Decision Making Profile of Positive and Negative Anticipatory Skin Conductance Responders in an Unlimited-Time Version of the IGT.

Based on the somatic marker hypothesis (Damasio, 1994), many studies have examined whether or not physiological responses are "somatic markers" that implicitly guide the decision making process. Vegetative or motor reactions that are produced by negative or positive stimuli generate a series of somatic markers. So, when a similar stimuli is encountered in the future, these somatic marks will facilitate favorable decisions and inhibit the disadvantageous ones (Martínez-Selva et al., 2006). The most widely studied physiological responses, as indicators of these markers, are heart rate and the skin conductance response (Damasio, 1994; Bechara et al., 1996). The Iowa Gambling Task (IGT) has been the most widely used tool in this research. The common IGT protocol for psychophysiological studies comprises limited inter-trial intervals, and does not distinguish participants as a function of relevant physiological traits, such as the anticipatory skin conductance response (aSCR). The objectives of this work were to determine whether "somatic markers" guide the decision making process without time restrictions and to examine the effects of opposite aSCR profiles on this process. Participants were 29 healthy subjects, divided into two groups according to positive (+) and negative (-) aSCR. Two different data analysis strategies were applied: firstly, gambling indices were computed and, secondly, we examined the parameters of the probabilistic Prospect Valence Learning (PVL) model in three versions: maximum likelihood estimation (MLE), PVL-Delta and PVL-Decay simulations with Hierarchical Bayesian analysis (HBA) for parameter estimation. The results show a significant group effect in gambling indices, with the aSCR+ group presenting lower risk in the decision making process than the aSCR- group. Significant differences were also observed in the Utility parameter of MLE-PVL, with the aSCR- group have low sensitivity to feedback outcomes, than aSRC+ group. However, data from the PVL simulations do not show significant group differences and, in both cases, the utility value denotes low sensitivity to feedback outcomes.

Differences between oral and written calculation: evidence from cognitive neuropsychology from six brain-damaged patients / Diferencias entre cálculo oral y escrito: evidencias desde la neuropsicología cognitiva a partir de seis casos de daño cerebral

Introduction: The study of patients with acquired brain injury shows the existence of several double dissociations in the calculation sys-tem. In this paper, we focus on the double dissociation observed between oral and written calculation. Method: Instrument: Battery of Evaluation and Numerical Processing and Calculation. Participants: Six patients with acquired brain injury who have different alterations in the processing of numbers and calculations. Data analysis: Difference of proportions. Results: MC and BET have impaired the written calculation but they preserve oral calculation (addition, subtraction and multiplication). The same is ob-served in MNL for addition and multiplication and in PP for subtraction. The reverse pattern is observed in IRS and ACH who have alterations in written calculation but preserve oral calculation (in multiplication and sub-traction, respectively). Conclusions: The results demonstrate the functional independence of oral and written calculation. This could indicate that the calculation system is not unitary and responsible for any calculation task, but a multi-componential system involving different processes and of a different nature

Introducción: El estudio de pacientes con daño cerebral adquirido pone de manifiesto la existencia de varias dobles disociaciones en el sistema de cálculo. En este trabajo nos centramos en la doble disociación observada entre cálculo oral y cálculo escrito. Método: Instrumento: Batería de Evaluación del Procesamiento Numérico y Cálculo. Participantes: Seis pacientes con daño cerebral adquirido que presentan distintas alteraciones en el procesamiento de los números y el cálculo. Análisis de los datos: Diferencia de proporciones. Resultados: MC y BET presentan alterado el cálculo escrito pero conservan el cálculo oral (suma, resta y multiplicación). Lo mismo sucede a MNL en suma y multiplicación y a PP en la resta. El patrón inverso, se observa en IRS y ACH con alteraciones en cálculo escrito y preservación del oral (en multiplicación y resta, respectivamente). Conclusiones: Los resultados ponen de manifiesto la independencia funcional entre cálculo oral y escrito. Esto podría indicar que el sistema de cálculo no es un todo unitario responsable de cualquier tarea de cálculo, sino que posiblemente sea un sistema multicomponencial en el que intervendrían distintos procesos y de diferente naturaleza

Independence of basic arithmetic operations: Evidence from cognitive neuropsychology / Independencia entre operaciones aritméticas básicas: evidencia desde la neuropsicología cognitiva

Los casos descritos en la literatura ponen de manifiesto que las operaciones aritméticas pueden funcionar independientemente, lo que permite inferir que los procesos cognitivos implicados en las distintas operaciones podrían ser distintos. El objetivo de este trabajo es determinar los distintos procesos implicados en la resolución de operaciones aritméticas: suma, resta y multiplicación. Método. Instrumento: Batería de evaluación del procesamiento numérico y el cálculo (Salguero y Alameda, 2007, 2011). Sujetos: pacientes con daño cerebral adquirido. Resultados y conclusiones: El paciente MNL conserva la suma y la multiplicación pero presenta alterada la resta. Por el contrario, el paciente PP manifiesta alteraciones en la suma y multiplicación pero conserva intacta la resta. ISR presenta un déficit selectivo para la multiplicación estando intactas la suma y la resta. Por último, ACH, conserva la suma pero tiene alteradas la resta y la multiplicación. Esta doble disociación confirma los postulados del modelo anatómico funcional de Dehaene y Cohen (1995, 1997), que plantea la existencia de una doble vía para la resolución de operaciones aritméticas simples: la ruta lingüística, para datos numéricos aprendidos memorísticamente, que se utilizaría para sumar y multiplicar, y por otro lado, la elaboración semántica, para la resta (AU)

The cases described in literature evidence that arithmetical operations can function independently, which allows to infer that the cognitive processes involved in the different operations might be different. Objective of that work is to determine the different processes involved in the resolution of arithmetical operations: addition, subtraction and multiplication. Method. Instrument: Assesment of Numeric Processing and Calculation Battery (Salguero & Alameda, 2007, 2011). Subjects. Patients of acquired cerebral injury. Results and conclusions. The patient MNL preserves the addition and the multiplication but he presents altered the subtraction. On the contrary, the patient PP shows alterations in addition and multiplication but he conserves the skills for the subtraction. ISR presents a selective deficit for multiplication with intact addition and substraction. Finally, ACH preserves the addition but presents deficit for substraction and multiplication. This double dissociation confirms the postulates of the anatomical functional model of Dehaene and Cohen (1995, 1997) that consider a double route for the resolution of arithmetical simple operations: linguistic route, for numerical information learned automatically (of memory) and would be used for the operations of addition and multiplication, on the other hand the semantic elaboration would be for substraction (AU)

[Quantitative numerical and lexical knowledge: evidence of double dissociation]. / Conocimiento numérico cuantitativo y léxico: evidencia de doble disociación.

The aim of this work was to explain the involvement of a specific brain injury in the numerical processing and calculation system. The method employed was > analysis and the administration of various cognitive neuropsychology tests. The results of this study revealed a double dissociation between quantitative numerical knowledge and qualitative or lexical numerical knowledge. Patient M.C. preserved quantitative numerical knowledge, as indicated by the results obtained in the numerical comprehension and calculation tasks. However, she showed a drastic deficit in qualitative numerical knowledge. On the other hand, patient M.L. preserved qualitative numerical knowledge, but she had serious problems in all the abilities that require internal manipulation of magnitude; that is, quantitative numerical knowledge. These results have two important implications, as conclusions: firstly, quantitative numerical knowledge may be made up of different elements susceptible to damage independently. And secondly, quantitative and qualitative numerical knowledge were functionally independent.