The Influence of Perceptual Training on Working Memory in Older Adults

Normal aging is associated with a degradation of perceptual abilities and a decline in higher-level cognitive functions, notably working memory. To remediate age-related deficits, cognitive training programs are increasingly being developed. However, it is not yet definitively established if, and by what mechanisms, training ameliorates effects of cognitive aging. Furthermore, a major factor impeding the success of training programs is a frequent failure of training to transfer benefits to untrained abilities. Here, we offer the first evidence of direct transfer-of-benefits from perceptual discrimination training to working memory performance in older adults. Moreover, using electroencephalography to evaluate participants before and after training, we reveal neural evidence of functional plasticity in older adult brains, such that training-induced modifications in early visual processing during stimulus encoding predict working memory accuracy improvements. These findings demonstrate the strength of the perceptual discrimination training approach by offering clear psychophysical evidence of transfer-of-benefit and a neural mechanism underlying cognitive improvement

Chronic lymphocytic leukaemia Australasian consensus practice statement

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in Australia and New Zealand (ANZ). Considerable changes to diagnostic and management algorithms have occurred within the last decade. The availability of next-generation sequencing and measurable residual disease assessment by flow cytometry allow for advanced prognostication and response assessments. Novel therapies, including inhibitors of Bruton's tyrosine kinase (BTKi) and B-cell lymphoma 2 (BCL2) inhibitors, have transformed the treatment landscape for both treatment-naïve and relapsed/refractory disease, particularly for patients with high-risk genetic aberrations. Recommendations regarding appropriate supportive management continue to evolve, and special considerations are required for patients with CLL with respect to the global SARS-CoV-2 pandemic. The unique funding and treatment environments in Australasia highlight the need for specific local guidance with respect to the investigation and management of CLL. This consensus practice statement was developed by a broadly representative group of ANZ experts in CLL with endorsement by peak haematology bodies, with a view to providing this standardised guidance

Adult age differences in effects of text spacing on eye movements during reading

Large-scale changes in text spacing, such as removing the spaces between words, disrupt reading more for older (65+ years) than younger (18-30 years) adults. However, it is unknown whether older readers show greater sensitivity to simultaneous subtle changes in inter-letter and inter-word spacing encountered in everyday reading. To investigate this, we recorded young and older adults' eye movements while reading sentences in which inter-letter and inter-word spacing was normal, condensed (10 and 20% smaller than normal), or expanded (10 or 20% larger than normal). Each sentence included either a high or low frequency target word, matched for length and contextual predictability. Condensing but not expanding text spacing disrupted reading more for the older adults. Moreover, word frequency effects (the reading time cost for low compared to high frequency words) were larger for the older adults, consistent with aging effects on lexical processing in previous research. However, this age difference in the word frequency effect did not vary across spacing conditions, suggesting spacing did not further disrupt older readers' lexical processing. We conclude that visual rather than lexical processing is disrupted more for older readers when text spacing is condensed and discuss this finding in relation to common age-related visual deficits

Novel therapies, mRNA expression profiling and immune failure in chronic lymphocytic leukaemia (CLL); applications for in vitro research and clinical management.

CLL is the most frequently diagnosed leukaemia in adults. For many patients CLL is a relatively indolent disease, but for those with symptomatic disease treatment may be indicated. In Australia, current front-line therapy most commonly remains chemoimmunotherapy (CIT). However, CLL therapy is in an era of unprecedented change with the development of the targeted therapies such as those discussed in this thesis. Microenvironmental niches have been shown to play a significant role in promoting CLL cell survival and proliferation. Several intracellular signaling pathways are now known to mediate the interaction between CLL cells and other cells. These pathways are key mediators of CLL cell survival and proliferation in vivo. A better understanding of the importance of the BCR signaling pathway in the pathogenesis of CLL has provided the rationale for trials of a range of novel, more targeted therapeutic agents. The marked genetic heterogeneity among CLL patients has a significant effect on response and survival rates following treatment with CIT and the novel agents. There are a number of well-established genetic lesions in CLL such as those affecting the TP53 and ATM genes and deletion of 13q14. However, none of these lesions are present in all cases and therefore it is believed there is no common pathogenic lesion in CLL. The marked improvement in survival of CLL patients in the CIT era and more recently with the novel therapies, has meant immune dysfunction, is becoming an increasingly common problem in CLL. Immune dysfunction in CLL is characterised by hypogammaglobulinaemia, increased risk of infection, autoimmune conditions and an increased risk of secondary malignancies. This thesis focuses on three important aspects of the management of CLL: novel therapeutic strategies, the effect of the tumour microenvironment on mRNA expression in CLL cells, and immune failure in CLL

On the Spatial Distribution of Visual Attention

An implication of the data analysis and presentation of Podgorny and Shepard (1983)is that subjects are able to attend simultaneously to more than one square of a grid display when the squares are separated by unattended areas: Attention to such nonunitary areas produces similar benefits as attention to unitary areas. These benefits are reflected in reaction times (RTs), which were reported by Podgorny and Shepard (1983)as being related to a measure of spatial dispersion (compactness) of the attended areas, but this measure does not signify whether these areas are unitary or not. A reanalysis of part of Podgorny and Shepard's (1983)data shows that RTs to attended and unattended squares are almost identical when the attended areas are nonunitary. This reanalysis also shows that RTs are related to compactness for unitary attended areas but that this relation breaks down when attention is focused on nonunitary areas. In addition, Podgorny and Shepard's (1983)data are presented in a way that demonstrates the importance of the actual grid location of probes on RTs. The failure of compactness to reflect these aspects of the spatial nature of attention suggests that this metric is deficient when applied to the study of the spatial determinants of attention

Time-to-Collision (TTC) judgements with offsize objects show that Tau needs to be intergrated with familiar size to explain TTC performance

Observers judged TTC with computer-generated displays simulating an approaching object in three familiar-size conditions:(i) Real-size (smaller, larger objects depicted as tennis, soccer balls respectively).(ii) Off-size (smaller, larger objects depicted as soccer, tennis balls respectively).(iii) Ambiguous-size (smaller, larger objects depicted as texture-less black balls of different size).Displays simulated objects approaching observers&iacute; viewpoint from 24.96 m, and disappearing at 5.76 m. Manipulation of approach velocities (4.8-19.2 msec-1) produced viewing times from 1.0 to 4.0 sec, and delays between object disappearance and tau-based TTC ranging from 0.3 to 1.2 sec. Motion characteristics of smaller and larger objects in the three familiar-size conditions simulated those of approaching real-sized tennis and soccer balls respectively; that is, for each approach velocity, tau&sbquo;-based TTC was the same across the three conditions for smaller and larger objects.Results showed that, consistent with the proposition of tau-determined TTC, TTC estimates in the real-size condition were uninfluenced by object size. This is contrary to previous reports that TTC for larger objects is underestimated relative to TTC for smaller objects. However, such size-dependent TTC differences were found in the ambiguous-size condition, with even larger differences in the off-size condition; TTCs for the &euml;larger&iacute; tennis ball were much less than TTCs to the &euml;smaller&iacute; soccer ball compared to corresponding TTCs in the ambiguous-size condition. These results are problematic for the proposition that tau solely determines TTC. We discuss the role of perceptual learning in resolving this problem.<br /

Investigations of perception and imagery using CAEs: The role of experimental design and psychophysical method

Orientation-contingent color aftereffects (CAEs) were measured using 174 observers ran-domly allocated to one of eight experimental conditions formed by the factorial combination of three two-level factors. These were experimental design (pretest and posttest measures taken vs. posttest measures taken alone), psychophysical method (forced-choice vs. magnitude estimation), and inspection procedure (inspection of real contours vs. inspection of imagined contours). In addition to color responses, written introspective reports of the strategies used in providing color responses were obtained. As a basis for the rejection of observers using inappropriate strategies, reported strategies were coded as appropriate or inappropriate. An analysis of the color reports of all observers was performed, as well as two analyses of the color reports of only those observers identified as using appropriate response strategies. In all cases, the results showed that CAEs were reported after inspection of real contours irrespective of the experimental design or psychophysical method used. There were no significant CAEs reported in any conditions that involved the imagination of contours. A separate analysis of the relationship between observers' response strategies, the coding of these strategies, and observers' actual color reports revealed some problems concerning the use of such introspective techniques. The implications of these findings are discussed in terms of theoretical assumptions about the nature of imagery and perception