The measurement of meaning

Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

https://www.zora.uzh.ch/id/eprint/77770/1/physiol_rev_93.pdf

About sleep's role in memory

Upward Spirals of Positive Emotions Counter Downward Spirals of Negativity: Insights from the Broaden-and-Build Theory and Affective Neuroscience on The Treatment of Emotion Dysfunctions and Deficits in Psychopathology

Context Psychopaths belong to a larger group of persons with antisocial personality disorder and are characterized by an inability to have emotional involvement and by the repeated violation of the rights of others. It was hypothesized that this behavior might be the consequence of deficient fear conditioning. Objective To study the cerebral, peripheral, and subjective correlates of fear conditioning in criminal psychopaths and healthy control subjects. Design An aversive differential pavlovian delay conditioning paradigm with slides of neutral faces serving as conditioned and painful pressure as unconditioned stimuli. Setting The Department of Medical Psychology at the University of Tubingen, Tubingen, Germany. Participants Ten male psychopaths as defined by the Hare Psychopathy Checklist–Revised and 10 age- and education-matched healthy male controls. The psychopaths were criminal offenders on bail and waiting for their trial or were on parole. The healthy controls were recruited from the community. Main Outcome Measures Brain activation based on functional magnetic resonance imaging, electrodermal responses, emotional valence, arousal, and contingency ratings. Results The healthy controls showed enhanced differential activation in the limbic-prefrontal circuit (amygdala, orbitofrontal cortex, insula, and anterior cingulate) during the acquisition of fear and successful verbal and autonomic conditioning. The psychopaths displayed no significant activity in this circuit and failed to show conditioned skin conductance and emotional valence ratings, although contingency and arousal ratings were normal. Conclusion This dissociation of emotional and cognitive processing may be the neural basis of the lack of anticipation of aversive events in criminal psychopaths.

https://jamanetwork.com/journals/jamapsychiatry/articlepdf/208744/yoa40213.pdf

Deficient Fear Conditioning in Psychopathy A Functional Magnetic Resonance Imaging Study

The whats and whens of sleep-dependent memory consolidation.

Background: The cyclic adenosine monophosphate response element-binding proteins (CREB) and their interaction with brain-derived neurotrophic factor (BDNF) are essential elements in

Changes in CREB phosphorylation and BDNF plasma levels during psychotherapy of depression.

It has been hypothesized that non-rapid eye movement (NREM) sleep facilitates declarative memory consolidation, and rapid eye movement (REM) sleep is particularly important in promoting procedural learning. The aim of this study was to examine the effects of pharmacological REM sleep suppression on performance in different neuropsychological tasks. For our baseline, we chose 41 moderately depressed patients (age range 19-44 years), who were not taking antidepressants. In the morning after polysomnography, we tested memory recall and cognitive flexibility by assessment of verbal and figural fluency, a shift of attention task and the Trail Making Test B. After recording baseline values, patients were assigned randomly to one of three treatment groups: medication with citalopram; medication with reboxetine; or exclusive treatment with psychotherapy. Retesting took place 1 week after onset of treatment. The main results were: (1) an association of slow-wave sleep with verbal memory performance at baseline; (2) a suppression of REM sleep in patients taking citalopram and reboxetine; (3) no differences regarding neuropsychological performance within the treatment groups; and (4) no association of REM sleep diminution with decreases in memory performance or cognitive flexibility in patients treated with citalopram or reboxetine. In line with other studies, our results suggest that there are no negative effects of a decrease in REM sleep on memory performance in patients taking antidepressants.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2869.2011.00914.x

Sleep and cognition at baseline and the effects of REM sleep diminution after 1 week of antidepressive treatment in patients with depression

Psychopathy, intelligence and conviction history

The current study investigated the prevalence of mental disorders among incarcerated juvenile offenders in Germany and sought to identify clinically relevant subgroups. In sum, 149 newly incarcerated male juvenile delinquents (M age = 19 years) were included. Diagnostic tools included the German version of the Structured Clinical Interview for DSM-IV and the Psychopathy Checklist-Screening Version. The most prevalent diagnoses in the sample included conduct disorders (81%), Cluster B personality disorders (up to 62%), and substance-related disorders (up to 60%). Moreover, psychopathic features were found among 21% of the participants. Cluster analysis distinguished three subgroups among this group of young offenders. The most problematic consisted of juveniles with multiple psychopathology, including antisocial traits, personality pathology, higher scores on the Psychopathy Checklist, as well as multiple substance abuse. Study outcomes are discussed in light of their implications for the development of effective treatment for juvenile offenders.

Christian Huchzermeier

Papers

Changes in CREB phosphorylation and BDNF plasma levels during psychotherapy of depression.

Sleep and cognition at baseline and the effects of REM sleep diminution after 1 week of antidepressive treatment in patients with depression

Psychopathy, intelligence and conviction history

The Prevalence of Mental Disorders in a German Sample of Male Incarcerated Juvenile Offenders

Are there age-related effects in antisocial personality disorders and psychopathy?