This thesis investigates two source memory errors: observation inflation, where observed actions are misremembered as being performed; and self-action inflation in which self-performed actions are misremembered as having been performed by somebody else. It has been proposed that these inflations occur because of overlapping brain activity during observation and performance. This has been attributed to mirror neurone activity. To test this, observation and self-action inflations are investigated for different types of actions (meaningful, meaningless and communicative) known to evoke different mirror neurone activity. Different age groups (young adult, and elderly) were studied as were the effects of relative ethnicity between observer and performer. The Remember-Know-Guess paradigm was used. This showed that people make inflations with high qualitative details and confidence. As anticipated, elderly participants made significantly more observation inflations than young adults. Across both age groups, significantly more inflations occurred for communicative and meaningful actions than for meaningless actions supporting the idea that mirror neurones may be involved in formation of inflations. However when the effects of relative ethnicity were included in the paradigm it was found that significantly more observation inflations were formed after observing different ethnicity actors. It has been hypothesised that if mirror neurone involvement is involved in observation inflations then the highest number of inflations are expected for the same ethnicity condition because of the overlap between participant and performer. This thesis therefore suggests a less simplistic explanation of the underlying mechanisms responsible for these types of memory error.

The present study examined source memory development in a sample of 4 and 6 year children. Patterns of brain electrical (EEG) activity were examined in order to provide a neural basis for the role of prefrontal cortex functioning during source monitoring. Children were taught a series of novel facts from two difference sources (either an experimenter or puppet) and their memory for both item and source information was later tested. Results demonstrated that, after controlling for language, patterns of frontal brain activity predicted 6 year item recall performance, and trends toward significance were observed for temporal brain activity predicting 6 year source recall performance. No associations between frontal or temporal EEG activity and episodic memory judgments were observed among 4-year-old children. Future investigations should examine how source memory, and on a more general level contextual memory binding, influence the development of episodic memory in early childhood. / Master of Science

This paper reports a series of experiments designed to compare memory for multiple kinds of source information in young and older adults. The older adults in these studies were classified as having well or poorly functioning frontal lobes. In EXPERIMENTS 1-3, three different sources that provided independent cues to item information were examined using a repeated-measures design. In particular, participants' memory for voice source information, spatial source information, and temporal source information was tested in separate blocks. The results indicated that the performance of both young and older adults depended upon the type of source tested: Voice source memory was superior to spatial source and temporal source memory, which did not differ. There was also an age effect that was mediated by frontal functioning. Only the low frontal older adults showed impairments in source memory. High frontal older adults were equivalent to young. In EXPERIMENT 4, sources that provided redundant cues to item information were investigated. Voice sources and spatial sources were perfectly matched during encoding such that Voice A always came from Location 1 and Voice B always came from Location 2. When sources provided redundant information in this manner, young and high frontal older adults improved their spatial source memory by making use of redundant voice information, whereas the low frontal older adults not only performed more poorly than both young and high frontal older adults, but were unable to benefit from the redundancy. No differences in item memory were found. The findings were interpreted in terms of the executive and working memory functions involved in the integration of various contextual elements of an experience with its content.

Thesis advisor: Scott D. Slotnick / Episodic memory is a constructive process in which a system of sensory and control processes works to transport one’s conscious mind through time–in essence, recreating a previous perceptual experience. For instance, sensory-specific activity that was associated with an original encoding experience is reinstated during retrieval–almost as if the sensory regions are processing the stimulus again, albeit this activation is smaller in spatial extent. This process of sensory-specific reinstatement occurs across all sensory modalities (e.g., Gottfried et al., 2004; Nyberg et al., 2001; Vaidya et al., 2002; Wheeler et al., 2000). That is, retrieval of a visually encoded stimulus (e.g., a picture of a dog) reinstates activity in the visual cortex, while retrieval of an aurally encoded stimulus (e.g., a barking dog) reinstates activity in the auditory cortex. In Chapter 1 and Chapter 2, I demonstrate the specificity of such sensory reinstatement during true memory for visual features and investigate the role of such sensory regions during the construction of false memory for visual features. In addition to sensory processes, our conscious experience of memory also relies on control regions. At the center of this memory control network sits a key memory structure, the hippocampus, as well as other important control regions such as the dorsolateral prefrontal cortex and the parietal cortex. Furthermore, the parahippocampal cortex appears to play a critical role in memory; however, the exact role of this region has been debated (Aminoff, Kverga, & Bar, 2013). In Chapter 3, I investigate the functional role of the parahippocampal cortex during true memory and false memory, and provide evidence that the parahippocampal cortex mediates general contextual processing.

Empathy and memory are two central aspects that make us human. In the following work, I combined these two areas with genetics and asked how they would interrelate against the background of age. At study, 28 younger and 32 older adults went through an item recognition/source memory paradigm with neutral and emotional (i.e., angry) faces. Dispositional empathy was measured using the Interpersonal Reactivity Index (IRI) and the Empathy Quotient (EQ). Further, 13 single-nucleotide polymorphisms (SNPs) from mainly oxytocin receptors (OXTR) were extracted. Results revealed that older adults had a lower score on the Fantasy dimension of the IRI. Younger and older adults did not differ in hit rate, but older adults showed a higher false alarm rate for neutral source memory. For emotional item recognition, older adults showed a higher liberal response bias whereas, for neutral source memory, younger adults showed a higher conservative response bias. For both memory and empathy, main effects and age interactions were found for OXTR rs237887, rs237897, rs2254298, rs4564970, and rs4686302. These findings illustrated the close interconnectivity of memory, empathy, and genetics over the human life span.

The research presented here focused primarily on an attempt to bridge the two literatures of source memory and metameory on the topic of 'monitoring'. The contributions were two-fold: an investigation of the viability of a metacognitive judgment for SM: the judgment of source learning (JOSL), and a simultaneous investigation of the relationship of age and 'monitoring' in source memory and metacognition. In the first experiment, young participants (18-25 years of age) were asked to predict (using JOSLs) whether they would be able to discriminate between pictures that were presented to them during study, images of words they generated during study, or words they never studied in a later memory test. Participants made either immediate or delayed JOSLs (on a 0-100 scale) for each item presented during the study phase. Experiment 2 was a cross-sectional study comparing young and old adults (60-80 years of age) using a modified version of the previous task. In both experiments, intraindividual correlations of JOSLs with SM (gammas) indicated that delayed JOSLs were accurate predictors of future SM performance. There were no effects of age on gamma correlations of JOSLs with SM. Based on these results, although SM showed an age-related deficit, metacognitive predictions of SM did not show this same effect.

abstract: Frequency effects favoring high print-frequency words have been observed in frequency judgment memory tasks. Healthy young adults performed frequency judgment tasks; one group performed a single task while another group did the same task while alternating their attention to a secondary task (mathematical equations). Performance was assessed by correct and error responses, reaction times, and accuracy. Accuracy and reaction times were analyzed in terms of memory load (task condition), number of repetitions, effect of high vs. low print-frequency, and correlations with working memory span. Multinomial tree analyses were also completed to investigate source vs. item memory and revealed a mirror effect in episodic memory experiments (source memory), but a frequency advantage in span tasks (item memory). Interestingly enough, we did not observe an advantage for high working memory span individuals in frequency judgments, even when participants split their attention during the dual task (similar to a complex span task). However, we concluded that both the amount of attentional resources allocated and prior experience with an item affect how it is stored in memory. / Dissertation/Thesis / M.S. Speech and Hearing Science 2013

Memory conformity effects occur when witnesses report misleading suggestions they learned about from another witness. Using a new paradigm the present thesis investigated whether what subject-witnesses report about an event also implies what they personally remember or know about that event. Subjects were tested in pairs, with each member of a pair shown a different version of a video using the MORI technique. There were critical details (e.g., theft of an iPod) in each of the following conditions: visible to only one member of each subject spair, visible to both members of the pair, and not visible to either member of the pair. Pairs subsequently completed a questionnaire together to remember details from the video. Subjects then individually completed a similar questionnaire. A source monitoring and subjective experiences test revealed that co-witness discussion does not necessarily lead people to experience illusory recollections for details they did not witness themselves.

Dans les dernières années, les études sur les maladies neurodégénératives telles que la maladie d’Alzheimer (MA) et la maladie de Parkinson sans démence (MP) et avec démence (MPD) ont été nombreuses, mais la différenciation de ces patients sur la base de leur profil cognitif doit être encore améliorée. Effectivement, l’évaluation clinique peut s’avérer difficile en raison du peu de spécificité dans la présentation de leurs déficits neuropsychologiques. Ceci s’explique par la variabilité et le chevauchement des processus cliniques et pathologiques affectant essentiellement les mêmes régions/fonctions, soit celles liées aux lobes temporaux médians (LTM)/Mémoire (fonction LTM/Mémoire) et aux lobes frontaux (LF)/Fonctions exécutives (fonction LF/Exécutive). Toutefois, il existerait une distinction critique au niveau de l’intégrité relative de ces fonctions dans ces maladies neurodégénératives, ce qui permettrait d’identifier des déficits cognitifs spécifiques à la MA, la MP et la MPD. La présente thèse s’inscrit dans cette volonté de caractériser les profils cognitifs propres à la MA, la MP et la MPD, plus précisément par l’étude novatrice de la mémoire de source et des faux souvenirs. Les quatre chapitres qui composent cette thèse servent donc à documenter la nature de ces mécanismes mnésiques, leurs patrons de performance spécifiques dans la MA, la MP et la MPD, et leur sensibilité aux atteintes des fonctions LTM/Mémoire et LF/Exécutive. Ainsi, le Chapitre I démontre la pertinence d’étudier la mémoire de source et les faux souvenirs dans la MA, la MP et la MPD, en décrivant leurs interactions avec les fonctions LTM/Mémoire et LF/Exécutive, toutes les deux atteintes dans ces maladies. Le Chapitre II, présenté sous forme d’article, révèle des déficits en mémoire de source chez des patients MP, mais seulement dans l’une des tâches employées. Également, malgré des atteintes des fonctions LF/Exécutive et LTM/Mémoire, il est démontré que seule la fonction LTM/Mémoire est liée à l’altération de la mémoire de source chez les patients MP. Le Chapitre III, également sous forme d’article, illustre un taux anormal de faux souvenirs chez des patients MA, tandis que chez des patients MP et MPD, il est démontré qu’ils ont un taux de faux souvenirs comparable à celui des participants contrôles. Il est également rapporté que malgré l’atteinte de la fonction LF/Exécutive chez les patients MA, MP et MPD, elle est seulement liée à l’augmentation des faux souvenirs chez les patients MA. Finalement, dans le dernier Chapitre (IV), les résultats obtenus sont discutés dans leur ensemble à la lumière des prédictions et connaissances actuelles, tout en identifiant les limites afin d’orienter les perspectives de recherche. / In the last years, there have been numerous studies on neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease without dementia (PD) and with dementia (PDD), but differentiation of these patients based on their cognitive profile remains to be better understood. Indeed, clinical diagnosis remains difficult given that their neuropsychological deficits lack specificity. An explanation lies in the variability and overlap in terms of both clinical and neuroanatomical signs affecting similar brain regions/functions, which are those linked to medial temporal lobes (MTL)/Memory (MTL/Memory function) and to frontal lobes (FL)/Executive functions (FL/Executive function). However, a critical distinction lies in the relative integrity of both functions across AD, PD and PDD patients, which likely allows the capture of diagnosis-specific patterns of performance. This thesis addresses the need to describe the cognitive deficits more precisely by using novel measures of source memory and false memory. In the next four chapters of this thesis, the mechanisms underlying these forms of memory will be described as well as specific patterns of performance in AD, PD and PDD in source memory and false memory and their link to MTL/Memory and FL/Executive dysfunction. In Chapter I, the relevance of studying source memory and false memory in AD, PD and PDD, is explained by describing their interaction with MTL/Memory and FL/Executive functions, both impaired in these diseases. In Chapter II, a first study found source memory deficits in PD patients but only on one of the tasks that were used. Also, despite impaired MTL/Memory and FL/Executive functions, only MTL/Memory function is linked to impaired source memory in PD. In Chapter III, a second study found abnormal false memory rates in AD patients while in PD and PDD patients, false memory rates are comparable to those of healthy controls. It is also reported that despite impaired FL/Executive functions in AD, PD and PDD patients FL/Executive function is only linked to an increase in false memory rates in AD patients. Finally, in the last Chapter (IV), results of this thesis as a whole are discussed in light of predictions and the current literature and future research perspectives are discussed.