The need for a unified framework: How Tulving's framework of memory systems, memory processes, and the SPI-model can guide and sharpen the understanding of déjà vu and involuntary autobiographical memories and add to conceptual clarity.

Barzykowski and Moulin link déjà vu and involuntary autobiographical memories to the process of retrieval. They make no reference to Tulving's SPI-model. In this, it is proposed that information is acquired serially (S), stored in parallel (P), and retrieved independently (I). This model offers an alternative, elegant, view of involuntary autobiographical memory retrieval, as well as of déjà vus.

Episodic memory is emotionally laden memory, requiring amygdala involvement.

The memory impairment of neurological and psychiatric patients is seen as occurring mainly in the autobiographical-episodic memory domain and this is considered to depend on limbic structures such as the amygdala or the septal nuclei. Especially the amygdala is a hub for giving an emotional flavor to personal memories. Bastin et al. fail to include the amygdala in their integrative memory model.

Neural correlates of free recall of "famous events" in a "hypermnestic" individual as compared to an age- and education-matched reference group.

BACKGROUND: Memory performance of an individual (within the age range: 50-55 years old) showing superior memory abilities (protagonist PR) was compared to an age- and education-matched reference group in a historical facts ("famous events") retrieval task. RESULTS: Contrasting task versus baseline performance both PR and the reference group showed fMRI activation patterns in parietal and occipital brain regions. The reference group additionally demonstrated activation patterns in cingulate gyrus, whereas PR showed additional widespread activation patterns comprising frontal and cerebellar brain regions. The direct comparison between PR and the reference group revealed larger fMRI contrasts for PR in right frontal, superior temporal and cerebellar brain regions. CONCLUSIONS: It was concluded that PR generally recruits brain regions as normal memory performers do, but in a more elaborate way, and furthermore, that he applied a memory-strategy that potentially includes executively driven multi-modal transcoding of information and recruitment of implicit memory resources.

Medial temporal lobe activation during autobiographical context memory retrieval of time and place and its dependency upon recency.

The contribution of the medial temporal lobe (MTL) to the retrieval of autobiographical memories is widely accepted. Results of former patient studies and functional imaging studies suggest different involvement of the MTL during the retrieval of autobiographical context information and the remoteness of these. Varying recency, the MTL contribution during chronological and locational autobiographical context information processing was investigated in this study. Thirteen males (mean = 25 years) judged the event's place or time in a two-choice recognition task. Subjects made significantly more errors on chronological judgments. Retrieval of chronological information activated the left MTL, while retrieval of locational information activated the MTL bilaterally. Retrieval of more recent than remote context information activated especially the right MTL. Our results underline different MTL contributions on the retrieval of autobiographical context information, depending on the content and on the remoteness of the event that took place.

Validation of diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy.

PURPOSE: This study aimed to evaluate the diagnostic accuracy of the Hamilton Rating Scale for Depression (HRSD), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), and the Hospital Anxiety and Depression Scale-Depression subscale (HADS-D) as diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). METHODS: One hundred three patients with drug-resistant MTLE-HS were enrolled. All patients underwent a neurological examination, interictal and ictal video-electroencephalogram (V-EEG) analyses, and magnetic resonance imaging (MRI). Psychiatric interviews were based on DSM-IV-TR criteria and ILAE Commission of Psychobiology classification as a gold standard; HRSD, BDI, HADS, and HADS-D were used as psychometric diagnostic tests, and receiver operating characteristic (ROC) curves were used to determine the optimal threshold scores. RESULTS: For all the scales, the areas under the curve (AUCs) were approximately 0.8, and they were able to identify depression in this sample. A threshold of ≥9 on the HRSD and a threshold of ≥8 on the HADS-D showed a sensitivity of 70% and specificity of 80%. A threshold of ≥19 on the BDI and HADS-D total showed a sensitivity of 55% and a specificity of approximately 90%. The instruments showed a negative predictive value of approximately 87% and a positive predictive value of approximately 65% for the BDI and HADS total and approximately 60% for the HRSD and HADS-D. CONCLUSIONS: HRSD≥9 and HADS-D≥8 had the best balance between sensitivity (approximately 70%) and specificity (approximately 80%). However, with these thresholds, these diagnostic tests do not appear useful in identifying depressive disorder in this population with epilepsy, and their specificity (approximately 80%) and PPV (approximately 55%) were lower than those of the other scales. We believe that the BDI and HADS total are valid diagnostic tests for depressive disorder in patients with MTLE-HS, as both scales showed acceptable (though not high) specificity and PPV for this type of study.

The nature of the semantic/episodic memory distinction: A missing piece of the "working through" process.

The relations between the semantic and episodic-autobiographical memory systems are more complex than described in the target article. We argue that understanding the noetic/autonoetic distinction provides critical insights into the foundation of the delineation between the two memory systems. Clarity with respect to the criteria for classification of these two systems, and the evolving conceptualization of episodic memory, can further neuroscientifically informed therapeutic approaches.

Deficient symbol processing in Alzheimer disease.

Symbols and signs have been suggested to improve the orientation of patients suffering from Alzheimer disease (AD). However, there are hardly any studies that confirm whether AD patients benefit from signs or symbols and which symbol characteristics might improve or impede their symbol comprehension. To address these issues, 30 AD patients and 30 matched healthy controls performed a symbol processing task (SPT) with 4 different item categories. A repeated-measures analysis of variance was run to identify impact of different item categories on performance accuracy in both the experimental groups. Moreover, SPT scores were correlated with neuropsychological test scores in a broad range of other cognitive domains. Finally, diagnostic accuracy of the SPT was calculated by a receiver-operating characteristic curve analysis. Results revealed a global symbol processing dysfunction in AD that was associated with semantic memory and executive deficits. Moreover, AD patients showed a disproportional performance decline at SPT items with visual distraction. Finally, the SPT total score showed high sensitivity and specificity in differentiating between AD patients and healthy controls. The present findings suggest that specific symbol features impede symbol processing in AD and argue for a diagnostic benefit of the SPT in neuropsychological assessment.

The perception of facial emotions--cues from the left amygdaloid complex.

The history and the behavioral profile of 2 patients with brain abnormalities in the region of the left amygdaloidal complex might suggest that the dysfunction of the neural pathways related to the left amygdala has to occur at an early developmental stage to result in impaired emotional judgments of facial expressions. This is in line with the hypothesis that emotional information processing is based on a distributed neural network which, during ontogenesis, gradually expands from the amygdala and the amygdaloidal complex to further components of the limbic system.

The Bergen left-right discrimination test: practice effects, reliable change indices, and strategic performance in the standard and alternate form with inverted stimuli.

Several authors pointed out that left-right discrimination (LRD) tasks may be entangled with differential demands on mental rotation (MR). However, studies considering this interrelationship are rare. To differentially assess LRD of stimuli with varying additional demands on MR, we constructed and evaluated an extended version of the Bergen right-left discrimination (BRLD) test including additional subtests with inverted stickmen stimuli in 174 healthy participants (50♂, 124♀) and measured subjective reports on participants' strategies to accomplish the task. Moreover, we analyzed practice effects and reliable change indices (RCIs) on BRLD performance, as well as gender differences. Performance significantly differed between subtests with high and low demands on MR with best scores on subtests with low demands on MR. Participants' subjective strategies corroborate these results: MR was most frequently reported for subtests with highest MR demands (and lowest test performance). Pronounced practice effects were observed for all subtests. Sex differences were not observed. We conclude that our extended version of the BRLD allows for the differentiation between LRD with high and low demands on MR abilities. The type of stimulus materials is likely to be critical for the differential assessment of MR and LRD. Moreover, RCIs provide a basis for the clinical application of the BRLD.

Dissociative Amnesia: Remembrances Under Cover.

The existence or questionability of "repressed memories" can be discussed as being a matter of definition. It seems, however, far-fetched to consider all "lost" memories as caused by encoding problems, brain damage, forgetfulness, failure to disclose events, and so on. We argue that dissociative amnesia (DA) (or "psychogenic amnesia," or "functional amnesia," or, as we favor to call it, "mnestic block syndrome") is caused by psychic alterations, but ultimately they can be traced to changes in the physiology of the brain, as we are of the opinion that all memory processes-positive or negative-alter brain functions, sometimes more permanently, sometimes transiently. We have proven this idea using functional imaging techniques, in particular fluoro-deoxy-d-glucose positron emission tomography. Having investigated dozens of patients with severe and long-lasting DA conditions, we believe it to be disrespectful to many (but not to all) of the affected patients to question their disease condition, which can be proven to be not caused by feigning, malingering, or direct brain damage.

Amnesic disorders.

Memory disturbances frequently occur after brain damage, but can be associated with psychiatric illnesses as well. Amnesia--the most severe form of memory impairment--has several variants, including anterograde and retrograde amnesia, material-specific and modality-specific amnesia, and transient global amnesia. We searched databases to obtain an overview of amnesia research from the past 5 years. Research into amnesia has increased exponentially, probably because of the availability of modern brain-imaging techniques. In line with the view that memory is not a unity but is organised into several systems, amnesia is described as a multifaceted disease with a frequently poor prognosis.

When solving 22-7 is much more difficult than 99-12.

We describe the case of a 69-year-old professor of mathematics (GV) who was examined 2 years after left-hemispheric capsular-thalamic haemorrhage. GV showed disproportionate impairment in subtractions requiring borrowing (22 - 7). For large subtraction problems without borrowing (99 - 12) performance was almost flawless. Subtractions with borrowing mostly relied on inadequate attempts to invert subtractions into the corresponding additions (22 - 7 = x as 7 + x = 22). The hypothesis is advanced that difficulty in the inhibitory components of attention tasks (Stroop test, go-no-go task) might be the responsible factor of his calculation impairment. A deficit in subtractions with borrowing might be related to left-hemispheric damage involving thalamo-cortical connections.

Learning real-life cognitive abilities in a novel 360°-virtual reality supermarket: a neuropsychological study of healthy participants and patients with epilepsy.

BACKGROUND: To increase the ecological validity of neuropsychological instruments the use of virtual reality (VR) applications can be considered as an effective tool in the field of cognitive neurorehabilitation. Despite the growing use of VR programs, only few studies have considered the application of everyday activities like shopping or travelling in VR training devices. METHODS: We developed a novel 360°-VR supermarket, which is displayed on a circular arrangement of 8 touch-screens--the "OctaVis". In this setting, healthy human adults had to memorize an auditorily presented shopping list (list A) and subsequently buy all remembered products of this list in the VR supermarket. This procedure was accomplished on three consecutive days. On day four, a new shopping list (list B) was introduced and participants had to memorize and buy only products of this list. On day five, participants had to buy all remembered items of list A again, but without new presentation of list A. Additionally, we obtained measures of participants' presence, immersion and figural-spatial memory abilities. We also tested a sample of patients with focal epilepsy with an extended version of our shopping task, which consisted of eight days of training. RESULTS: We observed a comprehensive and stable effect of learning for the number of correct products, the required time for shopping, and the length of movement trajectories in the VR supermarket in the course of the training program. Task performance was significantly correlated with participants' figural-spatial memory abilities and subjective level of immersion into the VR. CONCLUSIONS: Learning effects in our paradigm extend beyond mere verbal learning of the shopping list as the data show evidence for multi-layered learning (at least visual-spatial, strategic, and verbal) on concordant measures. Importantly, learning also correlated with measures of figural-spatial memory and the degree of immersion into the VR. We propose that cognitive training with the VR supermarket program in the OctaVis will be efficient for the assessment and training of real-life cognitive abilities in healthy subjects and patients with epilepsy. It is most likely that our findings will also apply for patients with cognitive disabilities resulting from other neurological and psychiatric syndromes.

The spaces left over between REM sleep, dreaming, hippocampal formation, and episodic autobiographical memory.

It is argued that Llewellyn's hypothesis about the lack of rapid eye movement (REM)-sleep dreaming leading to loss of personal identity and deficits in episodic memory, affectivity, and prospection is insufficiently grounded because it does not integrate data from neurodevelopmental studies and makes reference to an outdated definition of episodic memory.

Behavioral, neurological, and psychiatric frailty of autobiographical memory.

Autobiographical-episodic memory is considered to be the most complex of the five long-term memory systems. It is autonoetic, which means, self-reflective, relies on emotional colorization, and needs the features of place and time; it allows mental time traveling. Compared to the other four long-term memory systems-procedural memory, priming, perceptual, and semantic memory-it develops the latest in phylogeny and ontogeny, and is the most vulnerable of the five systems, being easily impaired by brain damage and psychiatric disorders. Furthermore, it is characterized by its fragility and proneness to distortion due to environmental influences and subsequent information. On the brain level, a distinction has to be made between memory encoding and consolidating, memory storage, and memory retrieval. For encoding, structures of the limbic system, with the hippocampus in its center, are crucial, for storage of widespread cortical networks, and for retrieval again a distributed recollection network, in which the prefrontal cortex plays a crucial role, is engaged. Brain damage and psychiatric diseases can lead to what is called "focal retrograde amnesia." In this context, the clinical picture of dissociative or functional or psychogenic amnesia is central, as it may result in autobiographical-emotional amnesia of the total past with the consequence of an impairment of the self as well. The social environment therefore can have a major impact on the brain and on autobiographical-episodic memory processing. This article is categorized under: Psychology > Memory.

Urbach-Wiethe disease in a young patient without apparent amygdala calcification.

Urbach-Wiethe disease is an extremely rare genetically-based syndrome which usually leads to dermatological and neurological changes. Neurologically, the amygdaloid region is primarily bilaterally affected. Therefore, several functions modulated by the amygdala are changed in patients with Urbach-Wiethe disease. As the neurological alterations evolve only gradually, it is particularly important to determine the cognitive and brain status of a juvenile. The patient described here was seen briefly at age 9 and tested neuropsychologically at age 19; furthermore, computer tomography and magnetic resonance imaging of his head was done. There were no important abnormalities in the brain, which is unusual in the light of previous data from other patients. On the cognitive level, the patient was generally within normal limits. However, he had mild problems in attention and concentration, and more prominent problems in emotional processing domain, and in personality dimensions. It is concluded that amygdala calcifications in Urbach-Wiethe disease take place progressively-possibly underpinned by genetic and gender variables; this can subsequently allow psychosocial-social factors (such a proper education and socialization) and biological factors (compensatory neuroplasticity) to retard and diminish the development of socio-emotional and cognitive deteriorations, though the outcome of questionnaires indicates that such patients may develop substantial concerns as to their future life and well-being.

A rapprochement between emotion and cognition: amygdala, emotion, and self-relevance in episodic-autobiographical memory.

Lindquist et al. remark that not all fear instances lead to heightened amygdalar activity and, instead, point to roles of the amygdala in detecting "motivationally salient "or "emotionally impactful" stimuli. By reviewing research on the amygdala's functions in episodic-autobiographical memory, we further emphasize the involvement of the amygdala in coding the subjective relevance and extracting the biological and social significance of the stimuli.

Memory, autonoetic consciousness, and the self.

Memory is a general attribute of living species, whose diversification reflects both evolutionary and developmental processes. Episodic-autobiographical memory (EAM) is regarded as the highest human ontogenetic achievement and as probably being uniquely human. EAM, autonoetic consciousness and the self are intimately linked, grounding, supporting and enriching each other's development and cohesiveness. Their development is influenced by the socio-cultural-linguistic environment in which an individual grows up or lives. On the other hand, through language, textualization and social exchange, all three elements leak into the world and participate to the dynamic shaping and re-shaping of the cultural scaffolding of the self, mental time traveling and EAM formation. Deficits in self-related processing, autonetic consciousness, emotional processing and mental time traveling can all lead to or co-occur with EAM disturbances, as we illustrate by findings from EAM impairments associated with neurological or psychiatric disorders.

Alterations of decision making and underlying neural correlates after resection of a mediofrontal cortical dysplasia: A single case study.

We investigated the impact of a congenital prefrontal lesion and its resection on decision making under risk and under ambiguity in a patient with right mediofrontal cortical dysplasia. Both kinds of decision making are normally associated with the medial prefrontal cortex. We additionally studied pre- and postsurgical fMRI activations when processing information relevant for risky decision making. Results indicate selective impairments of ambiguous decision making pre- and postsurgically. Decision making under risk was intact. In contrast to healthy subjects the patient exhibited no activation within the dysplastic anterior cingulate cortex but left-sided orbitofrontal activation on the fMRI task suggesting early reorganization processes.

Psychogenic amnesia--a malady of the constricted self.

Autobiographical-episodic memory is the conjunction of subjective time, autonoetic consciousness and the experiencing self. Understanding the neural correlates of autobiographical-episodic memory might therefore be essential for shedding light on the neurobiology underlying the experience of being an autonoetic self. In this contribution we illustrate the intimate relationship between autobiographical-episodic memory and self by reviewing the clinical and neuropsychological features and brain functional imaging correlates of psychogenic amnesia - a condition that is usually characterized by severely impaired retrograde memory functioning, in absence of structural brain damage as detected by standard imaging. We demonstrate that in this disorder the autobiographical-episodic memory deficits do not exist in isolation, but occur with impairments of the autonoetic self-consciousness, emotional processing, and theory of mind or executive functions. Furthermore functional and metabolic brain alterations involving regions that are agreed upon to exert crucial roles in memory processes were frequently found to accompany the psychogenic memory "loss".