Chronological Effects of Emotional Valence on the Self-selected Retrieval of Autobiographical Memories.

Background And Objective: Salience of emotional autobiographical memories may have temporal patterns associated with valence. Recall of negative emotional memories is often important in survival and well-being. Based on the possible survival value of negative memories, we posited that when given an open-ended request to recall either a sad or a happy memory, people are more likely to recall an older sad memory than a happy one.

Asymmetrical distractibility of global and focal visuospatial attention during segmental and total compound line bisections.

Background/objectives: Compound horizontal lines are composed of 2 segments of unequal length and width. Line bisection requires that the participants attend to the entire line (global attention). The longer segment often distracts participants, suggesting that attention directed to this segment (focal attention) disrupts the allocation of global attention.

Background distraction during vertical solid and character line bisections.

Unlabelled: Background-objectives: When vertical lines are positioned above or below the center of the page, line bisection deviates toward the center of the page, suggesting that the edges of the page distract the allocation of attention to the line. A letter-character line (LCL) bisection requires both global and focal attention, to identify the target letter closest to the line's center. If more focal and less global attention is allocated to a LCL, more global attentional resources may be available and inadvertently allocated to the page.

Effects of aging on action-intentional programming.

Background: Action-intentional programs control "when" we initiate, inhibit, continue, and stop motor actions. The purpose of this study was to learn if there are changes in the action-intentional system with healthy aging, and if these changes are asymmetrical (right versus left upper limb) or related to impaired interhemispheric communication.

Methods: We administered tests of action-intention to 41 middle-aged and older adults (61.

Callosal disconnection neglect: reassessment after 34 years.

In 1984, Watson and Heilman reported a patient with a partial callosal disconnection following an infarction of the anterior portion of her corpus callosum. This woman's performance on line-bisection tasks revealed "callosal disconnection neglect." The objective of this research is to reexamine this woman 34 years after her callosal disconnection to gain information about her recovery.

The aging brain: Movement speed and spatial control.

Background/objectives: With aging, people commonly develop motor slowing (bradykinesia). Although this slowness with aging may be entirely related to degradation of the cerebral networks important in motor programing, it is possible that, at least in part, it may be a learned procedure for enhancing the accuracy and/or precision of movements. The goal of this study is to test these contradictory hypotheses.

Allocentric But Not Egocentric Pseudoneglect of Peripersonal Space.

Background And Objective: Healthy adults often deviate leftward on line bisection tasks (allocentric pseudoneglect) but rightward on body part bisection tasks (egocentric pseudoneglect). People visually estimate distance in peripersonal space by comparing the distance to the length of a body part such as an arm's length (an egocentric reference) or using standard units of distance such as inches (an allocentric reference). Our objective was to learn whether people have pseudoneglect when estimating distances in peripersonal space using egocentric versus allocentric reference frames.

Callosal apraxia: a 34-year follow-up study.

Loss of ability of the left upper limb (LUL) to correctly produce spatial and temporal components of skilled purposeful movements was reported 34 years ago in a woman with a callosal infarction. To learn about recovery, we recently reexamined this woman. This woman was tested for ideomotor apraxia by asking her to pantomime to command and to seeing pictures of tools.

Cognitive-motor dysfunction after severe traumatic brain injury: A cerebral interhemispheric disconnection syndrome.

Background/objectives: In most right-handed people, the left hemisphere is dominant for programming the temporal and spatial "how" (praxis) aspects of purposeful skilled movements, and the right hemisphere is dominant for control of the intentional "when" aspects of actions that mediate initiation, persistence, termination, and inhibition. Since the interhemispheric axons of the corpus callosum are especially susceptible to shearing from torsional forces during traumatic brain injury (TBI), the goal of this study was to learn whether participants with a history of severe traumatic brain injury demonstrate three types of cognitive-motor impairments that may result from callosal injury: ideomotor apraxia of the left hand, limb kinetic apraxia of the left hand, and hypokinesia of the right hand in response to left hemispatial stimuli.

Method: Nine participants with severe TBI and nine healthy control participants were studied for the presence of ideomotor apraxia, limb kinetic apraxia, and hypokinesia.

Abnormal tactile pressure perception in Parkinson's disease.

Background/objective: Some of the behavioral disorders associated with Parkinson's disease (PD), such as the reduced magnitude of actions (hypometria) may be related to an impairment in cognitive disengagement. A reduced ability to disengage attention from previous sensory stimuli will alter perception with a reduced range of estimated stimulus magnitudes (contraction to the mean). To test this disengagement hypothesis, participants with PD were tested to learn whether they had abnormal sensory perception with overestimation of the relative magnitude of weaker tactile stimuli and underestimation of the relative magnitude of stronger tactile stimuli in relation to a reference stimulus.

Functional Brain Correlates of Upper Limb Spasticity and Its Mitigation following Rehabilitation in Chronic Stroke Survivors.

Background. Arm spasticity is a challenge in the care of chronic stroke survivors with motor deficits. In order to advance spasticity treatments, a better understanding of the mechanism of spasticity-related neuroplasticity is needed.

Global attentional neglect of segmented lines in Parkinson's disease.

Global attention requires disengagement from focal elements of stimuli. Since people with Parkinson's disease (PD) may reveal impaired disengagement, this study attempted to learn if people with PD may be impaired at allocating global attention. Healthy adults and people with PD attempted to bisect lines of uniform thickness and lines composed of two segments of unequal thickness and length.

Hypometric allocentric and egocentric distance estimates in Parkinson disease.

Objective And Background: Persons with Parkinson disease (PD) show hypometric movements and make hypometric estimates of imagined actions. These deficits may be related to misestimates of the length of body parts. Our objective was to learn whether patients with PD are impaired in their estimations of their arm's length and standard units of distance.

Hemispheric differences in ischemic stroke: is left-hemisphere stroke more common?

Background And Purpose: Understanding the mechanisms underlying stroke can aid the development of therapies and improve the final outcome. The purposes of this study were to establish whether there are characteristic mechanistic differences in the frequency, severity, functional outcome, and mortality between left- and right-hemisphere ischemic stroke and, given the velocity differences in the carotid circulation and direct branching of the left common carotid artery from the aorta, whether large-vessel ischemia (including cardioembolism) is more common in the territory of the left middle cerebral artery.

Methods: Trial cohorts were combined into a data set of 476 samples.

Praxis and writing in a right-hander with crossed aphasia.

Studies of patients with brain lesions have demonstrated that language and praxis are mediated by dissociable networks. However, language has the capacity to influence the selection of purposeful actions. The abilities to use language and to program purposeful movements are often mediated by networks that have anatomic proximity.

Vertical line quadrisection: "what" it represents and who gets the upper hand.

Background: Normal adults demonstrate a slight upward bias (vertical pseudoneglect) when attempting vertical line bisection. The mechanism for this bias is unknown. Activation of the allocentric (object-centered) ventral visual system during attempted bisection may induce this bias.

The relationship between semantic knowledge and conceptual apraxia in Alzheimer disease.

Background: Conceptual apraxia (CA), a feature of Alzheimer disease (AD), can be detected by asking participants to identify the correct tool to act on an object. Assessment can be based on either learned associations (a tool selection test) or the mechanical properties that the tool needs to alter the target object (an alternative tool selection test).

Objectives: We wanted to determine whether knowledge of semantic taxonomic relations (intrinsic properties shared by items) correlated with performance on tests for CA in people with AD or amnestic mild cognitive impairment (aMCI).

Alternate but do not swim: a test for executive motor dysfunction in Parkinson disease.

The objective of this study is to learn if participants with Parkinson disease (PD), when compared to normal controls, are impaired in making simultaneous but independent right and left hand movements. Participants were tested with Luria's Alternating Hand Postures (AHP) test and modified AHP tests. Twelve PD participants without dementia and twelve matched controls were assessed for their ability to perform the parallel AHP test (both hands remaining in the same coronal plane) and with modifications of this test into swimming (alternative arm extension with finger extension and arm flexion with finger flexion) and reverse swimming (alternative arm extension-finger flexion and arm flexion-finger extension) movements.

Sign language aphasia from a neurodegenerative disease.

While Alois Alzheimer recognized the effects of the disease he described on speech and language in his original description of the disease in 1907, the effects of Alzheimer's disease (AD) on language in deaf signers has not previously been reported. We evaluated a 55-year-old right-handed congenitally deaf woman with a 2-year history of progressive memory loss and a deterioration of her ability to communicate in American Sign Language, which she learned at the age of eight. Examination revealed that she had impaired episodic memory as well as marked impairments in the production and comprehension of fingerspelling and grammatically complex sentences.

Famous faces but not remembered spaces influence vertical line bisections.

Whereas the ventral visual processing stream mediates facial and object recognition, the dorsal stream mediates recognition of spatial relationships. In addition, ventral lesions have been reported to induce visual inattention to the upper visual field and dorsal lesions inattention to the lower field. The purpose of this study is to test the hypothesis that activation of the ventral stream will induce an upward attentional bias and activation of the dorsal stream, a downward bias, as assessed by vertical line bisection tests.

Right up there: hemispatial and hand asymmetries of altitudinal pseudoneglect.

Background: Pseudoneglect is a normal left sided spatial bias observed with attempted bisections of horizontal lines and a normal upward bias observed with attempted bisections of vertical lines. Horizontal pseudoneglect has been attributed to right hemispheric dominance for the allocation of attention. The goal of this study was to test the hypothesis that the upward bias in vertical line bisection may also relate to right hemispheric dominance for the allocation of attention and/or action-intention.

Radiographic and pathologic findings in an atypical brainstem variant of reversible posterior leukoencephalopathy syndrome.

Background: Reversible posterior leukoencephalopathy syndrome (RPLS) and hypertensive encephalopathy (HE) are terms generally used interchangeably to describe a syndrome characterized by encephalopathy, focal deficits, and vasogenic edema seen on magnetic resonance imaging, which are potentially reversible with treatment. The underlying pathologic changes are less well defined. Previously, the only pathologic data available came from a single autopsy series.