Individual differences in semantic switching flexibility: Effects of handedness

2009 ◽  
Vol 15 (6) ◽  
pp. 1023-1027 ◽  
Author(s):  
VARALAKSHMI SONTAM ◽  
STEPHEN D. CHRISTMAN ◽  
JOHN D. JASPER
Keyword(s):  
Individual Differences ◽  
Cognitive Deficits ◽  
Right Hemisphere ◽  
Assessment Tool ◽  
Normal Population ◽  
Semantic Fluency ◽  
Per Se ◽  
Animal Names ◽  
The Right ◽  
Fluency Task

AbstractThe semantic fluency task is a widely used assessment tool for evaluating memory-related cognitive deficits in neurological and neuropsychiatric disorders. The present study investigates individual differences in performance on this task in a normal population. The aim is to explore handedness differences in switching and clustering tendencies when performing this task. Consistent with our prediction, when asked to produce as many animal names as possible in 1 min, mixed handers demonstrated greater switching between different subcategories of animals than strong handers. These findings are interpreted in terms of the more diffuse spread of activation among conceptual representations in the right hemisphere, and greater access to right hemisphere processes in mixed handers. The findings have implications for the research communities using the semantic fluency task, irrespective of whether or not they are looking at handedness differences per se. (JINS, 2009, 15, 1023–1027.)

scholarly journals Patients with Lesions to Left Prefrontal Cortex (BA 9 and BA 10) Have Less Entrenched Beliefs and Are More Skeptical Reasoners

2019 ◽  
Vol 31 (11) ◽  
pp. 1674-1688
Author(s):  
Vinod Goel ◽  
Miriam Marling ◽  
Vanessa Raymont ◽  
Frank Krueger ◽  
Jordan Grafman
Keyword(s):  
Individual Differences ◽  
Brain Injuries ◽  
Right Hemisphere ◽  
Normal Population ◽  
Dependent Measure ◽  
Lesion Symptom Mapping ◽  
Considerable Individual Variation ◽  
The Right ◽  
Normal Controls

The effect of prior beliefs on reasoning and decision-making is a robust, poorly understood phenomenon, exhibiting considerable individual variation. Neuroimaging studies widely show the involvement of the left pFC in reasoning involving beliefs. However, little patient data exist to speak to the necessity and role of the left pFC in belief-based inference. To address this shortcoming, we tested 102 patients with unilateral focal penetrating traumatic brain injuries and 49 matched controls. Participants provided plausibility ratings (plausible/implausible) to simple inductive arguments and (separately) strength of believability ratings of the conclusion to those same arguments. A voxel-based lesion symptom mapping analysis identified 10 patients, all with lesions to the left pFC (BA 9 and BA 10) as rating significantly fewer arguments with highly believable conclusions as “plausible,” compared with all other patients. Subsequent analyses, incorporating the right hemisphere homologue of these patients ( n = 12) and normal controls ( n = 24), revealed patients with lesions to left pFC found fewer arguments plausible in the high believable than either of these groups, and there was no difference in the behavioral scores of the right pFC patients and normal controls. Further analysis, utilizing the belief ratings as the dependent measure, revealed a Group × Belief Rating interaction, with left pFC patients having less intense beliefs about the conclusions of moderately believable and highly believable arguments. We interpreted these results to indicate that lesions to left pFC (BA 9, BA 10) increase incredulity and make these patients more skeptical reasoners. The former can partially, but not fully, explain the latter. The other relevant factor may be that unilateral left pFC lesions disrupt hemispheric equilibrium and allow for an increased inhibitory role of the right pFC. We speculate that individual differences in belief bias in reasoning in the normal population may be a function of individual differences in the left and right pFC interactional dynamics.

scholarly journals Resting state alpha oscillatory activity is a valid and reliable marker of schizotypy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jelena Trajkovic ◽  
Francesco Di Gregorio ◽  
Francesca Ferri ◽  
Chiara Marzi ◽  
Stefano Diciotti ◽  
...  
Keyword(s):  
At Risk ◽  
Resting State ◽  
Right Hemisphere ◽  
Normal Population ◽  
Alpha Activity ◽  
Oscillatory Activity ◽  
Loop Current ◽  
Clinical Tool ◽  
Reliable Marker ◽  
The Right

AbstractSchizophrenia is among the most debilitating neuropsychiatric disorders. However, clear neurophysiological markers that would identify at-risk individuals represent still an unknown. The aim of this study was to investigate possible alterations in the resting alpha oscillatory activity in normal population high on schizotypy trait, a physiological condition known to be severely altered in patients with schizophrenia. Direct comparison of resting-state EEG oscillatory activity between Low and High Schizotypy Group (LSG and HSG) has revealed a clear right hemisphere alteration in alpha activity of the HSG. Specifically, HSG shows a significant slowing down of right hemisphere posterior alpha frequency and an altered distribution of its amplitude, with a tendency towards a reduction in the right hemisphere in comparison to LSG. Furthermore, altered and reduced connectivity in the right fronto-parietal network within the alpha range was found in the HSG. Crucially, a trained pattern classifier based on these indices of alpha activity was able to successfully differentiate HSG from LSG on tested participants further confirming the specific importance of right hemispheric alpha activity and intrahemispheric functional connectivity. By combining alpha activity and connectivity measures with a machine learning predictive model optimized in a nested stratified cross-validation loop, current research offers a promising clinical tool able to identify individuals at-risk of developing psychosis (i.e., high schizotypy individuals).

scholarly journals Assessing animal individuality: links between personality and laterality in pigs

2018 ◽  
Vol 65 (5) ◽  
pp. 541-551 ◽  
Author(s):  
Charlotte Goursot ◽  
Sandra Düpjan ◽  
Ellen Kanitz ◽  
Armin Tuchscherer ◽  
Birger Puppe ◽  
...  
Keyword(s):  
Individual Differences ◽  
Personality Traits ◽  
Right Hemisphere ◽  
Motor Functions ◽  
Salivary Testosterone ◽  
Single Motor ◽  
Selective Forces ◽  
The Right ◽  
And Coping ◽  
Cerebral Processing

Abstract Animal individuality is challenging to explain because individual differences are regulated by multiple selective forces that lead to unique combinations of characteristics. For instance, the study of personality, a core aspect of individuality, may benefit from integrating other factors underlying individual differences, such as lateralized cerebral processing. Indeed, the approach-withdrawal hypothesis (the left hemisphere controls approach behavior, the right hemisphere controls withdrawal behavior), may account for differences in boldness or exploration between left and right hemispheric dominant individuals. To analyze the relationships between personality and laterality we tested 80 male piglets with established laterality patterns for 2 motor functions (tail curling direction and the side of the snout used for manipulation) and a combined classification integrating both motor functions using cluster analysis. We analyzed basal salivary testosterone and cortisol along with their behavior in standardized tests as pre-established indicators of different personality traits (Boldness, Exploration, Activity, Sociability, and Coping). We found that the direction of the single motor biases showed significant associations with few personality traits. However, the combined laterality classification showed more, and more robust, significant associations with different personality traits compared with the single motor biases. These results supported the approach-withdrawal hypothesis because right-biased pigs were bolder and more explorative in a context of novelty. Additionally, right-biased pigs were more sociable than left-biased pigs. Therefore, the present study indicates that personality is indeed related to lateralized cerebral processing and provides insight into the multifactorial nature of individuality.

Verbal and design fluency in patients with frontal lobe lesions

2001 ◽  
Vol 7 (5) ◽  
pp. 586-596 ◽  
Author(s):  
JULIANA V. BALDO ◽  
ARTHUR P. SHIMAMURA ◽  
DEAN C. DELIS ◽  
JOEL KRAMER ◽  
EDITH KAPLAN
Keyword(s):  
Frontal Cortex ◽  
Frontal Lobe ◽  
Verbal Fluency ◽  
Right Hemisphere ◽  
Verbal Fluency Task ◽  
Frontal Lobe Lesions ◽  
Design Fluency ◽  
The Right ◽  
Frontal Lesions ◽  
Fluency Task

The ability to generate items belonging to categories in verbal fluency tasks has been attributed to frontal cortex. Nonverbal fluency (e.g., design fluency) has been assessed separately and found to rely on the right hemisphere or right frontal cortex. The current study assessed both verbal and nonverbal fluency in a single group of patients with focal, frontal lobe lesions and age- and education-matched control participants. In the verbal fluency task, participants generated items belonging to both letter cues (F, A, and S) and category cues (animals and boys' names). In the design fluency task, participants generated novel designs by connecting dot arrays with 4 straight lines. A switching condition was included in both verbal and design fluency tasks and required participants to switch back and forth between different sets (e.g., between naming fruits and furniture). As a group, patients with frontal lobe lesions were impaired, compared to control participants, on both verbal and design fluency tasks. Patients with left frontal lesions performed worse than patients with right frontal lesions on the verbal fluency task, but the 2 groups performed comparably on the design fluency task. Both patients and control participants were impacted similarly by the switching conditions. These results suggest that verbal fluency is more dependent on left frontal cortex, while nonverbal fluency tasks, such as design fluency, recruit both right and left frontal processes. (JINS, 2001, 7, 586–596.)

scholarly journals Asymmetric, dynamic adaptation in prefrontal cortex during dichotic listening tasks

2019 ◽  
Author(s):  
J. A. N. Fisher ◽  
I. Gumenchuk ◽  
O. Rogovin ◽  
A. G. Yodh ◽  
D. R. Busch
Keyword(s):  
Blood Flow ◽  
Prefrontal Cortex ◽  
Otoacoustic Emissions ◽  
Dichotic Listening ◽  
Right Hemisphere ◽  
Assessment Tool ◽  
Regional Blood Flow ◽  
Speech Comprehension ◽  
Distortion Product ◽  
The Right

AbstractSpeech comprehension relies on highly distributed, dynamically interconnected neuroanatomical loci. Accordingly, performance on complex speech processing tasks such as dichotic listening can be used to assess the integrity and health of many functional and structural aspects of the brain. Despite the potential merits as a clinical assessment tool, however, the neural substrates activated during dichotic listening remain relatively opaque at higher processing levels. Ultimately, this knowledge gap limits diagnostic use of the task. At the level of the prefrontal cortex, dichotic listening induces an asymmetric response wherein regions on the right hemisphere exhibit a higher functional activation than on the left. Superficially, this finding is counterintuitive given the left hemisphere’s dominance for speech and language. To obtain a more in-depth perspective on the potentially distinct roles of the right and left prefrontal cortex, we optically monitored cerebral blood flow in the dorsolateral prefrontal cortex (DLPFC) during dichotic listening tasks in human subjects. The method permitted us to avoid systematic experimental confounds that functional magnetic resonance imaging (fMRI) measurements suffer from, namely the influence of scanner noise. In addition to reproducing the documented larger activation amplitude in the right hemisphere, we also found that repeated listening task blocks were associated with altered kinetics of blood flow in the right, but not the left DLPFC. Interestingly, subjects with the most prominent regional blood flow changes in the right hemisphere also displayed large distortion product otoacoustic emissions (DPOAEs) in the left ear, possibly signaling a correlation between prefrontal activity and top-down listening control infrastructure through medial olivocochlear efferent projections to the inner ear. Overall, our results suggest that the right prefrontal cortical regions play an active role in optimizing task performance.

scholarly journals Viability in Multiplex Lexical Networks and Machine Learning Characterizes Human Creativity

2019 ◽  
Vol 3 (3) ◽  
pp. 45 ◽  
Author(s):  
Massimo Stella ◽  
Yoed N. Kenett
Keyword(s):  
Machine Learning ◽  
Individual Differences ◽  
Language Learning ◽  
Conceptual Knowledge ◽  
Area Under The Curve ◽  
Mental Lexicon ◽  
Network Models ◽  
Semantic Fluency ◽  
Multiplex Network ◽  
Fluency Task

Previous studies have shown how individual differences in creativity relate to differences in the structure of semantic memory. However, the latter is only one aspect of the whole mental lexicon, a repository of conceptual knowledge that is considered to simultaneously include multiple types of conceptual similarities. In the current study, we apply a multiplex network approach to compute a representation of the mental lexicon combining semantics and phonology and examine how it relates to individual differences in creativity. This multiplex combination of 150,000 phonological and semantic associations identifies a core of words in the mental lexicon known as viable cluster, a kernel containing simpler to parse, more general, concrete words acquired early during language learning. We focus on low (N = 47) and high (N = 47) creative individuals’ performance in generating animal names during a semantic fluency task. We model this performance as the outcome of a mental navigation on the multiplex lexical network, going within, outside, and in-between the viable cluster. We find that low and high creative individuals differ substantially in their access to the viable cluster during the semantic fluency task. Higher creative individuals tend to access the viable cluster less frequently, with a lower uncertainty/entropy, reaching out to more peripheral words and covering longer multiplex network distances between concepts in comparison to lower creative individuals. We use these differences for constructing a machine learning classifier of creativity levels, which leads to an accuracy of 65 . 0 ± 0 . 9 % and an area under the curve of 68 . 0 ± 0 . 8 % , which are both higher than the random expectation of 50%. These results highlight the potential relevance of combining psycholinguistic measures with multiplex network models of the mental lexicon for modelling mental navigation and, consequently, classifying people automatically according to their creativity levels.

A-52 Evolving Cognitive and Neuropsychiatric Sequelae of Ruptured Arteriovenous Malformation Following Neurosurgical Intervention

2021 ◽  
Vol 36 (6) ◽  
pp. 1093-1094
Author(s):  
Shelby Ming ◽  
John B O'Hara ◽  
Carolina Posada
Keyword(s):  
Formal Education ◽  
Right Hemisphere ◽  
External Ventricular Drain ◽  
Occipital Lobe ◽  
Intracerebral Hematoma ◽  
Neuropsychological Evaluation ◽  
Semantic Fluency ◽  
Congenital Origin ◽  
History Of ◽  
The Right

Abstract Objective Arteriovenous malformations (AVMs) are tangled masses of arteries and veins of congenital origin. AVMs are rare (~4.3% in the general population) and symptomatic cases are rarer still (0.1–1%). AVMs account for strokes in 1–2% of cases. We present the case of a 59-year-old, right-handed, Caucasian male, with nine years of formal education, who was evaluated as an inpatient following a ruptured AVM. Method Patient with known history of AVM (Figure 1) presented with headache and new onset seizure. Computerized tomography (CT) revealed rupture of an AVM at the right temporal-occipital junction, with resulting intraparenchymal hemorrhage within the right parieto-occipital lobe and the right ventricular system and 0.8 cm left midline shift (Figure 2). The patient underwent emergency craniotomy for evacuation of intracerebral hematoma, resection of AVM, and placement of right external ventricular drain (EVD). Electroencephalograom (EEG) revealed focal cortical dysfunction over the right hemisphere and moderate encephalopathy. Results (Table 1). Neuropsychological evaluation six days following emergency craniotomy revealed primary impairment in visuoperceptual and visuoconstructional skills (including left neglect; Figures 3 & 4), impairments in working memory, learning/memory of verbal information (with intact recognition), as well as impairment in aspects of language (semantic fluency). These were accompanied by dense anosagnosia pertaining to cognitive deficits, but intact insight related to his hospitalization. Conclusions This is a rare case of symptomatic AVM with neuropsychological evaluation data highlighting the associated evolving cognitive (e.g., left neglect and visuoperceptual disturbance) and neuropsychiatric deficits (e.g., dense anosagnosia) in the context of recent neurosurgical interventions (e.g., evacuation of hemorrhage, placement of EVD, etc.).

scholarly journals Lateralized Cerebellar Contributions to Word Generation: A Phonemic and Semantic Fluency Study

2010 ◽  
Vol 23 (1-2) ◽  
pp. 31-37 ◽  
Author(s):  
Tom A. Schweizer ◽  
Michael P. Alexander ◽  
B. A. Susan Gillingham ◽  
Michael Cusimano ◽  
Donald T. Stuss
Keyword(s):  
Verbal Fluency ◽  
Cerebellar Lesion ◽  
Healthy Controls ◽  
Semantic Fluency ◽  
Word Generation ◽  
Phonemic Fluency ◽  
Cerebellar Lesions ◽  
The Right ◽  
Fluency Task ◽  
Neuropsychological Findings

Impairment on verbal fluency tasks has been one of the more consistently reported neuropsychological findings after cerebellar lesions, but it has not been uniformly observed and the possible underlying cognitive basis has not been investigated. We tested twenty-two patients with chronic, unilateral cerebellar lesions (12 Left, 10 Right) and thirty controls on phonemic and semantic fluency tasks. We measured total words produced, words produced in the initial 15 seconds, errors and strategy switches. In the phonemic fluency task, the right cerebellar lesion (RC) group produced significantly fewer words compared to the left cerebellar lesion (LC) group and healthy controls, particularly over the first 15 seconds of the task with no increase in errors and significantly fewer switches over the entire task. In the semantic fluency task there was only a modest decrease in total words in the RC group compared to controls. RC lesions impair fluency with many of the same performance characteristics as left prefrontal lesions. This supports the hypotheses of a prefrontal-lateral cerebellar system for modulation of attention/executive or strategy demanding tasks.

Differences in Task and Use of Language: A Study of Lateral Eye Movement

1981 ◽  
Vol 52 (3) ◽  
pp. 995-1002 ◽  
Author(s):  
Joan Katz ◽  
Patricia Salt
Keyword(s):  
Individual Differences ◽  
Eye Movements ◽  
Test Performance ◽  
Right Hemisphere ◽  
Scholastic Aptitude Test ◽  
Aptitude Test ◽  
College Majors ◽  
Scholastic Aptitude ◽  
Lateral Eye ◽  
The Right

The lateral eye movements of 25 right-handed, native-English speakers 18 to 30 yr. of age were recorded. Both task and individual differences in the utilization of cerebral hemispheres were found. Earlier findings of task differences in the direction of eye movements for verbal and spatial questions were confirmed, and previous evidence of the involvement of the right hemisphere with “unpleasant” emotion was supported. No differences in performance on the Scholastic Aptitude Test were found between consistent and inconsistent eye movers. Individual differences between right-eye movers and left-eye movers were found in their choice of college majors, Scholastic Aptitude Test performance, and in their course preferences. The current study also presents evidence of differences in language use by adults which seem related to cerebral hemispheric activity.

Auditory Hallucinations of Hearing Voices in 375 Normal Subjects

1983 ◽  
Vol 3 (2) ◽  
pp. 99-113 ◽  
Author(s):  
Thomas B. Posey ◽  
Mary E. Losch
Keyword(s):  
Right Hemisphere ◽  
Normal Population ◽  
Normal Subjects ◽  
Auditory Hallucinations ◽  
Cerebral Laterality ◽  
Hearing Voices ◽  
Weak Support ◽  
Clinical Literature ◽  
The Subject ◽  
The Right

Jaynes' elaborate theory of the evolution of human consciousness speculates that unconscious language use by the right hemisphere produced frequent auditory hallucinations in primitive people [1]. Jaynes offers some explanation as to why hearing voices would now be less common. It is parsimonious, however, to predict that hearing voices is still common, although usually unreported, in the modern normal population. Some clinical literature gives support to this prediction. This study tested the prediction by means of surveying 375 college students with a two-part questionnaire. The first section presented fourteen different examples of auditory hallucinations and asked whether the subject had experienced such occurrences. The second section asked for information concerning the characteristics of any hallucinated voices and for information about the subject that might relate to cerebral laterality. The results support the prediction that hearing voices is common within the normal population. Overall, 71 percent of the sample reported some experience with brief, auditory hallucinations of the voice type in wakeful situations. Hypnagogic and hypnopompic hallucinations were also reported. The most frequent incidents were hearing a voice call one's name aloud when alone (36%) and hearing one's thoughts as if spoken aloud (39%). Interviews and MMPI results obtained from twenty selected subjects suggested that these reports of hearing voices were not related to pathology. Further findings of a significant relationship between high rates of auditory hallucinations and the extent to which subjects reported skills in music, art, and poetry were interpreted as weak support for Jaynes' speculation that right hemisphere activity may account for auditory hallucinations. Overall, the results are seen as supportive of several of Jaynes' theoretical points.

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