scholarly journals Dissociated visual perceptual and spatial deficits in focal lesions of the right hemisphere

1969 ◽  
Vol 32 (2) ◽  
pp. 73-81 ◽  
Author(s):  
F. Newcombe ◽  
W. R. Russell
2018 ◽  
Author(s):  
J. Bernardo Barahona-Corrêa ◽  
Gonçalo Cotovio ◽  
Rui M. Costa ◽  
Ricardo Ribeiro ◽  
Ana Velosa ◽  
...  

ABSTRACTBackgroundDespite claims that lesional mania is associated with right-hemisphere lesions, supporting evidence is scarce, and association with specific brain areas has not been demonstrated.AimsTo test whether focal brain lesions in lesional mania are more often right-than left-sided, and if lesions converge on areas relevant to mood regulation.MethodsWe performed a systematic literature search (PROSPERO registration CRD42016053675) on PubMed and Web-Of-Science, using terms that reflected diagnoses and structures of interest, and lesional mechanisms. Two researchers reviewed the articles separately according to PRISMA Guidelines, to select reports of adult-onset hypomania, mania or mixed state following a focal brain lesion. When available, eligible lesion images were manually traced onto the corresponding slices of MNI space, and lesion topography analyzed using standard brain atlases. Pooled-analyses of individual patient data were performed.ResultsData from 207 lesional mania patients was extracted from 110 reports. Among patients with focal lesions (N=197) more patients had lesions involving the right (84.3%) than the left (34.5%) hemisphere. Among 54 lesion images that were available, right-sided predominance of lesions was confirmed, and found to be was conserved across multiple brain regions, including the temporal lobe, fusiform gyrus and thalamus. These, in addition to several frontal lobe areas, were also identified as preferential lesion sites in comparisons with control lesions.ConclusionsPooled-analyses, based on the most comprehensive dataset of lesional mania available to date, confirm a preferential association with right-hemisphere lesions, while suggesting that several brain areas/circuits, relevant to mood regulation, are most frequently affected.


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):  
Gregor Volberg

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.


1990 ◽  
Vol 35 (6) ◽  
pp. 544-547
Author(s):  
Randi C. Martin
Keyword(s):  

2020 ◽  
Author(s):  
Isabelle Hesling

The modalities of communication are the sum of the expression dimension (linguistics) and the expressivity dimension (prosody), both being equally important in language communication. The expressivity dimension which comes first in the act of speech, is the basis on which phonemes, syllables, words, grammar and morphosyntax, i.e., the expression dimension of speech is superimposed. We will review evidence (1) revealing the importance of prosody in language acquisition and (2) showing that prosody triggers the involvement of specific brain areas dedicated to sentences and word-list processing. To support the first point, we will not only rely on experimental psychology studies conducted in newborns and young children but also on neuroimaging studies that have helped to validate these behavioral experiments. Then, neuroimaging data on adults will allow for concluding that the expressivity dimension of speech modulates both the right hemisphere prosodic areas and the left hemisphere network in charge of the expression dimension


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