Central auditory processing is complex and can not be evaluated by a single method. This thesis focuses on assessment of some aspects of central auditory functions by the use of dichotic speech tests and cognitive tests that tax functions important for speech processing. Paper A deals with the cognitive effects in dichotic speech testing in elderly hearing-impaired subjects. It was found that different listening tasks in the dichotic tests put different demands on cognitive ability, shown by a varying degree of correlation between cognitive functions and dichotic test parameters. Age-related cognitive decline was strongly connected with problems to perceive stimuli presented to the left ear. Paper B presents a new cognitive test battery sensitive for functions important for speech processing and understanding, performed in text, auditory and audiovisual modalities. The test battery was evaluated in four groups, differing in age and hearing status, and has proven to be useful in assessing the relative contribution of different input-modalities and the effect of age, hearingimpairment and visual contribution on functions important for speech processing. In Paper C the test battery developed in Paper B was used to study listening situations with different kinds of background noise. Interfering noise at +10 dB signal-to-noise ratio has significant negative effects on performance in speech processing tasks and on the effort perceived. Hearing-impaired subjects showed poorer results in noise with temporal variations, and elderly subjects were more distracted by noise with temporal variations, especially by noise with meaningful content. In noise, all subjects, particularly those with impaired hearing, were more dependent upon visual cues than in the quiet condition. Hearing aid benefit in speech processing with and without background noise was studied in Paper D. The test battery developed in Paper B was used together with a standard measure of speech recognition. With hearing aids, speech recognition was improved in the background condition without noise and in the background condition of ordinary speech. Significantly less effort was perceived in the cognitive tests when hearing aids were used, although only minor benefits of hearing aid amplification were seen. This underlines the importance of considering perceived effort as a dimension when evaluating hearing aid benefit, in further research as well as in clinical practice. The results from the studies contribute to the knowledge about speech processing but also to the search for more specific evaluation of speech understanding, incorporating both sensory and cognitive factors. / The ISBN 91-85297-49-6 in the printed verison is incorrect. The correct ISBN is 91-85297-93-3.

Decreased amyloid-ß42 (Aß42), increased total tau (t-tau) and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) reflect histopathological core changes in the most common dementia disorder, Alzheimer’s disease (AD). They discriminate AD from healthy controls and predict conversion to AD with a relatively high accuracy. Memantine, an uncompetitive NMDA-receptor antagonist, is indicated for symptomatic treatment of AD. The first aim of this thesis was to investigate effects of memantine on CSF concentrations of Aβ42, tau and p-tau. Secondly, the aim was to explore the relation between these CSF biomarkers and retention of the amyloid biomarker Pittsburgh compound B using positron emission tomography (PIB PET), regional glucose metabolism measured with 18Fluoro-2-deoxy-d-glucose (FDG) PET and neuropsychological test performance. The third aim was to investigate their possible utility as predictors of future rate of AD dementia deterioration. All patients in the studies were recruited from the Memory Clinic, Uppsala University Hospital. In study I CSF p-tau concentrations in 11 AD patients were reduced after twelve months treatment with memantine, indicating that this compound may affect a key pathological process in AD. Results from study II showed that the concentrations of CSF Aß42 are lower in PIB+ patients than in PIB- patients, and that the PIB retention was stable during 12 months. In study III 10 patients with the diagnoses AD (6 PIB+/4 PIB-) and 8 subjects (1 PIB+/7 PIB-) with frontotemporal dementia were included. PIB+ patients had lower psychomotor speed measured by performance on the Trail Making Test A and impaired visual episodic memory compared to the PIB- patients. The initial clinical diagnoses were changed in 33% of the patients (6/18) during follow-up. Study IV is the first-ever report of an association between high CSF tau and dying in severe dementia. These 196 AD patients were followed up to nine years after baseline lumbar puncture. Moreover, CSF t-tau concentrations above median was associated with an increased risk of rapid cognitive decline (OR 3.31 (95% CI 1.53-7.16), independently of baseline functional stage. Thus, a clear association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease was shown.

Thesis (M.A.)--The University of North Carolina at Greensboro, 2008. / Directed by Thomas Kwapil; submitted to the Dept. of Psychology. Title from PDF t.p. (viewed Jan. 28, 2010). Includes bibliographical references (p. ).

Objective: The nature of disaster research makes it difficult to adequately measure the impact that significant events have on a population. Large, representative samples are required, ideally with comparable data collected before the event. When Christchurch, New Zealand, was struck by multiple, devastating earthquakes, there presented an opportunity to investigate the effects of dose-related quakes (none, one, two or three over a 9-month period) on the cognition of Canterbury’s elderly population through the New Zealand Brain Research Institute’s (NZBRI’s) cognitive screening study. The related effects of having a concomitant medical condition, sex, age and estimated- full scale IQ (Est-FSIQ) on cognition were also investigated. Method: 609 participants were tested on various neuropsychological tests and a self-rated dementia scale in a one hour interview at the NZBRI. Four groups were established, based on the number of major earthquakes experienced at the time of testing: “EQ-dose: None” (N = 51) had experienced no quakes; “EQ-dose: One” (N = 193) had experienced the initial quake in September 2010; “EQ-dose: Two” (N = 82) also experienced the most devastating February 2011 quake; and “EQ-dose: Three” (N = 265) also the June 2011 quake at testing. Results: Two neuropsychological variables of Trail A and the AD8 were impacted by an EQ-dose effect, while having a medical condition was associated with poorer function on the MoCA, Rey Copy and Recall, Trail A, and AD8. Having a major medical condition led to worse performance on the Rey Copy and Recall following the major February earthquake. Males performed significantly better on Trail A and Rey Planning, while females better on the MoCA. Older participants (>73) had significantly lower scores on the MoCA than younger participants (<74), while those with a higher Est-FSIQ (>111) had better scores on the MoCA and Rey Recall than participants with a lower Est-FSIQ. Finally, predicted variable analysis (based on calculated, sample-specific Z-scores) failed to find a significant earthquake effect when variables of age, sex and Est-FSIQ were controlled for, while there was a significant effect of medical condition on each measure. Conclusion: The current thesis provides evidence suggesting resilience amongst Canterbury’s elderly population in the face of the sequence of significant quakes that struck the region over a year from September 2010. By contrast, having a major medical condition was a ‘more significant life event’ in terms of impact on cognition in this group.

Using orthogonal subtractions of performance in selected conditions the attentional network test (ANT) measures the efficacy of three isolable components of attention: alerting, orienting, and executive control. This dissertation evaluated: 1) the relationship between these attention networks and absentmindedness measured by the Cognitive Failures Questionnaire (CFQ) and 2) stability, isolability, robustness, and reliability of the two versions of the ANT (Fan et al., 2002 and Callejas et al., 2005) with young adults and older adults and of the child version of the ANT (Rueda et al., 2004) with young children when tested over 10 sessions. A greater degree of absentmindedness as measured with CFQ was associated with a greater alerting network score in RT and with a greater orienting network scores in error rate when the ANT-I was used. However, a greater degree of absentmindedness was associated with a smaller orienting network score in error rate when the ANT was used. These results suggest that the alerting and the orienting networks are related to absentmindedness. However, the orienting networks in the two ANTs were related to absentmindedness differently which supports the proposal (Klein, 2009) that there are fundamental differences between attention when controlled endogenously (ANT) as opposed to exogenously (ANT-I). For young adults and older adults, all network scores in RT remained robust even after nine previous sessions despite some practice effects especially in the executive network both with the ANT and the ANT-I. There was some evidence that the networks do not operate independently in all situations. As expected, reliability increased as more data are added. For young children, only the alerting network scores remained robust over time. Learning effects were observed only with the executive network. The reliability was poor even when more data were added. This made it difficult to assess the isolability of the network scores. The ANT and the ANT-I were associated to the CFQ scores in a limited way. The ANT and the ANT-I can be used for applications requiring repeated testing, but the child ANT may not be suitable for such purpose. / This is a thesis that is manuscript-based.

The present study investigated the neuropsychological predictors of auditory/verbal and visual/written arithmetic performance in a large sample of children with learning disorders. In addition, the efficacy of a cognitive based arithmetic problem solving model (Dinnel, Glover, & Halpain, in press; Dinnel, Glover, & Ronning, 1984) in accounting for neuropsychological functioning in arithmetic performance was considered. Subjects were from a small midwestern school district, and were identified as learning disabled in accord with state (i.e., Rule S-1) and federal guidelines (i.e., PL-94-142). Specifically, subjects' scores on the Halstead-Reitan Neuropsychological Battery (HRNB) (Reitan, 1969) for older children and the Wechsler Intelligence Scale for Children-Revised (WISC-R) (Wechsler, 1974) were used to predict performance on the Wide Range Achievement Test (WRAT) Arithmetic subtest, and WISC-R Arithmetic subtest. Analyses were conducted with criterion measures considered separately and as a composite. In an attempt to examine the utility of the Dinnel et al., (in press; 1984) model, a simple index was formed using the criterion measures. This index was then predicted using the HRNB and WISC-R variables. Neuropsychological variables were found to account for some 31%, and 36% of the variability in visual/written and auditory/verbal arithmetic performance, respectively. However, neuropsychological variables accounted for some 87% of the shared variance when arithmetic measures were considered as a linear composite. Neuropsychological variables predicted a mere 12% of the variability associated with the index designed to test the Dinnel et al. (in press; 1984) arithmetic problem solving model. These data offered some support to Dinnel and others' (Dinnel et al., in press; 1984) formulations accounting for arithmetic performance under visual/stimulus conditions. However, the present findings indicated a more complex neuropsychological underpinning for overall arithmetic problem solving. Moreover, the neuropsychological constructs predicting arithmetic scores varied as a function of the stimulus/performance modes required for problem solving.Auditory-verbal attention and short-term memory, remote verbal memory, symbolic language integration, mental flexibility, and nonverbal abstract reasoning were the common neuropsychological constructs underpinning both auditory/verbal and visual/written arithmetic performance. Verbal facility, verbal abstract reasoning, nonverbal short term memory, and nonverbal concrete concept formation were uniquely implicated in auditory/verbal arithmetic performance. Visual/written arithmetic performance was uniquely related to nonverbal attention and intermediate nonverbal memory functions. In overview, it would seem that neuropsychological measures would be clinically useful in identifying deficits underlying poor arithmetic performance. / Department of Educational Psychology

The present thesis describes the development and assessment of two computer-game-like tests designed to measure two cognitive abilities currently of considerable interest to many researchers: processing speed (Gs) and working memory (WM). It is hoped that such tests could provide a unique and important addition to the range of tests currently employed by researchers interested in these constructs. The results of five separate studies are presented across three published papers. In Paper 1-Study 1 (N = 49) a speeded computerized coding test (Symbol Digit) using the mouse as the response device was assessed. Because speeded tests are thought to be highly sensitive to response methods (Mead & Drasgow, 1994) it was deemed important to first assess how a mouse response method might affect the underlying construct validity of a speeded coding test independently of whether it was game-like. Factor analytic results indicated that the computerized coding test loaded strongly on the same factor as paper-andpencil measures of Gs. For Paper 2-Study 1 (N = 68) a more computer-game-like version of Symbol Digit was developed, Space Code. Development of Space Code involved the provision of a cover story, the replacing of code symbols with ‘spaceship’ graphics, the situating of the test within an overall ‘spaceship cockpit’, and numerous other graphical and aural embellishments to the task. Factor analytic results indicated that Space Code loaded strongly on a Gs factor but also on a factor comprised of visuo-spatial (Gv) ability tests. This finding was further investigated in the subsequent study. Paper 2-Study 2 (N = 74) involved a larger battery of ability marker tests and a range of additional computer-game-like elements were added to Space Code. Space Code included a scoring system, a timer with additional voice synthesized countdowns, aversive feedback for errors, and background music. Factor analysis indicated that after a general factor was extracted Space Code loaded on the same factor as paper-and-pencil measures of Gs and did not load on a factor comprised of non-speeded Gv tests. Paper 3-Study 1 (N = 74) was aimed at assessing a computer-game-like test of WM (Space Matrix) and further assessing Space Code within a broader network of tests. Space Matrix used a dual task format combining a simple version of Space Code with a visually presented memory task based on the Dot Matrix test (Miyake, Friedman, Rettinger, Shah, & Hegarty, 2001). The cover story and scoring system for Space Code was expanded to incorporate this additional memory element. Factor analysis indicated that Space Matrix was loaded on the same first order factor as standard WM tests and the Raven’s Advanced Progressive Matrices (Gf). Space Code was substantially loaded on the second order factor but was weakly loaded on each of two first order factors interpreted as Gs and WM/Gf. A final study is presented (Paper 3-Study2) in which Space Code and Space Matrix was administered to a school aged sample (N=94). Space Matrix exhibited construct validity as well as predictive validity (as a predictor of school grades), while results for Space Code were less encouraging. Space Matrix and Raven’s Progressive Matrices showed comparable relationships to school grades for Mathematics, English and Science subjects. It is concluded that the development of computer-game-like tests represents a promising new format for research and applied assessment of known cognitive abilities. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342350 / Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 2008

While the cognitive disturbances that frequently follow severe TBI are relatively well understood, the ways in which these affect the psychosocial functioning of people with TBI are yet to be determined and have thus received little attention in treatment research. Growing evidence indicates that that a significant proportion of individuals with TBI demonstrate deficits in the perception of affective information from the face, voice, bodily movement and posture. As accurate evaluation of emotion in others is critical for the successful negotiation of social interactions, effective treatments are necessary. Until recently, however, there have been no rehabilitation efforts in this area with TBI groups. The present research aims to redress this absence. The literature on emotion perception deficits in TBI is examined, and a theoretical rationale for intervention is presented. Several lines of research are reviewed which suggest that rehabilitation targeting such deficits is tenable. These include research on emotion perception remediation with other cognitively impaired populations, findings from cognitive neuroscience suggesting the potential for neuronal restoration after brain damage, and the successful applications of remediation techniques, in particular errorless learning and self-instruction, for treating other cognitive deficits in a range of neurological disorders and TBI. Discussion of this research is followed by a description of two randomised controlled trials aimed at improving emotion perception in individuals with TBI. The findings are discussed with reference to useful theoretical models of rehabilitation, learning and emotion perception. Suggestions for future directions of research are outlined together with relevant design issues.

The present thesis describes the development and assessment of two computer-game-like tests designed to measure two cognitive abilities currently of considerable interest to many researchers: processing speed (Gs) and working memory (WM). It is hoped that such tests could provide a unique and important addition to the range of tests currently employed by researchers interested in these constructs. The results of five separate studies are presented across three published papers. In Paper 1-Study 1 (N = 49) a speeded computerized coding test (Symbol Digit) using the mouse as the response device was assessed. Because speeded tests are thought to be highly sensitive to response methods (Mead & Drasgow, 1994) it was deemed important to first assess how a mouse response method might affect the underlying construct validity of a speeded coding test independently of whether it was game-like. Factor analytic results indicated that the computerized coding test loaded strongly on the same factor as paper-andpencil measures of Gs. For Paper 2-Study 1 (N = 68) a more computer-game-like version of Symbol Digit was developed, Space Code. Development of Space Code involved the provision of a cover story, the replacing of code symbols with ‘spaceship’ graphics, the situating of the test within an overall ‘spaceship cockpit’, and numerous other graphical and aural embellishments to the task. Factor analytic results indicated that Space Code loaded strongly on a Gs factor but also on a factor comprised of visuo-spatial (Gv) ability tests. This finding was further investigated in the subsequent study. Paper 2-Study 2 (N = 74) involved a larger battery of ability marker tests and a range of additional computer-game-like elements were added to Space Code. Space Code included a scoring system, a timer with additional voice synthesized countdowns, aversive feedback for errors, and background music. Factor analysis indicated that after a general factor was extracted Space Code loaded on the same factor as paper-and-pencil measures of Gs and did not load on a factor comprised of non-speeded Gv tests. Paper 3-Study 1 (N = 74) was aimed at assessing a computer-game-like test of WM (Space Matrix) and further assessing Space Code within a broader network of tests. Space Matrix used a dual task format combining a simple version of Space Code with a visually presented memory task based on the Dot Matrix test (Miyake, Friedman, Rettinger, Shah, & Hegarty, 2001). The cover story and scoring system for Space Code was expanded to incorporate this additional memory element. Factor analysis indicated that Space Matrix was loaded on the same first order factor as standard WM tests and the Raven’s Advanced Progressive Matrices (Gf). Space Code was substantially loaded on the second order factor but was weakly loaded on each of two first order factors interpreted as Gs and WM/Gf. A final study is presented (Paper 3-Study2) in which Space Code and Space Matrix was administered to a school aged sample (N=94). Space Matrix exhibited construct validity as well as predictive validity (as a predictor of school grades), while results for Space Code were less encouraging. Space Matrix and Raven’s Progressive Matrices showed comparable relationships to school grades for Mathematics, English and Science subjects. It is concluded that the development of computer-game-like tests represents a promising new format for research and applied assessment of known cognitive abilities. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342350 / Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 2008

The present thesis describes the development and assessment of two computer-game-like tests designed to measure two cognitive abilities currently of considerable interest to many researchers: processing speed (Gs) and working memory (WM). It is hoped that such tests could provide a unique and important addition to the range of tests currently employed by researchers interested in these constructs. The results of five separate studies are presented across three published papers. In Paper 1-Study 1 (N = 49) a speeded computerized coding test (Symbol Digit) using the mouse as the response device was assessed. Because speeded tests are thought to be highly sensitive to response methods (Mead & Drasgow, 1994) it was deemed important to first assess how a mouse response method might affect the underlying construct validity of a speeded coding test independently of whether it was game-like. Factor analytic results indicated that the computerized coding test loaded strongly on the same factor as paper-andpencil measures of Gs. For Paper 2-Study 1 (N = 68) a more computer-game-like version of Symbol Digit was developed, Space Code. Development of Space Code involved the provision of a cover story, the replacing of code symbols with ‘spaceship’ graphics, the situating of the test within an overall ‘spaceship cockpit’, and numerous other graphical and aural embellishments to the task. Factor analytic results indicated that Space Code loaded strongly on a Gs factor but also on a factor comprised of visuo-spatial (Gv) ability tests. This finding was further investigated in the subsequent study. Paper 2-Study 2 (N = 74) involved a larger battery of ability marker tests and a range of additional computer-game-like elements were added to Space Code. Space Code included a scoring system, a timer with additional voice synthesized countdowns, aversive feedback for errors, and background music. Factor analysis indicated that after a general factor was extracted Space Code loaded on the same factor as paper-and-pencil measures of Gs and did not load on a factor comprised of non-speeded Gv tests. Paper 3-Study 1 (N = 74) was aimed at assessing a computer-game-like test of WM (Space Matrix) and further assessing Space Code within a broader network of tests. Space Matrix used a dual task format combining a simple version of Space Code with a visually presented memory task based on the Dot Matrix test (Miyake, Friedman, Rettinger, Shah, & Hegarty, 2001). The cover story and scoring system for Space Code was expanded to incorporate this additional memory element. Factor analysis indicated that Space Matrix was loaded on the same first order factor as standard WM tests and the Raven’s Advanced Progressive Matrices (Gf). Space Code was substantially loaded on the second order factor but was weakly loaded on each of two first order factors interpreted as Gs and WM/Gf. A final study is presented (Paper 3-Study2) in which Space Code and Space Matrix was administered to a school aged sample (N=94). Space Matrix exhibited construct validity as well as predictive validity (as a predictor of school grades), while results for Space Code were less encouraging. Space Matrix and Raven’s Progressive Matrices showed comparable relationships to school grades for Mathematics, English and Science subjects. It is concluded that the development of computer-game-like tests represents a promising new format for research and applied assessment of known cognitive abilities. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342350 / Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 2008