scholarly journals Neurophysiological Subtypes of Depressive Disorders

Psychiatry ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 63-76
Author(s):  
I. A. Lapin ◽  
T. A. Rogacheva ◽  
A. A. Mitrofanov
Keyword(s):  
Depressive Disorders ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Statistical Research ◽  
Atypical Depression ◽  
Leading Role ◽  
Gamma Coherence ◽  
Left And Right ◽  
The Right ◽  
Bipolar Affective Disorders

Background: the clinical polymorphism of depressive disorders, together with the available data on the different responses of patients to treatment, motivate modern neuroscience to search for models that can explain such heterogeneity.Objective: to identify neurophysiological subtypes of depressive disorders.Patients and methods: 189 patients with moderate depression in the structure of a depressive episode (n = 42), recurrent depressive (n = 102) and bipolar affective disorders (n = 45); 56 healthy subjects. Clinical-psychopathological, psychometric, neurophysiological and statistical research methods were used in the work.The results: with the help of coherent EEG analysis, it is possible to identify at least 6 subtypes of the disorder, which characterize various branches of the pathogenesis of affective pathology, which go beyond the currently accepted nomenclature. The selected subtypes were determined by the profi les of dysfunctional interaction of various cortical zones in the alpha, beta and gamma ranges of the EEG. Subtype 1 was characterized by a decrease relative to the norm of imaginary alpha-coherence between the right parietal and left central, right parietal and left anterior temporal, as well as the right parietal and right anterior temporal EEG leads (P4-C3, P4-F7, P4-F8) and explained part of depressions, in the pathogenesis of which the leading role was played by violations of the promotion of positive and suppression of negative affect. Subtype 2 — an increase in beta-2-imaginary-coherence between the frontal leads of the left and right hemispheres, between the left frontal and right central cortex (F3-F4; F3-C4) and its decrease between the central cortical zones (C4-C3), in clinical terms this subtype was characterized by a persistent hedonic response and was associated with the clinical picture of atypical depression. Subtype 3 — an increase in imaginary alpha-coherence between the frontal (F4-F3) and its decrease between the central leads of the left and right hemisphere (C4-C3), correlated with the severity of depressive rumination. Subtype 4 — a decrease in imaginary alpha-coherence between the anterior temporal and frontal, as well as the anterior temporal and central cortex of the right hemisphere (F8-F4 and F8-C4), explained part of the depressions that developed against the background of avoidance personality disorder. Subtype 5 — a decrease in imaginary gamma coherence between the frontal and parietal, as well as the central and occipital cortical zones of the left hemisphere (F3-P3 and C3-O1), was associated with an outwardly oriented utilitarian style of thinking (alexithymia). Subtype 6 — a decrease in imaginary beta-1 coherence between the left central and right anterior temporal cortex (C3-F8), explained part of the depression with phobic and hypochondriacal disorders in the structure of recurrent depressive disorder. Such a clinical and biological typology seems new and promising in terms of searching for specifi c neurophysiological disorders in different types of depression and, accordingly, reaching differentiated therapeutic recommendations.

Dissociating Verbal and Nonverbal Conceptual Processing in the Human Brain

2006 ◽  
Vol 18 (6) ◽  
pp. 1018-1028 ◽  
Author(s):  
Guillaume Thierry ◽  
Cathy J. Price
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Functional Neuroimaging ◽  
Temporal Cortex ◽  
Conceptual System ◽  
Conceptual Processing ◽  
Making Sense ◽  
Left And Right ◽  
Neuropsychological Evidence ◽  
The Right

Functional neuroimaging has highlighted a left-hemisphere conceptual system shared by verbal and nonverbal processing despite neuropsychological evidence that the ability to recognize verbal and nonverbal stimuli can doubly dissociate in patients with left- and right-hemisphere lesions, respectively. Previous attempts to control for perceptual differences between verbal and nonverbal stimuli in functional neuroimaging studies may have hidden differences arising at the conceptual level. Here we used a different approach and controlled for perceptual confounds by looking for amodal verbal and nonverbal conceptual activations that are common to both the visual and auditory modalities. In addition to the left-hemisphere conceptual system activated by all meaningful stimuli, we observed the left/right double dissociation in verbal and nonverbal conceptual processing, predicted by neuropsychological studies. Left middle and superior temporal regions were selectively more involved in comprehending words—heard or read—and the right midfusiform and right posterior middle temporal cortex were selectively more involved in making sense of environmental sounds and images. Thus, the neuroanatomical basis of a verbal/nonverbal conceptual processing dissociation is established.

scholarly journals Localization of Syntactic and Semantic Brain Responses using Magnetoencephalography

2007 ◽  
Vol 19 (7) ◽  
pp. 1193-1205 ◽  
Author(s):  
Elisabet Service ◽  
Päivi Helenius ◽  
Sini Maury ◽  
Riitta Salmelin
Keyword(s):  
Temporal Lobe ◽  
Semantic Processing ◽  
Sentence Comprehension ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Word Class ◽  
Sentence Reading ◽  
Word Onset ◽  
Semantic Errors ◽  
The Right

Electrophysiological methods have been used to study the temporal sequence of syntactic and semantic processing during sentence comprehension. Two responses associated with syntactic violations are the left anterior negativity (LAN) and the P600. A response to semantic violation is the N400. Although the sources of the N400 response have been identified in the left (and right) temporal lobe, the neural signatures of the LAN and P600 have not been revealed. The present study used magnetoencephalography to localize sources of syntactic and semantic activation in Finnish sentence reading. Participants were presented with sentences that ended in normally inf lected nouns, nouns in an unacceptable case, verbs instead of nouns, or nouns that were correctly inflected but made no sense in the context. Around 400 msec, semantically anomalous last words evoked strong activation in the left superior temporal lobe with significant activation also for word class errors (N400). Weaker activation was seen for the semantic errors in the right hemisphere. Later, 600-800 msec after word onset, the strongest activation was seen to word class and morphosyntactic errors (P600). Activation was significantly weaker to semantically anomalous and correct words. The P600 syntactic activation was localized to bilateral sources in the temporal lobe, posterior to the N400 sources. The results suggest that the same general region of the superior temporal cortex gives rise to both LAN and N400 with bilateral reactivity to semantic manipulation and a left hemisphere effect to syntactic manipulation. The bilateral P600 response was sensitive to syntactic but not semantic factors.

Bihemispheric Language: How the Two Hemispheres Collaborate in the Processing of Language

2004 ◽  
Author(s):  
Norman D. Cook
Keyword(s):  
Language Processing ◽  
Right Hemisphere ◽  
Central Question ◽  
Linguistic Processing ◽  
Figures Of Speech ◽  
Language Functions ◽  
Left And Right ◽  
Level Of Understanding ◽  
The Right

Speech production in most people is strongly lateralized to the left hemisphere (LH), but language understanding is generally a bilateral activity. At every level of linguistic processing that has been investigated experimentally, the right hemisphere (RH) has been found to make characteristic contributions, from the processing of the affective aspects of intonation, through the appreciation of word connotations, the decoding of the meaning of metaphors and figures of speech, to the understanding of the overall coherency of verbal humour, paragraphs and short stories. If both hemispheres are indeed engaged in linguistic decoding and both processes are required to achieve a normal level of understanding, a central question concerns how the separate language functions on the left and right are integrated. This chapter reviews relevant studies on the hemispheric contributions to language processing and the role of interhemispheric communications in cognition.

Cross-modal Processing in the Occipito-temporal Cortex: A TMS Study of the Müller-Lyer Illusion

2011 ◽  
Vol 23 (8) ◽  
pp. 1987-1997 ◽  
Author(s):  
Flavia Mancini ◽  
Nadia Bolognini ◽  
Emanuela Bricolo ◽  
Giuseppe Vallar
Keyword(s):  
Temporal Cortex ◽  
Visual Modality ◽  
Lateral Occipital Complex ◽  
Lyer Illusion ◽  
Superior Parietal Cortex ◽  
Left And Right ◽  
Neural Underpinnings ◽  
The Right ◽  
Underlying Processes

The Müller-Lyer illusion occurs both in vision and in touch, and transfers cross-modally from vision to haptics [Mancini, F., Bricolo, E., & Vallar, G. Multisensory integration in the Müller-Lyer illusion: From vision to haptics. Quarterly Journal of Experimental Psychology, 63, 818–830, 2010]. Recent evidence suggests that the neural underpinnings of the Müller-Lyer illusion in the visual modality involve the bilateral lateral occipital complex (LOC) and right superior parietal cortex (SPC). Conversely, the neural correlates of the haptic and cross-modal illusions have never been investigated previously. Here we used repetitive TMS (rTMS) to address the causal role of the regions activated by the visual illusion in the generation of the visual, haptic, and cross-modal visuo-haptic illusory effects, investigating putative modality-specific versus cross-modal underlying processes. rTMS was administered to the right and the left hemisphere, over occipito-temporal cortex or SPC. rTMS over left and right occipito-temporal cortex impaired both unisensory (visual, haptic) and cross-modal processing of the illusion in a similar fashion. Conversely, rTMS interference over left and right SPC did not affect the illusion in any modality. These results demonstrate the causal involvement of bilateral occipito-temporal cortex in the representation of the visual, haptic, and cross-modal Müller-Lyer illusion, in favor of the hypothesis of shared underlying processes. This indicates that occipito-temporal cortex plays a cross-modal role in perception both of illusory and nonillusory shapes.

Right hemisphere speech perception revealed by amobarbital injection and electrical interference

Neurology ◽  
1998 ◽  
Vol 51 (2) ◽  
pp. 458-464 ◽  
Author(s):  
D. Boatman ◽  
J. Hart ◽  
R. P. Lesser ◽  
N. Honeycutt ◽  
N. B. Anderson ◽  
...  
Keyword(s):  
Speech Perception ◽  
Left Hemisphere ◽  
Temporal Lobe ◽  
Right Hemisphere ◽  
Adult Brain ◽  
Left Posterior ◽  
Left And Right ◽  
Sodium Amobarbital ◽  
The Right ◽  
Electrical Interference

Objective: To investigate the right hemispheric speech perception capabilities of an adult right-handed patient with seizures.Methods: Consecutive, unilateral, intracarotid sodium amobarbital injections and left hemispheric electrical interference mapping were used to determine lateralization and localization of speech perception, measured as syllable discrimination.Results: Syllable discrimination remained intact after left and right intracarotid sodium amobarbital injections. Language otherwise strongly lateralized to the left hemisphere. Despite evidence of bilateral speech perception capabilities, electrical interference testing in the left posterior temporal lobe impaired syllable discrimination.Conclusions: The results suggest a functionally symmetric, parallel system in the adult brain with preferential use of left hemispheric pathways for speech perception.

Hemispheric Asymmetries in a Signal Detection Task

1983 ◽  
Vol 57 (3) ◽  
pp. 923-929 ◽  
Author(s):  
John L. Andreassi ◽  
Charles S. Rebert ◽  
Ferol F. Larsen
Keyword(s):  
Signal Detection ◽  
Right Hemisphere ◽  
Reaction Times ◽  
Vigilance Task ◽  
Verbal Stimulus ◽  
Right Visual Field ◽  
Left And Right ◽  
The Right ◽  
Male Subjects ◽  
Central Fixation

Reaction time and signal detection performance were measured during a 78-min. vigilance task. 12 right-handed male subjects served in two experimental sessions. Subjects focused on a central fixation point and responded to signals presented at unpredictable times in one of three locations: 2.5° to right of central fixation, central, and 2.5° to the left of center. Subjects decided whether to press a response key with either the left or right hand with each presentation. Over-all vigilance performance (signal detections and response time) was similar for left and right visual-field presentations. Evidence from reaction times indicated that responses controlled by the left hemisphere were faster to a verbal stimulus (T) while reactions controlled by the right hemisphere were faster to an apparent non-verbal stimulus, an inverted T.

A Functional Neuroimaging Description of Two Deep Dyslexic Patients

1998 ◽  
Vol 10 (3) ◽  
pp. 303-315 ◽  
Author(s):  
C. J. Price ◽  
D. Howard ◽  
K. Patterson ◽  
E. A. Warburton ◽  
K. J. Friston ◽  
...  
Keyword(s):  
Left Hemisphere ◽  
Word Processing ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Broca's Area ◽  
Enhanced Activity ◽  
Left Posterior ◽  
Deep Dyslexia ◽  
The Right

Deep dyslexia is a striking reading disorder that results from left-hemisphere brain damage and is characterized by semantic errors in reading single words aloud (e.g., reading spirit as whisky). Two types of explanation for this syndrome have been advanced. One is that deep dyslexia results from a residual left-hemisphere reading system that has lost the ability to pronounce a printed word without reference to meaning. The second is that deep dyslexia reflects right-hemisphere word processing. Although previous attempts to adjudicate between these hypotheses have been inconclusive, the controversy can now be addressed by mapping functional anatomy. In this study, we demonstrate that reading by two deep dyslexic patients (CJ and JG) involves normal or enhanced activity in spared left-hemisphere regions associated with naming (Broca's area and the left posterior inferior temporal cortex) and with the meanings of words (the left posterior temporo-parietal cortex and the left anterior temporal cortex). In the right-hemisphere homologues of these regions, there was inconsistent activation within the normal group and between the deep dyslexic patients. One (CJ) showed enhanced activity (relative to the normals) in the right anterior inferior temporal cortex, the other (JG) in the right Broca's area, and both in the right frontal operculum. Although these differential right-hemisphere activations may have influenced the reading behavior of the patients, their activation patterns primarily reflect semantic and phonological systems in spared regions of the left hemisphere. These results preclude an explanation of deep dyslexia in terms of purely right-hemisphere word processing.

Cortical Representation of Swallowing: A Modified Dual Task Paradigm

2002 ◽  
Vol 94 (3) ◽  
pp. 1029-1040 ◽  
Author(s):  
Stephanie K. Daniels ◽  
David M. Corey ◽  
Cristen L. Barnes ◽  
Nikki M. Faucheaux ◽  
Daniel H. Priestly ◽  
...  
Keyword(s):  
Dual Task ◽  
Right Hemisphere ◽  
Index Finger ◽  
Finger Tapping ◽  
Left Index Finger ◽  
Cortical Representation ◽  
Word Repetition ◽  
Dual Task Paradigm ◽  
Left And Right ◽  
The Right

It is unclear whether the cortical representation of swallowing is lateralized to the left cerebral hemisphere, right hemisphere, or bilaterally represented. As dysphagia is common in acute stroke, it is important to elucidate swallowing lateralization to facilitate earlier detection of stroke patients who may be at greater risk for dysphagia and aspiration. In this study, a modified dual task paradigm was designed to study laterality of swallowing in a group of 14 healthy, young, right-handed, male adults. The subjects were studied at baseline and with interference. Baseline conditions, performed separately, were continuous swallowing, finger tapping using the right and left index fingers, and word repetition. Interference tasks, including tapping with the right index finger, tapping with the left index finger, and word repetition, were completed with and without swallowing. Finger-tapping rate was measured, and x-ray samples of the swallowing task were taped to measure swallowing rate and volume swallowed. At baseline, the rate of tapping the right index finger was significantly faster than that of the left index finger. There was a significant decline in the tapping rates of both left and right index fingers with swallowing interference. The volume per swallow was significantly reduced during the interfering language task of silent repetition. These results offer partial support for a bilateral representation of swallowing as well as suggest an important left hemispheric contribution to swallowing. However, it cannot be concluded that the left hemisphere is more important than the right, as a comparable right hemisphere task was not studied.

scholarly journals Drawing with the Non-dominant Hand: Implications for the Study of Construction

1998 ◽  
Vol 25 (4) ◽  
pp. 306-309 ◽  
Author(s):  
Sherma Zacharias ◽  
Andrew Kirk
Keyword(s):  
Neurological Disease ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Elderly Subjects ◽  
Dominant Hand ◽  
Left Hand ◽  
Right Hand ◽  
Left And Right ◽  
The Right ◽  
Right And Left Hand

ABSTRACT:Background:Constructional impairment following left vs. right hemisphere damage has been extensively studied using drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects.Methods:Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs testResults:Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand.Conclusions:The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LHD is due to an elementary motor disturbance related to use of the non-dominant hand.

scholarly journals Asymmetries in numerical density of pyramidal neurons in the fifth layer of the human posterior parietal cortex

2012 ◽  
Vol 69 (8) ◽  
pp. 681-685
Author(s):  
Natasa Djukic-Macut ◽  
Slobodan Malobabic ◽  
Natalija Stefanovic ◽  
Predrag Mandic ◽  
Tatjana Filipovic ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Pyramidal Neurons ◽  
Right Hemisphere ◽  
Numerical Density ◽  
Group I ◽  
Posterior Parietal ◽  
Left And Right ◽  
Layer V ◽  
The Right

Background/Aim. Both superior parietal lobule (SPL) of dorsolateral hemispheric surface and precuneus (PEC) of medial surface are the parts of posterior parietal cortex. The aim of this study was to determine the numerical density (NV) of pyramidal neurons in the layer V of SPL and PEC and their potential differences. Methods. From 20 (40 hemispheres) formaline fixed human brains (both sexes; 27- 65 years) tissue blocks from SPL and PEC from the left and right hemisphere were used. According to their size the brains were divided into two groups, the group I with the larger left (15 brains) and the group II with the larger right hemisphere (5 brains). Serial Nissl sections (5 ?m) of the left and right SPL and PEC were used for stereological estimation of NV of the layer V pyramidal neurons. Results. NV of pyramidal neurons in the layer V in the left SPL of brains with larger left hemispheres was significantly higher than in the left SPL of brains with larger right hemisphere. Comparing sides in brains with larger left hemisphere, the left SPL had higher NV than the right one, and then the left PEC, and the right SPL had significantly higher NV than the right PEC. Comparing sides in brains with the larger right hemisphere, the left SPL had significantly higher NV than left PEC, but the right SPL had significantly higher NV than left SPL and the right PEC. Conclusion. Generally, there is an inverse relationship of NV between the medial and lateral areas of the human posterior parietal cortex. The obtained values were different between the brains with larger left and right hemispheres, as well as between the SPL and PEC. In all the comparisons the left SPL had the highest values of NV of pyramidal neurons in the layer V (4771.80 mm-3), except in brains with the larger right hemisphere.

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