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1.
Mol Psychiatry ; 27(7): 2976-2984, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35422471

RESUMEN

Functional impairment is a core feature of both autism and schizophrenia spectrum disorders. While diagnostically independent, they can co-occur in the same individual at both the trait and diagnostic levels. The effect of such co-occurrence is hypothesized to worsen functional impairment. The diametric model, however, suggests that the disorders are etiologically and phenotypically diametrical, representing the extreme of a unidimensional continuum of cognition and behavior. A central prediction of this model is that functional impairment would be attenuated in individuals with mixed symptom expressions or genetic liability to both disorders. We tested this hypothesis in two clinical populations and one healthy population. In individuals with chronic schizophrenia and in individuals with first episode psychosis we evaluated the combined effect of autistic traits and positive psychotic symptoms on psychosocial functioning. In healthy carriers of alleles of copy number variants (CNVs) that confer risk for both autism and schizophrenia, we also evaluated whether variation in psychosocial functioning depended on the combined risk conferred by each CNV. Relative to individuals with biased symptom/CNV risk profiles, results show that functional impairments are attenuated in individuals with relatively equal levels of positive symptoms and autistic traits-and specifically stereotypic behaviors-, and in carriers of CNVs with relatively equal risks for either disorder. However, the pattern of effects along the "balance axis" varied across the groups, with this attenuation being generally less pronounced in individuals with high-high symptom/risk profile in the schizophrenia and CNV groups, and relatively similar for low-low and high-high individuals in the first episode psychosis group. Lower levels of functional impairments in individuals with "balanced" symptom profile or genetic risks would suggest compensation across mechanisms associated with autism and schizophrenia. CNVs that confer equal risks for both disorders may provide an entry point for investigations into such compensatory mechanisms. The co-assessment of autism and schizophrenia may contribute to personalized prognosis and stratification strategies.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Trastornos Psicóticos , Esquizofrenia , Trastorno del Espectro Autista/complicaciones , Trastorno del Espectro Autista/genética , Trastorno Autístico/complicaciones , Variaciones en el Número de Copia de ADN , Humanos , Funcionamiento Psicosocial , Trastornos Psicóticos/genética
2.
Psychol Sci ; 32(12): 1918-1936, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34825598

RESUMEN

Age-related decline in theory of mind (ToM) may be due to waning executive control, which is necessary for resolving conflict when reasoning about other individuals' mental states. We assessed how older (n = 50) and younger (n = 50) adults were affected by three theoretically relevant sources of conflict within ToM: competing self-other perspectives, competing cued locations, and outcome knowledge. We examined which best accounted for age-related difficulty with ToM. Our data show unexpected similarity between age groups when people are representing a belief incongruent with their own. Individual differences in attention and response speed best explained the degree of conflict experienced through incompatible self-other perspectives. However, older adults were disproportionately affected by managing conflict between cued locations. Age and spatial working memory were most relevant for predicting the magnitude of conflict elicited by conflicting cued locations. We suggest that previous studies may have underestimated older adults' ToM proficiency by including unnecessary conflict in ToM tasks.


Asunto(s)
Envejecimiento Saludable , Teoría de la Mente , Anciano , Cognición/fisiología , Función Ejecutiva/fisiología , Humanos , Memoria a Corto Plazo , Pruebas Neuropsicológicas , Teoría de la Mente/fisiología
3.
Proc Biol Sci ; 287(1925): 20200244, 2020 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-32290800

RESUMEN

The commonly used paradigm to investigate Dennet's 'intentional stance' compares neural activation when participants compete with a human versus a computer. This paradigm confounds whether the opponent is natural or artificial and whether it is intentional or an automaton. This functional magnetic resonance imaging study is, to our knowledge, the first to investigate the intentional stance by orthogonally varying perceptions of the opponents' intentionality (responding actively or passively according to a script) and embodiment (human or a computer). The mere perception of the opponent (whether human or computer) as intentional activated the mentalizing network: the temporoparietal junction (TPJ) bilaterally, right temporal pole, anterior paracingulate cortex (aPCC) and the precuneus. Interacting with humans versus computers induced activations in a more circumscribed right lateralized subnetwork within the mentalizing network, consisting of the TPJ and the aPCC, possibly reflective of the tendency to spontaneously attribute intentionality to humans. The interaction between intentionality (active versus passive) and opponent (human versus computer) recruited the left frontal pole, possibly in response to violations of the default intentional stance towards humans and computers. Employing an orthogonal design is important to adequately capture Dennett's conception of the intentional stance as a mentalizing strategy that can apply equally well to humans and other intentional agents.


Asunto(s)
Teoría de la Mente , Mapeo Encefálico/métodos , Computadores , Humanos , Imagen por Resonancia Magnética , Lóbulo Parietal , Lóbulo Temporal
4.
Cogn Process ; 21(3): 341-363, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32152767

RESUMEN

Motor participation in phonological processing can be modulated by task nature across the speech perception to speech production range. The pars opercularis of the left inferior frontal gyrus (LIFG) would be increasingly active across this range, because of changing motor demands. Here, we investigated with simultaneous tDCS and fMRI whether the task load modulation of tDCS effects translates into predictable patterns of functional connectivity. Findings were analysed under the "multi-node framework", according to which task load and the network structure underlying cognitive functions are modulators of tDCS effects. In a within-subject study, participants (N = 20) performed categorical perception, lexical decision and word naming tasks [which differentially recruit the target of stimulation (LIFG)], which were repeatedly administered in three tDCS sessions (anodal, cathodal and sham). The LIFG, left superior temporal gyrus and their right homologues formed the target network subserving phonological processing. C-tDCS inhibition and A-tDCS excitation should increase with task load. Correspondingly, the larger the task load, the larger the relevance of the target for the task and smaller the room for compensation of C-tDCS inhibition by less relevant nodes. Functional connectivity analyses were performed with partial correlations, and network compensation globally inferred by comparing the relative number of significant connections each condition induced relative to sham. Overall, simultaneous tDCS and fMRI was adequate to show that motor participation in phonological processing is modulated by task nature. Network responses induced by C-tDCS across phonological processing tasks matched predictions. A-tDCS effects were attributed to optimisation of network efficiency.


Asunto(s)
Estimulación Transcraneal de Corriente Directa , Atención , Humanos , Imagen por Resonancia Magnética , Corteza Prefrontal , Habla
5.
J Neurosci Res ; 97(11): 1430-1454, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31254311

RESUMEN

Transcranial direct current stimulation (tDCS) effects in cognition are inconsistent across studies. This study aimed to discuss why typical models might be insufficient to explain these effects, and to investigate a brain state factor, task load, with behavioral experiments on phonological processing. The motor theory of speech perception states that motor codes for articulation take part in speech perception, a view sharpened by neuroimaging findings, which show that the motor role in phonological processing is weighted by the nature of the tasks. Three groups of 20 participants, each under a different tDCS condition (anodal, cathodal, or sham), performed a categorical perception (CP), a lexical decision (LD), and a word naming (WN) task while stimulated on the pars opercularis of the left inferior frontal gyrus, a language area typically involved with the motor role. These tasks were assumed to be subserved by a network of nodes which included the target, believed to be increasingly relevant for performance from speech perception to speech production. A-tDCS facilitation and C-tDCS downregulation should directly increase with the relevance of the target for the task. Downregulation of a low relevance node could result in facilitation by compensation from other nodes. Overall, our brain stimulation findings support the neuroimaging literature in that motor participation in phonological processing depends on task nature and show that tDCS effects are modulated by task load relative to the target. Outcomes such as the improved performance following cathodal tDCS in CP and WN suggest that compensatory mechanisms may take place when the tasks involve more complex neuronal networks.


Asunto(s)
Área de Broca/fisiología , Percepción del Habla/fisiología , Habla/fisiología , Estimulación Transcraneal de Corriente Directa , Adulto , Femenino , Humanos , Masculino , Desempeño Psicomotor , Adulto Joven
6.
J Neurosci ; 37(26): 6231-6241, 2017 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-28546307

RESUMEN

Mounting evidence indicates that posterolateral portions of the cerebellum (right Crus I/II) contribute to language processing, but the nature of this role remains unclear. Based on a well-supported theory of cerebellar motor function, which ascribes to the cerebellum a role in short-term prediction through internal modeling, we hypothesize that right cerebellar Crus I/II supports prediction of upcoming sentence content. We tested this hypothesis using event-related fMRI in male and female human subjects by manipulating the predictability of written sentences. Our design controlled for motor planning and execution, as well as for linguistic features and working memory load; it also allowed separation of the prediction interval from the presentation of the final sentence item. In addition, three further fMRI tasks captured semantic, phonological, and orthographic processing to shed light on the nature of the information processed. As hypothesized, activity in right posterolateral cerebellum correlated with the predictability of the upcoming target word. This cerebellar region also responded to prediction error during the outcome of the trial. Further, this region was engaged in phonological, but not semantic or orthographic, processing. This is the first imaging study to demonstrate a right cerebellar contribution in language comprehension independently from motor, cognitive, and linguistic confounds. These results complement our work using other methodologies showing cerebellar engagement in linguistic prediction and suggest that internal modeling of phonological representations aids language production and comprehension.SIGNIFICANCE STATEMENT The cerebellum is traditionally seen as a motor structure that allows for smooth movement by predicting upcoming signals. However, the cerebellum is also consistently implicated in nonmotor functions such as language and working memory. Using fMRI, we identify a cerebellar area that is active when words are predicted and when these predictions are violated. This area is active in a separate task that requires phonological processing, but not in tasks that require semantic or visuospatial processing. Our results support the idea of prediction as a unifying cerebellar function in motor and nonmotor domains. We provide new insights by linking the cerebellar role in prediction to its role in verbal working memory, suggesting that these predictions involve phonological processing.


Asunto(s)
Cerebelo/fisiología , Lateralidad Funcional/fisiología , Lenguaje , Memoria a Corto Plazo/fisiología , Red Nerviosa/fisiología , Aprendizaje Verbal/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto Joven
7.
J Cogn Neurosci ; 30(6): 851-866, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29393718

RESUMEN

Visual attention allows the allocation of limited neural processing resources to stimuli based on their behavioral priorities. The selection of task-relevant visual targets entails the processing of multiple competing stimuli and the suppression of distractors that may be either perceptually salient or perceptually similar to targets. The posterior parietal cortex controls the interaction between top-down (task-driven) and bottom-up (stimulus-driven) processes competing for attentional selection, as well as spatial distribution of attention. Here, we examined whether biparietal transcranial direct current stimulation (tDCS) would modulate the interaction between top-down and bottom-up processes in visual attention. Visual attention function was assessed with a visual discrimination task, in which a lateralized target was presented alone or together with a contralateral, similar or salient, distractor. The accuracy and RTs were measured before and during three stimulation sessions (sham, right anodal/left cathodal, left anodal/right cathodal). The analyses demonstrated (i) polarity-dependent effects of tDCS on the accuracy of target discrimination, but only when the target was presented with a similar distractor; (ii) the tDCS-triggered effects on the accuracy of discriminating targets, accompanied by a similar distractor, varied according to the target location; and (iii) overall detrimental effects of tDCS on RTs were observed, regardless of target location, distractor type, and polarity of the stimulation. We conclude that the observed polarity, distractor type, and target location-dependent effects of biparietal tDCS on the accuracy of target detection resulted from both a modulation of the interaction between top-down and bottom-up attentional processes and the interhemispheric competition mechanisms guiding attentional selection and spatial deployment of attention.


Asunto(s)
Atención/fisiología , Lóbulo Parietal/fisiología , Percepción Visual/fisiología , Adulto , Femenino , Humanos , Masculino , Estimulación Luminosa , Desempeño Psicomotor , Tiempo de Reacción , Estimulación Transcraneal de Corriente Directa , Adulto Joven
8.
Hum Brain Mapp ; 39(3): 1354-1366, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29250867

RESUMEN

Huntington's disease (HD) can impair social cognition. This study investigated whether patients with HD exhibit neural differences to healthy controls when they are considering mental and physical states relating to the static expressions of human eyes. Thirty-two patients with HD and 28 age-matched controls were scanned with fMRI during two versions of the Reading the Mind in the Eyes Task: The standard version requiring mental state judgments, and a comparison version requiring judgments about age. HD was associated with behavioral deficits on only the mental state eyes task. Contrasting the two versions of the eyes task (mental state > age judgment) revealed hypoactivation within left middle frontal gyrus and supramarginal gyrus in HD. Subgroup analyses comparing premanifest HD patients to age-matched controls revealed reduced activity in right supramarginal gyrus and increased activity in anterior cingulate during mental state recognition in these patients, while manifest HD was associated with hypoactivity in left insula and left supramarginal gyrus. When controlling for the effects of healthy aging, manifest patients exhibited declining activation within areas including right temporal pole. Our findings provide compelling evidence for a selective impairment of internal emotional status when patients with HD appraise facial features in order to make social judgements. Differential activity in temporal and anterior cingulate cortices may suggest that poor emotion regulation and emotional egocentricity underlie impaired mental state recognition in premanifest patients, while more extensive mental state recognition impairments in manifest disease reflect dysfunction in neural substrates underlying executive functions, and the experience and interpretation of emotion.


Asunto(s)
Encéfalo/fisiopatología , Reconocimiento Facial/fisiología , Enfermedad de Huntington/fisiopatología , Reconocimiento en Psicología/fisiología , Percepción Social , Teoría de la Mente/fisiología , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Emociones/fisiología , Femenino , Humanos , Enfermedad de Huntington/diagnóstico por imagen , Enfermedad de Huntington/tratamiento farmacológico , Enfermedad de Huntington/psicología , Juicio/fisiología , Imagen por Resonancia Magnética , Masculino
9.
Hum Brain Mapp ; 37(10): 3502-14, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27195942

RESUMEN

When required to represent a perspective that conflicts with one's own, functional magnetic resonance imaging (fMRI) suggests that the right ventrolateral prefrontal cortex (rvlPFC) supports the inhibition of that conflicting self-perspective. The present task dissociated inhibition of self-perspective from other executive control processes by contrasting belief reasoning-a cognitive state where the presence of conflicting perspectives was manipulated-with a conative desire state wherein no systematic conflict existed. Linear modeling was used to examine the effect of continuous theta burst stimulation (cTBS) to rvlPFC on participants' reaction times in belief and desire reasoning. It was anticipated that cTBS applied to rvlPFC would affect belief but not desire reasoning, by modulating activity in the Ventral Attention System (VAS). We further anticipated that this effect would be mediated by functional connectivity within this network, which was identified using resting state fMRI and an unbiased model-free approach. Simple reaction-time analysis failed to detect an effect of cTBS. However, by additionally modeling individual measures from within the stimulated network, the hypothesized effect of cTBS to belief (but, importantly, not desire) reasoning was demonstrated. Structural morphology within the stimulated region, rvlPFC, and right temporoparietal junction were demonstrated to underlie this effect. These data provide evidence that inconsistencies found with cTBS can be mediated by the composition of the functional network that is being stimulated. We suggest that the common claim that this network constitutes the VAS explains the effect of cTBS to this network on false belief reasoning. Hum Brain Mapp 37:3502-3514, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Encéfalo/fisiología , Conflicto Psicológico , Imagen por Resonancia Magnética , Solución de Problemas/fisiología , Teoría de la Mente/fisiología , Estimulación Magnética Transcraneal , Adulto , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Función Ejecutiva/fisiología , Femenino , Humanos , Inhibición Psicológica , Modelos Lineales , Masculino , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiología , Pruebas Neuropsicológicas , Tiempo de Reacción , Descanso , Adulto Joven
10.
Cereb Cortex ; 25(7): 1715-23, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24448559

RESUMEN

Prior evidence for early activity in Broca's area during reading may reflect fast access to articulatory codes in left inferior frontal gyrus pars opercularis (LIFGpo). We put this hypothesis to test using a benchmark for articulatory involvement in reading known as the masked onset priming effect (MOPE). In masked onset priming, briefly presented pronounceable strings of letters that share an initial phoneme with subsequently presented target words (e.g., gilp-GAME) facilitate word naming responses compared with unrelated primes (dilp-GAME). Crucially, these priming effects only occur when the task requires articulation (naming), and not when it requires lexical decisions. A standard explanation of masked onset priming is that it reflects fast computation of articulatory output codes from letter representations. We therefore predicted 1) that activity in left IFG pars opercularis would be modulated by masked onset priming, 2) that priming-related modulation in LIFGpo would immediately follow activity in occipital cortex, and 3) that this modulation would be greater for naming than for lexical decision. These predictions were confirmed in a magnetoencephalography (MEG) priming study. MOPEs emerged in left IFG at ∼100 ms posttarget onset, and the priming effects were more sustained when the task involved articulation.


Asunto(s)
Encéfalo/fisiología , Área de Broca/fisiología , Reconocimiento Visual de Modelos/fisiología , Lectura , Mapeo Encefálico , Toma de Decisiones/fisiología , Femenino , Humanos , Pruebas del Lenguaje , Magnetoencefalografía , Masculino , Pruebas Neuropsicológicas , Tiempo de Reacción , Memoria Implícita/fisiología , Adulto Joven
11.
Proc Biol Sci ; 282(1808): 20150563, 2015 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-25972469

RESUMEN

Difficulties with the ability to appreciate the perspective of others (mentalizing) is central to both autism and schizophrenia spectrum disorders. While the disorders are diagnostically independent, they can co-occur in the same individual. The effect of such co-morbidity is hypothesized to worsen mentalizing abilities. The recent influential 'diametric brain theory', however, suggests that the disorders are etiologically and phenotypically diametrical, predicting opposing effects on one's mentalizing abilities. To test these contrasting hypotheses, we evaluated the effect of psychosis and autism tendencies on the perspective-taking (PT) abilities of 201 neurotypical adults, on the assumption that autism tendencies and psychosis proneness are heritable dimensions of normal variation. We show that while both autism tendencies and psychosis proneness induce PT errors, their interaction reduced these errors. Our study is, to our knowledge, the first to observe that co-occurring autistic and psychotic traits can exert opposing influences on performance, producing a normalizing effect possibly by way of their diametrical effects on socio-cognitive abilities. This advances the notion that some individuals may, to some extent, be buffered against developing either illness or present fewer symptoms owing to a balanced expression of autistic and psychosis liability.


Asunto(s)
Trastorno Autístico/psicología , Trastornos Psicóticos/psicología , Teoría de la Mente , Adulto , Femenino , Humanos , Masculino , Adulto Joven
12.
J Cogn Neurosci ; 26(4): 683-98, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24236763

RESUMEN

The medial pFC (mPFC) is frequently reported to play a central role in Theory of Mind (ToM). However, the contribution of this large cortical region in ToM is not well understood. Combining a novel behavioral task with fMRI, we sought to demonstrate functional divisions between dorsal and rostral mPFC. All conditions of the task required the representation of mental states (beliefs and desires). The level of demands on cognitive control (high vs. low) and the nature of the demands on reasoning (deductive vs. abductive) were varied orthogonally between conditions. Activation in dorsal mPFC was modulated by the need for control, whereas rostral mPFC was modulated by reasoning demands. These findings fit with previously suggested domain-general functions for different parts of mPFC and suggest that these functions are recruited selectively in the service of ToM.


Asunto(s)
Cognición , Juicio , Corteza Prefrontal/fisiología , Teoría de la Mente/fisiología , Encéfalo/fisiología , Mapeo Encefálico , Cultura , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Tiempo de Reacción , Percepción Social , Análisis y Desempeño de Tareas , Adulto Joven
13.
J Cogn Neurosci ; 24(3): 718-35, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22066584

RESUMEN

Because of our limited processing capacity, different elements of the visual scene compete for the allocation of processing resources. One of the most striking deficits in visual selection is simultanagnosia, a rare neuropsychological condition characterized by impaired spatial awareness of more than one object at time. To decompose the neuroanatomical substrates of the syndrome and to gain insights into the structural and functional organization of visuospatial attention, we performed a systematic evaluation of lesion patterns in a group of simultanagnosic patients compared with patients with either (i) unilateral visuospatial deficits (neglect and/or extinction) or (ii) bilateral posterior lesions without visuospatial deficits, using overlap/subtraction analyses, estimation of lesion volume, and a lesion laterality index. We next used voxel-based morphometry to assess the link between different visuospatial deficits and gray matter and white matter (WM) damage. Lesion overlap/subtraction analyses, lesion laterality index, and voxel-based morphometry measures converged to indicate that bilateral parieto-occipital WM disconnections are both distinctive and necessary to create symptoms associated with simultanagnosia. We also found that bilateral gray matter damage within the middle frontal area (BA 46), cuneus, calacarine, and parieto-occipital fissure as well as right hemisphere parietal lesions within intraparietal and postcentral gyri were associated with simultanagnosia. Further analysis of the WM based on tractography revealed associations with bilateral damage to major pathways within the visuospatial attention network, including the superior longitudinal fasciculus, the inferior fronto-occipital fasciculus, and the inferior longitudinal fasciculus. We conclude that damage to the parieto-occipital regions and the intraparietal sulcus, together, with bilateral WM disconnections within the visuosptial attention network, contribute to poor visual processing of multiple objects and the loss of processing speed characteristic of simultanagnosia.


Asunto(s)
Atención/fisiología , Mapeo Encefálico , Lateralidad Funcional/fisiología , Trastornos de la Percepción/patología , Percepción Espacial/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Índice de Severidad de la Enfermedad , Adulto Joven
14.
Neuroimage ; 61(4): 921-30, 2012 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-22440654

RESUMEN

Belief-desire reasoning is a core component of 'Theory of Mind' (ToM), which can be used to explain and predict the behaviour of agents. Neuroimaging studies reliably identify a network of brain regions comprising a 'standard' network for ToM, including temporoparietal junction and medial prefrontal cortex. Whilst considerable experimental evidence suggests that executive control (EC) may support a functioning ToM, co-ordination of neural systems for ToM and EC is poorly understood. We report here use of a novel task in which psychologically relevant ToM parameters (true versus false belief; approach versus avoidance desire) were manipulated orthogonally. The valence of these parameters not only modulated brain activity in the 'standard' ToM network but also in EC regions. Varying the valence of both beliefs and desires recruits anterior cingulate cortex, suggesting a shared inhibitory component associated with negatively valenced mental state concepts. Varying the valence of beliefs additionally draws on ventrolateral prefrontal cortex, reflecting the need to inhibit self perspective. These data provide the first evidence that separate functional and neural systems for EC may be recruited in the service of different aspects of ToM.


Asunto(s)
Encéfalo/fisiología , Función Ejecutiva/fisiología , Vías Nerviosas/fisiología , Teoría de la Mente/fisiología , Adolescente , Adulto , Mapeo Encefálico , Cultura , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Inhibición Psicológica , Imagen por Resonancia Magnética , Masculino , Adulto Joven
15.
J Neurosci ; 30(15): 5229-33, 2010 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-20392945

RESUMEN

Debate surrounds the precise cortical location and timing of access to phonological information during visual word recognition. Therefore, using whole-head magnetoencephalography (MEG), we investigated the spatiotemporal pattern of brain responses induced by a masked pseudohomophone priming task. Twenty healthy adults read target words that were preceded by one of three kinds of nonword prime: pseudohomophones (e.g., brein-BRAIN), where four of five letters are shared between prime and target, and the pronunciation is the same; matched orthographic controls (e.g., broin-BRAIN), where the same four of five letters are shared between prime and target but pronunciation differs; and unrelated controls (e.g., lopus-BRAIN), where neither letters nor pronunciation are shared between prime and target. All three priming conditions induced activation in the pars opercularis of the left inferior frontal gyrus (IFGpo) and the left precentral gyrus (PCG) within 100 ms of target word onset. However, for the critical comparison that reveals a processing difference specific to phonology, we found that the induced pseudohomophone priming response was significantly stronger than the orthographic priming response in left IFG/PCG at approximately 100 ms. This spatiotemporal concurrence demonstrates early phonological influences during visual word recognition and is consistent with phonological access being mediated by a speech production code.


Asunto(s)
Encéfalo/fisiología , Reconocimiento Visual de Modelos/fisiología , Fonética , Lectura , Habla/fisiología , Potenciales Evocados , Femenino , Lóbulo Frontal/fisiología , Humanos , Magnetoencefalografía , Masculino , Pruebas Neuropsicológicas , Factores de Tiempo , Adulto Joven
16.
Eur J Neurosci ; 33(3): 539-48, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21175881

RESUMEN

Logographic symbols are visually complex, and thus children's abilities for visual short-term memory (VSTM) predict their reading competence in logographic systems. In the present study, we investigated the importance of VSTM in logographic reading in adults, both behaviorally and by means of fMRI. Outside the scanner, VSTM predicted logographic Kanji reading in native Japanese adults (n=45), a finding consistent with previous observations in Japanese children. In the scanner, participants (n=15) were asked to perform a visual one-back task. For this fMRI experiment, we took advantage of the unique linguistic characteristic of the Japanese writing system, whereby syllabic Kana and logographic Kanji can share the same sound and meaning, but differ only in the complexity of their visual features. Kanji elicited greater activation than Kana in the cerebellum and two regions associated with VSTM, the lateral occipital complex and the superior intraparietal sulcus, bilaterally. The same regions elicited the highest activation during the control condition (an unfamiliar, unpronounceable script to the participants), presumably due to the increased VSTM demands for processing the control script. In addition, individual differences in VSTM performance (outside the scanner) significantly predicted blood oxygen level-dependent signal changes in the identified VSTM regions, during the Kanji and control conditions, but not during the Kana condition. VSTM appears to play an important role in reading logographic words, even in skilled adults, as evidenced at the behavioral and neural level, most likely due to the increased VSTM/visual attention demands necessary for processing complex visual features inherent in logographic symbols.


Asunto(s)
Mapeo Encefálico , Encéfalo/fisiología , Memoria a Corto Plazo/fisiología , Reconocimiento Visual de Modelos/fisiología , Lectura , Adulto , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Lenguaje , Imagen por Resonancia Magnética , Masculino
17.
Front Psychiatry ; 12: 719961, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34504448

RESUMEN

Thought action fusion (TAF), whereby internal thoughts are perceived to exert equivalent effects to external actions, is a form of magical thinking. Psychiatric disorders associated with TAF (e.g. schizophrenia; obsessive compulsive disorder) can feature atypical social cognition. We explored relationships between TAF and empathy in 273 healthy young adults. TAF was directly correlated with higher personal distress, but not perspective taking, fantasy or empathic concern. TAF moral (the belief that thinking about an action/behaviour is morally equivalent to actually performing that behaviour) was predicted by emotion contagion, alexithymia and need for closure. TAF likelihood (the belief that simply having a thought about an event makes that event more likely to occur) was predicted by personal distress, sense of agency and alexithymia. Both cognitive (TAF and negative sense of agency) and emotional (emotion contagion, alexithymia) factors contributed to personal distress. TAF, negative sense of agency and personal distress mediated the effect of emotion contagion on alexithymia. Our findings reveal complex relationships between emotional processes and TAF, shedding further light on the social cognitive profile of disorders associated with magical thinking. Furthermore, they emphasise the potential importance of alexithymia and emotion contagion as mediators or potential risk factors in the development of psychiatric symptoms linked to TAF, such as intrusive thoughts about harm to others.

18.
Neuroimage ; 49(4): 3489-97, 2010 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19761849

RESUMEN

The main aim of this study was to characterize neural correlates of analogizing as a cognitive contributor to fluid and crystallized intelligence. In a previous fMRI study which employed fluid analogy letter strings as criteria in a multiple plausibility design (Geake and Hansen, 2005), two frontal ROIs associated with working memory (WM) load (within BA 9 and BA 45/46) were identified as regions in which BOLD increase correlated positively with a crystallized measure of (verbal) IQ. In this fMRI study we used fluid letter, number and polygon strings to further investigate the role of analogizing in fluid (transformation string completion) and non fluid or crystallized (unique symbol counting) cognitive tasks. The multi stimulus type (letter, number, polygon) design of the analogy strings enabled investigation of a secondary research question concerning the generalizability of fluid analogizing at a neural level. A selective psychometric battery, including the Raven's Progressive Matrices (RPM), measured individual cognitive abilities. Neural activations for the effect of task-fluid analogizing (string transformation plausibility) vs. crystallized analogizing (unique symbol counting)-included bilateral frontal and parietal areas associated with WM load and fronto parietal models of general intelligence. Neural activations for stimulus type differences were mainly confined to visually specific posterior regions. ROI covariate analyses of the psychometric measures failed to find consistent co-relationships between fluid analogizing and the RPM and other subtests, except for the WAIS Digit Symbol subtest in a group of bilateral frontal cortical regions associated with the maintenance of WM load. Together, these results support claims for separate developmental trajectories for fluid cognition and general intelligence as assessed by these psychometric subtests.


Asunto(s)
Corteza Cerebral/fisiología , Cognición/fisiología , Inteligencia , Imagen por Resonancia Magnética , Red Nerviosa/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
19.
Cogn Neuropsychol ; 27(3): 277-303, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-21058077

RESUMEN

Insights into the functional nature and neuroanatomy of spatial attention have come from research in neglect patients but to date many conflicting results have been reported. The novelty of the current study is that we used voxel-wise analyses based on information from segmented grey and white matter tissue combined with diffusion tensor imaging to decompose neural substrates of different neglect symptoms. Allocentric neglect was associated with damage to posterior cortical regions (posterior superior temporal sulcus, angular, middle temporal and middle occipital gyri). In contrast, egocentric neglect was associated with more anterior cortical damage (middle frontal, postcentral, supramarginal, and superior temporal gyri) and damage within subcortical structures. Damage to intraparietal sulcus (IPS) and the temporo-parietal junction (TPJ) was associated with both forms of neglect. Importantly, we showed that both disorders were associated with white matter lesions suggesting damage within long association and projection pathways such as the superior longitudinal, superior fronto-occipital, inferior longitudinal, and inferior fronto-occipital fascicule, thalamic radiation, and corona radiata. We conclude that distinct cortical regions control attention (a) across space (using an egocentric frame of reference) and (b) within objects (using an allocentric frame of reference), while common cortical regions (TPJ, IPS) and common white matter pathways support interactions across the different cortical regions.


Asunto(s)
Corteza Cerebral/patología , Fibras Nerviosas Mielínicas/patología , Vías Nerviosas/patología , Trastornos de la Percepción/patología , Adulto , Anciano , Anciano de 80 o más Años , Mapeo Encefálico/métodos , Imagen de Difusión Tensora/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fibras Nerviosas Amielínicas/patología , Percepción Espacial
20.
PLoS One ; 15(7): e0235529, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32701998

RESUMEN

We explored factors associated with performance on the Reading the Mind in the Eyes Test (RMET). 180 undergraduate students completed the human RMET requiring forced-choice mental state judgment; a control human Age Eyes Test (AET) requiring age judgment; a Cat Eyes Test (CET) requiring mental state judgment; and measures of executive function, empathy and psychopathology. Versions of the CET and AET were created that matched the RMET for difficulty (accuracy 71%). RMET and CET performance were strongly correlated after accounting for AET performance. Working memory, schizotypal personality and empathy predicted RMET accuracy but not CET scores. Liking dogs predicted higher accuracy on all eyes tasks, whereas liking cats predicted greater mentalizing but reduced emotional expression. Importantly, we replicated our core findings relating to accuracy and correlations between the CET and RMET in a second sample of 228 students. In conclusion, people can apply similar skills when interpreting cat and human expressions. As RMET and CET performance were found to be differentially affected by executive function and psychopathology, the use of social cognitive measures featuring non-human animals may be of particular use in future clinical research.


Asunto(s)
Ojo , Procesos Mentales , Adulto , Empatía , Función Ejecutiva , Femenino , Humanos , Masculino , Psicometría , Adulto Joven
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