Differential impact of executive function on visual memory tasks

Despite their common use in neuropsychological evaluation, little is known about the differential contribution of executive functioning to visual memory tests. In this study, hierarchical regression was used to determine the role of executive functioning on the Visual Reproduction subtest of the Wechsler Memory Scale--Third Edition, and the Rey-Osterrieth Complex Figure (ROCF) in a mixed neurological sample of 193 patients. Executive functioning was predictive of Visual Reproduction but not ROCF recall variables after accounting for demographic variables and global cognitive functioning. Only executive tests with a visuospatial component, the Trail-Making Test Part B and Wisconsin Card Sorting Test perseverative responses, were predictive of recall of Visual Reproduction stimuli. Organization of the ROCF was predictive of both Visual Reproduction and ROCF recall. These findings increase our understanding of the executive contribution to two common visual memory tests and may aid in the clinical interpretation of seemingly discrepant visual memory performance.     

MRI extrahippocampal volumes and visual memory: correlations independent of MRI hippocampal volumes in temporal lobe epilepsy patients.

Limbic system atrophy and memory dysfunction are common in patients with temporal lobe epilepsy (TLE). However, the relationship between extrahippocampal limbic structures and memory functioning within TLE has received little attention. The present study examined associations of MRI volumetric measurements of the mammillary body, fornix, amygdala, and hippocampus to measures of episodic verbal and visual memory. The Logical Memory and Visual Reproduction subtests from the Wechsler Memory Scale were administered to 47 unilateral TLE patients (25 right, 22 left). Normalized right and left MRI volumes were determined for each patient by cursor tracing 1.5 mm slices from 3D-MRI. Significant associations were found between left hippocampal volume and the immediate, delayed, and percent retention scores of the Logical Memory Test; between the left mammillary body volume and the Logical Memory Test delayed and percent retention scores; immediate Visual Reproduction performance was significantly related to the right and left amygdala volumes, and right mammillary body volume; only the right amygdala and right mammillary body volume were associated with the delayed Visual Reproduction trial. However, neither right nor left hippocampal volumes were related to visual memory performance. Multiple limbic system structural volumes were independently associated with verbal and nonverbal memory performance. Results suggest that visual memory, as measured by the Visual Reproduction Test, may be uniquely associated with extrahippocampal volumes in patients with TLE.     

Validity of the Boston qualitative scoring system for the Rey-Osterrieth complex figure among depressed elderly patients

A recent qualitative scoring method for the Rey-Osterrieth Complex Figure (ROCF), the Boston Qualitative Scoring System (BQSS), purports to assess visuospatial organization, visual memory and executive function by using multiple series of scores with well-defined criteria. The first objective of this study was to determine whether the BQSS cores correlated with scores derived from the tradition Osterrieth scoring method and which method was more efficient at separating the diagnostics groups. The second objective was to correlate the BQSS executive scores to other nonverbal and verbal tests of executive function, working memory, processing speed, and episodic memory to determine what cognitive abilities the BQSS scores were measuring. The subjects, older depressed patients and healthy controls, were free of any clinical sign of incipient dementia or comorbid neurological disease. Their ROCF drawings were scored using both the Osterrieth and BQSS methods. The BQSS summary drawing scores correlated well with the Osterrieth summary scores for the copy and short-delay recall phases, the percent retained over the delay period and recognition. The BQSS executive scores for Planning, which included both copy and recall phases, correlated with Matrix Reasoning indicating that they assessed nonverbal reasoning but they did not correlate with other traditional executive tests. Planning also contributed to the separation of diagnostics groups and was the most effective score for predicting the percent of the ROCF retained over a short delay. The remaining executive scores did not show a pattern of correlations with other nonverbal executive or working memory scores that would satisfy concerns regarding their interpretation or internal validity when used in an older and/or depressed population. No differences emerged between the two scoring methods in their efficiency for predicting depression.     

The Rey-Osterrieth Complex Figure as a measure of executive function in childhood

In adults, the Rey–Osterrieth Complex Figure (ROCF) can be used for the assessment of not only visuoconstructional ability and visual memory, but also executive function in adults. We studied whether ROCF scores also correlated with executive function in childhood. The subjects consisted of 56 patients with various neurological diseases (5 years 7 months–14 years 11 months; mean: 8 years 8 months; M 42, F 14) whose full-scale IQs were 70 or higher (mean: 93.3). All subjects underwent the Wechsler Intelligence Scale for children third edition (WISC-III) and various psychological tests focusing on executive function. We evaluated the ROCF with the Boston Qualitative Scoring System (BQSS). We calculated the partial correlation coefficients between the BQSS Summary Scores and representative scores of other executive function tests, using age as the control variable. Among the scores of the various examinations, the Perseverative Errors of Nelson of the Wisconsin Card Sorting Test, the raw scores of the Mazes (WISC-III), the Digit Span (WISC-III), and the Block Design (WISC-III) were correlated significantly with two to four BQSS Summary Scores (P<0.05 or P<0.01). In contrast, the scores of the Trail Making Test, the Stroop Test, and the Commission Error of Continuous Performance Test-II did not show a significant correlation with any of the BQSS Summary Scores. The ROCF evaluated with the BQSS reflects not only visuoperceptual ability and visuoconstructional ability, but also executive function, especially planning and organization. However, a new BQSS Summary Score should be devised since no existing BQSS index specifically reflects executive functions with an outstandingly strong correlation.     

Episodic memory in schizophrenic patients and their relatives

BACKGROUND: Memory dysfunction among healthy relatives of patients with schizophrenia suggests that genetic liability to the disorder can also be manifested as cognitive impairment. This study was designed to further elucidate the nature of the memory dysfunction being transmitted. METHOD: Memory function was assessed in 62 schizophrenic patients, 98 of their healthy relatives and 66 controls. Material-specific immediate/delayed recall and percentage retention were investigated using the Logical Memory and Visual Reproduction tests of the Wechsler Memory Scale (WMS). A third subtest of the WMS, the Associate Learning and a visual analogue of it, the Abstract Paired Associates, were used to measure verbal and visual learning. Current general intellectual function was assessed using a five-subtest short-form of the Wechsler Adult Intelligence scale-Revised (WAIS-R). RESULTS: Schizophrenic patients performed significantly worse than controls on nearly all measures. Their relatives also showed significant deficit on the immediate and delayed recall of the Logical Memory, immediate recall of the Visual Reproduction, and the Abstract Paired Associates tests. Logical memory was substantially more impaired than the other measures for both patients and relatives. The deficit in immediate recall of the Logical Memory remained significant even after excluding those relatives with an Axis I diagnosis and schizotypal personality disorder. These findings were despite the relatives having an equivalent level of general intellectual function to that of controls. CONCLUSION: Familial, presumed genetic, liability to schizophrenia may be expressed as dysfunction in verbal memory.     

Organizational Strategy Use in Children Aged 5–7: Standardization and Validity of the Rey Complex Figure Organizational Strategy Score (RCF-OSS)

This study investigated psychometric properties (standardization and validity) of the Rey Complex Figure Organizational Strategy Score (RCF-OSS) in a sample of 217 healthy children aged 5–7 years. Our results showed that RCF-OSS performance changes significantly between 5 and 7 years of age. While most 5-year-olds used a local approach when copying the Rey-Osterrieth Complex Figure (ROCF), 7-year-olds increasingly adopted a global approach. RCF-OSS performance correlated significantly, but moderately with measures of ROCF accuracy, executive functioning (fluency, working memory, reasoning), and non-executive functioning (visual-motor integration, visual attention, processing speed, numeracy). These findings seem to indicate that RCF-OSS performance reflects a range of cognitive skills at 5 to 7 years of age, including aspects of executive and non-executive functioning.     

Executive dysfunction in patients with spinocerebellar ataxia type 3

The aim of this study was to assess the cognitive functions of patients with spinocerebellar ataxia type 3(SCA3). We examined 15 patients with genetically confirmed SCA3 and 15 healthy control subjects matched for age, years of education, and intellectual ability. We administered verbal memory (word recall and word recognition) and executive function tasks (word fluency test, forward and backward digit and visual span tests, Kana Pick-out Test, Trail Making Test, and conflicting instructions and a Go/NoGo task from the Frontal Assessment Battery). We found that patients with SCA3 had significantly lower scores than the healthy control subjects on the word recall, semantic, and letter fluency, and backward digit span tests, while word recognition was well preserved. The other executive function tests showed preserved functions in the SCA3 group, indicating that visual working memory, and attention and inhibition control were not affected. The patients with SCA3 showed impaired word recall and intact word recognition, and accordingly, episodic memory encoding and storage processes in short-term memory were preserved. In category and letter-fluency tests, impairment was attributable to word-retrieval from semantic memory. Impaired verbal working memory may be involved in the retrieval of verbal information from phonological storage by means of continuous subvocal rehearsal, rather than a deficit in initial phonological encoding. Essential executive dysfunction in patients with SCA3 may be due to damage in the cerebellar cortex–ventral dentate nucleus–thalamus–prefrontal cortex circuits, which are involved in strategic retrieval of verbal information from different modes of memory storage.     

Verbal and Visual Memory Impairments in Bipolar I and II Disorder

Objective

To compare verbal and visual memory performances between patients with bipolar I disorder (BD I) and patients with bipolar II disorder (BD II) and to determine whether memory deficits were mediated by impaired organizational strategies.

Methods

Performances on the Korean-California Verbal Learning Test (K-CVLT) and the Rey-Osterrieth Complex Figure Test (ROCF) in 37 patients with BD I, 46 patients with BD II and 42 healthy subjects were compared. Mediating effects of impaired organization strategies on poor delayed recall was tested by comparing direct and mediated models using multiple regression analysis.

Results

Both patients groups recalled fewer words and figure components and showed lower Semantic Clustering compared to controls. Verbal memory impairment was partly mediated by difficulties in Semantic Clustering in both subtypes, whereas the mediating effect of Organization deficit on the visual memory impairment was present only in BD I. In all mediated models, group differences in delayed recall remained significant.

Conclusion

Our findings suggest that memory impairment may be one of the fundamental cognitive deficits in bipolar disorders and that executive dysfunctions can exert an additional influence on memory impairments.     

The prospective memory of patients with idiopathic REM sleep behavior disorder

BackgroundIdiopathic rapid eye movement sleep behavior disorder (iRBD) likely represents the prodromal stage of synucleinopathy. The present study was to investigate if there was prospective memory (PM) impairment and the relationship between different PM tasks and traditional cognitive tests in patients with iRBD.MethodsA total of 28 patients with iRBD, 25 with Parkinson's disease (PD) and 21 healthy controls were included. The Cambridge Prospective Memory Test (CAMPROMPT) was used to measure the PM including time-based (TBPM) and event-based PM (EBPM). Standard cognitive tests were administered to all participants.ResultsEBPM scores were lower only in patients with iRBD, while the obvious PM abnormalities were found in patients with PD. The patients with iRBD and PD performed worse on delayed recall of the Rey Auditory Verbal Learning Test (RAVLT) and copy of the Rey–Osterrieth complex figure (ROCF). The EBPM correlated with attention, executive function, and immediate memory besides working memory in patients with iRBD. The PM tasks involved in more memory functions in PD patients.ConclusionsThe patients with iRBD were impaired on both episodic memory and EBPM tasks that correlated with attention, executive function, and immediate memory. The PM abnormality was an early cognitive change in iRBD to which more attention should be paid more attention.     

The Boston Qualitative Scoring System as a measure of executive functioning in Rey-Osterrieth Complex Figure performance

The Boston Qualitative Scoring System (BQSS) for the Rey-Osterrieth Complex Figure (ROCF) includes five scores (Planning, Fragmentation, Neatness, Perseveration, and Organization) developed to measure the executive aspects of ROCF productions. To assess the convergent and discriminant validity of the BQSS, these five scores were compared to scores on four traditional tests of executive functioning, as well as to three non-executive measures, in 141 adult patients. BQSS executive variables significantly correlated with the traditional executive measures and were less correlated with discriminant measures. The BQSS Organization summary score also significantly differentiated patients with either no, mild, or severe executive dysfunction. These results support the construct validity of the BQSS and demonstrate that the ROCF may be a useful measure of executive functioning.     

The Boston Qualitative Scoring System as a Measure of Executive Functioning in Rey-Osterrieth Complex Figure Performance

The Boston Qualitative Scoring System (BQSS) for the Rey-Osterrieth Complex Figure (ROCF) includes five scores (Planning, Fragmentation, Neatness, Perseveration, and Organization) developed to measure the executive aspects of ROCF productions. To assess the convergent and discriminant validity of the BQSS, these five scores were compared to scores on four traditional tests of executive functioning, as well as to three non-executive measures, in 141 adult patients. BQSS executive variables significantly correlated with the traditional executive measures and were less correlated with discriminant measures. The BQSS Organization summary score also significantly differentiated patients with either no, mild, or severe executive dysfunction. These results support the construct validity of the BQSS and demonstrate that the ROCF may be a useful measure of executive functioning.     

Attention and executive control predict Alzheimer disease in late life: results from the Berlin Aging Study (BASE).

OBJECTIVE: Longitudinal studies of neuropsychological changes in the preclinical phase of Alzheimer disease (AD) have yielded mixed results. Although some studies report tests of episodic memory, others report tests of attention and executive functions as reliable predictors of subsequent AD. Following theoretical models of neuropsychological processes before AD onset, the authors examined the predictive value of attention and executive function in the preclinical phase of AD in old age. METHODS: Authors studied the cognitive performance of 187 initially normal participants of the Berlin Aging Study, a community-based representative sample of Berlin citizens age 70 to 103, over a period of 4 years. Tests of attention and executive function (Digit Letter Test, Trailmaking Part B Test, Digit Symbol Substitution Test, and Identical Pictures Test) and of learning and recall functions (Activity Recall, Memory for Text, and Paired-Associate Learning) were administered at baseline. Diagnosis of AD was made according to NINCDS-ADRDA criteria (probable AD). Receiver operating characteristics curve analyses and Cox regression analyses were used to assess the diagnostic accuracy and predictive value of the neuropsychological tests at baseline for incident AD after 4 years. RESULTS: After 4 years, 15 participants had developed AD. Tests of attention and executive function discriminated best between nonconverters and incident AD cases. A similar pattern was found in survival analyses; attention and executive function tests, together with tests of learning and recall, significantly predicted incident AD over and above age, gender, and education. CONCLUSION: These results support theoretical models of attention and executive function in the preclinical phase of AD in old age.     

Effect of organizational strategy on visual memory in patients with schizophrenia

Aims:  The aim of the present study was to examine how copy organization mediated immediate recall among patients with schizophrenia using the Rey–Osterrieth Complex Figure Test (ROCF).
Methods:  The Boston Qualitative Scoring System (BQSS) was applied for qualitative and quantitative analyses of ROCF performances. Subjects included 20 patients with schizophrenia and 20 age- and gender-matched healthy controls.
Results:  During the copy condition, the schizophrenia group and the control group differed in fragmentation; during the immediate recall condition, the two groups differed in configural presence and planning; and during the delayed recall condition, they differed in several qualitative measurements, including configural presence, cluster presence/placement, detail presence/placement, fragmentation, planning, and neatness. The two groups also differed in several quantitative measurements, including immediate presence and accuracy, immediate retention, delayed retention, and organization. Although organizational strategies used during the copy condition mediated the difference between the two groups during the immediate recall condition, group also had a significant direct effect on immediate recall.
Conclusion:  Schizophrenia patients are deficient in visual memory, and a piecemeal approach to the figure and organizational deficit seem to be related to the visual memory deficit. But schizophrenia patients also appeared to have some memory problems, including retention and/or retrieval deficits.     

The role of perceptual bias in complex figure recall

Several studies have demonstrated that constructional and organizational abilities affect how well visual stimuli are remembered. The purpose of the present study was to determine whether perceptual bias, independent of constructional ability, influenced visual memory performance. Participants were 118 normal adults who were administered the Rey-Osterrieth Complex Figure (ROCF) and a similarity judgement task requiring then to decide which of two hierarchically constructed comparison figures most resemble a standard figure. The initial steps of a multiple regression analysis indicated that delayed recall of the ROCF was directly related to copy accuracy, inversely related to age, and better in males than females. In the final step of the regression model, performance on the similarity judgement task also predicted ROCF recall, with a more global perceptual bias predicting better recall. Results indicate that even when copy accuracy and demographic variables are accounted for, components of visual perception influence how well visual stimuli are encoded and recalled. Findings are consistent with research correlating global processing and spatial ability, and suggest that in addition to copy ability and organization, visuoperceptual bias must be considered as a moderator variable when interpreting performance as a visual memory test.     

Declarative memory and WCST-64 performance in subjects with schizophrenia and healthy controls

The Wisconsin Card Sorting Test (WCST) is a set-switching task used extensively to study impaired executive functioning in schizophrenia. Declarative memory deficits have also been associated with schizophrenia and may affect WCST performance because continued correct responding depends on remembering the outcome of previous responses. This study examined whether performance in visual and verbal declarative memory tasks were associated with WCST performance. Subjects comprised 30 patients with schizophrenia or schizoaffective disorder (SCZ) and 30 demographically matched healthy controls (CON) who were tested on the WCST, the Benton Visual Retention Test (BVRT), the California Verbal Learning Test (CVLT), and the Continuous Performance Test (CPT). SCZ subjects showed significant correlations between visual and verbal declarative memory and performance on the WCST-64 that were in the hypothesized direction such that worse memory performance was associated with worse performance on the WCST. CON subjects did not show a significant relationship between visual or verbal memory and WCST-64 performance. Fisher's r to z transformations indicated that the associations between declarative memory and WCST-64 performance in the SCZ subjects differed significantly from those of CON subjects. The findings suggest that interpretations of WCST-64 scores for subjects with schizophrenia should be considered in light of their declarative memory functioning.     

Self-Ordered Pointing Performance Following Severe Closed-Head Injury

This study investigated executive aspects of working memory in a severe closed-head injured (CHI) population. Thirty-four severe CHI participants (&gt;1 year postinjury) and 34 controls completed an design version of Petrides and Milner’s (1982) self-ordered pointing task. CHI participants made more errors than controls on the 16-item trial, but not the 9-item trial. Both CHI and control participants were able to make use of strategic processing to improve SOPT performance. As anticipated, errors on the SOPT were associated with another measure of working memory (i.e., Reading Span Test) for the control group. In contrast, for the CHI participants, errors on the SOPT were associated with a measure of delayed visual memory (i.e., Wechsler Memory Scale – Revised Visual Reproduction II subtest). Our findings suggest that, as a group, the primary factor resulting in poorer SOPT performance by the CHI group was a memory deficit and not the ability to utilize executive aspects of working memory.     

Self-ordered pointing performance following severe closed-head injury

This study investigated executive aspects of working memory in a severe closed-head injured (CHI) population. Thirty-four severe CHI participants (>1 year postinjury) and 34 controls completed an abstract design version of Petrides and Milner's (1982) self-ordered pointing task. CHI participants made more errors than controls on the 16-item trial, but not the 9-item trial. Both CHI and control participants were able to make use of strategic processing to improve SOPT performance. As anticipated, errors on the SOPT were associated with another measure of working memory (i.e., Reading Span Test) for the control group. In contrast, for the CHI participants, errors on the SOPT were associated with a measure of delayed visual memory (i.e., Wechsler Memory Scale-Revised Visual Reproduction II subtest). Our findings suggest that, as a group, the primary factor resulting in poorer SOPT performance by the CHI group was a memory deficit and not the ability to utilize executive aspects of working memory.     

Relationship of affect recognition with psychopathology and cognitive performance in schizophrenia.

The purpose of the present study was to explore the relationship between emotion perception and both psychopathology and cognitive functioning in a group of Greek patients with schizophrenia. Thirty-five patients with schizophrenia were assessed with computerized tests of emotion perception, using visual faces (Kinney's Affect Matching Test, KAMT), prosody (Affective Prosody Test, APT), and visual everyday scenarios (Fantie's Cartoon Test, FCT), as well as a facial recognition test (Kinney's Identity Matching Test, KIMT). The patients were also evaluated with the symptoms dimensions derived from the PANSS (positive, negative, cognitive, depression, and excitement) and a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and visual scanning/psychomotor speed. The three emotion perception and face recognition tests correlated significantly with each other. The KAMT was significantly related to the cognitive symptoms dimension of the PANSS and executive functions. The FCT was significantly related to level of education and attention. Finally, the APT was significantly related to the cognitive symptoms dimension, executive functions, and attention. Our findings regarding the significant relationships of affect perception, both facial and vocal, as well as in everyday scenarios, with several cognitive abilities support the notion that deficits in decoding affective information in schizophrenia could be attributed to impairment in more basic neurocognitive domains.     

The effect of encoding condition on free recall in Parkinson's disease: incidental and intentional memory are equally affected

Free recall memory deficits are common at early stages of Parkinson's disease (PD). As most studies have used intentional memory tasks, there is little information on how non-intentional, incidental encoding conditions affect memory performance in PD. We studied possible differences between PD patients and controls on free recall using incidental and intentional visual memory tasks. Free recall was examined in relation to attentive/executive functioning and subjective memory complaints. A total of 29 non-demented, medicated PD patients (age 60, disease duration 19 months) and 29 healthy controls (age 61) participated in the study. Incidental free recall was studied using a memory-modification of the Boston naming test (Memo-BNT) and intentional free recall with the 20 Objects test. There was a significant main effect for group due to worse free recall performances in the PD group. No statistically significant interaction between group and encoding condition was observed. The free recall deficit in the PD group was related to cognitive/psychomotor slowing, but not to attentive/executive task demands, or to subjective memory complaints. The results indicate that PD patients are impaired on free recall irrespective of encoding condition.     

Utility of behavioral versus cognitive measures in differentiating between subtypes of frontotemporal lobar degeneration and Alzheimer's disease

We hypothesized that a modified version of the Frontal Behavioral Inventory (FBI-mod), along with a few cognitive tests, would be clinically useful in distinguishing between clinically defined Alzheimer's disease (AD) and subtypes of frontotemporal lobar degeneration (FTLD): frontotemporal dementia (dysexecutive type), progressive nonfluent aphasia, and semantic dementia. We studied 80 patients who were diagnosed with AD (n = 30) or FTLD (n = 50), on the basis of a comprehensive neuropsychological battery, imaging, neurological examination, and history. We found significant between-group differences on the FBI-mod, two subtests of the Rey Auditory Verbal Learning Test (verbal learning and delayed recall), and the Trail Making Test Part B (one measure of 'executive functioning'). AD was characterized by relatively severe impairment in verbal learning, delayed recall, and executive functioning, with relatively normal scores on the FBI-mod. Frontotemporal dementia was characterized by relatively severe impairment on the FBI-mod and executive functioning in the absence of severe impairment in verbal learning and recall. Progressive nonfluent aphasia was characterized by severe impairment in executive functioning with relatively normal scores on verbal learning and recall and FBI-mod. Finally, semantic dementia was characterized by relatively severe deficits in delayed recall, but relatively normal performance on new learning, executive functioning, and on FBI-mod. Discriminant function analysis confirmed that the FBI-mod, in conjunction with the Rey Auditory Verbal Learning Test, and the Trail Making Test Part B categorized the majority of patients as subtypes of FTLD or AD in the same way as a full neuropsychological battery, neurological examination, complete history, and imaging. These tests may be useful for efficient clinical diagnosis, although progressive nonfluent aphasia and semantic dementia are likely to be best distinguished by language tests not included in standard neuropsychological test batteries.