Thursday, June 20, 2013


Web of Knowledge Table of Contents Alert
Attention-Deficit/Hyperactivity Disorder (ADHD) and Working Memory in Adults: A Meta-Analytic Review

Alderson, RM; Kasper, LJ; Hudec, KL; Patros, CHG

*NEUROPSYCHOLOGY*, 27 (3):287-302; MAY 2013

Objective: Within the last decade, working memory (WM) has garnered
increased interest as a potential core deficit or endophenotype of
attention-deficit/hyperactivity disorder (ADHD). The current study is
the first meta-analytic review to examine several subject and task
moderator variables' (e. g., percent female, diagnostic selection
procedure, trials per set size, response demands, type of dependent
variable, and central executive [CE] demands) effect on between-group
phonological (PH) and visuospatial (VS) WM in adults with ADHD, relative
to healthy controls. Method: Literature searches were conducted using
the PsycINFO, Web of Science, and PubMed databases, and yielded 38
studies of WM in adults with ADHD. Results: Results revealed
moderate-magnitude between-group effect sizes (ESs) across both WM
domains. In addition, several task-moderating variables explained
significant ES variability among PH and VS studies. Conclusions:
Collectively, these findings indicate that WM deficits persist into
adulthood and suggest that methodological variability may explicate why
WM deficits have not been uniformly detected in previous experimental


*Pages: 303-313 (Article)
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Working Memory in Parkinson's Disease: The Effects of Depression and Side of Onset of Motor Symptoms

Foster, PS; Yung, RC; Drago, V; Crucian, GP; Heilman, KM

*NEUROPSYCHOLOGY*, 27 (3):303-313; MAY 2013

Objective: Previous research has examined the neurocognitive effects of
depression in Parkinson's disease (PD), finding worse performance on
tests of cognitive functioning in PD patients with depression as
compared to those without depression. However, this research has not
considered the effect of side of onset of motor symptoms. Hence, we
sought to investigate the interaction between depression and side of
onset on working memory in patients with PD. Method: A total of 66
patients with PD completed the Digit Span Backward subtest of the
Wechsler Memory Scale-III as well as two other tests of executive
functioning. Groups of left hemibody onset (LHO) with and without
depression and right hemibody onset (RHO) with and without depression
were created. Results: The results indicated significantly lower
performance on the measure of working memory for the LHO with depression
group, relative to both the LHO without depression and the RHO with
depression groups. Conclusion: These findings indicate that working
memory is worse in patients with LHO of motor symptoms who are also
depressed, and they suggest that this group of patients might experience
greater disability and lower quality of life.


*Pages: 314-321 (Article)
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Implicit Perceptual-Motor Skill Learning in Mild Cognitive Impairment and Parkinson's Disease

Gobel, EW; Blomeke, K; Zadikoff, C; Simuni, T; Weintraub, S; Reber, PJ

*NEUROPSYCHOLOGY*, 27 (3):314-321; MAY 2013

Objective: Implicit skill learning is hypothesized to depend on
nondeclarative memory that operates independent of the medial temporal
lobe (MTL) memory system and instead depends on cortico striatal
circuits between the basal ganglia and cortical areas supporting motor
function and planning. Research with the Serial Reaction Time (SRT) task
suggests that patients with memory disorders due to MTL damage exhibit
normal implicit sequence learning. However, reports of intact learning
rely on observations of no group differences, leading to speculation as
to whether implicit sequence learning is fully intact in these patients.
Patients with Parkinson's disease (PD) often exhibit impaired sequence
learning, but this impairment is not universally observed. Method:
Implicit perceptual-motor sequence learning was examined using the
Serial Interception Sequence Learning (SISL) task in patients with
amnestic Mild Cognitive Impairment (MCI; n = 11) and patients with PD (n
= 15). Sequence learning in SISL is resistant to explicit learning and
individually adapted task difficulty controls for baseline performance
differences. Results: Patients with MCI exhibited robust sequence
learning, equivalent to healthy older adults (n = 20), supporting the
hypothesis that the MTL does not contribute to learning in this task. In
contrast, the majority of patients with PD exhibited no
sequence-specific learning in spite of matched overall task performance.
Two patients with PD exhibited performance indicative of an explicit
compensatory strategy suggesting that impaired implicit learning may
lead to greater reliance on explicit memory in some individuals.
Conclusion: The differences in learning between patient groups provides
strong evidence in favor of implicit sequence learning depending solely
on intact basal ganglia function with no contribution from the MTL
memory system.


*Pages: 322-332 (Article)
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Cognitive Consequences of High A beta Amyloid in Mild Cognitive Impairment and Healthy Older Adults: Implications for Early Detection of Alzheimer's Disease

Lim, YY; Ellis, KA; Harrington, K; Kamer, A; Pietrzak, RH; Bush, AI;
Darby, D; Martins, RN; Masters, CL; Rowe, CC; Savage, G; Szoeke, C;
Villemagne, VL; Ames, D; Maruff, P

*NEUROPSYCHOLOGY*, 27 (3):322-332; MAY 2013

`Background: It has been proposed that only mild cognitive impairment
(MCI) with high A beta amyloid is indicative of incipient Alzheimer's
disease (AD), yet MCI with low A beta amyloid may reflect other
neurode-generative processes. We aimed to determine the extent to which
high A beta amyloid influenced cognitive function in healthy older
adults and adults with MCI. Method: Healthy controls ( HC; n = 178) and
adults with MCI ( n = 56) enrolled in the Australian Imaging,
Biomarkers, and Lifestyle study, underwent positron emission tomography
neuroimaging for A beta amyloid and completed an extensive
neuropsychological battery, assessing the cognitive domains of verbal
and visual episodic memory, executive function, visuoconstruction,
attention and processing speed, and language at baseline. Results: MCI
with low A beta performed worse than MCI with high A beta on measures of
executive function, attention, visuoconstruction and language. No
differences were observed between HC high and low A beta groups. When
compared with HC with low A beta, both MCI high and low A beta groups
performed worse on measures of episodic memory. However, only the MCI
low A beta group performed worse than HC low A beta on measures of
executive function, attention, visuoconstruction, and language.
Conclusions: When compared with HC with low A beta amyloid, MCI with
high A beta amyloid present with impairments restricted to episodic
memory, and the episodic memory impairments in MCI with low A beta
amyloid were accompanied by impairments in executive function,
attention, visuoconstruction, and language, suggesting that MCI with
high A beta amyloid reflects prodromal AD, although further longitudinal
data is required to confirm this.


*Pages: 333-342 (Article)
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Recognition of Famous Names Predicts Cognitive Decline in Healthy Elders

Seidenberg, M; Kay, CD; Woodard, JL; Nielson, KA; Smith, JC; Kandah, C;
Breting, LMG; Novitski, J; Lancaster, M; Matthews, M; Hantke, N; Butts,
A; Rao, SM

*NEUROPSYCHOLOGY*, 27 (3):333-342; MAY 2013

Objective: The ability to recognize familiar people is impaired in both
Mild Cognitive Impairment (MCI) and Alzheimer's Dementia (AD). In
addition, both groups often demonstrate a time-limited temporal gradient
(TG) in which well known people from decades earlier are better recalled
than those learned recently. In this study, we examined the TG in
cognitively intact elders for remote famous names (1950-1965) compared
to more recent famous names (1995-2005). We hypothesized that the TG
pattern on a famous name recognition task (FNRT) would predict future
cognitive decline, and also show a significant correlation with
hippocampal volume. Method: Seventy-eight healthy elders (ages 65-90)
with age-appropriate cognitive functioning at baseline were administered
a FNRT. Follow-up testing 18 months later produced two groups: Declining
(>= 1 SD reduction on at least one of three measures) and Stable (< 1
SD). Results: The Declining group (N = 27) recognized fewer recent
famous names than the Stable group (N = 51), although recognition for
remote names was comparable. Baseline MRI volumes for both the left and
right hippocampi were significantly smaller in the Declining group than
the Stable group. Smaller baseline hippocampal volume was also
significantly correlated with poorer performance for recent, but not
remote famous names. Logistic regression analyses indicated that
baseline TG performance was a significant predictor of group status
(Declining vs. Stable) independent of chronological age and APOE epsilon
4 inheritance. Conclusions: The TG for famous name recognition may serve
as an early preclinical cognitive marker of cognitive decline in healthy
older individuals.


*Pages: 343-355 (Article)
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Which Neuropsychological Tests Predict Progression to Alzheimer's Disease in Hispanics?

Weissberger, GH; Salmon, DP; Bondi, MW; Gollan, TH

*NEUROPSYCHOLOGY*, 27 (3):343-355; MAY 2013

Objective: To investigate which neuropsychological tests predict
eventual progression to Alzheimer's disease (AD) in both Hispanic and
non-Hispanic individuals. Although our approach was exploratory, we
predicted that tests that underestimate cognitive ability in healthy
aging Hispanics might not be sensitive to future cognitive decline in
this cultural group. Method: We compared first-year data of 22 older
adults (11 Hispanic) who were diagnosed as cognitively normal but
eventually developed AD (decliners), to 60 age-and education-matched
controls (27 Hispanic) who remained cognitively normal. To identify
tests that may be culturally biased in our sample, we compared Hispanic
with non-Hispanic controls on all tests and asked which tests were
sensitive to future decline in each cultural group. Results: Compared to
age-, education-, and gender-matched non-Hispanic controls, Hispanic
controls obtained lower scores on tests of language, executive function,
and some measures of global cognition. Consistent with our predictions,
some tests identified non-Hispanic, but not Hispanic, decliners
(vocabulary, semantic fluency). Contrary to our predictions, a number of
tests on which Hispanics obtained lower scores than non-Hispanics
nevertheless predicted eventual progression to AD in both cultural
groups (e. g., Boston Naming Test [BNT], Trails A and B). Conclusions:
Cross-cultural variation in test sensitivity to decline may reflect
greater resistance of medium difficulty items to decline and bilingual
advantages that initially protect Hispanics against some aspects of
cognitive decline commonly observed in non-Hispanics with preclinical
AD. These findings highlight a need for further consideration of
cross-cultural differences in neuropsychological test performance and
development of culturally unbiased measures.


*Pages: 356-363 (Article)
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Association of Serum Dehydroepiandrosterone Sulfate and Cognition in Older Adults: Sex Steroid, Inflammatory, and Metabolic Mechanisms

Hildreth, KL; Gozansky, WS; Jankowski, CM; Grigsby, J; Wolfe, P; Kohrt,

*NEUROPSYCHOLOGY*, 27 (3):356-363; MAY 2013

Objective: Dehydroepiandrosterone sulfate (DHEAS) levels and cognitive
function decline with age, and a role for DHEAS in supporting cognition
has been proposed. Higher DHEAS levels may be associated with better
cognitive performance, although potential mechanisms for this
relationship are not well established. Method: We performed a
cross-sectional study of the relationship between serum DHEAS and three
aspects of cognition-executive function, working memory, and processing
speed-in 49 men and 54 women, aged 60-88 years, with low serum DHEAS
levels. We examined three potential mechanisms of DHEAS action-sex
hormone sufficiency, inflammatory status, and glucose regulation.
Results: After adjustment for multiple covariates, higher serum DHEAS
levels were associated with better working memory (standardized beta
coefficient 0.50, p < .05), with a trend toward better executive
function (standardized beta coefficient 0.37, p < .10) in men only.
There was a nonsignificant trend toward a negative association between
levels of tumor necrosis factor alpha (TNF alpha) and working memory in
the combined population (standardized beta coefficient -0.22, p < .10).
None of the glucoregulatory measures was associated with cognitive
function. Conclusions: The relationship between DHEAS and cognition is
complex and differs by sex and cognitive domain. This study supports the
need for further investigations of the sex-specific effects of DHEAS on
cognition and its underlying mechanisms of action.


*Pages: 364-377 (Article)
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Relation of Neural Structure to Persistently Low Academic Achievement: A Longitudinal Study of Children With Differing Birth Weights

Clark, CAC; Fang, H; Espy, KA; Filipek, PA; Juranek, J; Bangert, B;
Hack, M; Taylor, HG

*NEUROPSYCHOLOGY*, 27 (3):364-377; MAY 2013

Objective: This study examined the relation of cerebral tissue
reductions associated with VLBW to patterns of growth in core academic
domains. Method: Children born < 750 g, 750 to 1,499 g, or > 2,500 g
completed measures of calculation, mathematical problem solving, and
word decoding at time points spanning middle childhood and adolescence.
K. A. Espy, H. Fang, D. Charak, N. M. Minich, and H. G. Taylor (2009,
Growth mixture modeling of academic achievement in children of varying
birth weight risk, Neuropsychology, Vol. 23, pp. 460 -474) used growth
mixture modeling to identify two growth trajectories (clusters) for each
academic domain: an average achievement trajectory and a persistently
low trajectory. In this study, 97 of the same participants underwent
magnetic resonance imaging (MRI) in late adolescence, and cerebral
tissue volumes were used to predict the probability of low growth
cluster membership for each domain. Results: Adjusting for whole brain
volume (wbv), each 1-cm3 reduction in caudate volume was associated with
a 1.7-to 2.1-fold increase in the odds of low cluster membership for
each domain. Each 1-mm(2) decrease in corpus callosum surface area
increased these odds approximately 1.02-fold. Reduced cerebellar white
matter volume was associated specifically with low calculation and
decoding growth, and reduced cerebral white matter volume was associated
with low calculation growth. Findings were similar when analyses were
confined to the VLBW groups. Conclusions: Reduced volume of structures
involved in connectivity, executive attention, and motor control may
contribute to heterogeneous academic trajectories among children with


*Pages: 378-389 (Article)
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Does Executive Control Really Play a Crucial Role in Explaining Age-Related Cognitive and Neural Differences?

Cona, G; Arcara, G; Amodio, P; Schiff, S; Bisiacchi, PS

*NEUROPSYCHOLOGY*, 27 (3):378-389; MAY 2013

Objective: The present study investigated the role of executive control
in accounting for the cognitive and electrophysiological alterations
occurring in healthy aging. Method: Younger and older adults performed
the inhibitory control task (ICT), a task composed of 3 types of trials
that vary in the degree and kind of executive control subprocesses
required. We analyzed event-related potentials (ERPs) elicited by these
ICT trials and focused on the ERP components related to executive
control subprocesses: P3b (updating), no-go P3 (inhibition), and
reorienting negativity (RON; shifting). Results: Compared with younger
adults, older adults exhibited worse performance on the ICT and a delay
in the latency of all the ERPs investigated. These age-related
differences occurred regardless of the amount of executive control
required because they were not influenced by the type of trial. The RON
amplitude, an index of shifting, was found markedly attenuated in older
adults relative to younger adults. Conclusions: Executive control, as a
unitary function, cannot explain the age-related differences observed,
which are more likely to reflect a general slowing of processes with
aging. However, when we take into account the specific subprocesses of
executive control, the one that seems to be particularly affected by
aging is shifting, as revealed by the age-related alterations in the RON

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