Transitional Information in Spatial Serial Memory: Path Characteristics Affect Recall Performance.

This study examined the role of stimulus characteristics in a visuospatial order reconstruction task in which participants were required to recall the order of sequences of spatial locations. The complexity of the to-be-remembered sequences, as measured by path crossing, path length, and angles, was found to affect serial memory, in terms of both recall accuracy and response times. The results demonstrate that not all sequences are remembered equally and that spatial characteristics of the sequences constitute an important variable in the understanding of visuospatial serial memory. More important, the data suggest that spatial path represents transitional information and that, as is the case in verbal serial memory, transitional information is of critical importance in serial memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive dysfunction and Alzheimer's disease: Performance on a test of planning ability, the Porteus Maze Test.

Planning ability, as measured by the Porteus Maze Test, was evaluated in 85 Alzheimer's disease (AD) patients and 65 controls. AD patients performed worse on Test Age and 2 of 5 qualitative error scores. Principal components analysis revealed 3 Porteus components: Test Age and First Third Errors; Cut Corner and Cross Line Errors; and Last Third Errors. Among AD patients, factor analysis of Porteus measures and other cognitive tests revealed 4 factors. A nonverbal factor included Test Age and 3 nonverbal measures. A verbal factor included no Porteus measure. The remaining factors resembled the last 2 components from the analysis of Porteus scores alone. Test Age and 4 other cognitive measures correlated with ratings on an activities of daily living scale. Porteus Maze performance was impaired in a substantial number of patients with dementia and may be a useful measure of executive function in this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in episodic memory: The impact of verbal and visuospatial ability.

The impact of verbal and visuospatial ability on sex differences in episodic memory was investigated. One hundred men and 100 women, 20–40 years old, participated in a series of verbal and visuospatial tasks. Episodic memory was assessed in tasks that, to a greater or lesser extent, were verbal or visuospatial in nature. Results showed that women excelled in verbal production tasks and that men performed at a superior level on a mental rotation task. In addition, women tended to perform at a higher level than men on most episodic memory tasks. Taken together, the results demonstrated that (a) women perform at a higher level than men on most verbal episodic memory tasks and on some episodic memory tasks with a visuospatial component, and (b) women's higher performance on episodic memory tasks cannot fully be explained by their superior performance on verbal production tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estradiol is related to visual memory in healthy young men.

The influence of testosterone and estrogen on memory was investigated in 33 healthy young men. Tests of visual memory, visuospatial ability, verbal memory, and attention were administered, and circulating levels of estradiol and free testosterone were measured. Participants with high levels of estradiol performed better on 2 measures of visual memory than did those with normal but lower levels. There were no differences between individuals with high and low levels of testosterone on any cognitive measure. These results support the contention that estradiol influences memory in young men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bcl-2 is located predominantly in the inner membrane and crista of mitochondria in rat liver

A modified "Samson" sucrose fading procedure was used to establish voluntary consumption of a 20% ethanol (EtOH) solution in male Sprague-Dawley rats for 18 consecutive months. Intakes were stable over the life span, and corresponded to the moderate to high levels of intake typically observed in human "social" drinkers and alcoholics. The Morris Water Maze (WM), Olton Radial Arm Maze (RM), and a "balance beam" test were used to assess the effects of alcohol and aging on spatial memory and motor function. Aged EtOH-consuming rats (AGED/ALC) demonstrated impaired task acquisition, relative to aged controls (AGED), not reaching criterion performance in either spatial memory task even when given four additional days of training. AGED/ALC rats scored significantly lower on percent correct out of the first eight arm entries, and committed more perseverative errors in the RM. There were no significant performance differences between AGED and AGED/ALC rats on a balance beam test of fine motor coordination and equilibrium, suggesting that deficits observed in the RM and WM were not related to differential motor functioning. These results demonstrated that long-term, moderate, oral self-administration of EtOH, within the range typically consumed by humans, had adverse effects on spatial memory in rats, and that such a pattern of EtOH consumption seemed to exacerbate the decline in cognitive functioning associated with normal aging.     

Influences of thyroid stimulating hormone on cognitive functioning in very old age

This study investigated the relationship of thyroxine (T4) and thyroid stimulating hormone (TSH) within normal ranges to cognitive performance in very old age. The participants (N = 200) were selected from a population-based study of nondemented persons aged 75 to 96 years (M = 83.9 years). Tasks assessing episodic memory, verbal fluency, visuospatial ability, short-term memory, and perceptual-motor speed were examined. Results indicated that T4 was unrelated to performance. However, TSH was positively related to episodic memory performance, and the effects were independent of the influence of age, level of education, and depressive mood symptoms. There was no reliable effect of TSH on verbal fluency, short-term memory, perceptual-motor speed, or visuospatial functioning. The influence of TSH on episodic memory was interpreted in terms of its potential effects on encoding and consolidation processes.     

Patterns of verbal learning after closed head injury.

Cluster analysis of the learning trials and delayed free-recall trials of 70 patients with closed head injury on the California Verbal Learning Test (CVLT) revealed 3 distinct patterns of memory performance. The clusters differed in the amount and rate of learning, retroactive interference, and the level of delayed recall. There was a significant positive relationship between performance on the CVLT and performance on concurrent measures of attention, semantic memory, and intellectual ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are working memory deficits in bipolar disorder markers for psychosis?

Working memory deficits have been identified in bipolar disorder, but there is evidence suggesting that these deficits may be markers for psychosis rather than affective disorder. The current study examined this issue by comparing two groups of individuals with bipolar disorder, one with psychotic features and one without psychotic features, with a group of normal controls. Working memory was conceptualized as a multicomponent system that includes auditory and visuospatial short-term stores, executive control processes, and an episodic buffer that allows for communication between short- and long-term memory stores (Baddeley & Logie, 1999). Results indicated that only executive control processes significantly differentiated the psychotic and nonpsychotic bipolar groups, although visuospatial working memory differentiated both bipolar groups from controls. The results support the idea that some aspects of working memory performance are markers for psychosis, while others may be more general markers for bipolar disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Problem solving as a function of children's defensiveness and parental behavior.

The performance of 2 groups of 16 5th-grade boys, one low defensive and low anxious (LD) and the other high defensive and low anxious (HD) on the Defensiveness and Test Anxiety Scales for Children, was compared on the Porteus Maze Test taken with mothers absent and on a different form of the Porteus plus a jigsaw puzzle test with mothers present. Mothers were rated on a set of rating scales as they helped their sons with the puzzle. The results suggest that (a) discrepancies between ability and qualitative performance in defensive boys are a function of defensiveness whereas such discripancies in quantitative performance are a function of certain salient components of the test situation, and (b) communication is less effective in families of HD boys than in families of LD boys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between the mini-mental state examination and cognitive functioning in normal elderly adults: a componential analysis

The relationship between the Mini-Mental State Examination (MMSE) and selected cognitive performance indices was examined in a sample of 251 non-demented adults over 75 years of age. MMSE items were divided into I 1 binomial content domains and an examination of these revealed that only seven had sufficient variability to predict cognitive performance. A factor analysis with these items yielded three factors, reflecting memory, spatial skill, and the ability to follow commands. After controlling for age and education, these factor scores were included as predictors of specific cognitive tasks including two measures of free recall, and two measures of visuospatial skill. The memory factor score was a strong predictor of the two free recall tasks and block design. The spatial factor score contributed to the prediction of the two visuospatial measures, as well as free recall of organizable words. The results suggest that, in normal ageing, the predictive value of the MMSE is due to subset of cognitively demanding items that are heavily influenced by both memory and visuospatial skills.     

Benton Visual Retention Test performance among normal and demented older adults.

Studied performance on the Benton Visual Retention Test Revised Edition both for memory and copy for 122 healthy older adults and 191 Ss (aged 51–96 yrs) with senile dementia of the Alzheimer type (DAT). Results suggest that, although deficits in visual memory are evident in the very mild stages of dementia, other visuoconstructional deficits do not appear until later stages of the disease. The summary scores were better indicators of dementia progression than were specific error types, although specific errors on the copy administration provided some insight into the nature of the visuospatial deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential effects of aging on directional and absolute errors in visuospatial memory.

Studied memory for visuospatial arrays in 28 male and 34 female healthy dextral adults (aged 20–90 yrs). 10 abstract figures were presented in each hemispace over a series of learning trials, and then delayed free recall of figure placement was obtained. Figures were misplaced significantly downward and leftward in both hemispaces. Both vertical and horizontal absolute error increased significanty with age, but no age effects on directional errors were observed. The increase in absolute error over age is consistent with decreased anterograde memory and visuospatial skills in the elderly. The directional errors are believed to result from an attentional shift toward proximal peripersonal space, in combination with attentional shifts from differential left vs right cerebral activation. Gender effects were also observed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological consequences of extreme weight loss and dietary restriction in patients with anorexia nervosa

This study examined the effects of weight loss and nutritional status on the cognitive performance of patients with anorexia nervosa. The intellectual, memory, attentional, verbal fluency and visuospatial abilities of 34 females with anorexia were compared to that of 31 normal weight-for-height females. Group differences in anxiety and depression were found but neither variable was related to the cognitive performance of patients with anorexia. Moreover, nutritional status and weight loss bore little relationship to the cognitive scores of the patient group. Overall, patients with anorexia were found to be deficient in their ability to recall meaningful prose and visuospatial information. The failure to find many cognitive deficits in this sample may reflect the fact that few patients with anorexia exhibited frank nutritional deficiencies.     

Neurophysiological indices of strategy development and skill acquisition

In order to examine neurophysiological changes associated with the development of cognitive and visuomotor strategies and skills, spectral features of the EEG were measured as participants learned to perform new tasks. In one experiment eight individuals practiced working memory tasks that required development of either spatial or verbal rehearsal and updating strategies. In a second experiment six individuals practiced a video game with a difficult visuomotor tracking component. The alpha rhythm, which is attenuated by functional cortical activation, was affected by task practice. In both experiments, a lower-frequency, centrally distributed alpha component increased between practice sessions in a task-independent fashion, reflecting an overall decrease in the extent of cortical activation after practice. A second, higher-frequency, posterior component of the alpha rhythm displayed task-specific practice effects. Practice in the verbal working memory task resulted in an increase of this signal over right posterior regions, an effect not seen after practice with the spatial working memory task or with the video game. This between-task difference presumably reflects a continued involvement of the posterior region of the right hemisphere in tasks that invoke visuospatial processes. This finding thus provides neurophysiological evidence for the formation of a task-specific neurocognitive strategy. In the second experiment a third component of the alpha rhythm, localized over somatomotor cortex, was enhanced in conjunction with acquisition of tracking skill. These alpha band results suggest that cortical regions not necessary for task performance become less active as skills develop. In both experiments the frontal midline (Fm) theta rhythm also displayed increases over the course of test sessions. This signal is associated with states of focused concentration, and its enhancement might reflect the conscious control over attention associated with maintenance of a task-appropriate mental set. Overall, the results suggest that the EEG can be used to monitor practice-related changes in the patterns of cortical activity that are associated with task processing. Additionally, these results highlight the importance of ensuring that subjects have developed stable strategies for performance before drawing inferences about the functional architecture underlying specific cognitive processes.     

Conditional discriminations based on external and internal cues in rats with cytotoxic hippocampal lesions.

Septal-hippocampal system lesions, mostly using aspiration techniques, have been reported to impair performance of conditional tasks. Rats with axon-sparing cytotoxic, hippocampal lesions were therefore tested in a range of instrumental conditional paradigms. They did not differ from controls in their ability to choose the appropriate object in a conditional object discrimination cued by internal state (hunger or thirst) or on performance of conditional visuospatial object discriminations. Acquisition of a conditional visuospatial discrimination with black and white boxes as stimuli was also unimpaired. In contrast, lesioned rats were profoundly impaired on an open T-maze task when cued by either their internal state (reference memory task) or their previous response (working memory task). The results indicate that perception or use of spatial cues, rather than conditional responding per se, is impaired by cytotoxic hippocampal lesions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oral contraceptives and androgenicity: Influences on visuospatial task performance in younger individuals.

The current study investigated whether the androgenic activity of oral contraceptives (OC) mediates performance on sexually dimorphic cognitive tasks in 155 younger individuals. Participants were categorized by hormonal contraceptive use (user vs. nonuser) and the androgenic activity of each OC (OC generation). OC generation was determined based on previous research in which users are grouped based on the type of progestin contained in each OC. Cognitive tasks included the mental rotation task (MRT) and a recognition memory task. In addition, we examined the correlates of both menstrual cycle phase and OC use, such as mood, premenstrual syndrome, depression, blood pressure, and body fat using standardized measures. The main result was that OC androgenicity influenced MRT performance. Second generation OCs are the most androgenic. Thus, MRT performance was best in these OC users as compared to third generation users, Yasmin users and nonusers. On the other hand, Yasmin, a newer generation of OC, contains an "antiandrogenic" progestin, dropirenone. Yasmin users not only performed more poorly on the MRT in comparison to second and third generation pill users, but they performed significantly worse than OC nonusers. Results show that the androgenic activity in OCs influences MRT performance in the presence of static estrogen levels. Overall, the resulting pattern is consistent with a broad range of results demonstrating that visuospatial performance may be enhanced in women who are exposed to androgenic treatments. Furthermore, visuospatial performance is hindered with the introduction of antiandrogenic preparations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cerebral blood flow velocity decreases during cognitive stimulation in Huntington's disease

OBJECTIVE: To examine whether activation of cerebral blood flow velocity during cognitive stimulation, as measured by transcranial Doppler ultrasonography (TCD), is altered in patients with Huntington's Disease (HD). BACKGROUND: Previous research suggests that resting cerebral blood flow in symptomatic and asymptomatic HD patients is reduced from expected premorbid levels. The effects of cognitive activation on this relative hypoperfusion in HD has not been studied extensively. METHODS: We measured TCD flow velocity during rest and cognitive testing with the Porteus Maze Test and the Trails Test in 12 normal control subjects and 10 gene-positive HD patients. Percent change (i.e., flow during testing/resting) of flow velocity in the anterior and middle cerebral arteries were compared between groups. Correlations among percent flow velocity change, a disability rating scale, and cognitive test scores were calculated. RESULTS: In control subjects, anterior cerebral artery flow velocity and middle cerebral artery velocity increased during cognitive testing (p=0.001). HD patients showed a smaller blood flow velocity increase in the anterior cerebral arteries during the Porteus Maze Test (p < 0.001) and the Trails Test, Part B (p < 0.001). In the left anterior cerebral artery, flow velocity fell an average of 4.2% below resting baseline levels during the Porteus Maze Test, and 1.2% below resting levels during the Trails Test. The magnitude of the cerebral blood flow velocity changes in the anterior cerebral artery correlated with a number of cognitive test scores and with a rating scale of functional disability. In addition, logistic regression was able to discriminate the HD patients from the control group based on blood flow velocity changes (p=0.0025). When HD patients were divided into more (i.e., HD with chorea; n=4) and less impaired (i.e., without chorea; n=6) groups, both showed significant decreases in left anterior cerebral artery flow velocity during visual spatial executive cognition testing compared with control subjects. CONCLUSIONS: These results suggest that activation of visual spatial executive functions cause decreased flow velocity in the anterior cerebral artery, but not the middle cerebral artery, in HD patients. These changes are related to test performance and functional capabilities.     

What one intelligence test measures: A theoretical account of the processing in the Raven Progressive Matrices Test.

The cognitive processes in a widely used, nonverbal test of analytic intelligence, the Progressive Matrices Test, are analyzed in terms of which processes distinguish between higher scoring and lower scoring subjects and which processes are common to all subjects and all items on the test. The analysis is based on detailed performance characteristics, such as verbal protocols, eye-fixation patterns, and errors. The theory is expressed as a pair of computer simulation models that perform like the median or best college students in the sample. The processing characteristic common to all subjects is an incremental, reiterative strategy for encoding and inducing the regularities in each problem. The processes that distinguish among individuals are primarily the ability to induce abstract relations and the ability to dynamically manage a large set of problem-solving goals in working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of clinical variables on neuropsychological performance in multiple sclerosis

The effects of age, educational level, duration and course of the disease, physical disability and mood status on several cognitive functions (short- and long-term memory, frontal functions, attention, language and visuospatial skills) have been evaluated in 42 multiple sclerosis (MS) patients. The Hamilton Depression Rating Scale (HDRS) scores and a secondary progressive disease course significantly influenced neuropsychological performance. Factorial analysis revealed that indexes of (1) frontal function impairment, (2) long-term verbal memory and language function impairment, and (3) visuospatial short- and long-term memory and visuoperceptive function impairment accounted for 85% of the variance in neuropsychological performance. Only the first factor was significantly related to the presence of depressive symptomatology, as assessed by the HDRS. These results indicate that both the course of the disease and the presence of affective disorders must be taken into account when evaluating the natural history of cognitive impairment in MS and suggest that depressive symptomatology and cognitive dysfunction in MS are related to the involvement of at least partially overlapping anatomofunctional circuits.     

Context processing in schizotypal personality disorder: Evidence of specificity of impairment to the schizophrenia spectrum.

Working memory abnormalities, which are particularly pronounced on context processing tasks, appear relatively specific to schizophrenia spectrum illnesses compared with other psychotic disorders. However, the specificity of context processing deficits to schizotypal personality disorder (SPD), a prototype of schizophrenia, has not been studied. The authors administered 3 versions of the modified AX Continuous Performance Test and an N-back working memory test to 63 individuals with SPD and 25 with other personality disorders, as well as 42 healthy controls. For the AX Continuous Performance Test standard and degraded versions, there was a significant Trial Type × Delay × Group interaction, as SPDs made significantly more errors reflecting poor maintenance of context and fewer errors reflecting good maintenance of context. SPDs also demonstrated poor performance on the N-back, especially at the 2-back condition. Context processing errors and N-back accuracy scores were related to disorganization symptoms. These findings, which are quite similar to those previously reported in patients with schizophrenia, suggest that context processing deficits are specific to the schizophrenia spectrum and are not a reflection of overall psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)