By utilizing new information from both clinical and experimental (lesion, electrophysiological, and gene-activation) studies with animals, the anatomy underlying anterograde amnesia has been reformulated. The distinction between temporal lobe and diencephalic amnesia is of limited value in that a common feature of anterograde amnesia is damage to part of an “extended hippocampal system” comprising the hippocampus, the fornix, the mamillary bodies, and the anterior thalamic nuclei. This view, which can be traced back to Delay and Brion (1969), differs from other recent models in placing critical importance on the efferents from the hippocampus via the fornix to the diencephalon. These are necessary for the encoding and, hence, the effective subsequent recall of episodic memory. An additional feature of this hippocampal–anterior thalamic axis is the presence of projections back from the diencephalon to the temporal cortex and hippocampus that also support episodic memory. In contrast, this hippocampal system is not required for tests of item recognition that primarily tax familiarity judgements. Familiarity judgements reflect an independent process that depends on a distinct system involving the perirhinal cortex of the temporal lobe and the medial dorsal nucleus of the thalamus. In the large majority of amnesic cases both the hippocampal–anterior thalamic and the perirhinal–medial dorsal thalamic systems are compromised, leading to severe deficits in both recall and recognition.

/pdf/episodic-memory-amnesia-and-the-hippocampal-anterior-50qwk8ap9b.pdf

Episodic memory, amnesia, and the hippocampal–anterior thalamic axis.

Summary Multiple sclerosis (MS) is a progressive disease of the CNS that is characterised by widespread lesions in the brain and spinal cord. MS results in motor, cognitive, and neuropsychiatric symptoms, all of which can occur independently of one another. The common cognitive symptoms include deficits in complex attention, efficiency of information processing, executive functioning, processing speed, and long-term memory. These deficits detrimentally affect many aspects of daily life, such as the ability to run a household, participate fully in society, and maintain employment—factors that can all affect the overall quality of life of the patient. The increased use of neuroimaging techniques in patients with MS has advanced our understanding of structural and functional changes in the brain that are characteristic of this disease, although much remains to be learned. Moreover, examination of efforts to treat the cognitive deficits in MS is still in the early stages.

https://www.thelancet.com/pdfs/journals/laneur/PIIS1474-4422(08)70259-X.pdf

Cognitive impairment in multiple sclerosis

Research over the past two decades broadly supports the claim that mindfulness meditation - practiced widely for the reduction of stress and promotion of health - exerts beneficial effects on physical and mental health, and cognitive performance. Recent neuroimaging studies have begun to uncover the brain areas and networks that mediate these positive effects. However, the underlying neural mechanisms remain unclear, and it is apparent that more methodologically rigorous studies are required if we are to gain a full understanding of the neuronal and molecular bases of the changes in the brain that accompany mindfulness meditation.

The neuroscience of mindfulness meditation

http://jtoomim.org/brain-training/Zeidan2010_Mindfulness_Meditation.pdf

Mindfulness meditation improves cognition: Evidence of brief mental training☆

Working memory (WM) is a cognitive system that strongly relates to a person’s ability to reason with novel information and direct attention to goal-relevant information. Due to the central role that WM plays in general cognition, it has become the focus of a rapidly growing training literature that seeks to affect broad cognitive change through prolonged training on WM tasks. Recent work has suggested that the effects of WM training extend to general fluid intelligence, attentional control, and reductions in symptoms of ADHD. We present a theoretically motivated perspective of WM and subsequently review the WM training literature in light of several concerns. These include (a) the tendency for researchers to define change to abilities using single tasks, (b) inconsistent use of valid WM tasks, (c) no-contact control groups, and (d) subjective measurement of change. The literature review highlights several findings that warrant further research but ultimately concludes that there is a need to directly demonstrate that WM capacity increases in response to training. Specifically, we argue that transfer of training to WM must be demonstrated using a wider variety of tasks, thus eliminating the possibility that results can be explained by task specific learning. Additionally, we express concern that many of the most promising results (e.g., increased intelligence) cannot be readily attributed to changes in WM capacity. Thus, a critical goal for future research is to uncover the mechanisms that lead to transfer of training.

https://analyseeconomique.files.wordpress.com/2012/10/is-working-memory-training-effective.pdf

Is working memory training effective

This study examined the relationships between processing speed and Implicit Association Test (IAT) performance using a race and a socially neutral IAT, in 51 European American adults ranging in age from 19 to 55. Simple reaction time was not correlated with IAT performance. However, faster higher-level processing speed on a 3-back task was correlated with lower transformed scores and shorter latencies on multiple implicit association race and neutral measures. Higher-level processing may account for approximately 70% of this relationship with general processing speed accounting for the remainder. The relationship between higher-level processing and implicit bias may be mediated by shared executive processes. However, patterns of neurobehavioral engagement and activation may also reflect a systemic response to diverse stimuli, suggesting that in individuals with lower implicit bias, executive processes are more efficient resulting in faster higher-level processing and in appearing or being less biased.

Implicit Bias, Executive Control and Information Processing Speed

https://link-springer-com-443.webvpn.jmu.edu.cn/content/pdf/10.1007%2F978-3-319-56782-2_2155-3.pdf

Anterior Communicating Artery

Efficient methods of analysis readily available for clinicians continue to be limited within neuropsychological assessment at the raw data level. Here, a novel approach for generating predictive response patterns and analysing neuropsychological raw data is offered. In order to assess the usefulness of association rule learning as an analysis tool for neuropsychological raw data, Frequent Pattern Growth (FP-Growth) was used to mine patterns from the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB) database. Complete assessment data for 84 post-mortem confirmed Alzheimer's disease (AD) cases and 294 age, race, and education matched controls were analysed across baseline and one-year follow-up using FP-Growth, for the purpose of assessing the clinical utility of a finer analysis at the raw data level and the feasibility of predicting response patterns for clinical/control groups. Output from FP-Growth, in terms of the number of frequent itemsets retained across both evaluation timepoints, was discernable between controls, mild, and moderate to severe Alzheimer's disease cases (p < .001, and η2  = .488). Patterns within raw data scores, both in terms of frequent itemsets and predictive association rules, appear to be differentiable across groups within neuropsychological analysis, which indicates that FP-Growth is applicable as a supplementary analysis tool for neuropsychological assessment by means of offering an additional level of data analysis, predictive item response capabilities, and aiding in clinical decision making.

Association rule learning in neuropsychological data analysis for Alzheimer's disease.

Six individuals with amnesia and matched healthy controls participated. There were two objectives. First, determine whether physiological activity at encoding relates to whether a word shows autonomic priming or is recognized. Second, propose a model for understanding relationships between recognition and autonomic priming. In amnesics, ‘unrecognized’ words were associated with better autonomic discrimination and lower levels of physiological activity at encoding. In healthy participants and amnesics, ‘recognized’ words were associated with poorer autonomic priming and higher levels of physiological activity at encoding. A state-dependent, activation-fractionation-inhibition model is proposed involving an orienting response elicited by preference and search and modulated by underlying memory strength.

Bruce J. Diamond

Papers

Implicit Bias, Executive Control and Information Processing Speed

Anterior Communicating Artery

Association rule learning in neuropsychological data analysis for Alzheimer's disease.

Priming, recognition and autonomic discrimination in amnesia.

Cognitive-Adaptive Instructional Systems for Special Needs Learners