Deductive and inductive conditional inferences: Two modes of reasoning

Electrophysiological connectivity of logical deduction: Early cortical MEG study

Complex human reasoning involves minimal abilities to extract conclusions implied in the available information. These abilities are considered "deductive" because they exemplify certain abstract relations among propositions or probabilities called deductive arguments. However, the electrophysiological dynamics which supports such complex cognitive processes has not been addressed yet. In this work we consider typically deductive logico-probabilistically valid inferences and aim to verify or refute their electrophysiological functional connectivity differences from invalid inferences with the same content (same relational variables, same stimuli, same relevant and salient features). We recorded the brain electrophysiological activity of 20 participants (age = 20.35 ± 3.23) by means of an MEG system during two consecutive reasoning tasks: a search task (invalid condition) without any specific deductive rules to follow, and a logically valid deductive task (valid condition) with explicit deductive rules as instructions. We calculated the functional connectivity (FC) for each condition and conducted a seed-based analysis in a set of cortical regions of interest. Finally, we used a cluster-based permutation test to compare the differences between logically valid and invalid conditions in terms of FC. As a first novel result we found higher FC for valid condition in beta band between regions of interest and left prefrontal, temporal, parietal, and cingulate structures. FC analysis allows a second novel result which is the definition of a propositional network with operculo-cingular, parietal and medial nodes, specifically including disputed medial deductive "core" areas. The experiment discloses measurable cortical processes which do not depend on content but on truth-functional propositional operators. These experimental novelties may contribute to understand the cortical bases of deductive processes.

Providers' Understanding of Cancer Aetiology and Supportive Features for Indigenous Palliative Cancer Care Service Provision in Kenya

Background

Palliative care is a fundamental component of providing people-centred health services to cancer patients. However, the primary pillars of indigenous palliative care such as provider understanding of cancer, its aetiology, and features are undocumented.

Objective

We sought to understand Traditional Health Providers (THPs) understanding of cancer aetiology, and the functional features that support indigenous palliative cancer care service provision in Kenya.

Method

The study used a mixed methods cross-sectional design. A semi-structured questionnaire was administered to 193 THPs, who self-reported to manage cancer patients. The findings were enriched and validated through member checking in 6 focus group discussions and five journey mapping in-depth interviews.

Results

Despite diversity in culture and experience among the indigenous providers in Kenya, their description of cancer etiology and their management practices and primary goal were similar. Cancer was consistently described as a deadly life-deforming disease by 61.1% of THPs (n = 118/193) and attributed to chemicals and toxins in the body 41.5% (n = 80). The indigenous palliative-care system was reported to be characterized by five tiered levels of care, diversity in expertise and experience, shared and consultative process (60%) and family involvement in medical decision (59.5%). Herbal regimen (60.1%) was found to be the cornerstone of informal palliative care blended with nutrition management 78.2% (n = 151), lifestyle changes 63.7% (n = 123) and counseling services 55.9% (n = 108). Payments for service were arbitrarily made in cash or in kind.

Conclusion

The features of indigenous palliative care services are informed by the providers' distinctive cultural terms and descriptions of cancer and cancer aetiology. Shared and consultative protocols, regimen exchange, referral to cascaded care, and caregiver involvement were all important palliative-care clues to saving and enhancing lives. The features provide context for development of indigenous palliative care framework, engagement of policy makers, and promotion of culturally-inclusive indigenous palliative care model for adoption.

Auditory brainstem measures and genotyping boost the prediction of literacy: A longitudinal study on early markers of dyslexia

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Multi-domain profiles advance retrospective prediction of emergent literacy.

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DCDC2 and KIAA0319 risk variants influence emergent spelling skills.

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Combined DYX2 and auditory brainstem measures enhance predictive model fits.

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Additional benefit of preliterate phonological awareness on predictive power.

Literacy acquisition is impaired in children with developmental dyslexia resulting in lifelong struggle to read and spell. Proper diagnosis is usually late and commonly achieved after structured schooling started, which causes delayed interventions. Legascreen set out to develop a preclinical screening to identify children at risk of developmental dyslexia. To this end we examined 93 preliterate German children, half of them with a family history of dyslexia and half of them without a family history. We assessed standard demographic and behavioral precursors of literacy, acquired saliva samples for genotyping, and recorded speech-evoked brainstem responses to add an objective physiological measure. Reading and spelling was assessed after two years of structured literacy instruction. Multifactorial regression analyses considering demographic information, genotypes, and auditory brainstem encoding, predicted children’s literacy skills to varying degrees. These predictions were improved by adding the standard psychometrics with a slightly higher impact on spelling compared to reading comprehension. Our findings suggest that gene-brain-behavior profiling has the potential to determine the risk of developmental dyslexia. At the same time our results imply the need for a more sophisticated assessment to fully account for the disparate cognitive profiles and the multifactorial basis of developmental dyslexia.

A test of two processes: The effect of training on deductive and inductive reasoning

Dual-process theories posit that separate kinds of intuitive (Type 1) and reflective (Type 2) processes contribute to reasoning. Under this view, inductive judgments are more heavily influenced by Type 1 processing, and deductive judgments are more strongly influenced by Type 2 processing. Alternatively, single-process theories propose that both types of judgments are based on a common form of assessment. The competing accounts were respectively instantiated as two-dimensional and one-dimensional signal detection models, and their predictions were tested against specifically targeted novel data using signed difference analysis. In two experiments, participants evaluated valid and invalid arguments, under induction or deduction instructions. Arguments varied in believability and type of conditional argument structure. Additionally, we used logic training to strengthen Type 2 processing in deduction (Experiments 1 & 2) and belief training to strengthen Type 1 processing in induction (Experiment 2). The logic training successfully improved validity-discrimination, and differential effects on induction and deduction judgments were evident in Experiment 2. While such effects are consistent with popular dual-process accounts, crucially, a one-dimensional model successfully accounted for the results. We also demonstrate that the one-dimensional model is psychologically interpretable, with the model parameters varying sensibly across conditions. We argue that single-process accounts have been prematurely discounted, and formal modeling approaches are important for theoretical progress in the reasoning field.

The Dialogical Entailment Task

In this paper, a critical discussion is made of the role of entailments in the so-called New Paradigm of psychology of reasoning based on Bayesian models of rationality (Elqayam & Over, 2013). It is argued that assessments of probabilistic coherence cannot stand on their own, but that they need to be integrated with empirical studies of intuitive entailment judgments. This need is motivated not just by the requirements of probability theory itself, but also by a need to enhance the interdisciplinary integration of the psychology of reasoning with formal semantics in linguistics. The constructive goal of the paper is to introduce a new experimental paradigm, called the Dialogical Entailment task, to supplement current trends in the psychology of reasoning towards investigating knowledge-rich, social reasoning under uncertainty (Oaksford & Chater, 2019). As a case study, this experimental paradigm is applied to reasoning with conditionals and negation operators (e.g. CEM and wide and narrow-scope negation). As part of the investigation, participants' entailment judgments are evaluated against their probability evaluations to assess participants' cross-task consistency over two experimental sessions.

Validity and Persuasiveness of Conditional Arguments

Forty college students evaluated 80 conditional arguments with respect to both validity and persuasiveness. The arguments were of four types, two valid (modus ponens and modus tollens) and two invalid (involving affirmation of the consequent and denial of the antecedent). Participants were not good at distinguishing between valid and invalid arguments, although they did so better than at chance. Invalid arguments that were considered to be persuasive were almost 3 times as likely to be judged to be valid as were invalid arguments that were considered not to be persuasive. Whether an argument was judged to be persuasive was influenced by several variables, including the argument’s logical status, its believed logical status, whether the conclusion was believed by the evaluator to be a true statement of fact, whether the minor premise alone could be considered to be an adequate basis for judging the conclusion to be true, whether the argument’s conclusion or any of its premises was (or could be considered to be) false, and how the antecedent and consequent of the major premise were related. Various models of reasoning that predict some of the results are discussed, but there is no extant model that fully explains the relationship between the perceived validity and the perceived persuasiveness of conditional arguments.

Inductive reasoning 2.0

Inductive reasoning entails using existing knowledge to make predictions about novel cases. The first part of this review summarizes key inductive phenomena and critically evaluates theories of induction. We highlight recent theoretical advances, with a special emphasis on the structured statistical approach, the importance of sampling assumptions in Bayesian models, and connectionist modeling. A number of new research directions in this field are identified including comparisons of inductive and deductive reasoning, the identification of common core processes in induction and memory tasks and induction involving category uncertainty. The implications of induction research for areas as diverse as complex decision-making and fear generalization are discussed. This article is categorized under: Psychology > Reasoning and Decision Making Psychology > Learning.

Does Global and Local Vision Have an Impact on Creative and Analytic Thought? Two Failed Replications

According to GLOMOsys (the GLObal versus LOcal processing MOdel, a systems account), an important distinction is that between a local and a global processing system: The former processes information in parts, the latter processes it globally. These systems can be activated by perceptual processing and carry over to subsequent conceptual processing, in particular to analytical and creative thought. A conceptual and a high-powered close replication of previously reported studies test predictions of GLOMOsys for analytical thought and for analytical and creative thought, respectively. The present studies found no evidence that processing style primed via the Navon letter task has an impact on creative or analytic thought.

Bayesian reasoning with ifs and ands and ors

The Bayesian approach to the psychology of reasoning generalizes binary logic, extending the binary concept of consistency to that of coherence, and allowing the study of deductive reasoning from uncertain premises. Studies in judgment and decision making have found that people’s probability judgments can fail to be coherent. We investigated people’s coherence further for judgments about conjunctions, disjunctions and conditionals, and asked whether their coherence would increase when they were given the explicit task of drawing inferences. Participants gave confidence judgments about a list of separate statements (the statements group) or the statements grouped as explicit inferences (the inferences group). Their responses were generally coherent at above chance levels for all the inferences investigated, regardless of the presence of an explicit inference task. An exception was that they were incoherent in the context known to cause the conjunction fallacy, and remained so even when they were given an explicit inference. The participants were coherent under the assumption that they interpreted the natural language conditional as it is represented in Bayesian accounts of conditional reasoning, but they were incoherent under the assumption that they interpreted the natural language conditional as the material conditional of elementary binary logic. Our results provide further support for the descriptive adequacy of Bayesian reasoning principles in the study of deduction under uncertainty.