The minimal computational substrate of fluid intelligence

The quantification of cognitive powers rests on identifying a behavioural task that depends on them. Such dependence cannot be assured, for the powers a task invokes cannot be experimentally controlled or constrained a priori, resulting in unknown vulnerability to failure of specificity and generalisability. Evaluating a compact version of Raven's Advanced Progressive Matrices (RAPM), a widely used clinical test of fluid intelligence, we show that LaMa, a self-supervised artificial neural network trained solely on the completion of partially masked images of natural environmental scenes, achieves human-level test scores a prima vista, without any task-specific inductive bias or training. Compared with cohorts of healthy and focally lesioned participants, LaMa exhibits human-like variation with item difficulty, and produces errors characteristic of right frontal lobe damage under degradation of its ability to integrate global spatial patterns. LaMa's narrow training and limited capacity -- comparable to the nervous system of the fruit fly -- suggest RAPM may be open to computationally simple solutions that need not necessarily invoke abstract reasoning.Comment: 26 pages, 5 figure

Neuroinformatics and Neuroimaging-based schizophrenia modeling and decision support

Ph.DDOCTOR OF PHILOSOPH

Classification of athletes with intellectual disabilities : towards the re-inclusion of athletes with intellectual disabilities in the Paralympics

Classification of athletes with intellectual disabilities : towards the re-inclusion of athletes with intellectual disabilities in the Paralympic

Language evolution and recursion : an empirical investigation of human hierarchical processing

Tese de doutoramento, Ciências Biomédicas (Neurociências), Universidade de Lisboa, Faculdade de Medicina, 2014Humans generate complex hierarchical structures in a variety of domains such as in language, social organization, music, action sequencing and visual arts. One cognitive capacity associated with this extraordinary generative power is recursion. Recursion is a very efficient method to process hierarchies and it allows the generation of unbounded hierarchical depth from finite means. Recursion can be defined as the ability to represent the embedding of hierarchies within hierarchies of the same kind. Although recursion has been hypothesized as uniquely human and primarily linguistic, the empirical investigation of these hypotheses has been hindered by the absence of methods to test for recursive capabilities outside the domain of language. In this thesis I present a novel task that can be used to investigate the ability to represent recursion (hierarchical self-similarity) in the visuo-spatial domain. I will describe a set of experiments in which I attempt to characterize recursion as a psychological entity by describing its relationship with other cognitive abilities, as well as its developmental patterns and neural underpinnings. The conclusions of this research program are the following: 1) humans can represent recursion in the visuo-spatial domain; 2) this ability requires the acquisition of abstract rules; 3) recursion can be efficiently used to represent information common to different levels of a hierarchy, and it enhances the ability to detect fine-grained hierarchical mistakes, 4) linguistic resources are not specifically active while processing visual recursion neither behaviorally nor at the neural level, however recursion seems to require the integration of spatial and categorical information. The novel task and results presented here open up exciting pathways in the investigation of recursion as a cognitive ability. Because it is a visual task, not requiring verbal instructions or responses, it can also be used to test non-human primates and clinical populations with language impairment.A espécie humana é capaz de produzir hierarquias complexas na linguagem, organização social, música, actividade motora e nas artes visuais. O poder generativo da cognição humana tem sido associado a um módulo computacional designado recursividade, que pode ser definido como a capacidade de representar a incorporação de hierarquias dentro de hierarquias do mesmo tipo. A recursividade pode ser usada de modo eficiente no processamento de hierarquias, permitindo a geração de estruturas infinitamente profundas partindo de um número finito de elementos. Esta capacidade tem sido postulada como exclusivamente humana e primariamente linguística. No entanto, a investigação empírica destas hipóteses tem sido dificultada pela ausência de um método para testar capacidades recursivas fora do domínio linguístico. Nesta tese irei apresentar um novo método para testar a capacidade de representar a recursividade no domínio visuo-espacial. Irei descrever uma série de experiências nas quais caracterizarei a recursividade como uma entidade psicológica, descrevendo de que forma se relaciona com outras capacidades cognitivas, o seu padrão de desenvolvimento e correlatos neurais. As conclusões deste programa de investigação são as seguintes: 1) a espécie humana é capaz de representar recursividade visuo-espacial; 2) esta capacidade requer a aquisição de regras abstractas; 3) a recursividade é usada para representar informação comum a vários níveis hierárquicos e melhora a capacidade de detectar erros estruturais ao nível dos pequenos detalhes; 4) o processamento de recursividade visual não activa especificamente recursos verbais, quer ao nível do comportamento quer ao nível neural, contudo esta capacidade requer a integração de informação espacial e categorial. A tarefa e os resultados inovadores aqui apresentados abrem novas vias de investigação relativamente à capacidade de utilizar recursividade ao nível cognitivo. Por ser uma tarefa visual não requer instruções nem respostas verbais, pelo que pode ser usada para testar primatas não humanos e populações clínicas com defeitos de linguagem.Fundação para a Ciência e a Tecnologia (FCT); European Research Council (ERC

Metacognitive Awareness Scale, Domain Specific (MCAS- DS): Assessing Metacognitive Awareness during Raven's Progressive Matrices

open access articleMetacognition, the cognition about cognition, is closely linked to intelligence and therefore understanding the metacognitive processes underlying intelligence test performance, specifically on Raven’s Progressive Matrices, could help advance the knowledge about intelligence. The measurement of metacognition, is often done using domain-general offline questionnaires or domain-specific online think-aloud protocols. This study aimed to investigate the relationship between metacognitive awareness and intelligence via the design and use of a novel Meta-Cognitive Awareness Scale – Domain Specific (MCAS-DS) that encourages reflection of task strategy processes. This domain-specific scale was first constructed to measure participants’ awareness of their own metacognition linked to Raven’s Progressive Matrices (SPM). Following discriminatory index, Exploratory Factor Analysis, a 15-item scale was devised. Exploratory Factor Analysis showed five factors: Awareness of Engagement in Self-Monitoring, Awareness of Own Ability, Awareness of Responding Speed/Time, Awareness of Alternative Solutions and Awareness of Requisite Problem-Solving Resources. The intelligence level of ninety-eight adults was then estimated using Raven’s Standard Progressive Matrices. Participants also completed the MCAS-DS, and further items that examined their test-taking behaviour and Confidence level. Metacognitive awareness was positively correlated to standardized IQ scores derived from the SPM whilst Over-Confidence derived using the Confidence level measure was negatively correlated to SPM. Despite some limitations, this study shows promise for elucidating the relationship between metacognitive awareness and intelligence using the task-specific scale

Arousal, exploration and the locus coeruleus-norepinephrine system

The studies described in this thesis address a range of topics related to arousal, exploration, temporal attention, and the locus coeruleus-norepinephrine (LC-NE) system. Chapters 2 and 3 report two studies that investigated a recent theory about the role of the LC-NE system in the regulation of the exploration-exploitation trade-off. Chapter 4 reports a study on neurocognitive function in patients with dopamine-β-hydroxylase (DβH) deficiency. Chapter 5 reports an fMRI study on the neural correlates of perceptual curiosity. Chapter 6 and 7 reported several experiments investigating the effects of ‘accessory stimuli’ and temporal certainty on information processing, using scalp electrophysiology and sequential-sampling models of decision making. Taken together, the studies reported in this thesis suggest that arousal, exploration and temporal attention are closely related, which is likely due to a shared neural basis.LEI Universiteit LeidenFSW - Action Control - Ou

The Cognitive Underpinnings of Ideological Thinking

The collective ideologies of the 20th and 21st century have illustrated the horrifying scale of human atrocities that can be committed in the name of ideological groups and causes. While philosophers and historians have developed rich accounts of the societal factors shaping the forces behind participation in collective ideologies, there has been remarkably little rigorous scientific investigation into the cognitive and neural factors that can increase an individual’s susceptibility to ideological dogmatism and extremism. The aim of the current doctoral research was therefore to examine what psychological traits make some individuals more vulnerable to ideological thinking than others. Theory-driven and data-driven approaches were employed to map out the cognitive underpinnings of ideological thinking. A series of large online studies encompassing over 1,500 participants revealed that ideological rigidity may be rooted in cognitive rigidity, such that the rigidity with which individuals process and evaluate neutral stimuli predicts the rigidity and extremity of their ideological beliefs. This relationship was corroborated across multiple ideological domains, including nationalism, religion, political partisanship, dogmatism, and extremist attitudes, uncovering a tight link between low-level perceptual processes and high-level ideological attitudes. Furthermore, a data-driven approach using Bayesian analyses was adopted to study the cognitive and personality signatures of political conservatism, nationalism, religiosity, and dogmatism. This exposed that psychological dispositions can predict ideological attitudes substantially better than traditional demographic variables, challenging the dominant perspective in the social sciences that socioeconomic indicators are the most powerful predictors of how citizens vote and what they believe. This research program therefore suggests that ideological attitudes are amenable to careful cognitive and computational analysis. The findings signify that individual differences in our cognitive dispositions may underpin the intensity of our ideological adherence – and so a rigorous scientific study of the ideological mind may illuminate pertinent societal questions facing modern democracies.Gates Cambridge Trus