Backward Span Research Articles

Development of executive functioning in school-age Tunisian children

Research regarding executive functioning (EF) in children rarely focuses on populations in African or Middle-Eastern Arabic-speaking countries. The current study used a cross-sectional design to examine the developmental trajectories of school-age Tunisian children in three domains of executive control (inhibition of prepotent responses, cognitive flexibility, and working memory) as well as their mutual interactions and the effects of gender and parents’ education level. Inhibitory processes, cognitive flexibility, and working memory were assessed using the Stroop test, a version of the Hayling test adapted for children, simple and alternating tasks of verbal fluency, and verbal and visuospatial span tasks (forward and backward spans). The study population included 120 7- to 12-year-old Tunisian children (60 girls, 60 boys) who were grouped and matched for age, gender, and parents’ education level. The results revealed an overall effect of age on executive performance, whereas gender and parents’ education level showed non-significant effects. In addition, executive indices were significantly associated with fluid intelligence level. Partial correlation analyses (controlled for age) found significant links between indices that assessed the same executive process, except for inhibitory processes; the temporal indices for inhibitory processes showed relative independence. The correlations between indices that assessed distinct executive processes were weaker (but significant). Overall, the results suggest that executive components in school-age Tunisian children operate according to relatively homogeneous developmental trajectories, marked by peaks of maturity that differ according to the assessed index. A transcultural approach to EF is discussed in terms of the unity and diversity of its components.

Working memory impairment in probands with schizoaffective disorder and first degree relatives of schizophrenia probands extend beyond deficits predicted by generalized neuropsychological impairment

ObjectiveWorking memory impairment is well established in psychotic disorders. However, the relative magnitude, diagnostic specificity, familiality pattern, and degree of independence from generalized cognitive deficits across psychotic disorders remain unclear. MethodParticipants from the Bipolar and Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study included probands with schizophrenia (N=289), psychotic bipolar disorder (N=227), schizoaffective disorder (N=165), their first-degree relatives (N=315, N=259, N=193, respectively), and healthy controls (N=289). All were administered the WMS-III Spatial Span working memory test and the Brief Assessment of Cognition in Schizophrenia (BACS) battery. ResultsAll proband groups displayed significant deficits for both forward and backward span compared to controls. However, after covarying for generalized cognitive impairments (BACS composite), all proband groups showed a 74% or greater effect size reduction with only schizoaffective probands showing residual backward span deficits compared to controls. Significant familiality was seen in schizophrenia and bipolar pedigrees. In relatives, both forward and backward span deficits were again attenuated after covarying BACS scores and residual backward span deficits were seen in relatives of schizophrenia patients. ConclusionsOverall, both probands and relatives showed a similar pattern of robust working memory deficits that were largely attenuated when controlling for generalized cognitive deficits.

Impairments of Working Memory in Schizophrenia and Bipolar Disorder: the Effect of History of Psychotic Symptoms and Different Aspects of Cognitive Task Demands

Introduction comparisons of cognitive impairments between schizophrenia (SZ) and bipolar disorder (BPD) have produced mixed results. Objectives this is the only study to assess different aspects of WM with respect to psychosis dimension in these patient populations. Aim to determine whether these groups of patients can be classified on the basis of WM performance. Methods we applied different working memory (WM) measures (Digit Span Forward and Backward, Short-delay and Long-delay CPT-AX, N-back) to patients with SZ(n=23),psychotic BPD(n=19) and non-psychotic BPD(n=24), as well as to healthy controls (HC) (n=18) in order to compare the level of WM impairments across the groups. Results with respect to the less demanding WM measures (Digit Span Forward and Backward, Short-delay CPT-AX), there were no between group differences in cognitive performance; however, with respect to the more demanding WM measures (Long-delay CPT-AX, N-back), we observed that the groups with psychosis (SZ, psychotic BPD) did not differ from one another, but performed poorer than the group without a history of psychosis (non-psychotic BPD). A history of psychotic symptoms may influence cognitive performance with respect to WM delay and load effects as measured by Long-delay CPT-AX and N-back tests, respectively. We observed a positive correlation of WM performance with antipsychotic treatment and a negative correlation with depressive symptoms in BPD and with negative symptoms in SZ subgroup. Conclusions our study suggests that WM dysfunctions are more closely related to a history of psychosis than to the diagnostic categories of SZ and BPD described by psychiatric classification systems.

Immediate effect of listening to Indian raga on attention and concentration in healthy college students: A comparative study

Background: Many studies with western music have shown enhancement in the cognitive performance task. The factors influencing the performance are a selection of dependent measures, choice of the piece of music, presentation order of the conditions. Research has shown that the specific choice of musical composition may help in the improvement of the particular cognitive task. Objectives: We chose to study the impact of Indian Raga on a memory task. Methods: In twenty-six volunteers both male and female (group average age ± S.D., 18.84±3.53 years) the immediate effect of two musical conditions and No music condition was studied on memory. All participants were assessed before and after (i) Indian Raga Bhupali(R) for 10 minutes on day one; (ii) an equal duration of Pop music (P); and (iii) an equal duration of Silence or no music (S) on next two different days respectively. A Section of the Wechsler memory scale (WMS) was used to assess; (i) attention and concentration (digit span forward and backward) before and immediately after the intervention. Results: There was a significant improvement in digit forward (P<0.05, increase of 3.17%) and backward span score after (p<0.05, an increase of 5.26%) immediately after the exposure to Indian Raga Bhupali. Conclusions: The combination of notes in Indian Raga Bhupali is said to instill Shringara rasa or the aesthetic mood of Love. The improvement is significant compared to the Pop music that is much preferred by the college students and Silence or No music conditions. It was concluded that Memory scores improved immediately after listening to Indian Raga Bhupali.

NC-01 * ATTENTIONAL AND LANGUAGE FUNCTIONING IN ADULT PATIENTS WITH GLIOMA: A VOXEL-BASED LESION-SYMPTOM MAPPING STUDY

OBJECTIVE: We statistically examined the relationship between lesion presence and neurocognitive performance on tasks of attention and language on a voxel-by-voxel basis in adult brain tumor patients using voxel-based lesion-symptom mapping (VLSM). VLSM is an innovative technique that has primarily been used in studies of stroke patients. METHODS: 98 right-handed adult patients with glioma were administered a neuropsychological battery comprised of 10 tasks: Digit Span Forward & Backward from the Wechsler Adult Intelligence Scale, Verbal Fluency (FAS, Animals), Woodcock-Johnson III Word Attack, and subtests of the Boston Diagnostic Aphasia Examination: Boston Naming Test, Complex Ideational Material, Commands, Responsive Naming, and Reading Sentences & Paragraphs. T2-weighted images were registered to a T1-weighted MNI atlas and the tumor region was contoured using a semi-automated thresholding technique. For a voxel, a general linear model was run to determine the relationship between cognitive performance and lesion presence, with medical and demographic characteristics specified as covariates. This analysis was repeated for each voxel with each subtest. Suprathreshold cluster-based analysis was used to correct for multiple comparisons. RESULTS: VLSM analysis identified several clusters of voxels with a significant relationship (p < .05) between lesion presence and neurocognitive performance on tasks of attention and language, and these significant clusters were depicted on high resolution statistical maps (1 mm3). Three composite maps were then generated, identifying the key anatomic structures involved in the attention/working memory cognitive domain (primarily frontal regions including dorsolateral prefrontal cortex), the expressive language cognitive domain (primarily lateral temporal regions), and the receptive language cognitive domain (primarily lateral and mesial temporal regions along with auditory cortex). CONCLUSION: These findings identify some of the key anatomic structures involved in attentional and language functioning in adult patients with glioma using an innovative lesion analysis technique.

Older adults with amnestic mild cognitive impairment exhibit exacerbated gait slowing under dual-task challenges.

With age, performance of motor tasks becomes more reliant on cognitive resources to compensate for the structural and functional declines in the motor control regions in the brain. We hypothesized that participants with amnestic mild cognitive impairment (aMCI) are more prone to motor dysfunctions than cognitively normal older adults under dual-task conditions where competitive demands challenge cognitive functions while performing a motor task simultaneously. Sixteen aMCI participants (females=9, age=64±5yrs, clinical dementia rating score=0.5) and 10 age- and education-matched cognitively normal adults (females=5, age=62±6yrs) participated. Using a 10-meter-walk test (10MW), gait velocity was recorded at baseline and under 4 different dual-task (DT) conditions designed to challenge working memory, executive function, and episodic memory. Specifically, DT1: verbal fluency; DT2: 5-digit backward span; DT3: serial-7 subtraction; and DT4: 3-item delayed recall. Physical function was measured by Timed Up-and-Go (TUG), simple reaction time (RT) to a free-falling yardstick, and functional reach (FR). No difference was found in physical functions, aerobic fitness, and exercise cardiopulmonary responses between aMCI participants and controls. However, aMCI participants showed more pronounced gait slowing from baseline when compared to the controls (p<0.05; p=0.001; p<0.001; p<0.001, respectively). Our finding supports the theory of shared resource of motor and cognitive control. Participants with aMCI manifested more gait slowing than cognitively-normal older adults under DT conditions, with the largest differences during tests of working and episodic memory. The outcome of dual-task assessment shows promise as a potential marker for detection of aMCI and early Alzheimer disease.

What is not working in working memory of children with literacy disorders? Evidence from a three-year-longitudinal study

The goals of this study were to explore the deficits in working memory associated with literacy disorders (i.e. developmental disorders of reading and/or spelling) and the developmental trajectories of these working memory deficits. The performance of 28 children with literacy disorders was compared to a non-disabled control group with the same group size at five bi-annual times of measurement in a three-year-longitudinal study beginning at the end of primary school (9.5 years of age). Storage capacity and central-executive working memory were assessed in phonological and visual-spatial modalities, the latter under static and dynamic conditions. Overall, children with literacy disorders were outperformed by their typical developing peers in all phonological and in dynamic visual-spatial storage and central-executive tasks except for the static visual-spatial storage task. Results at single times of measurement revealed that the most consistent deficit was found in the storage capacity of the phonological loop. An additional central-executive impairment is supported by low backward spans. The causes for output deficits in dynamic visual-spatial tasks and good performance under static visual-spatial condition are discussed.

Working memory capacity: the need for process task-analysis

Working memory capacity: the need for process task-analysis

Forward and backward span for verbal and visuo-spatial data: standardization and normative data from an Italian adult population

The Digit span and Corsi span tasks are frequently used to assess verbal and visuo-spatial short-term memory. Forward versions of these tasks, in which sequences of items of increasing length have to be reproduced in the order they were presented, are believed to primarily evaluate the functioning of the working memory material-specific slave systems (i.e. the phonological loop and the visuo-spatial sketchpad for verbal and visuo-spatial data, respectively). The backward versions of both tasks, in which sequences of items have to be reproduced in the reverse order, are believed to primarily tax Central Executive resources. Here, we report normative data on the forward and backward versions of the Digit span and Corsi span tasks that was collected from 362 healthy Italians ranging in age from 20 to 90 years. The results show a decremental effect of age on performance in all tasks and an ameliorative effect of education in all tasks except the Corsi span backwards. We provide correction grids for age and literacy that derive from results of the regression analyses.

Musicians' Working Memory for Tones, Words, and Pseudowords

Studies investigating factors that influence tone recognition generally use recognition tests, whereas the majority of the studies on verbal material use self-generated responses in the form of serial recall tests. In the present study we intended to investigate whether tonal and verbal materials share the same cognitive mechanisms, by presenting an experimental instrument that evaluates short-term and working memories for tones, using self-generated sung responses that may be compared to verbal tests. This paradigm was designed according to the same structure of the forward and backward digit span tests, but using digits, pseudowords, and tones as stimuli. The profile of amateur singers and professional singers in these tests was compared in forward and backward digit, pseudoword, tone, and contour spans. In addition, an absolute pitch experimental group was included, in order to observe the possible use of verbal labels in tone memorization tasks. In general, we observed that musical schooling has a slight positive influence on the recall of tones, as opposed to verbal material, which is not influenced by musical schooling. Furthermore, the ability to reproduce melodic contours (up and down patterns) is generally higher than the ability to reproduce exact tone sequences. However, backward spans were lower than forward spans for all stimuli (digits, pseudowords, tones, contour). Curiously, backward spans were disproportionately lower for tones than for verbal material-that is, the requirement to recall sequences in backward rather than forward order seems to differentially affect tonal stimuli. This difference does not vary according to musical expertise.

Abstract 3837: Vascular Risk Profiles and Cognitive Impairment in a 20-year Follow-up of Three Ethnic Groups: the Southall and Brent REvisited (SABRE) Cohort

Introduction: There is substantial ethnic variation in vascular risk profiles and their outcomes. For example, stroke risk is raised by 50-100% in Black and South Asian compared to White UK residents but is more strongly associated with diabetes than hypertension in the former two groups. Associations with cognitive outcomes have not been previously compared. Hypothesis: Mid-life hypertension and diabetes will be more strongly associated with later life cognitive impairment in Black and South Asian compared to White residents. Methods: SABRE is a UK community based tri-ethnic (White, Black and South Asian) cohort of male and female London residents aged 40-69 years at baseline (1988-1990), and 58-86 years at follow up (2008-2011). Hypertension at baseline (resting blood pressure &gt;140/90 or antihypertensive treatment) and diabetes at either exam were investigated in relation to cognitive impairment at follow-up. Cognitive impairment was ascertained as the lowest 10% of averaged z-scores calculated separately within the 3 ethnic groups for 9 tests: immediate and delayed word list recall, digit span forwards and backwards, verbal fluency, Color Trailmaking Tests A and B, delayed visual recall and the Community Screening Instrument for Dementia. Age, gender and years of education were entered as covariates. Results: Prospective data were analysed on 570 White, 432 South Asian and 185 Black residents. Baseline hypertension prevalences in these three groups were 14.8%, 27.1% and 37.2% respectively and diabetes prevalences were 19.5%, 43.4% and 41.3% respectively. Hypertension (p=0.005) and diabetes (p=0.029) were associated with follow-up cognitive impairment after full adjustment. On stratifying by ethnic group, no significant associations were found in White participants, hypertension was only associated with cognitive impairment in South Asians and diabetes only in Black participants. Hypertension and diabetes in combination were associated with cognitive impairment to a similar extent in both South Asian and Black participants, but not in Europeans. Conclusion: Vascular risk factors vary in their impact on cognitive impairment between ethnic groups which may reflect underlying differences in risk profiles and modification of their impact on end-organ damage. Multi-ethnic cohorts present a valuable opportunity for investigating more heterogeneous risk profiles and better clarifying mechanisms underlying the impact of individual risk factors.

Abstract 3021: Areas of Chronic Infarct Associated with Impaired Verbal Working Memory

Background: Functional imaging studies consistently show activation of Broca's area (Brodmann's area 44 and 45) in verbal working memory (VWM) tasks such as backward digit span, indicating that this area is an important node in the network underlying VWM. We have recently shown acute infarcts in Brodmann’s area (BA) 45 are associated with impaired VWM. However, there is surprising little evidence that chronic lesions of Broca's cause deficits in VWM, although there are case reports and small series of patients with both with normal and impaired VWM. Other areas of the brain might assume this function during recovery. We tested the hypothesis that chronic infarcts in BA 44 and 45 are associated with reduced backward digit span. Methods: Patients had tests of backward digit span and MRI at least 6 months after first left supratentorial ischemic stroke. Technicians blinded to digit span results analyzed FLAIR sequences for infarct in BA 4, 6, 10, 11, 19, 20, 21, 22, 37, 38, 39, 40, 44, 45, anterior and posterior insula. Associations between between VWM and ROIs were identified using Fisher's exact tests for dichotomous data. Differences in mean span length between those with and without lesions in each area were identified with t-tests. Additionally, using linear regression analysis (adjusted for age and education level), we determined which areas, when infarcted, predicted backward span length. Results: 79 patients (mean age 57.2 years; mean education 13.6 years) were included. Reduced VWM (defined as backward digit span &lt;3) was associated with infarct in BA 44 (p=0.002) and BA 45 (p=0.001). Patients with infarct in Broca’s area had significantly shorter backward digit spans than those without (BA 44: 1.3 vs 4.2; p=.003; BA 45: 1.0 vs 4.15; p= 0.006). Using linear regression, infarct in BA 44 was associated with, on average, 2.5 fewer digits on digit span backwards compared to cases without BA 44 infarct (adjusted beta=-2.5; 95% CI -3.4, -1.7), BA 45 (beta=-2.8, 95% CI -3.6, -2.0). BA 39 (adjusted beta=-1.8, 95% CI -2.9, -0.7) or BA 40 (adjusted beta=-2.1, 95% CI -3.0, -1.1) also predicted digit span backwards. Conclusion: Left BA 44, 45 (Broca’s area) and 39 and 40 (inferior parietal lobule) are crucial brain regions for recovery of VWM.

P-357 - Assessing working memory in two arabic cultures: Evidence from confirmatory factor analysis

Introduction To date, few studies have examined the extent to which the performances of Working Memory (WM) tasks vary with cultural and demographic variations. Objective The present study compared the performance between Kuwaiti and Egyptian children at grade 4 using a WM battery comprising six tasks, which measures both verbal and visuospatial WM. Method The Arabic Automated WM Battery (Alloway, 2007) was administered to a 384 primary school children: 192 Kuwaitis (96 males and 96 females) and 192 Egyptians (96 males and 96 females). Results The WM construct has the same factorial structure across the Kuwaiti and Egyptian cultures. Moreover, a significant difference between groups on 5 out of 6 WM tests, but no significant gender differences in (listening recall, counting recall, backward digit recall, Mr. X and spatial span), Furthermore, the backward digit recall task varied as a function of gender across cultures. Conclusion The factor structure of the Automated WM battery was validated across the two Arab cultures. Although this study was conducted in two collectivistic cultures, it refers to the impact of the sociocultural context on both verbal and visuospatial WM performance. However, the effects of size were low, which reflects a limited impact. This finding is useful for depicting cognitive profiles of these collectivistic cultures. Future research in this area should expand our investigations to a number of collectivistic Arab cultures and extend the comparison to include analytic culture.

No Association of Angiotensin I Converting Enzyme I/D Polymorphism with Domain-Specific Cognitive Function in Aged Men without Dementia

Previous research studies have related the insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme (ACE) gene to cognitive function in various neuropsychiatric or neurodegenerative disorders, but not yet investigated its genetic association with specific cognitive domains. Thus, the aim of this study was to assess the possible association of the ACE I/D polymorphism with domain-specific cognitive function in normal cognitive aging. Four hundred and sixty-nine-aged ethnic Chinese men without dementia were enrolled for genotyping and evaluated using several neuropsychological tests [Mini-Mental Status Examination (MMSE), Digit Span Forward and Backward, and Cognitive Ability Screening Instrument Chinese language version (CASI C-2.0)]. No direct association was found between ACE genotypes and the MMSE, Digit Span tests, or CASI total scores. Although subjects with I/I genotype had the lowest cognitive performance in the CASI visual construction domain (P=0.031), this statistical difference disappeared after correction for multiple comparisons. This study suggests that the ACE I/D polymorphism does not have any genetic association with global or specific cognitive domain in aged men without dementia.

Effects of driving fatigue on working memory

Objective To investigate effects of driving fatigue on working memory. Methods The control group included 12 taxi drivers after adequate rest while the fatigue group included 27 taxi drivers who had been driving for 10h. Digit memory span, words span, Digit Subtraction Test, Random Number Generation test were used. Results Compared with the control(6.60 ±0.40,90.67 ±6.65,158.27 ±29.12,0.30 ±0.06,24.29 ±10.59,35.90 ± 10.64 ), driving fatigue group were significantly( P ＜ 0.05 )different in the number of backward number memory span( 5.37 ± 0.72 ), percentage of number of right reaction of the number of total reaction of Digit Subtraction Test(79.95 ± 8.04), total number of RNG( 88.33 ± 19.48 ), RNG(0.40 ± 0.05 ), Coupon( 12.35 ±12.88), NSQ(49.72 ± 8.06). Conclusion Driving fatigue can decline the working memory. Key words: Driving fatigue; Working memory; Memory span; Random number generation

Orbitofrontal contributions to human working memory.

Although cognitive neuroscience has made remarkable progress in understanding the involvement of the prefrontal cortex in human memory, the necessity of the orbitofrontal cortex for key competencies of working memory remains largely unexplored. We therefore studied human brain lesion patients to determine whether the orbitofrontal cortex is necessary for working memory function, administering subtests of the Wechsler memory scale, the Wechsler adult intelligence scale, and the n-back task to 3 participant groups: orbitofrontal lesions (n = 24), prefrontal lesions not involving orbitofrontal cortex (n = 40), and no brain lesions (n = 54). Orbitofrontal damage was reliably associated with deficits on neuropsychological tests involving the coordination of working memory maintenance, manipulation, and monitoring processes (n-back task) but not on pure tests of working memory maintenance (digit/spatial span forward) or manipulation (digit/spatial span backward and letter-number sequencing). Our findings elucidate a central component of the neural architecture of working memory, providing key neuropsychological evidence for the necessity of the orbitofrontal cortex in executive control functions underlying the joint maintenance, manipulation, and monitoring of information in working memory.

Improving digit span assessment of short-term verbal memory

We measured digit span (DS) in two experiments that used computerized presentation of randomized auditory digits with performance-adapted list length adjustment. A new mean span (MS) metric of DS was developed that showed reduced variance, improved test–retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures. The MS metric also enhanced the sensitivity of forward versus backward span comparisons, enabled the development of normative performance criteria with subdigit precision, and elucidated changes in DS performance with age and education level. Computerized stimulus delivery and improved scoring metrics significantly enhance the precision of DS assessments of short-term verbal memory.

Processes contributing to forward and backward span: an ERP investigation

Reversal of the order in which items are recalled reduces verbal span more than visuospatial span. We investigated behavioral performance and event-related potential components elicited during novel recognition span tasks with verbal (digits) and visuospatial (blocks) stimuli. Reversing item order reduced behavioral span and the amplitudes of the P3a and P3b event-related potential components in the verbal but not in the visuospatial tasks. P3a is thought to reflect detection of deviance from expectation, and hence the smaller P3a suggests expectancy of the stimulus sequence is attenuated in the digits backward task. P3b is thought to reflect allocation of attention to updating memory representations, hence the smaller P3b suggests attenuation of these attentional resources when the demanding operation of verbal order reversal is required in the digits backward span task.

Gender-related Differences in Visuospatial Memory Persist in Alzheimer's Disease

Gender differences in visuospatial cognition favoring men are larger in tasks requiring active information manipulation than in tasks requiring passive storage. This study was designed to determine whether male advantage in active manipulation of visuospatial information can still be evidenced in Alzheimer's disease (AD). Twenty male and 20 female AD patients with equivalent age, education, dementia severity (Mini-Mental State Examination and Mattis Dementia Rating Scale), and visual discrimination abilities were recruited. We administered the forward span of Corsi block-tapping task and Vecchi's matrix memory task involving passive temporary retention of stimuli location. Active manipulation of visuospatial information was assessed with the backward span of Corsi block-tapping task and Vecchi's pathway task in which patients were required to mentally generate a pathway within a matrix. The results showed that scores on the tasks involving passive storage of visuospatial information were equivalent between the two groups of patients, whereas men performed significantly better than women in tasks requiring active manipulation of visuospatial information. This result was limited to visuospatial processing since no difference between male and female patients was evidenced in the verbal short-term memory tasks, neither when the task involved passive storage nor when the task required active processing. Therefore, this study suggests that, besides other variables such as education or lifestyle factors, gender might also modulate the cognitive manifestation of AD.

The effects of incentives on visual-spatial working memory in children with attention-deficit/hyperactivity disorder.

Working memory is one of several putative core neurocognitive processes in attention-deficit/hyperactivity disorder (ADHD). The present work seeks to determine whether visual-spatial working memory is sensitive to motivational incentives, a laboratory analogue of behavioral treatment. Participants were 21 children (ages 7-10) with a diagnosis of ADHD-combined type. Participants completed a computerized spatial span task designed to assess storage of visual-spatial information (forward span) and manipulation of the stored information (backward span). The spatial span task was completed twice on the same day, once with a performance-based incentive (trial-wise feedback and points redeemable for prizes) and once without incentives. Participants performed significantly better on the backward span when rewarded for correct responses, compared to the no incentive condition. However, incentives had no effect on performance during the forward span. These findings may suggest the use of motivational incentives improved manipulation, but not storage, of visual-spatial information among children with ADHD. Possible explanations for the differential incentive effects are discussed, including the possibility that incentives prevented a vigilance decrement as task difficulty and time on task increased.