Differential Activity for Animals and Manipulable Objects in the Anterior Temporal Lobes

Neuropsychological evidence has highlighted the role of the anterior temporal lobes in the processing of conceptual knowledge. That putative role is only beginning to be investigated with fMRI as methodological advances are able to compensate for well-known susceptibility artifacts that affect the quality of the BOLD signal. In this article, we described differential BOLD activation for pictures of animals and manipulable objects in the anterior temporal lobes, consistent with previous neuropsychological findings. Furthermore, we found that the pattern of BOLD signal in the anterior temporal lobes is qualitatively different from that in the fusiform gyri. The latter regions are activated to different extents but always above baseline by images of the preferred and of the nonpreferred categories, whereas the anterior temporal lobes tend to be activated by images of the preferred category and deactivated (BOLD below baseline) by images of the nonpreferred category. In our experimental design, we also manipulated the decision that participants made over stimuli from the different semantic categories. We found that in the right temporal pole, the BOLD signal shows some evidence of being modulated by the task that participants were asked to perform, whereas BOLD activity in more posterior regions (e.g., the fusiform gyri) is not modulated by the task. These results reconcile the fMRI literature with the neuropsychological findings of deficits for animals after damage to the right temporal pole and suggest that anterior and posterior regions within the temporal lobes involved in object processing perform qualitatively different computations.Psycholog

Evidence for a deep, distributed and dynamic code for animacy in human ventral anterior temporal cortex.

Funder: European Research Council; Grant(s): GAP: 502670428 - BRAIN2MIND_NEUROCOMPHow does the human brain encode semantic information about objects? This paper reconciles two seemingly contradictory views. The first proposes that local neural populations independently encode semantic features; the second, that semantic representations arise as a dynamic distributed code that changes radically with stimulus processing. Combining simulations with a well-known neural network model of semantic memory, multivariate pattern classification, and human electrocorticography, we find that both views are partially correct: information about the animacy of a depicted stimulus is distributed across ventral temporal cortex in a dynamic code possessing feature-like elements posteriorly but with elements that change rapidly and nonlinearly in anterior regions. This pattern is consistent with the view that anterior temporal lobes serve as a deep cross-modal 'hub' in an interactive semantic network, and more generally suggests that tertiary association cortices may adopt dynamic distributed codes difficult to detect with common brain imaging methods

The semantic representation of social groups and its neural substrate

Neuropsychological studies described brain damaged patients with a deficit at recognizing exemplars from some semantic categories while being still able to recognize exemplars from other categories, and vice versa. This evidence suggested that categories such as animals, plants, artifacts and conspecifics might be independently organized in the brain. Several theories tried to explain the category specificity, and proposed that concepts are represented in the brain according to the modality of their features, on the relevance of a domain for survival or on the degree of inter-correlation between features. Perhaps one limitation on investigation on how categories are represented in the brain has to do with the poor characterization of the concept about conspecifics often limited to famous and familiar persons as unique entities, and as such not very comparable with the other categories of stimuli. Recent findings suggested that even the knowledge about categories of conspecifics defined as social groups might well be represented independently of other categories.In the current thesis I investigated whether social group knowledge is indeed represented independently of other categories, consistently with previous findings, and the eventual neural substrates of such knowledge. In two different studies, I tested the knowledge of patients with brain tumors and neurodegenerative diseases about social groups, animate and inanimate entities. Correlating patients\u2019 behavioural performance with structural MRI data, I found that the lesion of a left-lateralized set of areas was selectively associated with the impairment in naming social group pictures. Specifically, inferior frontal gyrus, insula and anterior temporal cortex were associated with social group processing in both the studies. Since these areas were reported to be involved in emotional processing, In a third study with healthy individuals, I tested whether one of the above brain regions, within the opercular part of inferior frontal gyrus, might be involved in processing social groups per se or in processing the valence of stimuli. Results revealed that this area was involved in the processing of negative stimuli and suggested that the semantic impairment in processing social groups might be related to the intrinsic emotional value of this category of stimuli. This pattern of findings suggests that human conceptual knowledge is associated with modality-specific processing areas, and that social group representation might interacts with emotional features

Insights into language processing in aphasia from semantic priming and semantic judgement tasks

The nature of semantic impairment in people with aphasia (PWA) provides the background to the current study, which examines whether different methods of semantic assessment can account for such deficits. Cognitive ability, which has previously been linked to language ability in PWA, may impact on test performance and was therefore also examined. The aims of the current study were to compare performance of control participants and PWA on implicit and explicit assessment of semantics, and to relate it to performance on tests of cognition. The impact of semantically similar versus associative relationship types between test stimuli was also considered. Three experimental semantic tasks were developed, including one implicit measure of semantic processing (Semantic Priming) and two explicit measures (Word to Picture Verification and Word to Picture Matching). Test stimuli were matched in terms of key psycholinguistic variables of frequency, imageability and length, and other factors including visual similarity, semantic similarity, and association. Performance of 40 control participants and 20 PWA was investigated within and between participant groups. The relationship between semantic task performance and existing semantic and cognitive assessments was also explored in PWA. An important finding related to a subgroup of PWA who were impaired on the explicit experimental semantic tasks but demonstrated intact semantic processing via the implicit method. Within tasks some differences were found in the effects of semantically related or associated stimuli. No relationships were found between experimental semantic task performance and cognitive task accuracy. The research offers insights into the role of implicit language testing, the impact of stimuli relationship type, and the complex relationship between semantic processing and cognition. The findings underline the need for valid and accurate measures of semantic processing to be in place to enable accurate diagnosis for PWA, in order to direct appropriate intervention choice and facilitate successful rehabilitation

A study about the semantic processing of counter-intuitive religious ideas with event-related potentials

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, Departamento de Psicobiología, leída el 12-12-2013Explorar las causas de la recurrencia y naturalidad del pensamiento religioso a lo largo de la evolución humana es una cuestión de creciente interés científico. Desde la Ciencia Cognitiva de la Religión se ha propuesto que los conceptos religiosos resultan especialmente atractivos porque son mínimamente contra-intuitivos. Según esta Hipótesis, las ideas religiosas se caracterizan por violar o transferir alguna propiedad (física, biológica o psicológica) que de forma intuitiva se aplica a objetos o agentes, a la vez que mantienen el resto de las propiedades intactas (p. ej. una montaña sabia). Esto las convierte en óptimos cognitivos; captan nuestra atención y conllevan un bajo coste de procesamiento, lo que facilita su recuerdo. Asímismo, la Teoría Contemporánea propone que las metáforas establecen relaciones entre conceptos a través de la transferencia de propiedades. Su procesamiento se lleva a cabo sin esfuerzo, ya que forman parte de nuestro sistema conceptual y constituyen una forma natural de pensamiento. El objetivo de este trabajo es explorar los mecanismos neurocognitivos implicados en el procesamiento de ideas contra-intuitivas religiosas presentadas fuera de un contexto narrativo, y su relación con el pensamiento metafórico. Para tal fin, se empleó la onda N400 de los Potenciales Evento-Relacionados como índice del grado de contra-intuición de una idea. El análisis semántico de una muestra de ideas extraídas de diferentes mitologías del mundo desveló que alrededor de un 80% eran contra-intuiciones. Además, se observó que estas ideas se integran más fácilmente en el sistema semántico, lo que se reflejó en una reducción de la N400, y que son difícilmente consideradas como anomalías cuando se comparan con otro tipo de contra-intuiciones no religiosas. En un segundo experimento se exploró si la mínima contra-intuición de las ideas religiosas está relacionada con el modo en que se interpretan. Para ello, se indujeron dos modos de interpretación, literal vs. metafórico, para cada una de las contra-intuiciones, formulando preguntas sobre su contenido semántico. Se observó que una interpretación metafórica facilita la integración semántica de las contra-intuiciones religiosas haciéndolas más aceptables, mientras que una interpretación literal las convierte en anomalías. Las evidencias presentadas demuestran una estrecha relación entre contra-intuiciones y metáforas para explicar la recurrencia cultural del pensamiento religioso. [ABSTRACT] Exploring the causes behind the fact that religious thought is recurring and naturally found throughout human evolution is a field of growing scientific interest. The Cognitive Science of Religion has proposed that religious concepts are especially appealing because they are minimally counterintuitive. According to this hypothesis, religious ideas are characterized by a violation or transfer of some property (physical, biological or psychological) that is intuitively applied to objects or agents while the rest of their properties remain intact (e.g., a wise mountain). This makes them cognitive optimums; they capture our attention and they have a low processing cost, which makes them easier to remember. In addition, Contemporary Theory suggests that metaphors establish maps between concepts through the transfer of properties. The processing of metaphors takes place effortlessly, since they already are part of our conceptual system and they constitute a natural and spontaneous form of thought. The objective of this research is to analyze the neurocognitive mechanisms involved in the processing of counter-intuitive religious ideas presented outside of a narrative context, along with their relationship with metaphorical thought. To that end, we used the N400 waveform of the Event-Related Potentials to indicate how counter-intuitive an idea was. The semantic analysis of a sample set of ideas taken from different mythologies from all over the world revealed that 80% were technically counter-intuitive, according to the cognitive models o religion. Furthermore, in the first experiment these ideas were observed to be integrated more easily into the semantic system, which was reflected by a reduction in the N400, and to be hardly considered like semantic anomalies, compared to other types of non-religious counter-intuitive ideas. In the second experiment, we investigated whether the minimally counter-intuitiveness of religious ideas is related to the mode in which they are interpreted. To that end, different modes of interpretation were prompted (literal vs. metaphorical) for each one of these counter-intuitive ideas by asking questions regarding their semantic content. It was observed that a metaphorical interpretation facilitated the semantic integration of counter-intuitive religious concepts, making them more acceptable (reduction of the N400), while a literal interpretation made them semantic anomalies. The evidence presented here shows that there is a close relationship between counter-intuitive ideas and metaphors to explain the cultural recurrence of religious thought during the evolution of human culturesDepto. de Psicobiología y Metodología en Ciencias del ComportamientoFac. de PsicologíaTRUEunpu