Mini Mental State

http://www.u.arizona.edu/~nadel/pdf/Papers%20as%20PDFs/1997%20PDFs/Current%20Opinion%201997.pdf

Memory consolidation, retrograde amnesia and the hippocampal complex

Episodic memory and semantic memory are two types of declarative memory. There have been two principal views about how this distinction might be reflected in the organization of memory functions in the brain. One view, that episodic memory and semantic memory are both dependent on the integrity of medial temporal lobe and midline diencephalic structures, predicts that amnesic patients with medial temporal lobe/diencephalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodic memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before much of an individual's semantic knowledge has been acquired, and 2) experimental studies with amnesic patients of fact and event learning, remembering and knowing, and remote memory. The data provide no compelling support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, episodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage.

/pdf/episodic-memory-semantic-memory-and-amnesia-1k9gfaxr2k.pdf

Episodic memory, semantic memory, and amnesia

Summary Sleep disturbances and cognitive impairment are common in older adults. Mounting evidence points to a potential connection between sleep and cognitive function. Findings from observational studies support a role for sleep disturbances (particularly for sleep duration, sleep fragmentation, and sleep-disordered breathing) in the development of cognitive impairment. Less consistent evidence exists for associations of insomnia and circadian rhythm dysfunction with cognition. These findings suggest that the sleep–wake cycle plays a crucial part in brain ageing, pointing to a potential avenue for improvement of cognitive outcomes in people at risk of cognitive decline and dementia. Several biological mechanisms might underlie the association between sleep and cognition, but these pathways are not completely understood. Future studies that aim to clarify the association between sleep and cognition might help to identify people at risk of cognitive disorders and to facilitate the development of novel therapies to treat and potentially prevent both sleep disturbances and cognitive impairment.

https://www.thelancet.com/pdfs/journals/laneur/PIIS1474-4422(14)70172-3.pdf

Connections between sleep and cognition in older adults

Summary This paper reviews disorders of memory. After a brief survey of the clinical varieties of the amnesic syndrome, transient and persistent, selected theoretical issues will be considered by posing a series of questions. (i) What is impaired and what is spared in anterograde amnesia? (ii) Do temporal lobe, diencephalic and frontal lobe amnesias differ? (iii) How independently semantic is semantic memory? (iv) What determines the pattern and extent of retrograde memory loss? (v) Can retrograde amnesia ever be ‘isolated’? (vi) Does psychogenic amnesia involve the same mechanisms as organic amnesia? (vii) How and when do false memories arise? Commonalities as well as differences across separate literatures will be emphasized, and the case for a more ‘dynamic’ (interactionist) approach to the investigation of amnesia will be advocated.

Disorders of memory

Observations in primates and patients with unilateral spatial neglect have suggested that patching of the eye ipsilateral to the injury and contralateral to the neglected space can sometimes improve attention to the neglected space. Investigators have generally attributed the effects of monocular eye patching to activation of subcortical centers that interact with cortical attentional systems. Eye patching is thought to produce preferential activation of attentional systems contralateral to the viewing eye. In this study we examined the effect of monocular eye patching on attentional biases in normal subjects. When normal subjects bisect vertical (radial) lines using both eyes, they demonstrate a far attentional bias, misbisecting lines away from their body. In a monocular viewing experiment, we found that the majority of subjects, who were right eye dominant, had relatively nearer bisections and a diminished far bias when they used their right eye (left eye covered) compared with when they used their left eye (right eye covered). The smaller group of subjects who were left eye dominant had relatively nearer bisections and a diminished far bias when they used their left eye compared with when they used their right eye. In the hemispatial placement experiment, we directly manipulated hemispheric engagement by having subjects perform the same task in right and left hemispace. We found that right eye dominant subjects had a diminished far bias in right hemispace relative to left hemispace. Left eye dominant subjects showed the opposite pattern and had a diminished far bias in left hemispace. For both groups, spatial presentation affected performance more for the non-dominant eye. The results suggest that monocular viewing is associated with preferential activation of attentional systems in the contralateral hemisphere, and that the right hemisphere (at least in right eye dominant subjects) is biased towards far space. Finally, the results suggest that the poorly understood phenomenon of eye dominance may be related to hemispheric specialization for visual attention.

https://darkwing.uoregon.edu/~prd/fragments/Nasal%20vs.%20temporal/Roth...%20&%20Heilman,%20Brain2002,%20Monocular%20viewing,%20eye%20dominance%20and%20spatial%20attention.pdf

Effects of monocular viewing and eye dominance on spatial attention.

Purpose We explored the reliability and validity of 2 quantitative approaches to document presence and severity of speech properties associated with apraxia of speech (AOS). Method A motor speech e...

Toward a Quantitative Basis for Assessment and Diagnosis of Apraxia of Speech.

To assess if amnesics have intact remote memory for general semantic information, we examined memory for vocabulary words with known dates of entry into the language between 1955 and 1989. Amnesics of mixed etiology with acute onset performed normally on both a recall and a recognition task. Korsakoff patients, in contrast, were impaired on both tasks and demonstrated a gradient such that their knowledge of words acquired during more recent time periods was worse than that of words acquired during more remote time periods. The improvement in performance associated with recognition testing was larger for Korsakoff patients than for control subjects and correlated significantly with a composite measure of frontal dysfunction. These findings suggest a deficit in the controlled search and retrieval of semantic information in Korsakoff patients. The implications of the differential performance of Korsakoff and mixed etiology amnesics for explanations of temporally graded retrograde amnesia are discussed.

Knowledge of New English vocabulary in amnesia: an examination of premorbidly acquired semantic memory

Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal–striatal and/or frontal–parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual–spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual–spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated. (JINS, 2003, 9, 1078–1087.)

Heidi L. Roth

Papers

Effects of monocular viewing and eye dominance on spatial attention.

Toward a Quantitative Basis for Assessment and Diagnosis of Apraxia of Speech.

Knowledge of New English vocabulary in amnesia: an examination of premorbidly acquired semantic memory

Mental object rotation in Parkinson's disease.

Foreign accent syndrome due to conversion disorder: Phonetic analyses and clinical course