Laterality of Lesions and Trait-Anxiety on Working Memory Performance

2002 ◽  
Vol 94 (2) ◽  
pp. 551-558 ◽  
Author(s):  
William D. S. Killgore

An asymmetry of anterior cerebral activation favoring the right hemisphere has been associated with dispositional negative affect including trait-anxiety, while the opposite appears true of cerebral asymmetry favoring the left hemisphere. It was hypothesized that an asymmetry of cerebral activation, as defined by scores on a measure of trait-anxiety, ipsilateral to the side of an anterior brain lesion would be associated with less efficient cognitive processing than greater activation in the hemisphere contralateral to the lesion. Patients with anterior left ( n = 16) or right ( n = 15) hemisphere lesions completed the State-Trait Anxiety Inventory and several neurocognitive tasks. Of the abilities tested, only Digit Span scores showed an interaction between side of lesion and presumed activation asymmetry. Patients with right- but not with left-hemisphere damage showed significant differences in working memory performance depending on the presumed direction of asymmetry of the two hemispheres, supporting the dual roles of the right hemisphere in affective processing and directed attention.

2011 ◽  
Vol 23 (3) ◽  
pp. 552-569 ◽  
Author(s):  
Michael Wolmetz ◽  
David Poeppel ◽  
Brenda Rapp

Innate auditory sensitivities and familiarity with the sounds of language give rise to clear influences of phonemic categories on adult perception of speech. With few exceptions, current models endorse highly left-hemisphere-lateralized mechanisms responsible for the influence of phonemic category on speech perception, based primarily on results from functional imaging and brain-lesion studies. Here we directly test the hypothesis that the right hemisphere does not engage in phonemic analysis. By using fMRI to identify cortical sites sensitive to phonemes in both word and pronounceable nonword contexts, we find evidence that right-hemisphere phonemic sensitivity is limited to a lexical context. We extend the interpretation of these fMRI results through the study of an individual with a left-hemisphere lesion who is right-hemisphere reliant for initial acoustic and phonetic analysis of speech. This individual's performance revealed that the right hemisphere alone was insufficient to allow for typical phonemic category effects but did support the processing of gradient phonetic information in lexical contexts. Taken together, these findings confirm previous claims that the right temporal cortex does not play a primary role in phoneme processing, but they also indicate that lexical context may modulate the involvement of a right hemisphere largely tuned for less abstract dimensions of the speech signal.


2019 ◽  
Vol 29 (11) ◽  
pp. 4580-4594 ◽  
Author(s):  
Chenxi Zhao ◽  
Liyuan Yang ◽  
Sheng Xie ◽  
Zhixin Zhang ◽  
Hui Pan ◽  
...  

AbstractTurner syndrome (TS) is caused by the congenital absence of all or part of one of the X chromosomes in females, offering a valuable human “knockout model” to study the functioning patterns of the X chromosome in the human brain. Little is known about whether and how the loss of the X chromosome influences the brain structural wiring patterns in human. We acquired a multimodal MRI dataset and cognitive assessments from 22 girls with TS and 21 age-matched control girls to address these questions. Hemispheric white matter (WM) networks and modules were derived using refined diffusion MRI tractography. Statistical comparisons revealed a reduced topological efficiency of both hemispheric networks and bilateral parietal modules in TS girls. Specifically, the efficiency of right parietal module significantly mediated the effect of the X chromosome on working memory performance, indicating that X chromosome loss impairs working memory performance by disrupting this module. Additionally, TS girls showed structural and functional connectivity decoupling across specific within- and between-modular connections, predominantly in the right hemisphere. These findings provide novel insights into the functional pathways in the brain that are regulated by the X chromosome and highlight a module-specific genetic contribution to WM connectivity in the human brain.


2004 ◽  
Vol 10 (5) ◽  
pp. 742-752 ◽  
Author(s):  
AMY E. LANSING ◽  
JEFFREY E. MAX ◽  
DEAN C. DELIS ◽  
PETER T. FOX ◽  
JACK LANCASTER ◽  
...  

Verbal learning and memory (VLM) following pediatric stroke was characterized in a cross-sectional neuropsychological and neuroimaging study of 26 subjects, aged 5 to 17, with a history of pediatric stroke and 26 age, SES, and gender matched orthopedic controls. Further comparisons were made between the VLM profiles of stroke subjects with rightversusleft hemisphere lesions and early (≤12 months)versuslate (>12 months) strokes. Overall, stroke subjects scored significantly lower than control subjects on several VLM indices (California Verbal Learning Test–Children; CVLT–C), as well as on measures of intellectual functioning (IQ) and auditory attention/working memory (Digit Span). Subgroup analyses of the stroke population foundnosignificant differences in VLM, Digit Span, Verbal IQ or Performance IQ when left-hemisphere lesion subjects were compared to right-hemisphere lesion subjects. In contrast, early strokes were associated with significantly fewer words recalled after delay, reduced discriminability (fewer correct hits relative to false positive errors on recognition testing), and relatively worse auditory attention/working memory scores (Digit Span). These findings indicate that pediatric stroke subjects demonstrated more VLM impairment than control subjects, and early strokes were associated with greater recall and recognition deficits. In stark contrast with adult-onset stroke, both left- and right-hemisphere lesions during childhood resulted in similar VLM performance. (JINS, 2004,10, 742–752.)


2013 ◽  
Vol 311 ◽  
pp. 196-201
Author(s):  
Chia Ju Liu ◽  
Chin Fei Huang ◽  
Chia Yi Chou ◽  
Ming Chi Lu ◽  
Yung Yi Chang ◽  
...  

The aim of this study was to apply frequency bands to explore how mental rotation strategies affect the identification of 2D figures. Eighteen adults were recruited for this study. In the ERP experiments, the participants were required to identify 2D figures with mental rotation. The results showed the differences between the high-achieving (HA) and low-achieving (LA) spatial ability participants in their use of mental rotation for identifying 2D figures. At 300-380 ms, the HA participants showed higher brain activity in the right hemisphere than in other brain areas, whereas the LA participants showed activity in the whole brain. At 520 to 620 ms, the areas of brain activity were in the opposite hemisphere for the HA and LA participants. The highest brain activity was shown in the left hemisphere of the HA participants and in the right hemisphere for the LA participants at 520 to 620 ms. The implication of this study is that right hemisphere specialization for mental rotation might appear in early cognitive processing, but in late cognitive processing, the left hemisphere specialization form of mental rotation might show an advantage.


1999 ◽  
Vol 5 (1) ◽  
pp. 69-74 ◽  
Author(s):  
AMANDA G. WOOD ◽  
MICHAEL M. SALING ◽  
MARIE F. O'SHEA ◽  
GRAEME D. JACKSON ◽  
SAMUEL F. BERKOVIC

Left-to-right reorganization of verbal memory following early left hemisphere damage has been reported in patients whose expressive language is governed by the right hemisphere. We present a case in which verbal memory performance was intact, despite severe left mesial temporal damage, and despite aphasia on left internal carotid sodium amytal ablation. The distribution and degree of left mesial temporal damage was assessed visually and quantitatively on MRI. These findings raise the possibility that verbal memory may shift to the language-nondominant hemisphere as a result of early left mesial temporal damage. (JINS, 1999, 5, 69–74.)


2013 ◽  
Vol 27 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Konstantinos Trochidis ◽  
Emmanuel Bigand

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.


Author(s):  
Elizabeth Schechter

This chapter defends the 2-agents claim, according to which the two hemispheres of a split-brain subject are associated with distinct intentional agents. The empirical basis of this claim is that, while both hemispheres are the source or site of intentions, the capacity to integrate them in practical reasoning no longer operates interhemispherically after split-brain surgery. As a result, the right hemisphere-associated agent, R, and the left hemisphere-associated agent, L, enjoy intentional autonomy from each other. Although the positive case for the 2-agents claim is grounded mainly in experimental findings, the claim is not contradicted by what we know of split-brain subjects’ ordinary behavior, that is, the way they act outside of experimental conditions.


Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.


1998 ◽  
Vol 353 (1377) ◽  
pp. 1819-1828 ◽  
Author(s):  
◽  
S. M. Courtney ◽  
L. Petit ◽  
J. V. Haxby ◽  
L. G. Ungerleider

Working memory enables us to hold in our ‘mind's eye’ the contents of our conscious awareness, even in the absence of sensory input, by maintaining an active representation of information for a brief period of time. In this review we consider the functional organization of the prefrontal cortex and its role in this cognitive process. First, we present evidence from brain–imaging studies that prefrontal cortex shows sustained activity during the delay period of visual working memory tasks, indicating that this cortex maintains on–line representations of stimuli after they are removed from view. We then present evidence for domain specificity within frontal cortex based on the type of information, with object working memory mediated by more ventral frontal regions and spatial working memory mediated by more dorsal frontal regions. We also propose that a second dimension for domain specificity within prefrontal cortex might exist for object working memory on the basis of the type of representation, with analytic representations maintained preferentially in the left hemisphere and image–based representations maintained preferentially in the right hemisphere. Furthermore, we discuss the possibility that there are prefrontal areas brought into play during the monitoring and manipulation of information in working memory in addition to those engaged during the maintenance of this information. Finally, we consider the relationship of prefrontal areas important for working memory, both to posterior visual processing areas and to prefrontal areas associated with long–term memory.


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