Cost of mental set reconfiguration between digits and their photisms in synaesthesia.

In this study we present an experiment investigating the reconfiguration process elicited by the task switching paradigm in synaesthesia. We study the time course of the operations involved in the activation of photisms. In the experimental Group, four digit-color synaesthetes alternated between an odd-even task and a color task (to indicate the photism elicited by each digit). In both tasks, the target stimuli were numbers between 1 and 9 written in white. One of the control groups ran the same tasks but this time with colored numbers (Naive Control Group). The results of these studies showed the expected pattern for the control group in the case of regular shift: a significant task switch cost with an abrupt offset and a cost reduction in long RSI. However for the experimental group, we found switch cost asymmetry in the short RSI and non-significant cost in the long RSI. A second control group performed exactly the same tasks as the experimental group (with white numbers as targets and a second imaginary color task) -Trained Control Group-. We found no cost for this second control group. This means that the cost of mental set reconfiguration between numbers (inducers) and their photisms (concurrent sensations) occurs, that there is a specific cost asymmetry (from photisms to inducers) and that this cost cannot be explained by associative learning. The results are discussed in terms of exogenous and endogenous components of mental set reconfiguration.

Cost of mental set reconfiguration between digits and their photisms in synaesthesia

In this study we present an experiment investigating the reconfiguration process elicited by the task switching paradigm in synaesthesia. We study the time course of the operations involved in the activation of photisms. In the experimental Group, four digit-color synaesthetes alternated between an odd-even task and a color task (to indicate the photism elicited by each digit). In both tasks, the target stimuli were numbers between 1 and 9 written in white. One of the control groups ran the same tasks but this time with colored numbers (Naïve Control Group). The results of these studies showed the expected pattern for the control group in the case of regular shift: a significant task switch cost with an abrupt offset and a cost reduction in long RSI. However for the experimental group, we found switch cost asymmetry in the short RSI and non-significant cost in the long RSI. A second control group performed exactly the same tasks as the experimental group (with white numbers as targets and a second imaginary color task) -Trained Control Group-. We found no cost for this second control group. This means that the cost of mental set reconfiguration between numbers (inducers) and their photisms (concurrent sensations) occurs, that there is a specific cost asymmetry (from photisms to inducers) and that this cost cannot be explained by associative learning. The results are discussed in terms of exogenous and endogenous components of mental set reconfiguration (AU)

En este estudio presentamos un experimento en el que se investiga el proceso de reconfiguración mental empleando el paradigma de cambio de tarea en sinestesia. Estudiamos el tiempo de preparación necesario en la activación de un fotismo. En el grupo experimental, cuatro sinestetas dígito-color alternaban entre una tarea de números (par-impar) y otra de color (indicar el fotismo evocado por cada dígito). En ambas tareas, el estímulo era un número entre el 1 y el 9 escrito en blanco. Uno de los grupos control realizó la misma tarea pero con los números coloreados (Naïve Control Group). Los resultados muestran el patrón de datos esperado para el grupo control en el caso de cambio de tarea predecible: un coste por cambio de tarea que desaparece en el primer ensayo de repetición usando un intervalo respuesta estímulo (RSI) largo. Sin embargo, en el grupo experimental, encontramos asimetrías en el patrón del costo usando RSI corto y un coste no significativo en el RSI largo. Un segundo grupo control realizó exactamente la misma tarea que el grupo experimental (con números en blanco y una segunda tarea de «color imaginario») -Trained Control Group-. Encontramos que no existe costo en este segundo grupo de control. Esto significa que el coste por la reconfiguración mental al alternar entre tarea de números (inductores) y su fotismo (sensación concurrente) ocurre, que hay una asimetría del costo específica (del fotismo a los inductores) y que este costo no puede ser explicado mediante el aprendizaje asociativo. Estos resultados se discuten en términos de los componentes exógenos y endógenos de la reconfiguración mental (AU)