与年龄及认知功能相关的成人脑波功率涨落图特点

对１２０名２０－７９岁正常受试者完成了与年龄及认知功能相关的脑涨落图特点的研究。结果表明：（１）脑波优势涨落功率空间构型额低枕高梯度的随龄减小过程,在认知测验差组较好组明显;（２）脑波优势涨落功率受年龄与认知因素的交互影响集中于左前右后脑轴上;（３）脑波优势涨落功率前后梯度和左右不对称性变化表明,脑波活动的前后和左右调控可能在不同层次上发挥作用,并且,前后脑和左右脑的协调活动与认知功能有密切关系。上述结果说明,脑波功率涨落与认知功能及其老化过程有密切关系。     

认知作业年老化的比较研究

用言语—操作和人机对话两种方式完成１２项认知作业年老化比较研究,被试２４２人,４６－７５岁。结果表明：（１）一些作业（符号数字、视觉数字广度、听觉数字广度、词对联想学习、图象自由回忆和无意图形再认）成绩随年老明显下降,另一些作业（图象分类、卡片分类、心算和矩阵填图）成绩不随年老明显降低;（２）再次验证心算、符号数字、数字鉴别和计数四项非词语性作业速度随年老进行性减慢。     

年老过程认知作业完成量与作业速度相互关系的研究

本工作应用自行设计的计算机逐级限速程序,研究了年老过程四项认知作业完成量与作业速度的相互关系。被试350人,46—75岁。研究结果表明:1、随着计算机所限时间的缩短,各项作业完成量均随年老下降迅速,作业完成量对于作业速度的依存关系随年老表现极为明显;2、在逐级限速条件下,四项认知作业完成量的年老敏感性顺序与作业速度的年老敏感性顺序基本相同,即是:符号数字、心算、计数和数字鉴别。     

中小学生智力发展的脑电图研究

利用脑ET技术对认知功能正常的被试进行智力发展的脑电图研究。结果表明:(1)随着年龄的增长,小学生脑α波的平均频率呈明显的上升趋势,而中学生的变化幅度不大,但明显超过60年代的同期水平;(2)脑波平均频率的空间分布表现出额低枕高的前后梯度,在年龄低组被试有逆转现象,随年龄的增长,逆转现象减少,大脑的有序程度逐渐增强;(3)小学生的信息加工速度与脑α波的关系并不十分明显,而其脑波频率的分布和发展特点与计算速度有着根本的联系。中学生的表象能力与不同脑区平均频率的关系因年龄不同而有所差异,主要表现为在右顶叶、右前颞叶、右后颞叶和左后颞叶区域,表象能力好组频率大于差组。     

非词语性认知作业速度年老衰减规律的数学描述

应用两维年龄多作业回归分析方法,研究了四项非词语性认知作业速度年老衰减规律的数学描述形式。被试共７３４名,４６─７５岁。结果表明：五个年老组与４６─５０岁组作业时间之间呈线性函数关系,其线性方程的斜率值随年老组的增龄而增大。     

不同认知作业年老化特点的比较研究

本工作应用自行设计的软件程序和微机人机对话方式,完成六项认知作业的年老化特点的比较研究,被试506人,46—75岁。研究结果表明:1)“心算”和“符号数字”两项作业完成速度随年老迅速减慢,但测验成绩随年老缓慢降低,速度变化是该两项作业年老化过程的主要特点;2)“数字鉴别”和“计数”两项作业完成速度随年老减慢较缓;3)“双位数字顺序回忆”和“无意义图形再认”两项作业测验成绩随年老下降迅速,但前者更为明显;4)速度和成绩两项指标的个体差异均随年老有增大趋向。     

与年龄相关的认知速度减慢及学习改善过程

该工作应用人机对话方式完成心算、符号数字、数字鉴别和计数四项作业认知速度年老减慢及学习改善过程的研究,被试３５０人,４６—７５岁。研究结果表明：四项认知作业速度随年老进行性减慢;然而,老年人经学习训练认知作业速度可明显改善。上述变化程度与作业所需时间有密切关系,提示年老过程中枢信息加工过程速度的减慢快于外周感觉─运动过程速度的减慢,学习改善作用也可能主要是中枢过程速度的提高。     

与年龄相关的认知速度减慢及学习改善过程

该工作应用人机对话方式完成心算、符号数字、数字鉴别和计数四项作业认知速度年老减慢及学习改善过程的研究,被试３５０人,４６—７５岁。研究结果表明：四项认知作业速度随年老进行性减慢;然而,老年人经学习训练认知作业速度可明显改善。上述变化程度与作业所需时间有密切关系,提示年老过程中枢信息加工过程速度的减慢快于外周感觉─运动过程速度的减慢,学习改善作用也可能主要是中枢过程速度的提高。     

成人脑波涨落图功率空间构型的年龄变化特点

本工作研究了１２０名２０－７９岁正常成人的脑波涨落功率空间构型的年龄变化特点。结果表明,随着年龄增长,脑波超慢涨落系统平均功率及主要谱线功率前脑与后脑（包括额区与枕区）比值明显增大,表明额低枕高的梯度减小以至逆转,左脑与右脑（包括左颞与右颞）比值趋近于１,表明左右不对称性程度减弱,但变化较小。     

加工速度和工作记忆在认知年老化过程中的作用

研究加工速度和工作记忆在认知能力年老化过程中的作用。被试为20-90岁的健康成人1350名,完成加工速度、工作记忆及一组认知能力测验,应用分层回归分析方法考查在年老化过程中加工速度和工作记忆对多项认知变量的作用量。结果表明,在年老化过程中,加工速度和工作记忆对认知变量的作用量分别约为87% 和76%;二者的综合作用量约为94%。说明加工速度和工作记忆在认知能力年老化过程中起决定作用     

A psychometric approach to intuitive physics

The literature on intuitive physics shows that many people exhibit systematic errors when predicting the behavior of simple physical events. Most previous research has attributed these errors to factors specific to a certain class of tasks. In the present study, we investigated the possibility that intuitive physics performance may be related to general measures of cognitive ability. Two hundred four adults (ages, 20-91 years) were presented with five pairs of intuitive physics questions. It was found that performance on the intuitive physics items was moderately intercorrelated, suggesting that they were tapping into a unitary construct. Despite the correlation with factors that decline with advancing age, intuitive physics performance was not correlated with age (r= .00). The findings are discussed in the context of research on intuitive physics, as well as research on cognitive aging.     

Blood flow velocity changes in anterior cerebral arteries during cognitive tasks performance

Objective

Transcranial Doppler sonography (TCD) enables monitoring of blood flow velocities (BFVs) in basal cerebral arteries during different cognitive tasks performance with great temporal resolution. So far, BFVs changes during mental activity were monitored primarily in middle cerebral arteries (MCAs) and little is known about these changes in anterior cerebral arteries (ACAs).

Aim

To determine the effect of different cognitive tasks performance on BFV changes and hemispheric dominance in ACAs and to assess the most suitable activation test for monitoring of BFV changes in ACAs.

Methods

Fourteen right-handed, healthy subjects aged 20–26 were included in the study. BFVs in both ACAs were recorded simultaneously during performance of cognitive tasks designed to activate frontal lobes: phonemic verbal fluency test (pVFT), Stroop tests and Trail Making Tests (TMTs).

Results

A statistically significant BFV increase was recorded in both ACAs during performance of all cognitive tasks. Statistically significant right ACA dominance was found during performance of pVFT and TMTB. The most significant BFV increase was obtained during performance of TMTB.

Conclusion

Our result addressed cognitive tests with great activation potential for monitoring of ACAs that might be used in distinguishing of healthy individuals and patients with neurovascular or neurodegenerative diseases.     

Frontal brain asymmetry in depression with comorbid anxiety: a neuropsychological investigation

The approach-withdrawal model posits that depression and anxiety are associated with a relative right asymmetry in frontal brain activity. Most studies have tested this model using measures of cortical brain activity such as electroencephalography. However, neuropsychological tasks that differentially use left versus right frontal cortical regions can also be used to test hypotheses from the model. In two independent samples (Study 1 and 2), the present study investigated the performance of currently depressed individuals with or without a comorbid anxiety disorder and healthy controls on neuropsychological tasks tapping primarily left (verbal fluency) or right (design fluency) frontal brain regions. Across both samples, results indicated that comorbid participants performed more poorly than depressed only and control participants on design fluency, while all groups showed equivalent performance on verbal fluency. Moreover, comorbid participants showed "asymmetrical" performance on these two tasks (i.e., poorer design [right frontal] relative to verbal [left frontal] fluency), whereas depressed only and control participants showed approximately symmetrical profiles of performance. Results from these two samples suggest an abnormal frontal asymmetry in neurocognitive performance driven primarily by right frontal dysfunction among anxious-depressed individuals and highlight the importance of considering comorbid anxiety when examining frontal brain functioning in depression.     

A self-referential default brain state: patterns of coherence,power, and eLORETA sources during eyes-closed rest and Transcendental Meditation practice

Activation of a default mode network (DMN) including frontal and parietal midline structures varies with cognitive load, being more active during low-load tasks and less active during high-load tasks requiring executive control. Meditation practices entail various degrees of cognitive control. Thus, DMN activation patterns could give insight into the nature of meditation practices. This 10-week random assignment study compared theta2, alpha1, alpha2, beta1, beta2 and gamma EEG coherence, power, and eLORETA cortical sources during eyes-closed rest and Transcendental Meditation (TM) practice in 38 male and female college students, average age 23.7 years. Significant brainwave differences were seen between groups. Compared to eyes-closed rest, TM practice led to higher alpha1 frontal log-power, and lower beta1 and gamma frontal and parietal log-power; higher frontal and parietal alpha1 interhemispheric coherence and higher frontal and frontal-central beta2 intrahemispheric coherence. eLORETA analysis identified sources of alpha1 activity in midline cortical regions that overlapped with the DMN. Greater activation in areas that overlap the DMN during TM practice suggests that meditation practice may lead to a foundational or ‘ground’ state of cerebral functioning that may underlie eyes-closed rest and more focused cognitive processes.     

Age-Related Changes in Neural Activation During Working Memory Performance

Changes in frontal lobe functions are a typical part of aging of the brain. There are age-related declines in working memory performance, a skill requiring frontal lobe activation. This study examined neural activation, using [15 O] water positron emission tomography (PET) methodology, during performance on two verbal working memory tasks in younger and older participants. The results demonstrated the typical areas of activation associated with working memory performance (e.g., dorsolateral prefrontal cortex and inferior parietal cortex) in both groups. However, the younger participants utilized the right dorsolateral prefrontal cortex and anterior cingulate gyrus significantly more than the older participants. In turn, the older participants used the left dorsolateral prefrontal cortex significantly more than the younger participants and maintained material-specific lateralization in their pattern of activation. These findings are consistent with a previous report of different age-related patterns of frontal activation during working memory.     

Age-Related Influences on Repetition Priming in the Verb Generation Task: Examining the Role of Response Competition

ABSTRACT

The identification-production framework suggests that aging is associated with a decline in production forms of repetition priming, particularly under test conditions that maximize response competition. The present study examined this prediction by testing young and healthy older adults in a single-encoding version of the verb generation task in which some items had one dominant verb response (low competition) or had no such dominant response (high competition). Further analyses examined whether priming and error rates were related to performance on neuropsychological tests purported to measure frontal lobe functioning. Priming was invariant across age groups and was not related to frontal lobe status in older adults, but frontal lobe status did predict task performance: low-frontal older adults made more errors than high-frontal older adults, particularly for high-competition items and items with high association strength. These results are not consistent with the identification-production framework, but are consistent with the conclusions that (a) aging is associated with invariance in the processes that support repetition priming in the verb generation task and (b) frontal lobe status in aging is related to verb generation performance.     

An age-related deficit in prefrontal cortical function associated with refreshing information

Older adults are slower than young adults to think of an item they just saw, that is, to engage or execute (or both) the simple reflective operation of refreshing just-activated information. In addition, they derive less long-term memory benefit from refreshing information. Using functional magnetic resonance imaging (fMRI), we found that relative to young adults, older adults showed reduced refresh-related activity in an area of dorsolateral prefrontal cortex (left middle frontal gyrus, Brodmann's Area 9), but not in other refresh-related areas. This provides strong evidence that a frontal component of the circuit that subserves this basic cognitive process is especially vulnerable to aging. Such a refresh deficit could contribute to poorer performance of older than young adults on a wide range of cognitive tasks.     

The effect of an intensive behavioral program on the distribution of EEG alpha power in stutterers during the processing of verbal and visuospatial information

Prior to an intensive behavioral treatment program, stutterers showed greater than normal activation of the posterior frontal region of the right hemisphere during the performance of speech tasks. After treatment they showed increases in proportional alpha for most regions of the two cerebral hemispheres, but most markedly for the posterior frontal region of the right hemisphere for both verbal and nonverbal tasks. This increase resulted in a reversal of the previous R/L interhemispheric alpha relationships with the left posterior frontal region showing greater activation during speech after treatment. The relationship of this finding to previous findings is briefly discussed and an hypothesis of decreased inhibitory control of the right hemisphere at the posterior frontal region by the left hemisphere during speech in stutterers is proposed and briefly expounded.     

Protective effect of practice on cognition during aging: implications for predictive characteristics of performance and efficacy of practice

In the present study, the effect of previous experience on spatial memory, which required the retention of information either over long intervals or within a single session, was longitudinally tested in the water maze in male F-344 rats that were from 6 to 24 months of age. Performance in these tasks was found to be age-dependent (Markowska, 1999). Other behavioral tasks in the straight alley and with a visible platform in the water maze controlled the noncognitive components of performance. For all tasks, performance was significantly correlated between 12-month-old and 18-month-old rats, indicating that cognitive performance at the early, but not advanced, stage of aging could be predicted from performance at a younger age if the novelty of the first exposure to the task was eliminated. The protective effect of experience was more robust in the reference memory task as compared to the working memory task and was modified by age when training was initiated. Behavior during the probe trials was more sensitive to the effect of aging and more resistant to the beneficial effect of practice as compared to the performance in the platform trials. The speed of swimming of experienced rats progressively decreased with age only when tested in the cognitive tasks but not in the straight alley. This indicates that speed of swimming during cognitive tasks does not exclusively reflect the ability to swim, but might be also affected by the cognitive demands of the task. Protective effect of experience on cognition was not modified by restriction in diet.