Implicit Memory in Korsakoff’s Syndrome: A Review of Procedural Learning and Priming Studies

Korsakoff's syndrome (KS) is characterized by dense anterograde amnesia resulting from damage to the diencephalon region, typically resulting from chronic alcohol abuse and thiamine deficiency. This review assesses the integrity of the implicit memory system in KS, focusing on studies of procedural learning and priming. KS patients are impaired on several measures of procedural memory, most likely due to impairment in cognitive functions associated with alcohol-related neural damage outside of the diencephalon. The pattern of performance on tasks of implicit priming suggests reliance on a residual, non-flexible memory operating more or less in an automatic fashion. Our review concludes that whether measures of implicit memory reveal intact or impaired performance in individuals with KS depends heavily on specific task parameters and demands, including timing between stimuli, the specific nature of the stimuli used in a task, and the integrity of supportive cognitive functions necessary for performance.     

Context Memory in Korsakoff’s Syndrome

Memory for contextual information and target-context integration are crucial for successful episodic memory formation and are impaired in patients with Korsakoff's syndrome. In this paper we review the evidence for the notion that a context memory deficit makes an important contribution to the amnesia in these patients. First, we focus on anterograde memory for contextual (spatial and temporal) information. Next, the use of contextual cues in memory retrieval is examined and their role in retrograde amnesia and confabulation. Evidence on the role of contextual cues and associations in working memory is discussed in relation to the underlying neurocognitive mechanisms and their dissociation from long-term encoding. Finally, we focus on implicit learning of contextual information in Korsakoff patients. It can be concluded that Korsakoff patients are impaired in the explicit processing of contextual information and in target-context binding, both in long-term (retrograde and anterograde) memory and in working memory. These results extend the context memory deficit hypothesis. In contrast, implicit contextual learning is relatively preserved in these patients. These findings are discussed in relation to evidence of dysfunction of the extended diencephalic-hippocampal memory circuit in Korsakoff's syndrome.     

Remote Memory Function and Dysfunction in Korsakoff’s Syndrome

Korsakoff's syndrome (KS) is a pervasive disorder of memory characterized by both anterograde and retrograde amnesia. Although retrograde memory impairment in KS has been less frequently studied, the status of remote memory in KS has been tested across a number of different tasks that measure knowledge of public information (e.g., famous faces/news events), general semantic information (e.g., vocabulary words), personal semantic information (e.g., facts about oneself), and autobiographical events (e.g., events from one's personal past). In each of these domains, Korsakoff patients demonstrate remote memory impairments that can extend back many years or decades. In addition, a majority of studies report that the extensive remote memory impairment in KS is temporally graded, with relative preservation of memories from childhood and early adulthood. The current paper reviews published experimental studies of remote memory in KS, with particular attention paid to (a) the selectivity of the deficit with respect to the age of the memory and (b) the relationship of memory impairment to underlying neuropathology. We discuss the significance of the reported pattern and extent of remote memory impairment with respect to theories about the nature of the underlying cognitive deficits in KS.     

Neuroimaging of Wernicke’s Encephalopathy and Korsakoff’s Syndrome

There is considerable evidence that neuroimaging findings can improve the early diagnosis of Wernicke's encephalopathy (WE) in clinical settings. The most distinctive neuroimaging finding of acute WE are cytotoxic edema and vasogenic edema, which are represented by bilateral symmetric hyperintensity alterations on T2-weighted MR images in the periphery of the third ventricle, periaqueductal area, mammillary bodies and midbrain tectal plate. An initial bout of WE can result in Korsakoff's syndrome (KS), but repeated bouts in conjunction with its typical comorbidity, chronic alcoholism, can result in signs of tissue degeneration in vulnerable brain regions. Chronic abnormalities identified with neuroimaging enable examination of brain damage in living patients with KS and have expanded the understanding of the neuropsychological deficits resulting from thiamine deficiency, alcohol neurotoxicity, and their comorbidity. Brain structure and functional studies indicate that the interactions involving the thalamus, mammillary bodies, hippocampus, frontal lobes, and cerebellum are crucial for memory formation and executive functions, and the interruption of these circuits by WE and chronic alcoholism can contribute substantially to the neuropsychological deficits in KS.     

Function and Dysfunction of Prefrontal Brain Circuitry in Alcoholic Korsakoff’s Syndrome

The signature symptom of alcohol-induced persisting amnestic disorder, more commonly referred to as alcoholic Korsakoff's syndrome (KS), is anterograde amnesia, or memory loss for recent events, and until the mid 20th Century, the putative brain damage was considered to be in diencephalic and medial temporal lobe structures. Overall intelligence, as measured by standardized IQ tests, usually remains intact. Preservation of IQ occurs because memories formed before the onset of prolonged heavy drinking--the types of information and abilities tapped by intelligence tests--remain relatively well preserved compared with memories recently acquired. However, clinical and experimental evidence has shown that neurobehavioral dysfunction in alcoholic patients with KS does include nonmnemonic abilities, and further brain damage involves extensive frontal and limbic circuitries. Among the abnormalities are confabulation, disruption of elements of executive functioning and cognitive control, and emotional impairments. Here, we discuss the relationship between neurobehavioral impairments in KS and alcoholism-related brain damage. More specifically, we examine the role of damage to prefrontal brain systems in the neuropsychological profile of alcoholic KS.     

Review of a Parent’s Influence on Pediatric Procedural Distress and Recovery

Understanding how parents influence their child’s medical procedures can inform future work to reduce pediatric procedural distress and improve recovery outcomes. Following a pediatric injury or illness diagnosis, the associated medical procedures can be potentially traumatic events that are often painful and distressing and can lead to the child experiencing long-term physical and psychological problems. Children under 6 years old are particularly at risk of illness or injury, yet their pain-related distress during medical procedures is often difficult to manage because of their young developmental level. Parents can also experience ongoing psychological distress following a child’s injury or illness diagnosis. The parent and parenting behavior is one of many risk factors for increased pediatric procedural distress. The impact of parents on pediatric procedural distress is an important yet not well-understood phenomenon. There is some evidence to indicate parents influence their child through their own psychological distress and through parenting behavior. This paper has three purposes: (1) review current empirical research on parent-related risk factors for distressing pediatric medical procedures, and longer-term recovery outcomes; (2) consider and develop existing theories to present a new model for understanding the parent–child distress relationship during medical procedures; and (3) review and make recommendations regarding current assessment tools and developing parenting behavior interventions for reducing pediatric procedural distress.     

Neuroanatomy and Neuropathology Associated with Korsakoff’s Syndrome

Although the neuropathology of Korsakoff's syndrome (KS) was first described well over a century ago and the characteristic brain pathology does not pose a diagnostic challenge to pathologists, there is still controversy over the neuroanatomical substrate of the distinctive memory impairment in these patients. Cohort studies of KS suggest a central role for the mammillary bodies and mediodorsal thalamus, and quantitative studies suggest additional damage to the anterior thalamus is required. Rare cases of KS caused by pathologies other than those of nutritional origin provide support for the role of the anterior thalamus and mammillary bodies. Taken together the evidence to date shows that damage to the thalamus and hypothalamus is required, in particular the anterior thalamic nucleus and the medial mammillary nucleus of the hypothalamus. As these nuclei form part of wider memory circuits, damage to the inter-connecting white matter tracts can also result in a similar deficit as direct damage to the nuclei. Although these nuclei and their connections appear to be the primary site of damage, input from other brain regions within the circuits, such as the frontal cortex and hippocampus, or more distant regions, including the cerebellum and amygdala, may have a modulatory role on memory function. Further studies to confirm the precise site(s) and extend of brain damage necessary for the memory impairment of KS are required.     

Working Memory and Learning in Early Alzheimer’s Disease

Cognitive deficits associated with early Alzheimers disease (AD) have been recently operationalised in terms of an acquisition deficit and the research supporting this view is presented. However, there is still debate concerning the nature of this deficit and how underlying cognitive processes may be detrimentally affecting the ability to acquire new information in early AD. This review argues that the pattern of cognitive deficits contributing to the acquisition impairment in early AD patients may be readily interpreted within the context of a working memory model. Isolating the component processes of working memory that underlie the acquisition deficit in early AD patients will aid in the design of clinical applications that are focussed at enhancing the ability to acquire new information in everyday life.     

Diagnostic Accuracy of Memory Measures in Alzheimer’s Dementia and Mild Cognitive Impairment: a Systematic Review and Meta-Analysis

With an increasing focus on biomarkers in dementia research, illustrating the role of neuropsychological assessment in detecting mild cognitive impairment (MCI) and Alzheimer’s dementia (AD) is important. This systematic review and meta-analysis, conducted in accordance with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) standards, summarizes the sensitivity and specificity of memory measures in individuals with MCI and AD. Both meta-analytic and qualitative examination of AD versus healthy control (HC) studies (n = 47) revealed generally high sensitivity and specificity (≥ 80% for AD comparisons) for measures of immediate (sensitivity = 87%, specificity = 88%) and delayed memory (sensitivity = 89%, specificity = 89%), especially those involving word-list recall. Examination of MCI versus HC studies (n = 38) revealed generally lower diagnostic accuracy for both immediate (sensitivity = 72%, specificity = 81%) and delayed memory (sensitivity = 75%, specificity = 81%). Measures that differentiated AD from other conditions (n = 10 studies) yielded mixed results, with generally high sensitivity in the context of low or variable specificity. Results confirm that memory measures have high diagnostic accuracy for identification of AD, are promising but require further refinement for identification of MCI, and provide support for ongoing investigation of neuropsychological assessment as a cognitive biomarker of preclinical AD. Emphasizing diagnostic test accuracy statistics over null hypothesis testing in future studies will promote the ongoing use of neuropsychological tests as Alzheimer’s disease research and clinical criteria increasingly rely upon cerebrospinal fluid (CSF) and neuroimaging biomarkers.     

Literature and the Expressions of Being in Merleau-Ponty’s Unpublished Course Notes

In this article I examine Merleau-Ponty’s understanding of the relation between literature, being and perception. I focus especially on two of Merleau-Ponty’s courses at Collège de France: the first course, Le monde sensible et le monde de l’expression, and the unpublished course Sur le problème de la parole. In the former Merleau-Ponty presents a new understanding of perception, according to which being is expressed in perception through the style of movement of the perceived phenomenon. In the latter he advances a notion of literary writing as an expression of the being that is itself expressed to us in perception. Through a reading of Proust’s work, he discusses how the literary writer makes his experience expressive by means of a stylization of what is experienced. Hence, literature expresses perception through an enhancement of the expressiveness that it already contains. This capacity of literature will be the main focus of my investigation.     

Sartre’s Dessin,Literature and the Ambiguities of the Representing Word

Phenomenology and the Cognitive Sciences - Seemingly a minor part of L’Imaginaire, Sartre’s literary examples therein are of great significance especially in the way they highlight the...     

Antecedent Strategies to Promote Children’s and Adolescents’ Compliance with Adult Requests: A Review of the Literature

Compliance with adult requests and directives has often been described as a keystone behavior in children, meaning it is associated with engagement in other desirable and socially appropriate behaviors. As such, a great deal of research has been directed toward identifying strategies that increase compliance in children. Antecedent strategies, which focus on increasing the probability of compliance prior to or during the delivery of the directive or request, are popular because they have the potential to prevent noncompliance; however, it is not clear which of the numerous antecedent strategies are effective or for whom. Therefore, a systematic review of the antecedent strategies for compliance was completed. Forty-two studies were identified evaluating eight different antecedent strategies for children aged 1–19. It was determined that high-probability command sequences, effective instruction delivery, and errorless compliance training may all be considered evidence-based antecedent strategies to increase children’s compliance with adult requests.     

The Significance of Shendu in the Interpretation of Classical Learning and Zhu Xi’s Misreading

According to recently excavated bamboo and silk material, the idea of du 獨 in the concept shendu 慎獨 does not refer to a spatial notion of dwelling in solitude or a solitary dwelling; rather it is the state before having made contact with external things, or the state “before feelings are aroused” (weifa 未發) of the inner heart/mind. It refers to internal thoughts and volitions, or “casting aside external sensations” (sheti 舍體). Shen 慎 should be glossed in accordance with the Erya 爾雅 (Approaching Elegance), rendering it as “sincerity” (cheng 誠). Shendu then means to “cause one’s will to be sincere” (chengqiyi 誠其意). Zheng Xuan 鄭玄, in explaining shendu as being “cautious of the actions one performs in private” (shen qi xianju suowei 慎其閒居所為), completely strayed from the original meaning as found in the bamboo-silk texts. Zhu Xi 朱熹, seeing the insufficiencies of Zheng Xuan’s interpretation of shendu, broadened the meaning of du, and in particular added a spiritual meaning to it. However, due to influence by Zheng Xuan, Zhu Xi still preserved some misreadings of the term; especially in his interpretation of shendu in the Daxue 大學 (Great Learning) and Zhongyong 中庸 (Doctrine of the Mean). Considering that the Neo-Confucian methods of cultivation embodied in the ideas of “abiding in reverence and enriching the self” (jujing hanyang 居敬涵養), and “being refined and focused” (weijing weiyi 惟精惟一) actually accorded more with the original meaning of shendu, Zhu Xi’s misreading of shendu is indirectly related to the loss of its original meaning due to the broken transmission of the ancient texts.     

History’s Ethical Demand: Memory,Denial, and Responsibility in the Wake of the Holocaust

What does it mean to discover an unspoken Nazi past in one’s own family? In a moment defined by chance and circumstance, I discovered that my German grandfather had joined the Nazi Party. Using my family’s struggle with memory as a site of inquiry, I examine the process of remembering, its transmission, and dissociation, particularly as it relates to past and present perpetrator groups. What lurks in the silences that are passed down between generations? How does our collective response to history’s atrocities shape what we what we know and remember as individuals? How do we define the moral obligations of memory, or understand the power of dissociation more than seven decades after the Holocaust? When does complacency in the face of past or present injustice make us complicit? Any answer to these questions points to the complexity of memory and the ethical demands of history. Connections between collective crimes of the past and social injustices in the present are considered and different forms of historical awareness and personal responsibility are discussed. In the face of overt prejudice and racism, “history’s call” and the work of psychoanalysis are inherently related.     

The Socialization of Children’s Memory: Linking Maternal Conversational Style to the Development of Children’s Autobiographical and Deliberate Memory Skills

Data from a large-scale, longitudinal research study with an ethnically and socioeconomically diverse sample were utilized to explore linkages between maternal elaborative conversational style and the development of children’s autobiographical and deliberate memory. Assessments were made when the children were aged 3, 5, and 6 years old, and the results reveal concurrent and longitudinal linkages between maternal conversational style in a mother–child reminiscing task and children’s autobiographical memory performance. Maternal conversational style while reminiscing was also significantly related to children’s strategic behaviors and recall in 2 deliberate memory tasks, both concurrently and longitudinally. Results from this examination replicate and extend what is known about the linkages between maternal conversational style, children’s abilities to talk about previous experiences, and children’s deliberate memory skills as they transition from the preschool years to early elementary school years.     

Children’s Binding of What-Where-When-Who in Episodic Memory: Identifying Oneself in the Past

It is usually accepted that the binding of what, where, and when is a central component of young children’s and animals’ nonconceptual episodic abilities. We argue that additionally binding self-in-past (what-where-when-who) adds a crucial conceptual requirement, and we ask when it becomes possible and what its cognitive correlates are. In the central task, children aged 3.5 years to 6.5 years watched a light display on Day 1, with 2 lights coming on simultaneously or in 1 of 2 orders. This light display was filmed from 1 of 3 positions: with the camera behind the child, above the child, or facing the child. On Day 2, children watched 3 videos from the original angle, and each represented 1 of the 3 light configurations, with the child in the video occluded. Participants had to decide which occluded child they were and justify their choice by reference to the lights. Above-chance performance was evident after 4.5 years of age. In addition, all children received the following tasks: spatial perspective taking, seeing leads to knowing, modus tollens reasoning, and second-order theory of mind. With age and verbal ability partialed out, only second-order theory of mind correlated significantly with performance on the central task.     

Does Maternal Prenatal Stress Adversely Affect the Child’s Learning and Memory at Age Six?

Prenatal maternal stress has been shown to affect postnatal development in animals and humans. In animals, the morphology and function of the offspring’s hippocampus is negatively affected by prenatal maternal stress. The present study prospectively investigated the influence of prenatal maternal stress on learning and memory of 112 children (50 boys, 62 girls, Age: M=6.7 years, SD=8.4 months), with the Test of Memory and Learning (TOMAL). Maternal stress levels were determined three times during pregnancy by self-report questionnaires. Furthermore, maternal saliva cortisol samples were used as a measure of hypothalamus-pituitary-adrenal axis functioning. Results of hierarchical multivariate regression analyses showed that maternal life events measured during the first part of pregnancy were negatively associated with the child’s attention/concentration index, while controlling for overall IQ, gender, and postnatal stress. No associations were found between prenatal maternal cortisol and the offspring’s learning and memory.