The impact of Parkinson's disease on sequence learning: perceptual pattern learning and executive function

The current study examined the contribution of brain areas affected by Parkinson's disease (PD) to sequence learning, with a specific focus on response-related processes, spatial attentional control, and executive functioning. Patients with mild PD, patients with moderate PD, and healthy age-matched participants performed three tasks-a sequence learning task with a spatial pattern that was incidental to response selection, a spatial cuing task, and neuropsychological tests of executive function. Whereas moderate PD patients failed to show significant sequence learning, mild PD patients performed comparably with controls. Neither group of PD patients was impaired in the control of spatial attention. Sequence learning was correlated with neuropsychological measures of executive function but not with the ability to control spatial attention. These results suggest that the contribution of the brain areas affected by PD to sequence learning extends beyond motor learning to include the learning of perceptual patterns and involves executive function, including cognitive flexibility and set shifting.     

Executive Function and the Frontal Lobes: A Meta-Analytic Review

Currently, there is debate among scholars regarding how to operationalize and measure executive functions. These functions generally are referred to as “supervisory” cognitive processes because they involve higher level organization and execution of complex thoughts and behavior. Although conceptualizations vary regarding what mental processes actually constitute the “executive function” construct, there has been a historical linkage of these “higher-level” processes with the frontal lobes. In fact, many investigators have used the term “frontal functions” synonymously with “executive functions” despite evidence that contradicts this synonymous usage. The current review provides a critical analysis of lesion and neuroimaging studies using three popular executive function measures (Wisconsin Card Sorting Test, Phonemic Verbal Fluency, and Stroop Color Word Interference Test) in order to examine the validity of the executive function construct in terms of its relation to activation and damage to the frontal lobes. Empirical lesion data are examined via meta-analysis procedures along with formula derivatives. Results reveal mixed evidence that does not support a one-to-one relationship between executive functions and frontal lobe activity. The paper concludes with a discussion of the implications of construing the validity of these neuropsychological tests in anatomical, rather than cognitive and behavioral, terms.     

An “alternating instructions” version of the Autobiographical Memory Test for assessing autobiographical memory specificity in non-clinical populations

There is limited research regarding how executive processes contribute to key cognitive deficits in depression, particularly impoverished retrieval of autobiographical memory. This study tested a novel version of the Autobiographical Memory Test (AMT), the “Alternating Instructions” AMT (AMT-AI), to determine how participants could flexibly retrieve specific and categoric autobiographical memories. The AMT-AI consisted of a standard AMT (AMT-S), a categoric version of the AMT (AMT-R), and a section of alternating instructions (AI) in which the rules required the participant to alternate between retrieval of categoric and specific memories. A total of 49 university students completed the AMT-AI, and self-report measures of depressive symptomatology and ruminative thinking. Results showed that the mean proportion of specific memories recalled on the AMT-AI was significantly lower than on the AMT-S. Also, reduced memory specificity on the AMT-AI, but not the AMT-S, was significantly negatively correlated with increased scores on measures of depressive symptomatology and ruminative thinking. Collectively the data suggested that the AMT-AI, relative to the traditional AMT, may be more sensitive to memory specificity in non-clinical populations. Future research is warranted to further determine the psychometric properties and utility of the AMT-AI.     

The Early Neuropsychological and Behavioral Characteristics of Frontotemporal Dementia

Frontotemporal lobar degeneration (FTLD) represent a constellation of disorders that may be overlooked or misdiagnosed, despite being fairly common presenile neurodegenerative diseases. Although the cognitive disorder can be difficult to document, particularly early in the dementia course, neuropsychological evaluation can assist in the diagnosis. Neuropsychologists are in an excellent position to draw from related disciplines like personality theory and social psychology to better assess the types of changes that characterize the prodromal and early phases of the disease. This review summarizes the current state of the field in the diagnosis of FTLD and discusses the emerging role of neuropsychology in elucidating the brain organization of complex processes including empathy, behavioral control and inhibition, reward systems, appetitive behaviors, emotional regulation, and goal-orientation. As this review underscores, frontotemporal dementia remains a powerful model for studying brain–behavior relationships.     

Neuropsychological functioning in kleptomania

Kleptomania is characterized by the failure to resist impulses to steal objects not needed for personal use or their monetary value. The objective of this study was to examine cognitive and executive functioning in subjects with kleptomania. Fifteen women with a primary DSM-IV diagnosis of kleptomania underwent a detailed psychiatric examination, including measures of kleptomania severity, and a battery of neuropsychological tests that emphasized executive functions. Correlational analyses were computed between measures of kleptomania severity and tests of executive functioning. Kleptomania subjects reported a mean duration of illness of 17.9 years and shoplifting a mean of 1.7 times per week. All subjects reported an inability to resist urges to shoplift. Neuropsychological testing revealed group mean test scores within 0.5 standard deviations of normative standards for age. Five subjects (33.3%), however, had below-average performance on at least one measure of executive functioning, and 4 (26.7%) had below-average scores on two executive measures. Correlational analyses revealed a statistically significant correlation between kleptomania severity and Wisconsin Card Sorting Test performance (r=-0.693, p=0.004). As a group, subjects with kleptomania did not demonstrate deficits on neuropsychological testing. Greater kleptomania symptom severity, however, was correlated with impairment in executive functioning.     

Parent rating of executive function in fetal alcohol spectrum disorder: A review of the literature and new data on Aboriginal Canadian children

Aboriginal children in Canada are at high risk of fetal alcohol spectrum disorder (FASD) but there is little research on the cognitive impact of prenatal alcohol exposure (PAE) in this population. This paper reviews the literature on parent report of executive functioning in children with FASD that used the Behavior Rating Inventory of Executive Function (BRIEF). New data on the BRIEF is then reported in a sample of 52 Aboriginal Canadian children with FASD for whom a primary caregiver completed the BRIEF. The children also completed a battery of neuropsychological tests. The results reveal mean scores in the impaired range for all three BRIEF index scores and seven of the eight scales, with the greatest difficulties found on the Working Memory, Inhibit and Shift scales. The majority of the children were reported as impaired on the index scores and scales, with Working Memory being most commonly impaired scale. On the performance-based tests, Trails B and Letter Fluency are most often reported as impaired, though the prevalence of impairment is greater for parent ratings than test performance. No gender difference is noted for the parent report, but the boys had slightly slower intellectual functioning and were more perseverative than the girls on testing. The presence of psychiatric comorbidity is unrelated to either BRIEF or test scores. These findings are generally consistent with prior studies indicating that parents observe considerable executive dysfunction in children with FASD, and that children with FASD may have more difficulty with executive functions in everyday life than is detected by laboratory-based tests alone.     

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.     

The relationship between bilingualism and selective attention in young adults: Evidence from an ambiguous figures task

Previous research has shown that bilinguals outperform monolinguals on a variety of tasks that have been described as involving executive functioning, but the precise mechanism for those effects or a clear definition for “executive function” is unknown. This uncertainty has led to a number of studies for which no performance difference between monolingual and bilingual adults has been detected. One approach to clarifying these issues comes from research with children showing that bilinguals were more able than their monolingual peers to perceive both interpretations of an ambiguous figure, an ability that is more tied to a conception of selective attention than to specific components of executive function. The present study extends this notion to adults by assessing their ability to see the alternative image in an ambiguous figure. Bilinguals performed this task more efficiently than monolinguals by requiring fewer cues to identify the second image. This finding has implications for the role of selective attention in performance differences between monolinguals and bilinguals.     

Neurodevelopmental Disorders Across the Lifespan: A Neuroconstructivist Approach.

Objectives. To investigate neuropsychological and neurobehavioral outcome in children with arterial ischemic stroke (AIS).

Background. Childhood stroke can have consequences on motor, cognitive, and behavioral development. We present a cross-sectional study of neuropsychological and neurobehavioral outcome at least one year poststroke in a uniquely homogeneous sample of children who had experienced AIS.

Method. Forty-nine children with AIS aged 6 to 18 years were recruited from a specialist clinic. Neuropsychological measures of intelligence, reading comprehension, attention, and executive function were administered. A triangulation of data collection included questionnaires completed by the children, their parents, and teachers, rating behavior, executive functions, and emotions.

Key Findings. Focal neuropsychological vulnerabilities in attention (response inhibition and dual attention) and executive function were found, beyond general intellectual functioning, irrespective of hemispheric side of stroke. Difficulties with emotional and behavioral regulation were also found. Consistent with an “early plasticity” hypothesis, earlier age of stroke was associated with better performance on measures of executive function.

Conclusions. A significant proportion of children poststroke are at long-term risk of difficulties with emotional regulation, executive function, and attention. Data also suggest that executive functions are represented in widespread networks in the developing brain and are vulnerable to unilateral injury.     

The contribution of “cool” and “hot” components of decision-making in adolescence: Implications for developmental psychopathology

Impairments in either “cool” or “hot” processes may represent two pathways to deficient decision-making. Whereas cool processes are associated with cognitive and rational decisions, hot processes are associated with emotional, affective, and visceral processes. In this study, 168 boys were administered a card-playing task at ages 13 and 14 years to assess response perseveration. This task was designed to initially reward playing and gradually associate playing with punishment. Measures of subjective ordering (cool processes) and neuroticism (hot processes) at age 13 years were used to examine how these individual characteristics relate to perseveration over time. A decrease in perseveration from age 13 to 14 was associated with cool processes whereas hot processes were associated with response perseveration only over time. A complementary but simultaneous assessment of cool and hot processes, such as neuropsychological and personality tests, could facilitate treatment planning of children with behavioral problems.     

Visuospatial Short-Term Memory Explains Deficits in Tower Task Planning in High-Functioning Children with Autism Spectrum Disorder

Previous findings on planning abilities in individuals with high-functioning autism spectrum disorder (HFA) are inconsistent. Exploring possible reasons for these mixed findings, the current study investigated the involvement of memory in planning performance in 15 children with HFA and 17 typically developing controls. In addition to planning abilities (measured with the Tower of London), short-term memory and delayed recall for verbal as well as visuospatial material were assessed. Findings suggest that particularly reduced efficiency in visuospatial short-term memory is associated with Tower task planning deficits in children with HFA.     

How divergent are children’s divergent movements? The role of cognition and expertise in a class-randomized cross-over trial

This study aimed at investigating (1) the cognitive and motor predictors of divergent movement ability (DMA) in childhood and (2) the role of sport and enriched physical education (PE) experience. Participants were 165 fifth graders, aged 10–11 years, with different histories (onset and duration) of participation in enriched PE. They were assessed in cognitive/attentional and motor/sport skills and active play/sport habits at baseline, and six months later in DMA. Results of regression analyses showed an overall prediction of DMA by sport practice and a nuanced prediction of individual DMA indices (fluency, flexibility, originality) by decision making and spatial attention ability. Linear mixed models revealed better DMA in children exposed to enriched PE, with differential effects on DMA indices depending on its duration and earlier/later onset. The results identify novel cognitive determinants of children’s DMA and suggest that sport practice and experience of designed enrichment in PE may benefit DMA.     

Assessment of children's receptive vocabulary using event-related brain potentials: Development of a clinically valid test

The combined verbal and motor impairments characteristic of children with disorders such as Cerebral Palsy (CP) frequently compromise the accuracy of standard psychometric assessments. What is needed is a test to measure language that does not require verbal or motor responses. This study was designed to determine whether single-word receptive vocabulary could be assessed in young children without CP, using an ERP-compatible test based on Form M of the Peabody Picture Vocabulary Test-Revised (PPVT-R). Fifteen 10-year-old children with normal levels of psychometric intelligence participated. Ninety pictures were selected from the PPVT-R (Form M), representing three levels of single-word receptive vocabulary (Preschool, Child-Adolescent, Adult). Each picture was presented twice (pseudo-random), once paired with a spoken word that was semantically congruent with the picture and once paired with a semantically incongruent word. The children's N400 was significantly larger to incongruent than to congruent pairs, but only when the vocabulary was within their repertoire. The results are discussed in terms of electrophysiologic correlates of acquired language and the clinical use of this ERP test as an adjunct to assessing patients with moderate to severe communication and/or motor impairments (e.g., cerebral palsy, autism, head injury).