Neuropsychology

Subthalamic nucleus stimulation affects fear and sadness recognition in Parkinson’s disease.
Bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson’s disease (PD) can produce emotional disorders that have been linked to disturbance of the STN’s limbic territory. The aim of this study was to confirm the impairment of the recognition of facial emotions (RFE) induced by STN DBS, not only ruling out the effect of the disease’s natural progression in relation to the effect of DBS, but also assessing the influence of modifications in dopamine replacement therapy (DRT) following STN DBS. RFE was investigated in 24 PD patients who underwent STN DBS and 20 PD patients treated with apomorphine. They were assessed 3 months before and after treatment. The 2 patient groups were compared with a group of 30 healthy matched controls. The results showed that RFE for negative emotions (fear and sadness) was impaired in only the STN DBS group in the posttreatment condition and was unrelated to DRT. Results confirm the selective reduction of RFE induced by STN DBS, due neither to the disease’s natural progression nor to modifications in DRT. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Association between depression severity and neurocognitive function in major depressive disorder: A review and synthesis.
The effects of major depressive disorder (MDD) on neurocognitive function remain poorly understood. Results from published studies vary widely in terms of methodological factors, and very little is known about the effects of depression severity and other clinical characteristics on neurocognitive function. The purpose of this review was to synthesize prior research findings regarding neurocognitive functioning in patients with MDD and varying levels of depression severity and to provide recommendations for future directions. Overall, this review suggests that MDD has been inconsistently associated with neurocognitive functioning and there is limited understanding regarding the relationship between depression severity and neurocognitive sequelae. There was much heterogeneity on depression severity-related factors across studies assessing neurocognitive function in MDD, as well as substantial variability in the consideration of depression severity among studies, which suggests a need to further explore this important issue. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Visual impairments in dementia with Lewy bodies and posterior cortical atrophy.
Dementia with Lewy bodies (DLB) and Posterior Cortical Atrophy (PCA), the visual variant of Alzheimer’s disease, are neurodegenerative diseases that present with progressive deterioration in visual perception. However, little is known about the precise nature underlying the complex visual deficits associated with both conditions. The present study compared DLB, PCA, and healthy control participants, in four visual tasks designed to measure the efficiency of the visual system at different levels of processing. In ascending order of complexity there were tasks of visual acuity, line orientation, contour integration, and rotated object comparison. DLB patients did not differ from controls in low level visual functions of visual acuity and line orientation, suggesting that early visual processing areas including V1 were relatively preserved, consistent with pathology evidence (Yamamoto et al., 2006). However, higher level visual functions of contour integration, mediated by extrastriatal areas, and the most complex task of object rotation, relying on processing within inferior temporal (IT), parietal, and frontal cortices, were impaired in DLB. In contrast, PCA patients were impaired in all tasks, consistent with evidence of widespread pathology within occipital and parietal areas in PCA. The latter suggests that both lower and higher level visual impairments contribute to the complex visual symptoms associated with PCA. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
The utility of placing recollection in opposition to familiarity in early discrimination of healthy aging and very mild dementia of the Alzheimer’s type.
This study explored the ability to control familiarity-based information in a memory exclusion paradigm in healthy young, older adults, and early stage DAT individuals. We compared the predictive power of memory exclusion performance to standard psychometric performance in discriminating between aging and the earliest stage of DAT and between APOe4-present and APOe4-absent genotype in healthy control individuals. Participants responded “yes” to words that were previously semantically encoded, and “no” to words that were previously read aloud and to new words. The number of targets and distractors on the read “distractor” list was manipulated to investigate the degree to which aging and DAT influence the ability to recollect in the face of distractor familiarity due to repetition. Memory exclusion performance was better for healthy older adults than very mild DAT individuals and better for healthy control individuals with APOe4 allele than those without APOe4 allele even after controlling for standard psychometric performance. Discussion focuses on the importance of attentional control systems in memory retrieval and the utility of the opposition paradigm for discriminating healthy versus pathological aging. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
A cross-sectional study of hormone treatment and hippocampal volume in postmenopausal women: Evidence for a limited window of opportunity.
The influence of hormone treatment on brain and cognition in postmenopausal women has been a controversial topic. Contradictory patterns of results have prompted speculation that a critical period, or limited window of opportunity, exists for hormone treatment to protect against neurocognitive. In this cross-sectional study of 102 postmenopausal women, we examined whether hippocampal, amygdala, or caudate nucleus volumes and spatial memory performance were related to the interval between menopause and the initiation of hormone treatment. Consistent with a critical period hypothesis, we found that shorter intervals between menopause and the initiation of hormone treatment were associated with larger hippocampal volumes compared with longer intervals between menopause and treatment initiation. Initiation of hormone treatment at the time of menopause was also associated with larger hippocampal volumes when compared with peers who had never used hormone treatment. Furthermore, these effects were independent from potentially confounding factors such as age, years of education, the duration of hormone treatment, current or past use of hormone therapy, the type of therapy, and age at menopause. Larger hippocampal volumes in women who initiated hormone treatment at the time of menopause failed to translate to improved spatial memory performance. There was no relationship between timing of hormone initiation, spatial memory performance, and amygdala or caudate nucleus volume. Our results provide support for a limited window of opportunity for hormone treatment to influence hippocampal volume, yet the degree to which these effects translate to improved memory performance is uncertain. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Response variability is associated with self-reported cognitive fatigue in multiple sclerosis.
Cognitive fatigue is a common, often debilitating symptom of multiple sclerosis (MS). Although MS patients frequently report that fatigue negatively affects cognitive functioning, most studies have found little evidence for a direct relationship between self-reported cognitive fatigue and traditional measures of neuropsychological functioning. The purpose of the present study was to examine the association between self-reported cognitive fatigue and a measure of response time variability (RTV). MS patients demonstrated significantly higher RTV than controls, and RTV was highly correlated with self-reported cognitive fatigue among relapsing-remitting and secondary progressive MS patients. Results highlight the need to implement newer methods to further elucidate the relationship between cognitive fatigue and neuropsychological functioning in MS. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Positive and negative emotion enhances the processing of famous faces in a semantic judgment task.
Previous work has consistently reported a facilitatory influence of positive emotion in face recognition (e.g., D’Argembeau, Van der Linden, Comblain, & Etienne, 2003). However, these reports asked participants to make recognition judgments in response to faces, and it is unknown whether emotional valence may influence other stages of processing, such as at the level of semantics. Furthermore, other evidence suggests that negative rather than positive emotion facilitates higher level judgments when processing nonfacial stimuli (e.g., Mickley & Kensinger, 2008), and it is possible that negative emotion also influences latter stages of face processing. The present study addressed this issue, examining the influence of emotional valence while participants made semantic judgments in response to a set of famous faces. Eye movements were monitored while participants performed this task, and analyses revealed a reduction in information extraction for the faces of liked and disliked celebrities compared with those of emotionally neutral celebrities. Thus, in contrast to work using familiarity judgments, both positive and negative emotion facilitated processing in this semantic-based task. This pattern of findings is discussed in relation to current models of face processing. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Difference rather than delay in development of elementary visuomotor processes in children born preterm without cerebral palsy: A quasi-longitudinal study.
Follow-up studies of preterm children without serious neonatal medical complications have consistently found poor visuomotor and visuospatial skills. In the first round of current follow-up study, we found a deficit in elementary visuomotor processes in preterm children without Cerebral Palsy (CP). To determine whether the development of these processes was delayed or different, we carried out a quasi-longitudinal study in which kinematic characteristics of pointing movements in 7- to 11-year-old preterm born children without CP and in an age-matched full-term group were analyzed. Multi-level analysis suggested a difference rather than a delay in the preterm born group: we found a regression around 8 years of age in the control but not in the preterm group. To our knowledge, this study is the first to provide longitudinal data confirming this regression in the development of movement control in typically developing children. Our results are also consistent in suggesting that elementary visuomotor processes are less efficient in preterm born children without CP: their movements were either slower or less accurate. While these differences were subtle, they persisted until 11 years of age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
Episodic memory and impairment of an early encoding process in schizophrenia.
Investigations of memory impairment in schizophrenia have frequently revealed a strategic processing deficit at encoding. The authors studied an early encoding process, refreshing (in this case, thinking of a stimulus that has just-previously been presented), and its impact on recognition memory in schizophrenia. Following simultaneous presentation of three words or a single word in the top, middle, or bottom position of the screen, 25 patients with schizophrenia and 25 control participants saw and read a new word (read condition), or a word presented on the previous screen (repeat condition), or saw a dot indicating that they should think of and say the last word to have appeared in that position (refresh condition). Later, on a surprise test, participants were asked to recognize words seen previously and give a Remember, Know, or Guess response according to whether they recognized each on the basis of conscious recollection, familiarity, or guessing. The cognitive operation of refreshing was impaired in schizophrenia: patients were slower on 1-word trials and less accurate on 3-word trials to refresh a word, and their Remember responses did not benefit from refreshing. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Course of neurocognitive deficits in the prodrome and first episode of schizophrenia.
Understanding the trajectory of cognitive changes in the development of schizophrenia may shed light on the neurodevelopmental processes in the beginning stage of illness. Subjects at risk for psychosis (AR, n = 48), patients in their first episode of schizophrenia (FE, n = 20), and normal comparison subjects (n = 29) were assessed on a neurocognitive battery at baseline and at a 6-month follow-up. There were significant group differences across all cognitive domains as well as a significant group by time interaction in the verbal learning domain. After statistically controlling for practice effects and regression to the mean, a high proportion of FE subjects showed an improvement in verbal learning, and a significant number of AR subjects improved in general intelligence. Moreover, a higher than expected percentage of FE subjects, as well as AR subjects who later converted to psychosis, showed a deterioration in working memory and processing speed. These inconsistent trajectories suggest that some domains may improve with stabilization in the early stages of psychosis, whereas others may decline with progression of the illness, indicating possible targets for cognitive remediation strategies and candidate vulnerability markers for future psychosis. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Comparing prefrontal gray and white matter contributions to intelligence and decision making in schizophrenia and healthy controls.
The authors examined the relationship between neuropsychological performance and MRI of the orbital frontal cortex (OFC) and diffusion tensor imaging (DTI) of the cingulum bundle (CB) within groups of patients with schizophrenia and healthy subjects. The authors analyzed data from subjects, who had participated in prior MRI, DTI, and neuropsychological studies (Nakamura et al., 2008; Nestor et al., 2008). In comparison to healthy subjects, patients showed the expected reductions across CB fractional anisotropy (white matter) and OFC gray matter volume as well as lower neuropsychological scores. In addition, in comparison to healthy subjects, patients showed a very different pattern of functional-anatomical correlates. For patients, CB white matter but not OFC gray matter correlated with various aspects of intelligence, including general abilities and working memory. For controls, OFC gray matter but not CB white matter correlated with scores on tests of intelligence and decision making. These results point to the potentially important role of CB white matter in the neuropsychological disturbance in schizophrenia. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
Semantic ambiguity resolution in positive schizotypy: A right hemisphere interpretation.
Positive schizotypal traits have been associated with right hemisphere activation. Previous research has indicated that the left and right hemispheres differ in their processing of semantic ambiguity; specifically, given sufficient time, the left hemisphere primes dominant meanings and inhibits subordinate meanings, and the right hemisphere primes both dominant and subordinate meanings. The authors examined whether individuals who differed in positive schizotypy demonstrated different patterns of priming on a semantic ambiguity task, reflective of differences in hemispheric activation. Individuals low in schizotypy demonstrated the expected pattern of priming the dominant meaning while inhibiting the subordinate meaning. Individuals high in schizotypy demonstrated similar priming of the dominant meaning but no inhibition of the subordinate meaning. The role of this failure of inhibition in the generation of schizotypal thought is discussed. (PsycINFO Database Record (c) 2009 APA, all rights reserved)

Neuropsychology - Vol 24, Iss 1