Dissociation between declarative and procedural learning in dementia and depression

Delivery of Neuropsychological Interventions for Adult and Older Adult Clinical Populations: An Australian Expert Working Group Clinical Guidance Paper

Delivery of neuropsychological interventions addressing the cognitive, psychological, and behavioural consequences of brain conditions is increasingly recognised as an important, if not essential, skill set for clinical neuropsychologists. It has the potential to add substantial value and impact to our role across clinical settings. However, there are numerous approaches to neuropsychological intervention, requiring different sets of skills, and with varying levels of supporting evidence across different diagnostic groups. This clinical guidance paper provides an overview of considerations and recommendations to help guide selection, delivery, and implementation of neuropsychological interventions for adults and older adults. We aimed to provide a useful source of information and guidance for clinicians, health service managers, policy-makers, educators, and researchers regarding the value and impact of such interventions. Considerations and recommendations were developed by an expert working group of neuropsychologists in Australia, based on relevant evidence and consensus opinion in consultation with members of a national clinical neuropsychology body. While the considerations and recommendations sit within the Australian context, many have international relevance. We include (i) principles important for neuropsychological intervention delivery (e.g. being based on biopsychosocial case formulation and person-centred goals); (ii) a description of clinical competencies important for effective intervention delivery; (iii) a summary of relevant evidence in three key cohorts: acquired brain injury, psychiatric disorders, and older adults, focusing on interventions with sound evidence for improving activity and participation outcomes; (iv) an overview of considerations for sustainable implementation of neuropsychological interventions as 'core business'; and finally, (v) a call to action.

Does Cognitive Impairment Impact Motor Learning? A Scoping Review of Elderly Individuals With Alzheimer's Disease and Mild Cognitive Impairment

Individuals with cognitive impairment may have motor learning deficits due to the high engagement of cognitive mechanisms during motor skill acquisition. We conducted a scoping review to address the quality of current research on the relationship between cognitive impairments (i.e., deficits in attention, memory, planning and executive functions) and motor learning among older adults with Alzheimer's Disease or Mild Cognitive Impairment. After screening thousands of articles, we selected 15 studies describing cognitive assessment tools, experimental designs, and the severity of cognitive impairment. Although seven studies reported that cognitive impairment impaired motor learning, most studies included a high risk of bias. We identified multiple assessment tools across these studies that make comparisons among findings difficult. Future research in this area should focus on the influence of increased practice days during motor learning acquisition and incorporate both retention and transfer tests. Cognitive assessments should target the specific cognitive skills or deficits most closely related to the motor learning process.

Dance movement therapy for neurodegenerative diseases: A systematic review

Background

The proportion of the world's elderly population continues to rise, and the treatment and improvement of neurodegenerative diseases have become issue of public health importance as people live longer and many countries have aging populations. This systematic review aims to discuss the effects of dance movement therapy (DMT) on motor function, cognitive deficit, mood, and quality of life in people with neurodegenerative diseases, such as Parkinson's disease (PD), mild cognitive impairment (MCI), Alzheimer's disease (AD).

Methods

Two reviewers independently conducted systematic search on the Cochrane library, PubMed database, Web of Science Core Collection database, and Physiotherapy Evidence database until February 1, 2022. Only systematic analyses and randomized controlled trials were included and further analyzed.

Results

Thirty-three studies on PD, 16 studies on MCI, 4 studies on AD were obtained. This systematic review found that DMT substantially improved the global cognitive function, memory, and executive function on the population with MCI. Compared with the non-dance group, DMT remarkably improved general disease condition, balance, and gait for individuals with PD. The evidence of the efficacy of DMT on AD is insufficient, and further research is needed.

Conclusion

DMT can effectively improve the motor function and cognitive deficits in neurodegenerative diseases. Positive effects of DMT on the mood and quality of life in ND patients are controversial and require further evidence. Future research on the effects of DMT on AD requires scientific design, large sample size, long-term comprehensive intervention, and clear reporting standards.

Systematic review registration

www.osf.io/wktez, identifier: 10.17605/OSF.IO/UYBKT.

Association between Montreal Cognitive Assessment Sub-Item Scores and Corresponding Cognitive Test Performance in Patients with Frontotemporal Dementia and Related Disorders

The Montreal Cognitive Assessment (MoCA), a brief screening test developed to detect patients with mild cognitive impairment, is used in clinical settings across North America [Nasreddine et al.: J Am Geriatr Soc 2005;53:695-699]. The MoCA has been demonstrated to be sensitive to cognitive deficits in frontotemporal dementias (FTD) and related disorders [Coleman et al.: Alzheimer Dis Assoc Disord 2016;30:258-263]. Given attentional impairments in patients with FTD, whether and to what extent the abbreviated items on the MoCA may predict performance on corresponding assessments is not known. Testing and demographic data were extracted from a clinical database using a sample of 91 patients with FTD and related disorders. The relationship between MoCA items and corresponding neuropsychological tasks was assessed through McNemar tests and Spearman correlations. While some MoCA items such as letter fluency, orientation, and clock drawing were strongly correlated with the corresponding standard cognitive test, the MoCA trails were insensitive to impairment compared to the full Trail Making B Test (p = 0.01). In contrast, MoCA naming and delayed recall sub-items detected cognitive impairment more frequently than available comparison tests. The MoCA is a sensitive screening measure to detect impairment in patients with FTD and related disorders, but cognitive deficits specific to FTD result in differential performance on MoCA items compared to longer standard cognitive tests.

Kai Xin San aqueous extract improves Aβ1-40-induced cognitive deficits on adaptive behavior learning by enhancing memory-related molecules expression in the hippocampus

ETHNOPHARMACOLOGICAL RELEVANCE

Kai Xin San (KXS), a traditional formula of Chinese medicine, has been used to treat dementia.

AIM OF THE STUDY

The present study aimed to investigate its ameliorating effects on Aβ_1-40-induced cognitive impairment in rats using a series of novel reward-directed instrumental learning tasks, and to determine its possible mechanism of action.

MATERIALS AND METHODS

Rats were pretreated with KXS aqueous extract (0.72 and 1.44g/kg, p.o.) for 10 days, and were trained to gain reward reinforcement by lever pressing at the meantime. Thereafter, rats received a bilateral microinjection of Aβ_1-40 in CA1 regions of the hippocampus. Cognitive performance was evaluated with the goal directed (higher response ratio) and habit (visual signal discrimination and extinction) learning tasks, as well as on the levels of memory-related biochemical parameters and molecules.

RESULTS

Our findings first demonstrated that KXS can improve Aβ_1-40-induced amnesia in RDIL via enhancing the comprehension of action-outcome association and the utilization of cue information to guide behavior. Then, its ameliorating effects should be attributed to the modulation of memory-related molecules in the hippocampus.

CONCLUSION

In conclusion, KXS has the potential to prevent and/or delay the deterioration of cognitive impairment in AD.

Predictors of Retest Effects in a Longitudinal Study of Cognitive Aging in a Diverse Community-Based Sample

Better performance due to repeated testing can bias long-term trajectories of cognitive aging and correlates of change. We examined whether retest effects differ as a function of individual differences pertinent to cognitive aging: race/ethnicity, age, sex, language, years of education, literacy, and dementia risk factors including apolipoprotein E ε4 status, baseline cognitive performance, and cardiovascular risk. We used data from the Washington Heights-Inwood Columbia Aging Project, a community-based cohort of older adults (n=4073). We modeled cognitive change and retest effects in summary factors for general cognitive performance, memory, executive functioning, and language using multilevel models. Retest effects were parameterized in two ways, as improvement between the first and subsequent testings, and as the square root of the number of prior testings. We evaluated whether the retest effect differed by individual characteristics. The mean retest effect for general cognitive performance was 0.60 standard deviations (95% confidence interval [0.46, 0.74]), and was similar for memory, executive functioning, and language. Retest effects were greater for participants in the lowest quartile of cognitive performance (many of whom met criteria for dementia based on a study algorithm), consistent with regression to the mean. Retest did not differ by other characteristics. Retest effects are large in this community-based sample, but do not vary by demographic or dementia-related characteristics. Differential retest effects may not limit the generalizability of inferences across different groups in longitudinal research.

Tong Luo Jiu Nao ameliorates Aβ1-40-induced cognitive impairment on adaptive behavior learning by modulating ERK/CaMKII/CREB signaling in the hippocampus

BACKGROUND

Tong Luo Jiu Nao (TLJN), a modern formula of Chinese medicine extracts on the basis of Traditional Chinese Medicine theory, has been used to treat dementia. The present study aimed to investigate its ameliorating effects on Aβ1-40-induced cognitive impairment in rats using a series of novel reward-directed instrumental learning (RDIL) tasks, and to determine its possible mechanism of action.

METHODS

Rats were pretreated with TLJN extract (0.9 and 1.8 g/kg, p.o.) for 10 daysbefore surgery, and were trained to gain reward reinforcement by lever pressing at the meantime. Thereafter, rats received a bilateral microinjection of Aβ1-40 in CA1 regions of the hippocampus. Cognitive performance was evaluated with the goal directed (higher response ratio) and habit (visual signal discrimination and extinction) learning tasks, as well as on the levels of biochemical parameters and molecules.

RESULTS

Our findings first demonstrated that TLJN can improve Aβ1-40-induced amnesia in RDIL via enhancing the comprehension of action-outcome association and the utilization of cue information to guide behavior. Then, its ameliorating effects should attribute to the modulation of ERK/CaMKII/CREB signaling in the hippocampus.

CONCLUSION

TLJN can markedly enhance cognitions of Aβ1-40 microinjection animal model in adaptive behavioral tasks. It has the potential, possibly as complementary and alternative therapy, to prevent and/or delay the deterioration of cognitive impairment in AD.

Memory systems

Converging evidence from patient and neuroimaging studies suggests that memory is a collection of abilities that use different neuroanatomic systems. Neurologic injury may impair one or more of these memory systems. Episodic memory allows us to mentally travel back in time and relive an episode of our life. Episodic memory depends on the hippocampus, other medial temporal lobe structures, the limbic system, and the frontal lobes, as well as several other brain regions. Semantic memory provides our general knowledge about the world and is unconnected to any specific episode of our life. Although semantic memory likely involves much of the neocortex, the inferolateral temporal lobes (particularly the left) are most important. Procedural memory enables us to learn cognitive and behavioral skills and algorithms that operate at an automatic, unconscious level. Damage to the basal ganglia, cerebellum, and supplementary motor area often impair procedural memory.

Terminal decline and practice effects in older adults without dementia: the MoVIES project

OBJECTIVE

To track cognitive change over time in dementia-free older adults and to examine terminal cognitive decline.

METHODS

A total of 1,230 subjects who remained free from dementia over 14 years of follow-up were included in a population-based epidemiologic cohort study. First, we compared survivors and decedents on their trajectories of 5 cognitive functions (learning, memory, language, psychomotor speed, executive functions), dissociating practice effects which can mask clinically significant decline from age-associated cognitive decline. We used longitudinal mixed-effects models with penalized linear spline. Second, limiting the sample to 613 subjects who died during follow-up, we identified the inflection points at which the rate of cognitive decline accelerated, in relation to time of death, controlling for practice effects. We used mixed-effects model with a change point.

RESULTS

Age-associated cognitive trajectories were similar between decedents and survivors without dementia. However, substantial differences were observed between the trajectories of practice effects of survivors and decedents, resembling those usually observed between normal and mildly cognitively impaired elderly. Executive and language functions showed the earliest terminal declines, more than 9 years prior to death, independent of practice effects.

CONCLUSIONS

Terminal cognitive decline in older adults without dementia may reflect presymptomatic disease which does not cross the clinical threshold during life. Alternatively, cognitive decline attributed to normal aging may itself represent underlying neurodegenerative or vascular pathology. Although we cannot conclude definitively from this study, the separation of practice effects from age-associated decline could help identify preclinical dementia.

The effects of perceived emotional distress on language performance in intractable epilepsy

We evaluated the potential moderating effect of emotional distress (Minnesota Multiphasic Personality Inventory 2, scales D and Pt) on language functioning (i.e., Boston Naming Test, phonemic paraphasic error production on the Boston Naming Test, Controlled Oral Word Association Task, Animal Naming, Token Test) in patients with left (N=43) and right (N=34) mesial temporal lobe epilepsy (MTLE) and frontal lobe epilepsy (FLE) (N=30). Video/EEG and brain imaging results confirmed localization. Logistic regression models revealed that perceived emotional distress moderated language performance. Performance of patients with left MTLE and that of patients with FLE were equally poor across language measures. Performance of patients with right MTLE was intact. Depression and anxiety differentially moderated performance. Anxiety was associated with better performance in patients with FLE on classically temporal lobe-mediated tasks (Boston Naming Test). Depression was associated with worse language performance on measures for which impaired performance was traditionally intrinsic to the underlying epileptogenic lesion (word fluency in FLE). Emotional distress influences language performance. Adequate treatment of mood should be considered when managing pharmacoresistant epilepsy.

Alzheimer's disease and implicit memory

Specific neuropsychiatric disorders, such as Alzheimer's disease (AD) affect some forms of memory while leaving others relatively intact. In this review, we investigate particularities of the relationship between explicit and implicit memories in AD. It was found that implicit memory is preserved in AD, irrespective of the task used; in other words, there was not interference from explicit memory. In addition, it was verified that is possible through implicit memory compensatory strategies such as, activities of daily living (ADL) to compensate for the explicit memory deficits. In this sense, cognitive rehabilitation (CR) demonstrates reasonable results in the process of compensation of explicit memory deficits. Concluding, the decline in explicit memory suggests that both systems are functionally independent even if the other is compromised. We expect that when explicit memory system is not involved in competition with the implicit system, the final effect of learning is better, because all of the implicit memory capacity is engaged in learning and not in competition with the explicit system.

Understanding memory dysfunction

BACKGROUND

Although traditionally memory has been viewed as a simple concept, converging and complementary evidence from patient studies and more recent neuroimaging research suggest that memory is a collection of mental abilities that use different neuroanatomical systems within the brain. Neurologic injury may cause damage to one or more of these memory systems.

REVIEW SUMMARY

In this review a number of different memory systems are discussed, including their function, neuroanatomy, and the different disorders that disrupt them. Episodic memory, the most clinically relevant memory system, depends upon the hippocampus and other medial temporal lobe structures, the limbic system, and the frontal lobes. Several other kinds of memory are contrasted with episodic memory, including semantic memory, simple classic conditioning, procedural memory, priming, and working memory.

CONCLUSION

Improved understanding of these different types of memory will aid the clinician in the diagnosis and treatment of the memory disorders of their patients. As more specific therapeutic strategies are developed for the treatment of diseases which cause memory dysfunction, this knowledge will become increasingly important.

Episodic-like and procedural memory impairments in histamine H1 Receptor knockout mice coincide with changes in acetylcholine esterase activity in the hippocampus and dopamine turnover in the cerebellum

We investigated episodic-like (ELM) and procedural memory (PM) in histamine H1 receptor knockout (H1R-KO) mice. In order to relate possible behavioral deficits to neurobiological changes, we examined H1R-KO and wild-type (WT) mice in terms of acetylcholine esterase (AChE) activity in subregions of the hippocampus and AChE and tyrosine hydroxylase (TH) expression in the striatum. Furthermore, we analyzed acetylcholine (ACh), 5-HT and dopamine (DA) levels, including metabolites, in the cerebellum of H1R-KO and WT mice. The homozygous H1R-KO mice showed impaired ELM as compared with the heterozygous H1R-KO and WT mice. The performance of homozygous H1R-KO mice in the ELM task was primarily driven by familiarity-based memory processes. While the homozygous H1R-KO mice performed similar to the heterozygous H1R-KO and WT mice during the acquisition of a PM, as measured with an accelerating rotarod, after a retention interval of 7 days their performance was impaired relative to the heterozygous H1R-KO and WT mice. These findings suggest that, both, ELM and long-term PM are impaired in the homozygous H1R-KO mice. Neurochemical assays revealed that the H1R-KO mice had significantly lower levels of AChE activity in the dentate gyrus (DG) and CA1 subregions of the hippocampus as compared with the WT mice. The homozygous H1R-KO mice also displayed significantly reduced dihydroxyphenylacetic acid (DOPAC) levels and a reduced DOPAC/DA ratio in the cerebellum, suggesting that the DA turnover in the cerebellum is decelerated in homozygous H1R-KO mice. In conclusion, homozygous H1R-KO mice display severe long-term memory deficits in, both, ELM and PM, which coincide with changes in AChE activity in the hippocampus as well as DA turnover in the cerebellum. The importance of these findings for Alzheimer's (AD) and Parkinson's disease (PD) is discussed.

Motor-skill learning in Alzheimer's disease: a review with an eye to the clinical practice

Since elderly people suffering from dementia want to go on living independently for as long as possible, they need to be able to maintain familiar and learn new practical skills. Although explicit or declarative learning methods are mostly used to train new skills, it is hypothesized that implicit or procedural techniques may be more effective in this population. The present review discusses 23 experimental studies on implicit motor-skill learning in patients with Alzheimer's disease (AD). All studies found intact implicit motor-learning capacities. Subsequently, it is elaborated how these intact learning abilities can be exploited in the patients' rehabilitation with respect to the variables 'practice' and 'feedback.' Recommendations for future research are provided, and it is concluded that if training programs are adjusted to specific needs and abilities, older people with AD are well able to (re)learn practical motor skills, which may enhance their autonomy.

Procedural and declarative memory in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) has been associated with frontostriatal abnormality. This has led to the hypothesis that the disorder is characterized by abnormality of procedural memory. However, evidence for either procedural or declarative memory disturbance has been mixed, and few studies have directly assessed both of these forms of memory in the same patient group. In the present study, we assessed encoding and retrieval in declarative memory using the Rey Auditory Verbal Learning Test (RAVLT), and procedural memory using the Pursuit Rotor Task, in 27 adults with OCD and 29 matched healthy controls. Groups did not differ with respect to salient demographic characteristics or memory on the RAVLT. In contrast, patients with OCD performed significantly better than controls during the early, but not later trial blocks of the Pursuit Rotor Task. This pattern of results indicates intact encoding and retrieval in declarative memory, but abnormally enhanced procedural memory during the early course of learning in OCD. These findings may be consistent with striatal overactivation observed in neuroimaging studies of OCD, as well as the prominent role of the striatum during early stages of procedural memory.

Hippocampal volume, spectroscopy, cognition, and mood in patients receiving corticosteroid therapy

BACKGROUND

Hippocampal volume reduction, declarative memory deficits, and cortisol elevations are reported in persons with major depressive disorder; however, data linking cortisol elevations with hippocampal atrophy are lacking. Prescription corticosteroid-treated patients offer an opportunity to examine corticosteroid effects on hippocampal volume and biochemistry and memory in humans.

METHODS

Seventeen patients on long-term prescription corticosteroid therapy and 15 controls of similar age, gender, ethnicity, education, height, and medical history were assessed with magnetic resonance imaging and proton magnetic resonance spectroscopy, the Rey Auditory Verbal Learning Test, Stroop Color Word Test and other neurocognitive measures, the Hamilton Rating Scale for Depression, Young Mania Rating Scale, and Brief Psychiatric Rating Scale.

RESULTS

Compared with controls, corticosteroid-treated patients had smaller hippocampal volumes and lower N-acetyl aspartate ratios, lower scores on the Rey Auditory Verbal Learning Test and Stroop Color Word Test, and higher Hamilton Rating Scale for Depression and Brief Psychiatric Rating Scale scores.

CONCLUSIONS

Patients receiving chronic corticosteroid therapy have smaller hippocampal volumes, lower N-acetyl aspartate ratios, and declarative memory deficits compared with controls. These findings support the idea that corticosteroid exposure appears to be associated with changes in hippocampal volume and functioning in humans.

Association of depression with medical illness: does cortisol play a role?

Elevated cortisol in a subset of depressed patients is an enduring and well-replicated finding. Much interest has focused on the possible effects of depression on the hippocampus; however, an emerging body of evidence suggests an association between depression and non-central nervous system illnesses. In this review, data on the effects of depression on the brain and other organ systems sensitive to elevated cortisol are discussed. From searches of the MEDLINE, PSYCHINFO, and Current Contents databases, and other sources, articles were found specifically related to depression and physical changes or medical conditions associated with corticosteroid excess in patients with Cushing's disease, including cognitive impairment, hippocampal atrophy, increased waist-to-hip ratio, bone loss, hypertension, diabetes, peptic ulcers, and hyperlipidemia. Data are strongest for a relationship between elevated cortisol and depression, hippocampal atrophy, cognitive impairment, abdominal obesity, and loss of bone density. Some evidence suggests an association between depression and hypertension, peptic ulcers, and diabetes. Depression does not appear to be associated with hyperlipidemia. The data provide some support for similar health effects in depressed patients and patients with Cushing's disease or the metabolic syndrome; however, additional studies are needed relating systemic effects of depression to cortisol. Limitations of the current literature, treatment implications, and possible directions for future research are discussed.

Skill learning in patients with moderate Alzheimer's disease: a prospective pilot-study of waltz-lessons

The authors report the effect of a 12-day prospective, blinded dance-learning trial in 5 patients with moderate Alzheimer's disease (AD) and 5 age-matched depressed patients. Patients with AD showed a significant effect in procedural learning whereas depressed patients did not. These findings suggest potential implications for therapeutic interventions in patients with moderate AD.

The canine as a model of human cognitive aging: recent developments

1. Aged dogs display many of the cognitive impairments associated with aging and dementia. 2. Aged dogs, like humans, display a wide range of individual variability in cognitive functioning (i.e., different cognitive functions decline at different rates in aged dogs). 3. Different categories of aged canines can be identified on the basis of neuropsychological test performance, and these categories can be used to model different subgroups of aged humans (i.e., dementia, mild cognitive impairment and successful aging). 4. Additional research is required to further validate the dog as a model of human cognitive aging and dementia.

Age-related working memory deficits in the allocentric place discrimination task: possible involvement in cholinergic dysfunction

It is well known that learning and memory ability declines with aging. Age-related long-term changes in learning and memory ability in rats were investigated with the place navigation task and the allocentric place discrimination task (APDT) in a water maze using the same animals for each task. In a working memory place navigation task, aged animals could learn the location of the platform as well as when they were young, although strategy shifts were observed. In contrast, accuracy in the APDT significantly declined from 90% to 65% with aging. This impairment was ameliorated by an acetylcholine esterase inhibitor physostigmine at 22-23 months old. No amelioration was, however, detected in the same animals tested when they further aged to 26-27 months old. These results suggest that the APDT performance is sensitive to age-related memory deficits and that this may be due to the cholinergic dysfunction.