Resumen de Neurobiología de la creatividad: resultados preliminares de un estudio de activación cerebral
Juan Carlos García Reyna, Ariel Graff Guerrero, Carlos S. Cruz Fuentes, Rosa Aurora Chávez, Víctor Vaugier
- español
La creatividad es importante para el bienestar individual y la supervivencia social y su estudio desde una perspectiva neurobiológica aún es un reto para los investigadores, ya que el proceso creativo implica la integración de diversas funciones mentales; así como de todos los componentes de la experiencia propia. Arieti propuso que la creatividad se asocia con el incremento en el funcionamiento de la corteza temporo-occipito-parietal (TOP) y con un incremento de su interacción con la corteza prefrontal (CPF), independientemente de la intensidad de los estímulos, manteniendo estas áreas una disposición a la activación. Martindale encontró diferencias electroencefalográficas en individuos con un alto índice de creatividad quienes presentaron una actividad mayor en las áreas parieto-temporales derechas, así como mayores índices de actividad alfa durante análogos de la inspiración, presentando dichos individuos además mayor tendencia a presentar una sobre-respuesta fisiológica. Miller y colaboradores documentaron tres casos de pacientes que incursionaron en una trayectoria artística pictórica tras haber iniciado con demencia frontotemporal, e incrementaron su productividad artística en los estadios temprano y medio de su enfermedad. Los autores sugieren que una disminución en la función temporal anterior puede asociarse con un incremento de la actividad artística ya que disminuye la inhibición de la corteza visual posterior lo cual conlleva experiencias visuales intensas y memorias visuales no filtradas. Carlsson y colaboradores encontraron que durante la realización de una tarea creativa los individuos con mayor índice de creatividad presentan mayor flujo cerebral en ambos lóbulos frontales. Bekhtereva y colaboradores encontraron que un mayor desempeño creativo se asocia con mayores valores de sincronización en áreas corticales anteriores, un incremento general en la coherencia de ambos frontales y un mayor flujo sanguíneo cerebral en las áreas de Brodmann 8-11 y 44-47.
Objetivo: El propósito de este estudio fue correlacionar el índice de creatividad, obtenido mediante instrumentos válidos y confiables para evaluar la creatividad, como las Pruebas de Torrance de Pensamiento Creativo (TTCT gráfica y verbal)con el flujo sanguíneo cerebral usando tomografía computarizada por emisión de fotón único (SPECT)y mapeo estadístico paramétrico.
Método: Se reclutaron 12 individuos sanos provenientes de una cohorte de 100 adultos, los cuales fueron seleccionados en base a su índice de creatividad. Se les administró una tarea de desempeño creativo tras la inyección intravenosa del radioligando Tc99m-ECD. Las imágenes de flujo sanguíneo cerebral se obtuvieron mediante SPECT. El análisis de las imágenes fue realizado con el software SPM2.El umbral significativo para las regiones a priori (fronto-temporal) fue t > 3, p-corregida < 0.01 y grupos (cluster) formados por mas de 10 voxeles. Se realizaron correlaciones entre el flujo sanguíneo cerebral en áreas específicas y el índice de creatividad (TTCT gráfica y verbal).Las pruebas de Torrance son los instrumentos más difundidos y usados para la evaluación de la creatividad debido a su confiabilidad y a su validez predictiva.
Resultados: Se encontró una correlación positiva entre el índice de creatividad y el flujo sanguíneo cerebral en las siguientes áreas: giro precentral derecho, cerebelo anterior derecho, giro frontal medio izquierdo, giro recto derecho, lóbulo parietal inferior derecho y giro parahipocámpico derecho.
Conclusiones: El índice de creatividad se correlaciona con el flujo cerebral en múltiples áreas de ambos hemisferios cerebrales, las cuales están involucradas en el procesamiento multimodal, en funciones cognitivas complejas y en el procesamiento de emociones. Esto lleva a proponer que el procesamiento central del proceso creativo se realiza en un sistema muy distribuido en el cerebro.
- English
Creativity is important for individuals and for societies. The study of creativity from a neurobiological perspective is still a challenge for researchers. The creative process involves the integration of several mental functions, but also involves all the components of life experience.
Chávez proposed that creativity is the process of generating something, transforming or transcending the existing. This process comprises three overlapping phases: (A) Association-integration: the individual makes associations between elements of the external world and the own subjectivity, becoming aware of these associations. The person continues to incorporate new elements from external reality and from the interior world, connecting ideas, images, sensations, perceptions, emotions; sometimes with periods of apparent latency. During this phase a perceptual, sensorial, cognitive and affective integration occurs. Different levels of consciousness are involved in this phase. (B) Elaboration: the person works with the association building a product, using her or his particular talents and abilities. This phase is conscious and involves volition. (C) Communication: by sharing the work the associations are transmitted and reproduced in others, as well as the sensorial and emotional experience. This leads the audience to produce new associations in themselves. Communication ends the process at the time that new creative processes begin in others.
Reality is, in consequence, understood from a new perspective.
Arieti proposed that creativity is associated with an increase in the temporo-occipito-parietal cortexes functioning; and also with an increase of the interactions between these areas and the prefrontal cortex, independently from the stimuli intensity; keeping the mentioned areas, a disposition to activation. Martindale found electroencephalographic differences in highly creative individuals.
These differences comprised greater activity in right parieto-temporal areas; higher alpha activity during analogs of inspiration;
and a greater tendency to present physiological over-response.
Miller and colleagues reported three cases of patients who began artistic production after the onset of fronto-temporal dementia.
These patients increased their artistic productivity during the early and middle stages of the disease. The authors suggest that a decrease in the anterior temporal function could be associated with an increase of the artistic activity because the posterior visual cortex becomes disinhibited, which could cause intense visual experiences and non filtered memories. Carlsson and cols.
found that during the performance of a creative task highly creative individuals display higher cerebral blood flow in right and left frontal regions when compared with low creative individuals.
Bekhtereva and colleagues found that greater creative achievement is associated to higher synchronization values in anterior cortical areas; it is also associated to an increase in the general coherence in right and left frontal lobes; and to a higher cerebral blood flow in Brodmann areas 8-11 and 44-47.
Objective The aim of the present research was to correlate the figural and verbal creativity indexes (obtained with a valid and reliable creativity measure such as the Torrance Tests of Creative Thinking) with the cerebral blood flow, using Single Photon Emission Computerized Tomography (SPECT) and statistical parametric mapping.
Method Healthy individuals were recruited from a cohort of 100 adults;
40% of the cohort was integrated by artists, researchers, writers and/or composers with substantial achievement, in the peak of their careers and having been awarded with national and international prizes in their fields. These individuals were members of the National System of Researchers, the National System of Creators or were awarded as Young Creators. These systems provide economic support to the most productive scientists and artists, and in order to remain in these systems, members have to prove having a relevant and constant production in their fields.
The cohort also recruited healthy control individuals from general population and psychiatric out-patients. The twelve individuals invited to participate in the brain images project were selected on behalf of their creativity index. The twelve subjects did not present medical, neurological, or psychiatric disorders, they were not under medication, and did not consume any psychoactive drug. The creativity index was obtained using the Torrance Tests of Creative Thinking (TTCT figural and verbal forms). The Torrance Tests are the most known and used creativity instruments;
they have shown high reliability and predictive validity in longitudinal studies (30 and 50 years). The figural and verbal TTCT provide a creativity index, which is an indicator of creative potential. The figural TTCT also provides scores on the following creative dimensions: fluency, originality, elaboration, abstraction, premature closure resistance. The verbal TTCT provides scores of fluency, flexibility and originality. Two TTCT verbal tasks were used when doing the brain images acquisition. The first task was a warm-up activity, whereas the second was administered after intravenous injection of the radiotracer Tc99m-ECD. Cerebral blood flow images were obtained by SPECT. The image processing and analysis were performed using statistical parametric mapping SPM2. The SPECT images were visually inspected for image quality. All the images were transformed to the ANALIZE format for their further automatic realignment. Images were spatially normalized using sinc-interpolation into the SPECT image template from the Montreal Neurological Institute (MNI). The significant threshold for a priori regions (fronto-temporal) was t > 3, p-corrected < 0.01 and clusters formed by more than 10 voxels.
Linear correlations between the figural and verbal creativity indexes and the cerebral blood flow were done. Results were graphically presented using the Talairach-Tournoux coordinates system.
Results It was found a positive significant correlation between the figural and verbal creativity indexes and the cerebral blood flow in the right precentral gyrus, Brodmann area(BA) 6 (p corrected <0.001).
The figural creativity index also showed correlation with the cerebral blood flow in the right anterior cerebellum (p corrected <0.005). The creativity index obtained with the TTCT verbal showed correlation with the right postcentral gyrus, BA 3 (p corrected <0.0001); the left middle frontal gyrus, BA 11 (p corrected <0.002); the right rectal gyrus, BA 11 (p corrected <0.002); the right inferior parietal lobule, BA 40 (p corrected <0.003); and the right parahippocampal gyrus, AB 35 (p corrected <0.006).
Conclusions According to what we know this is the first study correlating the figural and verbal creativity indexes obtained by the Torrance Tests of Creative Thinking with the cerebral blood flow. Most of the brain areas that showed correlation correspond to the right cerebral hemisphere, however, correlations were observed in both cerebral hemispheres suggesting that creative thinking involves bilateral activation. Both figural and verbal creativity indexes showed a high correlation with the cerebral blood flow in the right precentral gyrus; this area has been involved in the assimilation of sensorial information, the modulation of impulses transmitted to motor areas, motor learning, in the perception of phantom limb movements, and in sexual arousal. Figural and verbal creativity indexes correlated with cerebral blood flow in multiple areas in both cerebral hemispheres; these areas are involved in multimodal processing, in complex cognitive functions (such as imagery, memory and novelty processing among others) and in emotion processing; thus proposing that creativity is performed by a highly distributed brain system.
