[pt] A memória se apresenta em sistemas distintos e interligados. Ela permite a constituição do sujeito e sua interação com o meio em que vive. Durante o desenvolvimento, mudanças biológicas e comportamentais vão ocorrendo, algumas vezes de forma rápida e outras, lentamente, respeitando a maturação neuronal, a interação social e a cultura em que vive. Nesse contexto, a emoção tem um papel modulador das funções cognitivas, fortalecendo ou enfraquecendo o armazenamento de uma informação, ou seja, influenciando a memória. Seu armazenamento pode ser sensorial, de curto e de longo prazo e ela pode se dividir em estágios (codificação, armazenamento e recuperação) e em tipos (explícita ou declarativa e implícita ou não declarativa). A memória explícita se subdivide em episódica e semântica, a implícita inclui os hábitos e habilidades, e a memória de curto prazo inclui a memória de trabalho. As áreas cerebrais envolvidas são o hipocampo, lobos frontal e temporal e a amígdala. Há distinção dos sistemas de memória durante o desenvolvimento: bebês reproduzem ações, reconhecem faces e eventos familiares e apresentam memória implícita (que não se altera muito ao longo do desenvolvimento); crianças pré-escolares apresentam uma memória mais sofisticada, organizando melhor as informações; e na fase escolar a memória já se encontra mais desenvolvida. O estudo mostrou que a memória semântica melhora gradualmente com a idade, acompanhando a ampliação de vocabulário; a memória episódica se desenvolve de forma mais pontual; e a memória de trabalho apresenta maturação mais tardia, acompanhando o desenvolvimento das funções executivas. / [en] The memory is divided into different systems and interconnected. It allows the creation of the subject and its interaction with the environment in which they live. During the development, behavioral and biological changes are occurring, sometimes quickly and others slowly, respecting the neuronal maturation, social interaction and culture in which they live. In this aspect, some skills are innate and others, acquired, learned. In this context, emotion plays a modulator of cognitive functions, strengthening or weakening the storage of information, ie, influencing memory. It can present divided into stages (sensory, short term and long term), in steps (encoding, storage and retrieval), and types (declarative or explicit and implicit or non-declarative). The explicit type is subdivided into episodic and semantic, the implicit include the habits and skills, and the short-term memory includes the working memory. The brain areas involved are the hippocampus, frontal and temporal lobes, and amygdale. in the formation of new memories and the recognition and consolidation during learning, and amygdala, allowing storage of the episodes that involve more emotion. There are distinctions in the memory systems during the development: babies reproduce actions, recognize faces and family events and have implicit memory (which does not change much throughout development), preschool children have a more sophisticated memory by organizing the information better; and during school memory is already more developed. The study showed that semantic memory improves gradually with age, following the expansion of vocabulary; episodic memory develops in a more timely, and working memory presents late maturation, following the development of executive functions.

Die Überwachung des zentralen Nervensystems (ZNS) während der Allgemeinanästhesie ist aus anästhesiologischer Sicht wünschenswert, um eine Über- oder Unterdosierung von Narkotika intraoperativ zu vermeiden. Narkosetiefe wird definiert als die Summe aller intraoperativ auf den Patienten einwirkenden sensorischen Stimuli und den zentralnervös dämpfenden Effekten der Anästhetika auf die zerebrale Aktivität. Während für die akustisch evozierten Potentiale diskutiert wird, ob sie die hypnotische Komponente der Allgemeinanästhesie erfassen, ist derzeit unklar, welchen Beitrag somatosensorisch evozierten Potentialen bei der Bestimmung von Narkosetiefe leisten können. Somatosensorisch evozierte Potentiale werden in der klinischen Routine zur Überwachung der Integrität von neuronalen Leitungsbahnen bei Operationen eingesetzt. Das Ziel der hier vorgestellten klinischen Untersuchungen, in denen somatosensorisch und akustisch evozierte Potentiale (SEP, AEP) als mögliche Parameter zur Quantifizierung von Narkosetiefe gegenübergestellt werden, bestand darin, nachfolgende Hypothesen zu überprüfen: 1. Die mittleren Komponenten von SEP und AEP verändern sich dosisabhängig in Abhängigkeit vom Narkotikum in Amplituden und Latenzen und eignen sich als Parameter zur Quantifizierung von Narkotikawirkungen auf das ZNS. 2. Die durch Anästhetika induzierten Veränderungen von SEP und AEP sind unter chirurgischer Stimulation reversibel. Daher eignen sich SEP und AEP als Parameter zur Quantifizierung von Narkosetiefe. 3. SEP und AEP sind geeignet, bei kritisch kranken Patienten den Grad der Analgosedierung quantitativ zu erfassen. 4. SEP und AEP lassen Rückschlüsse auf die Modulation kognitiver Prozesse unter Narkotika zu. In mehreren klinischen Studien an narkotisierten oder analgosedierten Patienten (n = 161) wurden die Wirkungen von Anästhetika auf SEP und AEP dokumentiert, bzw. der Einfluß von chirurgischen oder pflegerischen Maßnahmen untersucht. Zielvariablen waren die Mittellatenz-Komponenten der SEP (N20, P25, N35, P45, N50) und der AEP (Na, Pa; Nb) im Vergleich zur klinischen Einschätzung der Narkosetiefe und den hämodynamischen Daten. Die statistische Analyse wurde mittelts multivariater Analysen durchgeführt, die prädiktive Aussagekraft anhand der prediction probability nach Smith berechnet. Unter Anästhetikagabe fand sich als grundlegendes Muster sowohl bei den SEP als auch bei den AEP eine Verlängerung der Latenzen bei Verminderung der korrespondierenden Amplituden, wobei die Effekte auf die späteren Komponenten > 35 ms deutlicher ausgeprägt waren. Während der Aufwachphase aus der Anästhesie, unter chirurgischen und pflegerischen Maßnahmen waren die anästhetikabedingten Veränderungen der EP-Komponenten teilweise reversibel. Darüberhinaus ließen die SEP-Latenzen P45 und N50 und die AEP-Latenz Nb während der Aufwachphase aus der Anästhesie Rückschlüsse auf die Wiederkehr des expliziten Erinnerungsvermögens nach Narkose zu. Im Gegensatz zu signifikanten Effekten im Gruppenvergleich war die prädiktive Aussagekraft der EP-Parameter im Individualfall gering. SEP sind unter den hier gewählten Narkotikaregimes geeignet, die Modulation der zerebralen Aktivität unter Anästhetika abzubilden. Im Sinne kortikaler Arousalreaktionen werden unter exogener Stimulation die durch Anästhetika induzierten Veränderungen der SEP teilweise antagonisiert. Bei der Interpretation der Befunde in Hinblick auf den Grad der Narkosetiefe ist zu berücksichtigen, daß die Effekte nicht unabhängig vom Anästhetikum sind und im Individualfall stark variieren können. Dennoch ist im Einzelfall der Einsatz von SEP als Monitor zur Narkosetiefe durchaus sinnvoll, z. B. wenn AEP oder andere Verfahren nicht durchführbar sind. Ein Einsatz der SEP als "idealer" Monitor zur Bestimmung des Grades der Narkosetiefe in der klinischen Routine ist zum jetzigen Zeitpunkt sicher nicht gerechtfertigt. Zweifelsohne können weitere Untersuchungen mit SEP zu wesentlichen Erkenntnissen in der klinisch anästhesiologischen Grundlagenforschung beitragen. / Monitoring of the functional state of the central nervous system is of major concern for the anaesthetist to avoid over- or undermedication with the possible sequelae for the patient during general anaesthesia. Depth of anaesthesia is defined as the sum of all excitatory stimuli during operation and the depressant effects of anaesthetics on the electrical activity of the brain. Currently it is discussed, whether the auditory evoked responses (AER) reflect the hypnotic component during anaesthesia. In contrast there is limited information about somatosensory evoked responses (SER) with respect to depth of anaesthesia, even though SER are used to monitor the integrity of the somatosensory pathway at risk during surgery. The aim of the present clinical investigations, in which SER and AER were investigated as parameters to quantify depth of anaesthesia, was to test the following hypotheses: 1. Anaesthetics induce dose-related changes in somatosensory and auditory evoked responses and quantify the anaesthetic action on the brain. 2. During surgical stimulation the anaesthetic induced changes are reversed in part. Therefore SERs and AERs are indicators of depth of anaesthesia. 3. SERs and AERs quantify the grade of analgosedation in critically ill patients. 4. SERs and AERs indicate modulation of cognitive function during recovery from anaesthesia. In clinical studies (n = 161 patients) we investigated the midlatency components of SER and AER during different anaesthetic drug combinations, their modulation during surgical stimulation or nursing care and during recovery from anaesthesia. The midlatency SER components N20, P25, N35, P45 and N50 and the AER components Na, Pa and Nb were studied in relation to the clinical assessment of anaesthetic depth and haemodynamic parameters. Statistical analyses were performed by multivariate analyses of variance for repeated measurements and by the calculation for the prediction probability according to Smith. Results: The main pattern of anaesthetic induced changes on midlatency SER and AER waves was as follows: Prolongation in the latencies and reduction of the corresponding amplitudes. The effect was more pronounced on the components > 35 ms. During recovery from general anaesthesia, during surgical stimulation or nursing care the anaesthetic induced changes were in part reversed. Moreover, changes of the SER components P45 and N50 and the AER component Nb differed in patients with respect to explicit memory performance during the wake-up phase from general anaesthesia. While the group effects were significant, the calculated values of the prediction probability indicated a low predictive potency for the individual case. Conclusions: The midlatency SER waves are indicative for changes in the electrical brain activity during different anaesthetic drug combinations. During surgery or other types of exogeneous intervention the anaesthetic induced changes of some SER and AER components are reversed indicating cortical arousal. Interpreting the results with respect to measure depth of anaesthesia it is important to know, that the changes of the evoked responses are dependent on the used anaesthetic and may differ markedly inter- and intraindividually. In a single case SER-recording can be useful to monitor anaesthetic depth, if e.g. AER monitoring is not possible. However, at the present time SER are not advocated as an "ideal" monitor to measure the level of anaesthesia during clinical routine. Without doubt further investigation elucidating the relation between SER and anaesthetics will contribute to our basic understanding of anaesthetic action on the brain.

The desire to enhance and make ourselves better is not a new one and it has continued to intrigue throughout the ages. Individuals have continued to seek ways to improve and enhance their well-being for example through nutrition, physical exercise, education and so on. Crucial to this improvement of their well-being is improving their ability to remember. Hence, people interested in improving their well-being, are often interested in memory as well. The rationale being that memory is crucial to our well-being. The desire to improve one’s memory then is almost certainly as old as the desire to improve one’s well-being. Traditionally, people have used different means in an attempt to enhance their memories: for example in learning through storytelling, studying, and apprenticeship. In remembering through practices like mnemonics, repetition, singing, and drumming. In retaining, storing and consolidating memories through nutrition and stimulants like coffee to help keep awake; and by external aids like notepads and computers. In forgetting through rituals and rites. Recent scientific advances in biotechnology, nanotechnology, molecular biology, neuroscience, and information technologies, present a wide variety of technologies to enhance many different aspects of human functioning. Thus, some commentators have identified human enhancement as central and one of the most fascinating subject in bioethics in the last two decades. Within, this period, most of the commentators have addressed the Ethical, Social, Legal and Policy (ESLP) issues in human enhancements as a whole as opposed to specific enhancements. However, this is problematic and recently various commentators have found this to be deficient and called for a contextualized case-by-case analysis to human enhancements for example genetic enhancement, moral enhancement, and in my case memory enhancement (ME). The rationale being that the reasons for accepting/rejecting a particular enhancement vary depending on the enhancement itself. Given this enormous variation, moral and legal generalizations about all enhancement processes and technologies are unwise and they should instead be evaluated individually. Taking this as a point of departure, this research will focus specifically on making a case for ME and in doing so assessing the ESLP implications arising from ME. My analysis will draw on the already existing literature for and against enhancement, especially in part two of this thesis; but it will be novel in providing a much more in-depth analysis of ME. From this perspective, I will contribute to the ME debate through two reviews that address the question how we enhance the memory, and through four original papers discussed in part three of this thesis, where I examine and evaluate critically specific ESLP issues that arise with the use of ME. In the conclusion, I will amalgamate all my contribution to the ME debate and suggest the future direction for the ME debate.