Illusory conjunctions in the time domain are errors made in binding stimulus features presented In the same spatial position in Rapid Serial Visual Presentation (RSVP) conditions. Botella, Barriopedro, and Suero (2001) devised a model to explain how the distribution of responses originating from stimuli around the target in the series is generated. They proposed two routes consisting of two sequential attempts to make a response. The second attempt (sophisticated guessing) is only employed if the first one (focal attention) fails in producing an integrated perception. This general outline enables specific predictions to be made and tested related to the efficiency of focal attention in generating responses in the first attempt. Participants had to report the single letter in an RSVP stream of letters that was presented in a previously specified color (first target, T1) and then report whether an X (second target, T2) was or was not presented. Performance on T2 showed the typical U-shaped function across the T1-T2 lag that reflects the attentional blink phenomenon. However, as was predicted by Botella, Barriopedro, and Suero's model, the time-course of the interference was shorter for trials with a correct response to T1 than for trials with a T1 error. Furthermore, longer time-courses of interference associated with pre-target and post-target errors to the first target were indistinguishable.

Pavlov's contribution to experimental psychology was to invent a technique that allowed him to undertake a prolonged and systematic series of well-controlled experiments that, astonishingly enough, uncovered many if not most of the phenomena of what is rightly called Pavlovian conditioning. It was not for another 30 years or more that English-speaking psychologists began to match that achievement. Of course there have been new developments and discoveries since his time. Two examples are discussed: the important role of variable associability or attention even in simple conditioning, and the rigorous application of associative learning theory to the behavior of adult humans.

The study of cardiac defense has a long tradition in psychological research both within the cognitive approach—linked to Pavlov, Sokolov, and Graham's work on sensory reflexes—and within the motivational one—linked to the work of Cannon and subsequent researchers on the concepts of activation and stress. These two approaches have been difficult to reconcile in the past. We summarize a series of studies on cardiac defense from a different perspective, which allows integration of the traditional approaches. This new perspective emphasizes a sequential process interpretation of the cardiac defense response. Results of descriptive and parametric studies, as well as those of studies examining the physiological and psychological mechanisms underlying the response, show a complex response pattern with both accelerative and decelerative components, with both sympathetic and parasympathetic influences, and with both attentional and emotional significance. The implications of this new look at cardiac defense are discussed in relation to defensive reactions in natural settings, the brain mechanisms controlling such reactions, and their effects on health and illness.

This study investigates whether threat-related words are especially likely to be perceived in unattended locations of the visual field. Threat-related, positive, and neutral words were presented at fixation as probes in a lexical decision task. The probe word was preceded by 2 simultaneous prime words (1 foveal, i.e., at fixation; 1 parafoveal, i.e., 2.2 deg. of visual angle from fixation), which were presented for 150 ms, one of which was either identical or unrelated to the probe. Results showed significant facilitation in lexical response times only for the probe threat words when primed parafoveally by an identical word presented in the right visual field. We conclude that threat-related words have privileged access to processing outside the focus of attention. This reveals a cognitive bias in the preferential, parallel processing of information that is important for adaptation.

This review describes a research program aimed at evaluating the validity and specificity of the Wisconsin Card Sorting Test (WCST), one of the most widely used tests of prefrontal function in clinical and experimental neuropsychology. In spite of its extensive use, voices of caution have arisen against the use of WCST scores as direct markers of prefrontal damage or dysfunction. Adopting a cognitive neuroscience approach, the present research program integrates behavioral, physiological, and anatomical information to investigate the cognitive and neural mechanisms behind WCST performance. The results show that WCST performance evokes conspicuous physiological changes over frontal as well as posterior brain regions. Moreover, WCST scores confound very heterogeneous cognitive and neural processes. This confounding effect may have led many authors to overlook the relative importance of certain dysfunctional states such as those indexed by random errors. These findings strongly suggest that WCST scores cannot be regarded as valid nor specific markers of prefrontal lobe function. However, they do provide some relevant clues to update our current knowledge about prefrontal function. In the long run, the integrative approach of cognitive neuroscience may help us design and develop more valid and sensitive tools for neuropsychological assessment.

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.

An experiment was conducted using a human instrumental learning task with the goal of evaluating the mechanisms underlying the deleterious effect of context-switching on responding to an unambiguous stimulus when contexts are informative to solve the task. Participants were trained in a context-based reversal discrimination in which two discriminative stimuli (X and Y) interchange their meaning across contexts A and B. In context A, discriminative stimulus Z consistently announced that the relationship between a specific instrumental response (R1) and a specific outcome (O1) was in effect. Performance in the presence of stimulus Z was equally deteriorated when the test was conducted outside the training context, regardless of whether the test context was familiar (context B) or new (context C). This result is consistent with the idea that participants code all the information presented in an informative context as context-specific with the context playing a role akin to an occasion setter.

Executive Control is required to deal with novel situations or when an action plan is needed. This study aimed to highlight the executive attention deficits of patients with frontal lobe damage. To do so, the ANT-I task (Attention Network Test-Interactions) was administered for the first time to a group of 9 patients with frontal damage caused by traumatic brain injury (TBI) and a matched control group. This task made it possible to measure the three attentional networks proposed by Posner and Dehaene (1994) and their interactions. Results on the alerting and orienting networks did not show any significant differences between the groups. However, a significant effect of group on the executive control network was observed. In addition, participants' personality was assessed with a clinical inventory (the Millon Personality Inventory) that showed a significant positive correlation between borderline personality disorder and the conflict index. These results suggest that frontal lobe damage causes an exclusive impairment in the conflict resolution network that is related to personality traits characterized by a lack of behavioral control. More research will be necessary to study this causal relationship.

El polimorfismo TaqIA vinculado al gen del receptor D2 de dopamina se ha asociado con el alcoholismo. El propósito de este trabajo es estudiar la atención y el control inhibitorio mediante el test de ejecución continua y la tarea de detención en una muestra de 50 pacientes varones alcohólicos españoles divididos en dos grupos segύn la presencia del alelo TaqIA1 en su genotipo. Nuestros resultados muestran que los alcoholicos portadores del alelo TaqIA1 presentan atención sostenida más baja y menos control inhibitorio que los pacientes sin ese alelo.

Los datos de investigaciones precl ínicas en organismos no humanos, ensayos clínicos al descubierto y un ensayo controlado individual encontraron que el tratamiento de nicotina agudo potenciaba hasta 4 semanas las reducciones inducidas por neurolépticos de los síntomas discinéticos que caracterizan al síndrome de la Tourette (ST). Dadas las perturbaciones de la atención asociadas con este síndrome, y las mejorías en los procesos atencionales comunicadas con la nicotina, este ensayo distribuido al azar doble ciego controlado con placebo exa- minó los efectos agudos (4 h) y sostenidos (2 semanas) de una dosis individual de nicotina transdérmica sobre los síntomas clínicos (es decir, los tics), atencionales (una tarea de ejecución continua, potenciales evocados cognitivos, los informes de los pacientes y los padres) y conductuales en 23 niños y adolescentes con ST que recibían tratamiento neuroléptico. En los 14 pacientes evaluables con datos de efi- cacia primarios completos, la nicotina (comparado con el placebo) no alteró los síntomas a las 4 h pero contrarrestó los signos de aten ción disminuida de la onda P300 de los potenciales evocados cognitivos (PEC) vistos 2 semanas después del tratamiento con placebo. Las medidas de eficacia secundarias, incluidos los autoinformes de los pacientes y las evaluaciones de los padres, encontraron que la nicoti na reducía los tics complejos y mejoraba las conductas relacionadas con el déficit de atención. Se requiere más trabajo con programas de dosis intermitentes para caracterizar los efectos clínicos y cognitivos óptimos con el tratamiento de nicotina.

La prueba de ejecución continua (CPT) se ha convertido en un componente esencial de la investigación neuropsicológica de la esquizofrenia. Además, un número considerable de estudios de imágenes cerebrales, en la mayor parte investigaciones de PET, ha empleado la CPT como estímulo cognitivo y ha establecido una hipofrontalidad relativa en los esquizofrénicos en comparación con los controles. El propósito de la presente investigación era clarificar si esta hipofrontalidad descrita antes se podía verificar también utilizando imágenes de resonancia magnética funcionales (fMRI). Se incluyó a 20 voluntarios sanos y 14 esquizofrénicos con medicación neuroléptica estable. La toma de imágenes se realizó utilizando la CPT, versión T doble, y un escáner clínico de MRI de 1,5 T con una técnica de rodaja única y una secuencia de gradiente de eco potenciado en T¡*. Los esquizofrénicos mostraron una activación disminuida en el córtex prefrontal medial derecho, el cingulado derecho y el tálamo izquierdo en comparación con los controles. Estos resultados obtenidos por fMRI se analizan con relación a los resultados publicados utilizando PET.

El propósito de este estudio era evaluar los efectos de la ansiedad sobre el funcionamiento de la atención con estímulos neutrales. Se estableció como sigue: se hizo una comparación cuádruple de la ansiedad de rasgo y de estado. Se incluyeron sesenta y dos estudiantes no graduados en el estudio, y se establecieron cuatro grupos de sujetos dividiendo por la mediana las puntuaciones obtenidas en el Inventario de la Ansiedad de Rasgo y de Estado de Spielberger (STAI): ansiedad de rasgo y de estado altas (N = 18); ansiedad de rasgo alta y ansiedad de estado baja (N = ll) ; ansiedad de rasgo y de estado bajas (N = 23) y ansiedad de rasgo baja y ansiedad de estado alta (N = 10). Se administró una batería informatizada de pruebas neuropsicológicas, la batería ACE, para proporcionar una evaluación multidimensional de la atención. La batería ACE comprende cinco pruebas que evalúan los aspectos siguientes de la atención: la capacidad para comprobar una tarea rutinaria; la preparación temporal; la detección visual; la amplitud de memoria, y la atención y memoria visual espacial. Los sujetos con ansiedad de estado alta mostraron deterioro en las funciones ejecutivas, manifestado por un nivel significativamente más alto de preparación motora en una tarea de tiempo de reacción (TR) simple y un intercambio de velocidad y precisión en una tarea de atención dividida; los sujetos con ansiedad de rasgo alta rindieron significativamente mejor en la tarea de detección visual. No se encontró interacción rasgo x estado. Se concluyó que la ansiedad de estado alta se asocia con alerta psicomotriz y la ansiedad de rasgo alta, con alerta perceptiva. Estas dos dimensiones de la ansiedad psicométrica parecen tener efectos sobre la atención que son independientes los unos de los otros y que se deberían analizar por separado en el futuro.