The Effects of Chronic Right Hemispheric Damage on the Allocation of Spatial Attention: Alterations of Accuracy and Reliability.

Right hemispheric damage (RHD) caused by strokes often induce attentional disorders such as hemispatial neglect. Most patients with neglect over time have a reduction in their ipsilesional spatial attentional bias. Despite this improvement in spatial bias, many patients remain disabled.

Dopamine does not appear to affect mental rotation in Parkinson's disease.

Objective: Patients with Parkinson's disease (PD) often have deficits with mental rotation (MR). The neuropathological factors underlying these deficits, however, remain to be elucidated. One hypothesis suggests that dopamine depletion in nigro-striatal systems adversely influences MR.

The influence of emotional faces on the spatial allocation of attention.

Objectives: Studies suggest that the right hemisphere is dominant for emotional facial recognition. In addition, whereas some studies suggest the right hemisphere mediates the processing of all emotions (dominance hypothesis), other studies suggest that the left hemisphere mediates positive emotions the right mediates negative emotions (valence hypothesis). Since each hemisphere primarily attends to contralateral space, the goals of this study was to learn if emotional faces would induce a leftward deviation of attention and if the valence of facial emotional stimuli can influence the normal viewer's spatial direction of attention.

Working memory in Parkinson's disease: the effects of depression and side of onset of motor symptoms.

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.

Frontal-executive constructional apraxia: when delayed recall is better than copying.

Unlabelled: In assessments of visuospatial function and memory, patients are often required to copy a figure and later to reproduce that figure from memory. Whereas most people perform better on a copying task than when drawing from memory, in this study we describe an unusual pattern of performance in which patients are better at drawing from memory than copying. Consecutive patients in a neurocognitive disorders clinic were given a battery of clinical cognitive tests that included copying a figure of intersecting pentagons and then drawing the figure from memory.

Mood disturbances and cognitive functioning in Parkinson's disease: the effects of disease duration and side of onset of motor symptoms.

Some research has supported differences in mood functioning in patients with Parkinson's disease (PD) whose motor symptoms begin at the left or right hemibody. Also, a relationship between disease duration and mood disturbances has been reported, but only for PD patients with right hemibody onset. There have been no investigations reported examining the potential interactions between side of onset of motor symptoms, mood, and disease duration on cognitive functioning.

Anxiety and depression severity are related to right but not left onset Parkinson's disease duration.

Depression and anxiety have both been associated with relative left frontal hypoactivation and the motor symptoms of Parkinson's disease typically begin in a lateral or asymmetrical fashion. Hence, PD patients with right hemibody onset may experience heightened depression and anxiety. However, research is mixed regarding whether right or left hemibody onset PD is associated with elevated levels of depression and anxiety.

Age-related changes in arm-hand postural knowledge.

Cognitive changes have been reported during healthy ageing, but there have been no investigations of older people's knowledge of transitive and intransitive forelimb postures and movements. A total of 18 healthy elderly participants in two age groups, old (66-76 years) and older (77-88 years), all of whom performed normally on the Mini-Mental Status Examination (MMSE) and Boston Naming Test (BNT), performed a transitive and intransitive gesture postural discrimination test. Whereas there were no significant differences between the two groups in education or performance on the MMSE and BNT, the older group performed significantly worse on both transitive and intransitive posture recognition with more errors in the recognition of transitive than in the recognition of intransitive postures.

Influence of left versus right hemibody onset Parkinson's disease on cardiovascular control.

Whereas the left hemisphere is involved in regulating the parasympathetic nervous system, the right hemisphere regulates the sympathetic. Given the asymmetrical onset of motor symptoms and neuropathology in PD, differences in cardiovascular functions might be expected between PD patients with left hemibody onset (LHO) versus right hemibody onset (RHO). A total of 66 PD patients served as participants, including 31 LHO patients and 35 RHO PD patients.

Verbal and visuospatial memory in lateral onset Parkinson disease: time is of the essence.

Objective: This investigation sought to study immediate and delayed verbal and visuospatial recall in Parkinson disease (PD) patients with left hemibody (LHO) and right hemibody (RHO) onset of motor symptoms and to examine the role of mental processing speed in recall of this information.

Background: Research is mixed regarding material specific memory impairments in LHO and RHO PD. However, earlier research has not used a factorial approach in investigating material specific memory in LHO and RHO PD.

Verbal learning in Alzheimer's disease: cumulative word knowledge gains across learning trials.

Research regarding learning in Alzheimer's disease (AD) patients has been mixed. Learning capacity might be better indexed using a score that reflects the interaction between the learning slope and total recall, referred to as the Cumulative Word Learning (CWL) score. We compared a group of AD patients to normal participants using a traditional index of learning and the CWL score that were derived from the Hopkins Verbal Learning Test-Revised (HVLT-R).

Virtual reality rehabilitation of spatial abilities after brain damage.

Current rehabilitation of navigation and spatial orientation ability after brain damage is generally focused on training within the rehabilitation hospital or the patient's home as part of common physio- and occupational therapy sessions. To further promote generalization of gained abilities and to quantify functional improvements, this project aims at developing a Virtual Reality (VR) application that can be used for training and assessment of spatial orientation and navigation skills in brain-damaged patients. The training is administered after the standard hospital rehabilitation training is completed.

Visual-spatial disembedding in Parkinson's disease.

Visual-spatial disembedding requires a person to visually scan the stimulus and allocate spatial selective attention to the locations of relevant stimuli. Parkinson's disease (PD) is often associated with visual-spatial deficits, but the influence of PD on disembedding is not entirely known. The goal of this study is to learn whether participants with PD have defective visuospatial disembedding and whether this defect responds to dopaminergic treatment.

A brief computerized self-screen for dementia.

Among his many contributions to the field of neuropsychology, Arthur Benton recognized the broad public health significance and unique ability of focused neuropsychological tests to screen for dementia. The need for validated screening tests for the presence of dementia will continue to grow as the cumulative prevalence of dementia grows and as our ability to treat or slow the progression of these diseases improves. We have developed a brief, self-administered computerized screening test for dementia, which is user friendly to the majority of elderly participants, including those with dementia.

Mild cognitive impairment in Parkinson's disease: the challenge and the promise.

This review addresses the literature surrounding Parkinson's disease (PD) and mild cognitive impairment (MCI). It discusses the neuropsychological, pharmaceutical, and pathological overlap, the socioeconomic impact of PD and MCI, and the value of recognizing, understanding, and treating MCI in PD. It is concluded from this review that MCI in PD does exist and should be considered in clinical and research investigations.

Effects of donepezil on verbal memory after semantic processing in healthy older adults.

Objective: To learn if acetylcholinesterase inhibitors alter verbal recall by improving semantic encoding in a double-blind randomized placebo-controlled trial.

Background: Cholinergic supplementation has been shown to improve delayed recall in adults with Alzheimer disease. With functional magnetic resonance imaging, elderly adults, when compared with younger participants, have reduced cortical activation with semantic processing.

Reduced verbal learning associated with posterior temporal lobe slow wave activity.

Functional imaging has revealed that during verbal-word learning there is activation of the left posterior temporo-parietal region (PTPL). The purpose of this study was to learn if differences in the ability of normal people to learn might be accounted for by differences in electrophysiological (EEG) measures of activation of their left, but not right, PTPL. The Rey Auditory Verbal Learning Test (RAVLT) was administered to 42 men without neurological diseases.

Greater motor improvement in right hemibody Parkinson's patients after dopaminergic medications.

Due to motor and neuropathological asymmetries, Parkinson's disease (PD) patients with right hemibody onset (RHO) of symptoms may experience greater benefit from dopaminergic enhancing medications, relative to patients with left hemibody onset (LHO). We investigated this possibility by measuring UPDRS scores of 20 PD patients with LHO and 13 patients with RHO, both prior and subsequent to taking dopaminergic enhancing medications. Following treatment, the motor score from the UPDRS improved for both groups of patients.

Spreading activation of lexical-semantic networks in Parkinson's disease.

Although dopamine may act as a neuromodulator of spreading activation within semantic networks, this role of dopamine in lexical networks has not been investigated. Hence, we sought to investigate the effects of Parkinson's disease (PD), which is associated with dopamine depletion, on spreading activation in the lexical networks. Ten Parkinson's disease patients and 11 normal controls performed the controlled oral word association test and the average word frequency for their responses was calculated and used as an index of spreading activation.

Emotional influences on spatial attention.

The relationships between the anterior-posterior and left-right regions of the brain have been characterized as mutually inhibitory. Whereas the left hemisphere attends to right proximal hemispace and is associated with positive emotions, the right hemisphere attends to left distal hemispace and is associated with negative emotions. Because of the excitatory and inhibitory influences between the left and right frontal and posterior regions of the brain, the expression of emotion will result in an ipsilateral attentional bias.

The crossed response inhibition task in Parkinson's disease: disinhibition hyperkinesia.

Patients with Parkinson's disease (PD) have dysfunction in frontal-basal ganglia networks. Many of these patients have difficulties with mental processing speed, response inhibition, and shifting between different conceptual sets, suggesting frontal-executive dysfunction. Since frontal lobe dysfunction is associated with disengagement deficits such as perseveration and echopraxia we wanted to learn if patients with PD demonstrated defective response inhibition.

Lateral and vertical attentional biases in normal individuals.

Background: When normal people attempt to bisect lines they often make their mark to the left of midline (pseudoneglect) and when attempting to bisect radial lines normal people tend to bisect distal to the actual midline. These biases might be related to asymmetrical activation induced by making spatial computations or attention-intentional preferences. The purpose of this study was to learn if in the absence of spatial computations normal subjects would demonstrate a left and upward bias.

Spatial-attention and emotional evocation: line bisection performance and visual art emotional evocation.

Lesion studies demonstrate that the right temporal-parietal region (RTP) is important for mediating spatial attention. The RTP is also involved in emotional experiences that can be evoked by art. Normal people vary in their ability to allocate spatial attention, thus, people who can better allocate attention might also be more influenced by the emotional messages of the paintings (evocative impact).

The effects of movement direction and hemispace on estimates of distance traveled.

Background/hypothesis: The degree of attention directed to a stimulus and the presence of anisometric representations can alter the perception of the magnitude of a stimulus. We wanted to learn if normal right-handed subjects' estimates of distance traveled are influenced by the right-left direction or hemispace of movements.

Methods: We had blindfolded participants estimate the distance their arm was moved in a rightward or leftward direction, in right and left hemispace.