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    The blue brain : hemispheric asymmetry in depression as an explanation for working memory impairment : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University, Manawatu, New Zealand
    (Massey University, 2015) Campbell, Kathryn
    Due to substantial variability in past research regarding the cognitive and neurobiological correlates of depression, the current study investigated whether taking the possible relationship between asymmetric brain activity and cognitive impairment into account would help to clarify the matter. A total of 78 participants including 36 currently depressed, 11 previously depressed, and 31 never depressed participants, completed three mood questionnaires (Beck Depression Inventory, Hamilton Depression Inventory Short-Form, and the State-Trait Anxiety Inventory), and four working memory tasks (a spatial and verbal variant of both the N-back and complex span task). All participants had their resting brain activity recorded using an electroencephalogram. It was hypothesised that depressed participants would show relatively reduced left frontal activity, since left frontal activity is linked to positive affect and approach motivation, and that participants with depression but low levels of anxiety would show reduced right parietal activity while those with high anxiety would show increased right parietal activity due to the role of the right parietal area in arousal. These hypotheses were not supported as there were no differences in asymmetry scores between the currently depressed and the never depressed groups. However, investigation of this hypothesis was hindered by the high comorbidity of anxiety and depression making it impossible to disentangle the effects of depression and anxiety on parietal activity. It was also hypothesised that participants with depression would show impaired working memory with disproportionate impairment in the verbal working memory tasks that are thought to utilise left frontal brain activity. There was no clear support for this hypothesis. In fact, there was a trend toward improved performance possibly related to increased attention to detail due to activation of stress systems signalling a potential threat in the environment. A final hypothesis was that there would be an association between different patterns of brain activity and WM impairment but no association was found. These results highlight problems with research in this field including the conceptualisation and measurement of depression and cognitive performance as well as problems distinguishing between anxiety and depression. Future research needs to address these issues.
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    Investigating working memory and metamemory in old age : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University
    (Massey University, 2002) Craighead, Cheryll L
    An investigation of metamemory for working memory was conducted in a group of older adults aged 60 to 74 years using a variation of the Daneman and Carpenter (1980) reading span task. There were twelve trials in each experiment, with each trial containing six sentences. Participants had to assess whether each sentence was true or false as well as remembering the last word of each sentence in correct order. In Experiment 1 words were phonologically similar (rhyming) and dissimilar (non-rhyming), whereas Experiment 2 presented one syllable (short) words and two syllable (long) words Half the participants were asked to predict how well they would remember the words and half were asked to postdict how well they had recalled the words. Participants were also asked to complete the Metamemory Functioning Questionnaire (Gilewski, Zelinski & Schaie, 1990) for a self-assessment of memory and this was compared to their memory performance on the recall task. Results indicated that older adults recalled more rhyming words than non-rhyming words, and more short words than long words. They overestimated the number of non-rhyming words they would remember but their estimates fluctuated in the same pattern as actual recall for the rhyming and non-rhyming words showing some accuracy in their metamemory. However, people unexpectedly estimated that they would do better with long than short words. For long words postdictions matched recall better than predictions which showed that older adults were able to gather information about their performance during the task. There was no correlation between the MFQ scores and the recall accuracy of the memory task probably because the questionnaire measured more general aspects of everyday memory, whereas the recall task involved a single and very specific aspect of memory. When compared to the younger adults the older adults showed poorer recall performance and overestimation was larger for older adults. These results showed us that to some extent, older adults are able to estimate their memory performance, using metamemory in a complex memory task.
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    Investigating the relationship between two approaches to verbal information processing in working memory : an examination of the construct of working memory coupled with an investigation of meta-working memory : submitted in partial fulfilment for the degree of Doctor of Philosophy in Psychology at Massey University
    (Massey University, 1996) Richards-Ward, Llewelyn A.
    Working memory is a process whereby persons can preserve information for a short time while concurrently engaging in other cognitive operations. The literature describes two approaches to working memory. The first approach (Baddeley, 1986) can be described as a complete model of working memory. However the second approach is not as clearly a distinct model, although its history, literature, application, simulation and operational definitions can arguably allow one to describe it as a separate model or strand of working memory for the present purposes. Rather, what will be termed the "quantitative/process model" deals only with verbal information and is far less complete than Baddeley's model in other domains. A central issue is thus how these two models relate with respect to how they handle verbal information. Baddeley (1986) delineated working memory as a set of interconnected components consisting of a Central Executive, a Phonological Loop, and a Visuo-Spatial Sketch-Pad. In this dissertation, this is termed the qualitative/structural model of working memory. Daneman and Carpenter (1980, 1983) delineated working memory as a process involving both a traditional span component and a concurrent operation. This approach, which will be referred to as the quantitative/process model of working memory, has been presumed to involve the Central Executive of the qualitative/structural model of working memory. This presumed relationship is scrutinised in the present dissertation in the context of an alternate hypothesis that the quantitative/process model involves more of the phonological loop than has been presumed. Thus, the first issue this dissertation addressed was how these two models or approaches to working memory account for verbal information. The second facet of the present investigation was to examine whether persons were able to report on their meta-memory for working memory. Seven linked experiments are reported in the present dissertation. Participants for all seven experiments were predominantly students at local tertiary institutions and ranged in age from 16 to 48 years. The experimental conditions were presented as a two-factor within-subjects design in Experiments 1 to 6. The first general factor was word-type varying either across word-length (Experiments 2, 4, and 6) or across phonological similarity (Experiments 1, 3, and 5). The second factor was whether articulatory suppression was used or not (Experiments 1 to 6). In Experiments 1 and 2, stimuli were presented as a complex-span task (sentence plus word), where in Experiments 3 to 6, stimuli were presented as a simple-span task (word only). Experiment 5 also had a between-subjects factor determined by whether words were sampled from a 10 item pool or from a pool without replacement. Experiment 6 had a between-subjects factor determined by the presentation pace of the stimuli (at 1 per second or self-paced). Finally, Experiment 7 directly compared complex-span and simple-span presentations against a second factor of word-type varying across both phonological similarity and word-length (control, phonologically similar, 3-syllable). In all seven experiments, participants were measured on dependent variables of recall in the correct serial position and recall in any serial position of the words that were presented. From the difference between these two measures of content, an estimate of the loss of order information (order errors) was calculated. A measure of the time each participant spent viewing (for simple-span tasks) or verifying (for complex-span tasks) the stimuli was made to assess processing time. Finally, before each trial, participants made an estimate of how many items they expected to recall in any order (a measure of their online meta-memory). In Experiments 5 to 7, a measure of the time each participant took to articulate the pool of words they had been asked to recall was taken to provide an estimate of their articulation rate. The main research questions for this set of studies were as follows: (1) that the quantitative/process model of working memory also uses the Phonological Loop, not just the Central Executive, and hence both models of working memory use the same process to preserve visually presented verbal information; (2) that measurement of dimensions of order and processing time, in addition to the dimension of content or capacity, will contribute independent information to the description of working memory function; and (3) that persons are able to monitor and report on their working memory. Data from the present set of studies provide support for these three hypotheses The raw data upon which this dissertation was based can be obtained in the first instance from the author at the following address: Llewelyn A. Richards-Ward, c/- Department of Psychology, Massey University, Private Bag 11222, Palmerston North, New Zealand. The present investigation showed that a concurrent operation does not preclude phonological similarity and word-length effects used to define the components of the qualitative/structural model of working memory. Concurrently, dimensions of content and order, but not processing time, were shown to be important in describing working memory. The conclusion from these results is that both models of working memory refer to the same construct and that preservation of verbal information can be better accounted for by a single process. Finally, in all instances persons were accurate in predicting their general working memory performance. The data also show that persons may be able to predict the effect of some parameter changes on their performance. The results of the present research suggest that verbal information is handled similarly in both models or approaches and tends to falsify that verbal information is retained primarily in the Central Executive in one model and the Phonological Loop in the other. Second the results suggest that persons do have a degree of meta-working memory. These results are discussed in terms of their implications for how working memory and meta-working memory can be described. Finally, some future directions for research are outlined.
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    Cross-sectional and longitudinal analyses of the effects of aging on memory in healthy young, middle-aged, and oldest-old adults : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University, Palmerston North, New Zealand
    (Massey University, 2006) Lamont, Allison
    While a growing body of research indicates that older adults typically perform more poorly on many types of memory tasks than do younger adults, relatively little research has addressed the question of whether this trend continues unchanged into the late ninth and tenth decades of life. Such decrements in memory have been reported as linear declines from early adulthood up until about 80 years of age. Questions arise as to whether such memory declines slow or accelerate in very advanced aging, and to what extent differences are due to aging, per se, or variables that intervene between age and memory.To address these two questions, six memory types - verbal recall, nonverbal recall, short-term memory, working memory, face recognition, and prospective memory - were examined using both cross-sectional and longitudinal methodologies. The six types of memory and the influence of verbal processing speed, nonverbal processing speed, and intelligence were examined in mixed-gender groups of 20 - 40 (n = 40, M = 30.7, SD = 5.52), 50 - 70 (n = 44, M = 59.2, SD = 4.94), and 85+ year olds (n = 42, M = 87.8, SD = 2.43), at two points, the second occurring two years after the first. Each participant completed tests of word recall, geometric shapes recall, short-term memory (digit span), working memory (letter-number sequencing), face recognition, and prospective memory. Additionally, there were two processing speed tasks (Identical Pictures and Finding As), and the National Adult Reading Test of verbal fluency was used to estimate intelligence. The Mini-Mental State Examination and the Beck Depression Inventory (BDI-II) were used to screen for dementia and depression, respectively.At Time 1 testing the 85+ participants showed declines in all memory types (compared to the 20 - 40 year olds). Nonverbal recall (66.2% lower than the young group), working memory (46.2%), verbal recall (45%), and prospective memory (38.2%) produced the largest differences, short-term memory (12.3%) and face recognition (14.7%) the least. Two years later, the 85+ years old participants had shown further declines, relative to the 20 - 40 years group. Nonverbal recall (72.3% lower than the young group), prospective memory (63.2%), working memory (55.3%), and verbal recall (54.7%) continued to produce the largest decrements, with short-term memory (18.9%) and face recognition (19.8%) the least. The results for the young and middle participants did not change appreciably between Time 1 and Time 2. The difference between unadjusted scores and scores adjusted for intelligence, verbal processing speed, and nonverbal processing speed, increased markedly between Time 1 and Time 2 testing for the oldest-old participants.These findings support the view that while memory declines may be approximately linear from age 20 to 80 years, there is a sharp decline in most types of memory after the age of 85 years, recall and working memory suffering the most. Intelligence and processing speed have an effect on some types of memory, but age is by far the largest contributor to memory decline. Furthermore, as expected, all memory types declined over the two-year period, with prospective memory, verbal recall, nonverbal recall, and working memory showing the greatest declines. Short-term memory and face recognition declined at a noticeably slower rate.
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    When prudence is reckless : rethinking the role of project risk management : a 152.785 (25 point) research report presented in partial fulfilment of the requirements for the degree of Master of Management at Massey University
    (Massey University. Department of Management, 2005) Busch, Adrian
    Despite the widespread use of project risk management, the results of such efforts are often underwhelming. Do project risk management practices somehow miss the point? To explore this idea I use a critical management studies framework to study project risk management. The approach prescribed in the Project Management Institute's Project Management Body of Knowledge is compared to the very different approach of a professional project manager. A theorised analysis of the difference between these approaches finds that they employ the logic of different knowledge-constitutive interests thereby making them suitable for different purposes. The study concludes with a discussion of how the results of this analysis can be presented to practitioners in a way consistent with the emancipatory agenda of critical management studies.