression approaches into structural equation modeling context, which can fruitfully complement traditionally used multiple-group approaches to investigate factorial dedifferentiation. In the following four manuscripts, we investigated individual and age-differences in face cognition. Results show that: 1). Face perception, face memory and the speed of face cognition remain differentiable throughout adulthood; 2). The speed of face cognition is not differentiable from the speed of perceiving emotional expressions in the face and complex objects, like houses; 3). Face perception and memory are clearly differentiable from abstract cognition throughout adulthood; and 4). A slight dedifferentiation occurs between face and object cognition. Implications are discussed in the manuscripts and the epilogue.

This document represents efforts to design and evaluate a new sign design for emergency route trailblazing in a two-part series. Study 1 was an off-road field experiment conducted to determine the best color combination and letter design for the emergency sign. Based upon Study 1 results, black on coral, black on light blue, and yellow on purple signs were chosen for further testing against a baseline black on orange sign, all with 125-mm, D series letters. Study 2 was an on-road field study of conspicuity, conducted using an instrumented vehicle through a construction zone-related detour, and a survey questionnaire. The findings indicated that use of a color combination other than traditional black on orange will improve driver performance and safety when used for trailblazing during critical incidents. Based on the conclusions and other anecdotal evidence, the following recommendations were made: 1) Do not use black on orange signs for trailblazing around a critical incident if an existing detour/construction zone is in place; 2) Do not use a black on coral sign for trailblazing around a critical incident; 3) A light blue on black sign is recommended due to generally favorable subjective ratings and for minimization of turn errors in an overlapping detour; however, the black on light blue sign may resemble regulatory signs when headlights reflect onto it; and 4) If reject black on light blue signs based on (3), consider using yellow on purple signs, which resulted in fewer turn errors than black on orange and received generally favorable ratings. / Master of Science

Technological advances will allow virtual agents to increasingly help individuals with daily activities. As such, virtual agents will interact with users of various ages and experience levels. Facial expressions are often used to facilitate social interaction between agents and humans. However, older and younger adults do not label human or virtual agent facial expressions in the same way, with older adults commonly mislabeling certain expressions. The dynamic formation of facial expression, or motion, may provide additional facial information potentially making emotions less ambiguous. This study examined how motion affects younger and older adults in recognizing various intensities of emotion displayed by a virtual agent. Contrary to the dynamic advantage found in emotion recognition for human faces, older adults had higher emotion recognition for static virtual agent faces than dynamic ones. Motion condition did not influence younger adults' emotion recognition. Younger adults had higher emotion recognition than older adults for the emotions of anger, disgust, fear, happiness, and sadness. Low intensities of expression had lower emotion recognition than medium to high expression intensities.