Assessing Decision Making Skill in Complex and Dynamic Environments Using Representative and Simulated Tasks

Traditional decision making research has often focused on one's ability to choose from a set of prefixed options, ignoring the process by which decision makers generate courses of action (i.e., options) in-situ (Klein, 1993). In complex and dynamic domains, this option generation process is particularly critical to understanding how successful decisions are made (Zsambok & Klein, 1997). When generating response options for oneself to pursue (i.e., during the intervention-phase of decision making) previous research has supported quick and intuitive heuristics, such as the Take-The-First heuristic (TTF; Johnson & Raab, 2003). When generating predictive options for others in the environment (i.e., during the assessment-phase of decision making), previous research has supported the situational-model-building process described by Long Term Working Memory theory (LTWM; see Ward, Ericsson, & Williams, 2013). In the first three experiments, the claims of TTF and LTWM are tested during assessment- and intervention-phase tasks in soccer. To test what other environmental constraints may dictate the use of these cognitive mechanisms, the claims of these models are also tested in the presence and absence of time pressure. In addition to understanding the option generation process, it is important that researchers in complex and dynamic domains also develop tools that can be used by `real-world' professionals. For this reason, three more experiments were conducted to evaluate the effectiveness of a new online assessment of perceptual-cognitive skill in soccer. This test differentiated between skill groups and predicted performance on a previously established test and predicted option generation behavior. The test also outperformed domain-general cognitive tests, but not a domain-specific knowledge test when predicting skill group membership. Implications for theory and training, and future directions for the development of applied tools are discussed.

Towards person-centered neuroimaging markers for resilience and vulnerability in Bipolar Disorder

Improved clinical care for Bipolar Disorder (BD) relies on the identification of diagnostic markers that can reliably detect disease-related signals in clinically heterogeneous populations. At the very least, diagnostic markers should be able to differentiate patients with BD from healthy individuals and from individuals at familial risk for BD who either remain well or develop other psychopathology, most commonly Major Depressive Disorder (MDD). These issues are particularly pertinent to the development of translational applications of neuroimaging as they represent challenges for which clinical observation alone is insufficient. We therefore applied pattern classification to task-based functional magnetic resonance imaging (fMRI) data of the n-back working memory task, to test their predictive value in differentiating patients with BD (n=30) from healthy individuals (n=30) and from patients' relatives who were either diagnosed with MDD (n=30) or were free of any personal lifetime history of psychopathology (n=30). Diagnostic stability in these groups was confirmed with 4-year prospective follow-up. Task-based activation patterns from the fMRI data were analyzed with Gaussian Process Classifiers (GPC), a machine learning approach to detecting multivariate patterns in neuroimaging datasets. Consistent significant classification results were only obtained using data from the 3-back versus 0-back contrast. Using contrast, patients with BD were correctly classified compared to unrelated healthy individuals with an accuracy of 83.5%, sensitivity of 84.6% and specificity of 92.3%. Classification accuracy, sensitivity and specificity when comparing patients with BD to their relatives with MDD, were respectively 73.1%, 53.9% and 94.5%. Classification accuracy, sensitivity and specificity when comparing patients with BD to their healthy relatives were respectively 81.8%, 72.7% and 90.9%. We show that significant individual classification can be achieved using whole brain pattern analysis of task-based working memory fMRI data. The high accuracy and specificity achieved by all three classifiers suggest that multivariate pattern recognition analyses can aid clinicians in the clinical care of BD in situations of true clinical uncertainty regarding the diagnosis and prognosis.

Hyperactivations frontales en mémoire de travail dans le trouble cognitif léger

Des études récentes ont rapporté que les individus âgés avec un trouble cognitif léger (TCL) ont de plus grandes activations en lien avec la réalisation d’une tâche cognitive que des personnes âgées saines. Des auteurs ont proposé que ces hyperactivations pourraient refléter des processus de plasticité cérébrale compensatoires ayant lieu pendant la phase précoce de la maladie d’Alzheimer. Des processus de compensations fonctionnelles pourraient émerger en réponse à une perte d’intégrité structurelle dans les régions du cerveau normalement requises pour compléter une tâche. Dans ce mémoire, j’ai évalué cette hypothèse chez des personnes avec TCL en faisant appel à une tâche de mémoire de travail comportant plusieurs niveaux de difficulté ainsi qu’aux techniques d’imagerie par résonnance magnétique (IRM) structurelle et fonctionnelle. Des analyses de régression multiples ont été utilisées afin d’identifier les régions cérébrales dont l’activité variait en fonction de l’intégrité neuronale telle que définie par le volume de l’hippocampe. Les valeurs estimées des paramètres du signal de ces régions furent ensuite extraites afin de procéder à des analyses corrélationnelles sur la performance ainsi que sur le volume de différentes structures cérébrales. Les résultats indiquent des hyperactivations dans les régions frontales droites chez les participants TCL souffrant d’une plus grande atteinte neuronale. De plus, le niveau d’activation est négativement corrélé au volume de structures frontales et pariétales. Ces résultats indique la présence d’une hyperactivation compensatoire dans la phase du TCL associée à la réalisation d’une tâche de mémoire de travail.

Cognitive and Visual Speech Contributions to Speech Perception in Challenging Listening Conditions

Speech perception routinely takes place in noisy or degraded listening environments, leading to ambiguity in the identity of the speech token. Here, I present one review paper and two experimental papers that highlight cognitive and visual speech contributions to the listening process, particularly in challenging listening environments. First, I survey the literature linking audiometric age-related hearing loss and cognitive decline and review the four proposed causal mechanisms underlying this link. I argue that future research in this area requires greater consideration of the functional overlap between hearing and cognition. I also present an alternative framework for understanding causal relationships between age-related declines in hearing and cognition, with emphasis on the interconnected nature of hearing and cognition and likely contributions from multiple causal mechanisms. I also provide a number of testable hypotheses to examine how impairments in one domain may affect the other. In my first experimental study, I examine the direct contribution of working memory (through a cognitive training manipulation) on speech in noise comprehension in older adults. My results challenge the efficacy of cognitive training more generally, and also provide support for the contribution of sentence context in reducing working memory load. My findings also challenge the ubiquitous use of the Reading Span test as a pure test of working memory. In a second experimental (fMRI) study, I examine the role of attention in audiovisual speech integration, particularly when the acoustic signal is degraded. I demonstrate that attentional processes support audiovisual speech integration in the middle and superior temporal gyri, as well as the fusiform gyrus. My results also suggest that the superior temporal sulcus is sensitive to intelligibility enhancement, regardless of how this benefit is obtained (i.e., whether it is obtained through visual speech information or speech clarity). In addition, I also demonstrate that both the cingulo-opercular network and motor speech areas are recruited in difficult listening conditions. Taken together, these findings augment our understanding of cognitive contributions to the listening process and demonstrate that memory, working memory, and executive control networks may flexibly be recruited in order to meet listening demands in challenging environments.

El videojuego League of legends y su efecto en memoria de trabajo visual y solución de problemas

El propósito de este estudio es medir los efectos que tiene el videojuego League of Legends en los procesos cognitivos de memoria de trabajo visual (MVT) y solución de problemas (SP). Para medir dichos efectos se implementó un diseño pre test-post con un grupo experimental y uno control, compuestos cada uno por siete participantes, en donde se evaluaron los procesos previamente mencionados utilizando los cubos de Corsi para MVT y las matrices del WAIS III para SP. Después de realizar los respectivos entrenamientos se encontraron resultados significativos en los diferentes momentos de aplicación. En el grupo experimental se encontraron diferencias en la variable dependiente SP, mientras que en el grupo control en MVT, pero no en la interacción entre grupos ni diferencias entre grupos, lo que sugiere un efecto de familiarización a la prueba.

Caracterización de la función cognitiva de niños con síndrome de down de 5 a 12 años en la ciudad de Bogotá

Los niños que padecen trisomía 21 poseen una serie de características físicas, neurológicas y neuropsicológicas específicas, las cuales han sido investigadas a profundidad en diferentes países, de lo cual se han desarrollado protocolos de evaluación para estos niños acorde a su nacionalidad (García, 2010). A pesar de que Colombia es uno de los países en los cuales el síndrome de Down se presenta con mayor frecuencia, hasta la fecha, no se encuentran estudios que enfaticen en las habilidades neuropsicológicas de esta población específica, por lo cual no se han desarrollado protocolos de evaluación adecuados para los niños con síndrome este síndrome. Esta investigación se llevó acabo con una población de 88 niños a los cuales se les aplicó el inventario de desarrollo BATTELLE, y se identificó que los niños con síndrome Down de 5 a 12 años obtienen un puntaje que se encuentra en 4 desviaciones estándar por debajo de la media típica. Lo anterior demuestra una característica específica de esta población en cuanto a patrones de desarrollo en las cuales, se evidencia dificultad más importante en las área cognición y de la comunicación expresiva. Con respecto a los intervalos de edad se identificó que a lo largo de estos el desempeño en las áreas evaluadas decrece. esto puede estar relacionado con la mayor complejidad de los hitos del desarrollo para una edad esperada. Debido a que los hitos del desarrollo esperados varían a lo largo de los periodos del ciclo vital del ser humano, estos tienden a aumentar su complejidad en etapas del desarrollo más avanzados; como estos niños poseen una serie de dificultades en las funciones ejecutivas y cognición, no lograrán alcanzar dichos hitos del desarrollo.

Analysis of Dyscalculia Evidences through Artificial Intelligence Systems

Dyscalculia is usually perceived of as a specific learning difficulty for mathematics or, more appropriately, arithmetic. Because definitions and diagnoses of dyscalculia are in their infancy and sometimes are contradictory. However, mathematical learning difficulties are certainly not in their infancy and are very prevalent and often devastating in their impact. Co-occurrence of learning disorders appears to be the rule rather than the exception. Co-occurrence is generally assumed to be a consequence of risk factors that are shared between disorders, for example, working memory. However, it should not be assumed that all dyslexics have problems with mathematics, although the percentage may be very high, or that all dyscalculics have problems with reading and writing. Because mathematics is very developmental, any insecurity or uncertainty in early topics will impact on later topics, hence to need to take intervention back to basics. However, it may be worked out in order to decrease its degree of severity. For example, disMAT, an app developed for android may help children to apply mathematical concepts, without much effort, that is turning in itself, a promising tool to dyscalculia treatment. Thus, this work will focus on the development of a Decision Support System to estimate children evidences of dyscalculia, based on data obtained on-the-fly with disMAT. The computational framework is built on top of a Logic Programming approach to Knowledge Representation and Reasoning, grounded on a Case-based approach to computing, that allows for the handling of incomplete, unknown, or even self-contradictory information.

Modificazioni del segnale EEG in un compito di memoria visiva con distrattori visivi ‘deboli’ e ‘forti’

La valutazione del segnale elettroencefalografico acquisito durante compiti di Working Memory è utile per indagare regioni e meccanismi cerebrali alla base della capacità di immagazzinare le informazioni provenienti dall’ambiente rilevanti per il task da svolgere e di inibire stimoli irrilevanti/distraenti. In questo lavoro di Tesi è stato condotto uno studio su 13 volontari che hanno svolto un compito di memoria di lavoro visiva, consistente di prove ripetute (trial) ognuna composta di diverse fasi: Encoding (memorizzazione del memory set), Retention (mantenimento in memoria) in cui si mostra un distrattore, che può essere weak (poco interferente) o strong (maggiormente interferente). Ciascun trial termina con la comparsa della Probe, a cui il soggetto deve rispondere indicando se apparteneva o meno al memory set. Durante il task è stato acquisito il segnale EEG da 64 elettrodi, ed analizzato per indagare i potenziali evocati (ERPs) e la sincronizzazione/desincronizzazione in banda alpha (8-12 Hz) e theta (4-8 Hz) correlata agli stimoli visivi; è stata svolta anche un’analisi preliminare ricostruendo l’attività delle sorgenti corticali dal segnale EEG. Dalle analisi emerge che gli ERPs sono visibili principalmente nelle fasi di Encoding e Distractor, e nelle regioni fronto-centrali e parieto-occipitali, e che nella fase di Distractor sono maggiori per distrattore weak rispetto a strong. Si conferma la natura inibitoria del ritmo alpha e il ruolo del ritmo theta nei processi cognitivi; infatti la potenza in banda alpha aumenta nella fase pre-distrattore (sia weak che strong) e la potenza in banda theta è sostenuta durante l’intero task. Non si osservano differenze in banda alpha e theta tra i due distrattori nella fase pre-distrattore, mentre si osserva una modulazione durante la presentazione del distrattore.

Effetto di distrattori acustici rispetto a distrattori visivi in un compito di memoria visiva: analisi del segnale EEG

Studi recenti hanno evidenziato cambiamenti nei ritmi alpha (8-12 Hz) e theta (4-8 Hz) in vari processi modulatori top-down e di controllo cognitivo come la memoria di lavoro (WM, working memory) e la soppressione di distrattori. I compiti di WM richiedono attenzione interna sostenuta per dare priorità alle informazioni rilevanti a discapito di quelle interferenti che distraggono dall’obiettivo. I meccanismi di attenzione in tali compiti sono associati ad aumento di potenza alpha, che riflette la funzione inibitoria di tale ritmo, in regioni che elaborano informazioni distraenti, e ad aumento di potenza theta, soprattutto in regioni frontali, che riflette funzioni di controllo cognitivo per raggiungere l’obiettivo pur in presenza di interferenze. Questo lavoro è volto ad indagare gli effetti di distrattori acustici rispetto a distrattori visivi in un compito di visual WM. A tale scopo sono stati acquisiti ed elaborati i segnali EEG di 12 soggetti volontari mentre eseguivano un compito di visual WM, in cui la fase di retention (mantenimento in memoria delle informazioni codificate) veniva interrotta con la presentazione di distrattori di due modalità sensoriali differenti (visiva e acustica), per valutare le variazioni dell’attività cerebrale in termini di ritmi alpha e theta e le regioni coinvolte. Si è osservato un aumento maggiore di potenza alpha (principalmente posteriore) in presenza del distrattore acustico rispetto al visivo sia nella fase pre-distrattore che nella fase distrattore, statisticamente significativo nella fase distrattore. Si è osservato un aumento maggiore di potenza theta (principalmente frontale) in presenza del distrattore acustico rispetto al visivo in tutte le fasi del task, statisticamente significativo nella fase iniziale di retention e nella fase del distrattore. I risultati potrebbero indicare una maggiore necessità di controllo cognitivo e di protezione da stimoli interferenti in caso di distrattore acustico rispetto al visivo.

Differences in the transduction of canonical wnt signals demarcate effector and memory CD8 T cells with distinct recall proliferation capacity.

Protection against reinfection is mediated by Ag-specific memory CD8 T cells, which display stem cell-like function. Because canonical Wnt (Wingless/Int1) signals critically regulate renewal versus differentiation of adult stem cells, we evaluated Wnt signal transduction in CD8 T cells during an immune response to acute infection with lymphocytic choriomeningitis virus. Whereas naive CD8 T cells efficiently transduced Wnt signals, at the peak of the primary response to infection only a fraction of effector T cells retained signal transduction and the majority displayed strongly reduced Wnt activity. Reduced Wnt signaling was in part due to the downregulation of Tcf-1, one of the nuclear effectors of the pathway, and coincided with progress toward terminal differentiation. However, the correlation between low and high Wnt levels with short-lived and memory precursor effector cells, respectively, was incomplete. Adoptive transfer studies showed that low and high Wnt signaling did not influence cell survival but that Wnt high effectors yielded memory cells with enhanced proliferative potential and stronger protective capacity. Likewise, following adoptive transfer and rechallenge, memory cells with high Wnt levels displayed increased recall expansion, compared with memory cells with low Wnt signaling, which were preferentially effector-like memory cells, including tissue-resident memory cells. Thus, canonical Wnt signaling identifies CD8 T cells with enhanced proliferative potential in part independent of commonly used cell surface markers to discriminate effector and memory T cell subpopulations. Interventions that maintain Wnt signaling may thus improve the formation of functional CD8 T cell memory during vaccination.

Short-term memory and the attentional blink: capacity versus content

When people monitor the rapid serial visual presentation (RSVP) of stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset, a phenomenon known as the attentional blink (AB). We found that overall performance in an RSVP task was impaired by a concurrent short-term memory (STM) task and, furthermore, that this effect increased when STM load was higher and when its content was more task relevant. Loading visually defined stimuli and adding articulatory suppression further impaired performance on the RSVP task, but the size of the AB over time (i.e., T1-T2 lag) remained unaffected by load or content. This suggested that at least part of the performance in an RSVP task reflects interference between competing codes within STM, as interference models have held, whereas the AB proper reflects capacity limitations in the transfer to STM, as consolidation models have claimed.

Neurological outcome, working capacity and prognostic factors of patients with SCIWORA

STUDY DESIGN: Retrospective case review. OBJECTIVES: In the present study, the neurological outcome, retirement and prognostic factors of patients with spinal cord injury without radiographic abnormality (SCIWORA) were evaluated. SETTING: Swiss national work accident insurance database. METHODS: The medical histories of 32 patients who were insured by the Swiss Accident Insurance Fund (SUVA) and had SCIWORA between 1995 and 2004 were evaluated thoroughly. Moreover, all available magnetic resonance imaging (MRI) scans were evaluated. RESULTS: At the last follow-up, none of the patients had complete spinal cord injury, only 4 patients had severe deficits and 12 patients had normal motor and sensory function in the neurological examination. However, only 7 out of 32 patients had returned to full-time work and 10 out of 32 patients were fully retired. Both the presence of spinal cord change (ρ=0.51) and higher maximum spinal cord compression (ρ=0.57) in MRI scan correlated with the likelihood for retirement; older age (ρ=0.38) and physical load of work (ρ=0.4) correlated with retirement to a lesser extent. CONCLUSION: Although the neurological outcome of SCIWORA is mostly good, the retirement rate is high. Presence of spinal cord change and severity of cord compression are the best predictors for the degree of retirement.

Concentration, Working Speed and Memory: Cognitive Problems in Young Childhood Cancer Survivors and Their Siblings.

BACKGROUND Cognitive problems can have a negative effect on a person's education, but little is known about cognitive problems in young childhood cancer survivors (survivors). This study compared cognitive problems between survivors and their siblings, determined if cognitive problems decreased during recent treatment periods and identified characteristics associated with the presence of a cognitive problem in survivors. METHODS As part of the Swiss Childhood Cancer Survivor Study, a questionnaire was sent to all survivors, aged 8-20 years, registered in the Swiss Childhood Cancer Registry, diagnosed at age <16 years, who had survived ≥5 years. Parent-reported (aged 8-15 years) and self-reported (aged 16-20 years) cognitive problems (concentration, working speed, memory) were compared between survivors and siblings. Multivariable logistic regression was used to identify characteristics associated with cognitive problems in survivors. RESULTS Data from 840 survivors and 247 siblings were analyzed. More often than their siblings, survivors reported problems with concentration (12% vs. 6%; P = 0.020), slow working speed (20% vs. 8%; P = 0.001) or memory (33% vs. 15%; P < 0.001). Survivors from all treatment periods were more likely to report a cognitive problem than were siblings. Survivors of CNS tumors (OR = 2.82 compared to leukemia survivors, P < 0.001) and those who had received cranial irradiation (OR = 2.10, P = 0.010) were most severely affected. CONCLUSION Childhood cancer survivors, even those treated recently (2001-2005), remain at risk to develop cognitive problems, suggesting a need to improve therapies. Survivors with cognitive problems should be given the opportunity to enter special education programs. Pediatr Blood Cancer © 2014 Wiley Periodicals, Inc.