Zopiclone, but not brotizolam, impairs memory storage during sleep

We compared the effect of a single bedtime dose of two short half-time hypnotics, brotizolam (0.25 mg) and zopiclone (7.5 mg), on memory storage during sleep in a double blind, placebo-controlled, three-way crossover design trial in eight healthy volunteers. Memory was evaluated using a standard word list free-recall test learned before the bedtime dose by the subjects, who were asked to remember the list the following morning. Digit Symbol Substitution Test revealed no residual sedation by brotizolam or zopiclone. Brotizolam did not affect the morning recall compared to placebo, but subjects remembered less words under zopiclone treatment, suggesting that this drug could affect memory storage during sleep.     

The association between neuropsychological scores and ethnicity, language, and acculturation variables in a large patient population.

The relationship between ethnicity and cognitive test performance was examined in a sample of 161 patients referred for evaluation at a public hospital-affiliated neuropsychology clinic; 83 patients were Caucasian (non-Hispanic), 31 were African-American, 30 were Hispanic, and 17 were Asian. Significant group differences were present on some measures of language (Boston Naming Test), attention (Digit Span ACSS), constructional ability (Rey-Osterrieth [RO] copy), nonverbal processing speed (Trails A), and executive skills (Wisconsin Card Sorting Test [WCST]). Comparison of those who spoke English as a first language (or who learned English concurrently with a second language) versus those who spoke English as a second language (ESL) revealed significantly higher performance in the non-ESL group for Digit Span, Boston Naming Test, and FAS, and a higher score in the ESL group for RO copy. Boston Naming Test scores were significantly related to years educated in the United States; Boston Naming Test and Digit Span scores were significantly correlated with age at which conversational English was first learned and number of years in the United States; and finally, FAS scores were also significantly related to number of years in the United States. These findings are consistent with data from published literature on ethnic differences and the effects of acculturation on cognitive test performance in nonpatients, and also indicate that these observations are not attenuated by the presence of psychiatric or neurologic illness. The results further caution that normative data derived on Caucasian samples may not be appropriate for use with other ethnic groups.     

DECEIVING THE ELDERLY: EFFECTS OF ACCESSIBILITY BIAS IN CUED-RECALL PERFORMANCE

Two experiments examined age-related differences in a misinformation paradigm. Young and elderly participants studied a list of related word pairs (e.g. bed sheet) and were then given a cued-recall test (“bed s_ee_” presented as cues for recall of “sheet”). A ‘prime’ stimulus was presented briefly before each test trial. On congruent trials the prime was the target word from study (sheet) whereas on incongruent trials the prime was a related word that was a plausible response but not the target (sleep). On baseline trials, the prime was a string of ampersands. When forced to respond (Expt. 1), both young and elderly participants demonstrated a bias to respond with the prime word, although the elderly showed a larger false memory effect as measured by higher false recalls on incongruent relative to baseline trials. When given the option to pass (Expt. 2), elderly participants continued to exhibit a large bias toward the prime word whereas young participants tended to pass when they were unable to recall the target. Results are interpreted in terms of an accessibility bias, which influences guessing and is a basis of responding independent of recollection. Discussion focuses on the importance of studying age-related changes in bias and recollection along with neural correlates of these changes.     

Acute exercise improves cognition in the depressed elderly: the effect of dual-tasks

OBJECTIVE:

The goal of this study was to assess the acute effect of physical exercise on the cognitive function of depressed elderly patients in a dual-task experiment.

INTRODUCTION:

Physical exercise has a positive effect on the brain and may even act as a treatment for major depressive disorder. However, the effects of acute cardiovascular exercise on cognitive function during and after one session of aerobic training in elderly depressive patients are not known.

METHODS:

Ten elderly subjects diagnosed with major depressive disorder performed neuropsychological tests during and after a moderate physical exercise session (65-75%HR_max). A Digit Span Test (Forward and Backward) and a Stroop Color-Word Test were used to assess cognitive function. The elderly participants walked on an electric treadmill for 30 minutes and underwent the same cognitive testing before, during, immediately after, and 15 minutes after the exercise session. In the control session, the same cognitive testing was conducted, but without exercise training.

RESULTS:

The results of the Digit Span Test did not change between the control and the exercise sessions. The results of the Stroop Color-Word Test improved after physical exercise, indicating a positive effect of exercise on cognition.

CONCLUSIONS:

These data suggest that the cognitive functions of depressed elderly persons, especially attention and inhibitory control, are not impaired during and after an acute session of physical exercise. In contrast, the effect of dual-tasks showed beneficial results for these subjects, mainly after exercise. The dual-task may be a safe and useful tool for assessing cognitive function.     

冠状动脉搭桥术患者围术期血浆神经元特异性烯醇化酶浓度与术后认知功能

目的研究冠状动脉搭桥术患者围术期血浆神经元特异性烯醇化酶（NSE）浓度及术后认知功能。方法40例接受冠状动脉搭桥术的男性患者，分为体外循环组和非体外循环组，每组20例。在术前、术后6、12、18和24h采血，用放射免疫方法测定血浆NSE浓度。在术前1天和术后7～10天进行神经心理测试。结果体外循环组患者术后6h血浆NSE浓度比术前显著升高，同时高于非体外循环组；非体外循环组患者各时点无差别。非体外循环组患者在数字广度测验（逆向）、斯特鲁字色干扰测验改正反应和阻塞反应的结果显著优于体外循环组患者。体外循环组患者术后6hNSE水平与连线测验A型相关，术后12hNSE浓度与数字广度测验（顺向）、连线测验A型、斯特鲁字色干扰测验时间分项相关。结论心脏手术后血浆NSE浓度的升高可在某种程度上反映术后认知功能障碍，但在具体应用时应考虑NSE的组织多源性及体外循环因素的影响。     

Psychosocial stress enhances non-drug-related positive memory retrieval in male abstinent heroin addicts

Stress exposure in addicted individuals is known to provoke drug craving, presumably through a memory-like process, but less is known about the effects of stress on non-drug-related affective memory retrieval per se in such individuals, which is likely to provide important insights into therapy for relapse. In present study, we explored the effect of stress on retrieval of neutral and emotionally valenced (positive and negative) words in abstinent heroin addicts. In present study, 28 male inpatient abstinent heroin addicts and 20 sex-, age-, education- and economic status-matched healthy control participants were assessed for 24 h delayed recall of valenced and neutral word lists on two occasions 4 weeks apart—once in a nonstress control condition, once after exposure to the Trier Social Stress Test in a counterbalanced design. In addition, attention, working memory, blood pressure, heart rate and salivary cortisol were assessed. We found acute stress at the time of word list recall enhanced retrieval of positively valenced words, but no effect on negative and neutral word retrieval in abstinent heroin addicts was observed. No changes were detected for attention and working memory. The stressor induced a significant increase in salivary free cortisol, blood pressure and heart rate. Stress can enhance non-drug-related positive memory in abstinent heroin addicts. Our findings will provide richer information in understanding dysregulation of their emotional memory processing under stress and hopefully provide insight into designing improved treatments for drug addiction.     

Effect of manipulation and irrelevant noise on working memory capacity of patients with Alzheimer's dementia

The effect of manipulation and distracting noise on immediate serial recall was measured in patients with dementia of the Alzheimer type (DAT), neurologically healthy elderly individuals, and young adults. In Experiment 1, the authors compared serial word recall with word recall in alphabetical order. Alphabetical recall requires the active manipulation of the contents of working memory. Findings indicated that DAT patients were severely impaired in the alphabetical recall task, whereas the performance of neurologically healthy elderly participants was comparable with the performance of young adult participants. In Experiment 2, the authors investigated the effect of different irrelevant auditory backgrounds on immediate digit recall. In this task, both elderly participants and DAT patients performed similarly to the group of young adult participants, indicating comparable efficacy to resist auditory distraction.     

The relationship between intelligence and verbal and spatial memory.

Administered the Logical Memory Test (LM) and the Rey-Osterreith Test (RO), which have been assumed to pertain to verbal and spatial cognitive functioning, to 150 Ss referred for neuropsychological screening. Ss also were administered the short version of the WAIS, plus Digit Span. It was found that LM did relate more to verbal IQ than to spatial IQ and vice-versa for RO. It was not clear exactly what aspect of cognitive functioning Digit Span was tapping. The clinical implications of the study are that LM scores must be viewed in the light of verbal IQ level, and RO scores interpreted in relation to both spatial IQ and age. Data are presented that can be used for the statistical interpretation of an individual case test scores.     

Postural Stability and Neuropsychological Deficits After Concussion in Collegiate Athletes

OBJECTIVE: Postural stability and neuropsychological testing are gradually becoming integral parts of postconcussion assessment in athletes. Clinicians, however, sometimes question the viability of instituting preseason baseline testing and the value of these results in making return-to-play decisions. Our purpose was to examine the course of recovery on various postural stability and neuropsychological measures after sport-related concussion. A secondary goal was to determine if loss of consciousness and amnesia, both of which are heavily weighted in most of the concussion classification systems, affect the rate of recovery. DESIGN AND SETTING: All subjects underwent a battery of baseline postural stability and neuropsychological tests before the start of their respective seasons. Any athletes subsequently injured were followed up at postinjury days 1, 3, and 5. Matched control subjects were assessed using the same test battery at the same time intervals. SUBJECTS: We studied 36 Division I collegiate athletes who sustained a concussion and 36 matched control subjects. MEASUREMENTS: We assessed postural stability using the Sensory Organization Test on the NeuroCom Smart Balance Master System and the Balance Error Scoring System. Neurocognitive functioning was measured with several neuropsychological tests: Trail-Making Test, Wechsler Digit Span Test, Stroop Color Word Test, and Hopkins Verbal Learning Test. RESULTS: Injured subjects demonstrated postural stability deficits, as measured on both the Sensory Organization Test and Balance Error Scoring System. These deficits were significantly worse than both preseason scores and matched control subjects' scores on postinjury day 1. Only the results on the Trail-Making Test B and Wechsler Digit Span Test Backward resulted in a logical recovery curve that could explain lowered neuropsychological performance due to concussive injury. Significant differences were revealed between the control and injured groups at day 1 postinjury, but a significant decline between baseline and postinjury scores was not demonstrated. Loss of consciousness and amnesia were not associated with increased deficits or slowed recovery on measures of postural stability or neurocognitive functioning. CONCLUSIONS: Athletes with cerebral concussion demonstrated acute balance deficits, which are likely the result of not using information from the vestibular and visual systems effectively. Neurocognitive deficits are more difficult to identify in the acute stages of concussion, although concentration, working memory, immediate memory recall, and rapid visual processing appear to be mildly affected. More research is necessary to determine the best neuropsychological test battery for assessing sport-related concussion.     

Pre-learning stress differentially affects long-term memory for emotional words, depending on temporal proximity to the learning experience

Stress exerts a profound, yet complex, influence on learning and memory and can enhance, impair or have no effect on these processes. Here, we have examined how the administration of stress at different times before learning affects long-term (24-hr) memory for neutral and emotional information. Participants submerged their dominant hand into a bath of ice cold water (Stress) or into a bath of warm water (No stress) for 3 min. Either immediately (Exp. 1) or 30 min (Exp. 2) after the water bath manipulation, participants were presented with a list of 30 words varying in emotional valence. The next day, participants' memory for the word list was assessed via free recall and recognition tests. In both experiments, stressed participants exhibited greater blood pressure, salivary cortisol levels, and subjective pain and stress ratings than non-stressed participants in response to the water bath manipulation. Stress applied immediately prior to learning (Exp. 1) enhanced the recognition of positive words, while stress applied 30 min prior to learning (Exp. 2) impaired free recall of negative words. Participants' recognition of positive words in Experiment 1 was positively associated with their heart rate responses to the water bath manipulation, while participants' free recall of negative words in Experiment 2 was negatively associated with their blood pressure and cortisol responses to the water bath manipulation. These findings indicate that the differential effects of pre-learning stress on long-term memory may depend on the temporal proximity of the stressor to the learning experience and the emotional nature of the to-be-learned information.     

Higher levels of plasma estradiol and testosterone in healthy elderly men compared with age-matched women may protect aspects of explicit memory

OBJECTIVE: To assess longitudinally the relationships between plasma levels of estradiol (E2) and free testosterone (T) and cognitive functioning in elderly men, women who use estrogen, and women who do not use estrogen. DESIGN: At two test times 18 months apart (time 1 and time 2), men (time 1, n = 31; time 2, n = 23), women who were using estrogen (time 1, n = 14; time 2, n = 10), and women who were not using estrogen (time 1, n = 41; time 2, n = 27), whose average age was 72.1 and 73.4 years at time 1 and time 2, respectively, were administered a battery of neuropsychological tests that measured verbal memory, visual memory, concentration and attention, language fluency, and semantic memory. Plasma levels of E2 and free T were assessed by radioimmunoassay. RESULTS: The men had higher free T levels than both groups of women at both test times. Although women who were using estrogen had higher E2 levels than those of the men and of the women who were not using estrogen, the men's E2 levels were also significantly higher than those of the women who were not using estrogen. Moreover, the women who were using estrogen and the men had higher Forward Digit Span scores compared with the women who were not using estrogen at both test times, and women who were using estrogen had higher Backward Digit Span scores than those who were not using estrogen. Both groups of women performed better than the men on the Category Retrieval Test (verbal fluency). The performance of women who were using estrogen on the Delayed Selective Reminding Test (long-term rote memory) improved over time compared with that of the men and of the women who were not using estrogen. CONCLUSIONS: These findings raise the possibility that higher E2 levels in elderly men and in women who use estrogen may protect against some declines in explicit memory with normal aging.     

Intraindividual variability as an indicator of malingering in head injury.

The utility of various measures of malingering was evaluated using an analog design in which half the participants (composed of three groups: naive healthy people, professionals working with head-injured people, individuals who suffered a head injury but not currently in litigation) were asked to try their best and the remainder was asked to feign believable injury. Participants were assessed with the Reliable Digit Span (RDS) task, the Victoria Symptom Validity Test (VSVT), and the Computerized Dot Counting Test (CDCT) on three separate occasions in order to determine whether repeat administration of tests improves prediction. The results indicated that regardless of an individual's experience, consideration of both level of performance (particularly on forced-choice symptom validity tasks) and intraindividual variability holds considerable promise for the detection of malingering.     

Effects of incentive and preparation time on performance and classification accuracy of standard and malingering-specific memory tests.

The effects of incentive and preparation on performance and classification accuracy of standard and malingering-specific tests were investigated in a simulation study using a 2 (no incentive vs. a $20 incentive) x 2 (immediate vs. delayed preparation) factorial design. Eighty undergraduate students and 15 individuals with traumatic brain injury were administered standard (viz., Digit Span and Visual Memory Span from the WMS-R) and malingering-specific (viz., the Rey 15-Item Memory Test and the Multi-Digit Memory Test) memory tests. Preparation time was found to have a significant effect on performance and classification accuracy on a number of these tests, but incentive was found to have a significant effect on the performance but not the classification accuracy of one test (viz., the Multi-Digit Memory Test). These findings suggest that extra-test variables such as incentive and preparation time should be taken into consideration in evaluating the utility of standard and malingering-specific memory tests in detecting malingering.     

Is sleep‐related verbal memory consolidation impaired in sleepwalkers?

In order to evaluate verbal memory consolidation during sleep in subjects experiencing sleepwalking or sleep terror, 19 patients experiencing sleepwalking/sleep terror and 19 controls performed two verbal memory tasks (16‐word list from the Free and Cued Selective Reminding Test, and a 220‐ and 263‐word modified story recall test) in the evening, followed by nocturnal video polysomnography (n = 29) and morning recall (night‐time consolidation after 14 h, n = 38). The following morning, they were given a daytime learning task using the modified story recall test in reverse order, followed by an evening recall test after 9 h of wakefulness (daytime consolidation, n = 38). The patients experiencing sleepwalking/sleep terror exhibited more frequent awakenings during slow‐wave sleep and longer wakefulness after sleep onset than the controls. Despite this reduction in sleep quality among sleepwalking/sleep terror patients, they improved their scores on the verbal tests the morning after sleep compared with the previous evening (+16 ± 33%) equally well as the controls (+2 ± 13%). The performance of both groups worsened during the daytime in the absence of sleep (?16 ± 15% for the sleepwalking/sleep terror group and ?14 ± 11% for the control group). There was no significant correlation between the rate of memory consolidation and any of the sleep measures. Seven patients experiencing sleepwalking also sleep‐talked during slow‐wave sleep, but their sentences were unrelated to the tests or the list of words learned during the evening. In conclusion, the alteration of slow‐wave sleep during sleepwalking/sleep terror does not noticeably impact on sleep‐related verbal memory consolidation.     

Factor structure of Benton's tests of visual retention, visual construction, and visual form discrimination.

The standard drawing and multiple-choice versions of the Benton Visual Retention Test (BVRT), the Visual Form Discrimination Test (VFDT), the Rey Auditory Verbal Learning Test (AVLT), and the Wechsler Adult Intelligence Scale-Revised Digit Span subtest were administered to a mixed sample of 97 psychiatric, neurologic, and control subjects. Factor analysis of the Benton test battery measures alone showed that the standard and multiple-choice BVRT protocols performed very similarly. Scoring of the standard BVRT for errors and number of correct items was shown to be statistically redundant for this sample. Possible simplification of standard BVRT scoring was suggested. Copying and immediate visual-memory skills emerged as separable factors on the standard BVRT. When the AVLT and Digit Span measures were factor analyzed with the Benton lest battery measures, however, simple factorial structure emerged only for the AVLT measures (one factor) and the BVRT copying measures that were grouped with the VFDT. A verbal mediation component was thought to be associated with the multifactorial BVRT and multiple-choice BVRT results in this analysis.     

Association study of a functional catechol-O-methyltransferase polymorphism and executive function in elderly males without dementia

Cognitive function in older people is a major factor influencing quality of life. The catechol-O-methyltransferase (COMT) gene, which is essential in the metabolic degradation of prefrontal dopamine, has been considered as a leading candidate gene in the variation in cognitive performance. The aim of this study was to investigate the effect of a functional COMT (Val158Met) polymorphism on several cognition domains in a relatively homogeneous population consisting of elderly Chinese males without dementia. Six neuropsychological measurements, including Spatial Span Forward and Backward, Digit Span Forward and Backward, and Trail Making Test-A and -B, were assessed in 161 aged males. It was found that the Met/Met carriers showed a better performance than the Val/Met and Val/Val subjects on the Digit Span Forward (a measure of general attention; p=0.017, after correction for education level) test, but not on the other cognitive tests. These findings suggest that the COMT Val158Met genotype may contribute to differences in normal cognitive aging, particularly in the area of general attention.     

Language of administration and neuropsychological test performance in neurologically intact Hispanic American bilingual adults

This study compared the performance of Hispanic American bilingual adults on Spanish and English language versions of a neuropsychological test battery. Language achievement test scores were used to divide 36 bilingual, neurologically intact, Hispanic Americans from south Texas into Spanish-dominant, balanced, and English-dominant bilingual groups. They were administered the eight subtests of the Bateria Neuropsicologica and the Matrix Reasoning subtest of the WAIS-III in Spanish and English. Half the participants were tested in Spanish first. Balanced bilinguals showed no significant differences in test scores between Spanish and English language administrations. Spanish and/or English dominant bilinguals showed significant effects of language of administration on tests with higher language compared to visual perceptual weighting (Woodcock-Munoz Language Survey-Revised, Letter Fluency, Story Memory, and Stroop Color and Word Test). Scores on tests with higher visual-perceptual weighting (Matrix Reasoning, Figure Memory, Wisconsin Card Sorting Test, and Spatial Span), were not significantly affected by language of administration, nor were scores on the Spanish/California Verbal Learning Test, and Digit Span. A problem was encountered in comparing false positive rates in each language, as Spanish norms fell below English norms, resulting in a much higher false positive rate in English across all bilingual groupings. Use of a comparison standard (picture vocabulary score) reduced false positive rates in both languages, but the higher false positive rate in English persisted.     

Alcoholics' recovery from cerebral impairment as a function of duration of abstinence

There is clear evidence in the literature for permanent cerebral impairment due to prolonged alcohol abuse. Observation also suggests that there is a component of this cerebral impairment that is found immediately subsequent to heavy drinking and that is reversible. This study examined the time-course of recovery from this temporary impairment and delineated more specifically the neuropsychological functions that participate in the recovery. Four groups (N = 87) of hospitalized male alcoholics were tested after 6, 15, 21, and 110 days of abstinence using the Raven Progressive Matrices, the Trail-Making Test, the Memory for Designs, and the following subscales of the WAIS: Arithmetic, Digit Span, Block Design, Similarities, and Digit Symbol. The results indicated that significant improvement occurred during the third week of abstinence (between 15 and 21 days) on the Digit Span, Block Design, Similarities, Memory for Designs, Raven, and Trail-Making tests, but not on the Arithmetic and Digit Symbol tests. These results suggest that treatment programs that use a preliminary “drying-out” period should consider lengthening this period to 3 weeks to insure that patients are maximally responsive to psychotherapy.     

Acute cortisol effects on immediate free recall and recognition of nouns depend on stimulus valence

The present study investigated the acute effects of cortisol administration in normal healthy male volunteers on immediate free recall and recognition of pleasant, unpleasant, and neutral nouns using a between-subjects double-blind design. Two hours after cortisol (10 mg) or placebo administration, impaired recall and recognition of neutral and pleasant words was found in the treatment group, whereas recall and recognition of unpleasant words was similar in both groups. The interaction between treatment and stimulus valence was not mediated by "semantic cohesion," nor does it seem to have been mediated by stimulus arousal. Cortisol did not change mood. The changes with cortisol in recall and recognition of pleasant and unpleasant words parallel those found in depression, a condition that is often accompanied by elevated basal cortisol levels.