Emilio Gómez Milán

Does IOR occur in discrimination tasks? Yes, it does, but later

When a stimulus appears in a previously cued location several hundred milliseconds after the cue, the time required to detect that stimulus is greater than when it appears in an uncued location. This increase in detection time is known as inhibition of return (IOR). It has been suggested that IOR reflects the action of a general attentional mechanism that prevents attention from returning to previously explored loci. At the same time, the robustness of IOR has been recently disputed, given several failures to obtain the effect in tasks requiring discrimination rather than detection. In a series of eight experiments, we evaluated the differences between detection and discrimination tasks with regard to IOR. We found that IOR was consistently obtained with both tasks, although the temporal parameters required to observe IOR were different in detection and discrimination tasks. In our detection task, the effect appeared after a 400-msec delay between cue and target, and was still present after 1,300 msec. In our discrimination task, the effect appeared later and disappeared sooner. The implications of these data for theoretical accounts of IOR are discussed.

A More Complete Task-Set Reconfiguration in Random than in Predictable Task Switch:

Three experiments are presented that compare the cost found when switching from one task to another in two different conditions. In one of them, the tasks switch in predictable sequences. In the other condition, the tasks alternate at random. A smaller time cost is found in the random-switch condition when enough preparation time is allowed. Such an effect is due to the random-switch cost continuing to decrease with preparation time after the predictable-switch cost has reached an asymptote. Although the relationship between number of repetitions of one task and time cost is different in the random- and the predictable-switch conditions, only the latter shows the presence of an “exogenous” component of cost. The implications of this finding are discussed in relationship with the usual distinction between an endogenous component of switch cost that is affected by preparation time and another exogenous, residual component (e.g., Rogers & Monsell, 1995). It is proposed that a different kind of task-set preparation is at work when tasks alternate at random.

Synaesthesia: The existing state of affairs

In synaesthesia one type of stimulation evokes the sensation of another, such as when hearing a sound produces photisms—that is, mental percepts of colours. In the past, the idiosyncrasy of this phenomenon, as well as the natural mistrust of scientists towards the subjective, consigned synaesthesia to the periphery of scientific interest. However, the landscape has changed radically in the last two decades. The labour of many researchers, inside as well as outside of cognitive neuroscience, has transformed synaesthesia into a scientific reality whose existence can be demonstrated and studied empirically. The present paper summarizes and reflects on our current knowledge concerning synaesthesia in all its aspects (cognition, behaviour, neurology, genetics, and demographics).

The nature of residual cost in task switching

Presentamos dos experimentos en los que se compara el coste que aparece al cambiar de una tarea a otra bajo condiciones predecibles. En nuestra investigacion comprobaremos la hipotesis de Rogers & Monsells (1995, Stimulus cued completion hypothesis), asi como sus variantes y alternativas. En nuestro primer experimento creamos dos condiciones: Linea base (estimulo-respuesta), se trata de una replica de Tornay y Milun (2001, Experimento 3); la segunda condicion (estimulo-NoRespuesta) es identica a la anterior, la unica diferencia es que los participantes debian prestar atencion al estimulo durante los ensayos de cambio de tarea, pero sin ejecutar respuesta alguna. Los resultados indican que, en la segunda condicion, en lugar de desaparecer el coste con los ensayos de primera repeticion, el coste desaparecia entre los ensayos de primera y segunda repeticion. Nuestro segundo experimento es similar a la segunda condicion del Experimento uno, pero los participantes no sabian si debian o no responder hasta el final de cada ensayo, momento en el que aparecia una senal go-nogo. En este caso, de nuevo el coste se desplaza desde los ensayos de cambio a los de primera repeticion. Podemos concluir que prestar atencion al estimulo o preparar una respuesta a el no es suficiente para completar la reconfiguracion. Debe emitirse una respuesta relevante para la tarea para que se consiga una completa reconfiguracion.

Decision-making and feedback sensitivity: A comparison between older and younger adults

This study investigated decision-making and feedback sensitivity in healthy older adults with a new task: the Pictures Decision Task. The study was conducted on 27 older (aged 64–88) and 26 younger adults (aged 25–57) matched for years of education. Results showed that older adults did not show the Jumping to Conclusions bias and that older adults had difficulty learning from feedback only when the context was ambiguous and not when they were given aids or interpretative information that decreased ambiguity. The Pictures Decision Task, with respect to the Iowa Gambling Task and the Wisconsin Card Sorting Test, allowed us to assess decision-making and feedback sensitivity under highly ambiguous conditions and therefore to add new insight into the reasoning process of older people.

La repetición de respuesta en situaciones de cambio de tarea

espanolPasar de una tarea a otra normalmente implica un coste en la ejecucion. Los experimentos de Rogers y Monsell (1995) han demostrado la existencia de una interaccion entre el costo por cambio de la disposicion de tarea y el llamado priming de repeticion. En la investigacion que se detalla en este articulo utilizamos dicha interaccion para estudiar la representacion de la respuesta implicada en el cambio de tarea. Segun los resultados del presente estudio la interaccion entre el coste por cambio de tarea y el priming de repeticion esta presente aun cuando las respuestas requeridas en la tareas que alternan no son las mismas, pero implican el uso del mismo dedo de la otra mano. Asi pues, parece que una representacion abstracta de la respuesta, basada en codigos de accion DERECHA-IZQUIERDA, es responsable de este efecto. Ademas, la representacion de la respuesta cambia a medida que aumenta el tiempo de preparacion, pasando de unos codigos relacionados con el efector fisico de la respuesta a una representacion mas abstracta. EnglishSwitching from one task to another usually produces a cost in performance. This switch has been shown to interact with repetition priming. In the present study we use this interaction to investigate the response representation involved in task switch. We find an interaction between switch cost and repetition priming even when the responses required in the two tasks are not the same but are made with corresponding fingers of different hands. We conclude that an abstract response representation, based on RIGHT-LEFT action codes, is responsible for the effect. Besides, response representation changes, as preparation time increases, from more physical, effector-related action codes to more abstract ones.