Behavioral and Psychological Symptoms that Predict Cognitive Decline or Impairment in Cognitively Normal Middle-Aged or Older Adults: a Meta-Analysis

Neuropsychology Review - Epidemiological studies have revealed that behavioral and psychological (or non-cognitive) symptoms are risk factors for cognitive decline in older adults. This study aimed...     

Development of a complex multiple schedule in the chimpanzee

The development of chimpanzee behavior on a four-component, three-lever multiple schedule is described. Component schedules included the Sidman avoidance procedure with a concurrent discriminated avoidance schedule on a second lever, fixed ratio performance for food, differential reinforcement of low rate for water requiring a dual response chain, and a symbol discrimination task for continuous food reinforcement using three levers. The avoidance component of this schedule was employed during the January 31, 1961 suborbital space flight of the chimpanzee “Ham.” On November 29, 1961, the chimpanzee “Enos” performed on the multiple schedule during three orbits around the earth in a Mercury capsule.     

Hypnotic discontinuation in chronic insomnia: impact of psychological distress, readiness to change, and self-efficacy.

OBJECTIVE: To compare individuals who were successful in discontinuing hypnotic medications against those who were not on measures of insomnia severity, medication withdrawal symptoms, psychological symptoms, perceived health, readiness to change and self-efficacy. DESIGN: Secondary analyses of a randomized clinical trial comparing a hypnotic taper intervention with or without self-help treatment for insomnia. MAIN OUTCOME MEASURES: Self-report measures of insomnia severity, medication withdrawal symptoms, depression and anxiety symptoms, physical and mental health, stages of change, readiness to change, decisional balance, and general and situational self-efficacy. RESULTS: There were no significant differences at baseline between medication-free individuals and those still using sleep medication at the end of a taper intervention. Group differences emerged midway through the 8-week withdrawal program and were accentuated after the intervention; participants who remained medication-free during the next six months had less severe insomnia and anxiety symptoms, a more positive perception of their health and higher self-efficacy to refrain from hypnotic use in various situations. Contrary to expectations, there were no differences between drug-free and nondrug-free participants on both readiness to change and stages of change. CONCLUSIONS: Chronic users of hypnotic medications entered a taper intervention with equal levels of psychological distress, health, self-efficacy, and readiness to change. Successful hypnotic discontinuation was associated with overall improvement of insomnia, anxiety and distress symptoms, perceived health and self-efficacy. More intensive and individualized therapeutic attention may be warranted for individuals experiencing worsening of insomnia symptoms, more withdrawal symptoms and psychological distress, and lower self-efficacy during medication discontinuation.     

The Effect of Training on Preparatory Attention in Older Adults: Evidence for the Role of Uncertainty in Age-Related Preparatory Deficits

Thirty-two older adults and 20 younger adults completed a simple visual detection task in which the preparatory interval (PI; 1, 3, and 5 s) that separates the warning signal from the target varied randomly on each trial. Participants were divided into two groups. In a control condition, participants completed four blocks of trials with the three PIs occurring equally often within a block. In the experimental condition, participants completed an equal probability block (Block 1) followed by two blocks (Blocks 2 and 3) in which the shortest PI (1 s) occurred on 2/3 of the trials, followed again by an equal probability block (Block 4). In Block 1, the results indicated a larger PI effect in older than younger participants, independent of general slowing. Increasing the likelihood of the shortest PI (Blocks 2 and 3 in the experimental condition) improved RT in older and younger adults and led to an equivalent PI effect in both age groups. This was not observed in the control condition, in which the age-related difference persisted during the four blocks of trials. Importantly, the improvement observed in the experimental group was maintained in the fourth block, where the PIs were reverted to an equal probability distribution. This supports the hypothesis that elderly participants prepare for events that have the greatest probability of occurrence and that this is a flexible process that can be modulated with brief training.     

Episodic Encoding in Normal Aging: Attentional Resources Hypothesis Extended to Musical Material

The goal of the present study was to examine age-related changes in musical episodic memory for novel tunes. This was conducted by manipulating the encoding condition in a recognition paradigm. After receiving memory instructions (intentional condition), older and younger participants obtained equivalent hits. In contrast, when intentional encoding was accompanied by a dancing judgment (dancing + intentional condition), the recognition performance of the older persons was severely impaired. Impaired recognition was also found when participants only judged the excerpts without being instructed to memorize them (dancing judgment condition). Although older participants demonstrated a preserved ability to perform the dancing judgment on its own, this ability was not optimal and likely precluded the initiation of more elaborate encoding strategies. These results suggest that asking older persons to divide their attention in the study phase reduces the quality of their musical encoding. Given this extension to musical material, we discuss the notion that the age-related attentional resource decline appears to be domain-general rather than specific to verbal material.     

Neuropsychological Measures that Predict Progression from Mild Cognitive Impairment to Alzheimer's type dementia in Older Adults: a Systematic Review and Meta-Analysis

This study aimed to determine the extent to which cognitive measures can predict progression from mild cognitive impairment (MCI) to Alzheimer’s type dementia (AD), assess the predictive accuracy of different cognitive domain categories, and determine whether accuracy varies as a function of age and length of follow-up. We systematically reviewed and meta-analyzed data from longitudinal studies reporting sensitivity and specificity values for neuropsychological tests to identify individuals with MCI who will develop AD. We searched articles in Medline, Cochrane, EMBASE, PsycINFO, and the Web of Science. Methodological quality was assessed using the STARDem and QUADAS standards. Twenty-eight studies met the eligibility criteria (2365 participants) and reported predictive values from 61 neuropsychological tests with a 31-month mean follow-up. Values were pooled to provide combined accuracy for 14 cognitive domains. Many domains showed very good predictive accuracy with high sensitivity and specificity values (≥ 0.7). Verbal memory measures and many language tests yielded very high predictive accuracy. Other domains (e.g., executive functions, visual memory) showed better specificity than sensitivity. Predictive accuracy was highest when combining memory measures with a small set of other domains or when relying on broad cognitive batteries. Cognitive tests are excellent at predicting MCI individuals who will progress to dementia and should be a critical component of any toolkit intended to identify AD at the pre-dementia stage. Some tasks are remarkable as early indicators, whereas others might be used to suggest imminent progression.     

False recognition in Lewy-body disease and frontotemporal dementia

The primary goal of this study was to evaluate the false recognition phenomenon in persons with frontotemporal dementia (FTD) and those with Lewy-body disease (LBD). Patients with LBD (n=10) or FTD (n=15) and their corresponding controls (n=30) were subjected to the Deese-Roediger-McDermott (DRM) paradigm to induce false recognition. Patients were first presented with items semantically related to a nonpresented critical target. The critical target was later included in a word list shown to patients to assess level of recognition. Both groups of patients showed a reduced level of false recognition of the critical target when controlling for their overall level of false alarms. This reduction was greater in persons with LBD than in those with FTD. Correlational analyses of performance on neuropsychological tests and the DRM variables indicated that the reduced DRM effect was associated with inhibition deficits in patients with LBD and with inhibition deficits and verbal memory in those with FTD. Our results support current models suggesting that these cognitive components contribute to the false recognition effect.     

Cognitive Processing of Drawing Abilities

This critical review examines constructional apraxia from a cognitive neuropsychological perspective. To our knowledge, van Sommers (1989) is the only researcher to present a global cognitive model of drawing abilities. He organizes it into two hierarchical systems: Marr's model of visual perception and a graphic production system. The latter comprises four hierarchically organized components: depiction decisions, production strategy, contingent planning, and articulatory and economic constraints. Van Sommers' model will be discussed in light of other models and on the basis of empirical neuropsychological studies (Farah, 1984; Kosslyn & Koenig, 1992; Roncato, Sartori, Masterson, & Rumiati, 1987; van Sommers, 1989). We find that: (1) the Kosslyn and Koenig visual perception model describes more accurately the perceptual components underlying copying than the visual perception system of van Sommers' drawing model, (2) Van Sommers' arguments in favor of a depiction processing as opposed to visual imagery are not convincing, (3) Van Sommers' assumption that a production strategy is a component is unclear, and (4) articulatory and economic constraints are not cognitive components, but constraints imposed during action programming. This literature review leads to a discussion of future research topics and the specificity of constructional apraxia.     

Behavioral regulation of gravity: schedule effects under escape-avoidance procedures

Squirrel monkeys were restrained in a centrifuge capsule and trained to escape and avoid increases in artificial gravity. During escape-avoidance, lever responses reduced centrifugally simulated gravity or postponed scheduled increases. The effect of variation in the interval of postponement (equal to the duration of decrease produced by escape responses) was studied under a multiple schedule of four components. Three components were gravity escape-avoidance with postponement times of 20, 40, and 60 sec. The fourth component was extinction. Each component was associated with a different auditory stimulus. Rate of responding decreased with increasing postponement time and higher mean g-levels occurred at shorter intervals of postponement. Effects of the schedule parameter on response rate and mean g-level were similar to effects of the schedule on free-operant avoidance and on titration behavior maintained by shock.