The effects of creatine supplementation on cognitive performance-a randomised controlled study

BACKGROUND

Creatine is an organic compound that facilitates the recycling of energy-providing adenosine triphosphate (ATP) in muscle and brain tissue. It is a safe, well-studied supplement for strength training. Previous studies have shown that supplementation increases brain creatine levels, which might increase cognitive performance. The results of studies that have tested cognitive performance differ greatly, possibly due to different populations, supplementation regimens, and cognitive tasks. This is the largest study on the effect of creatine supplementation on cognitive performance to date.

METHODS

Our trial was preregistered, cross-over, double-blind, placebo-controlled, and randomised, with daily supplementation of 5 g for 6 weeks each. We tested participants on Raven's Advanced Progressive Matrices (RAPM) and on the Backward Digit Span (BDS). In addition, we included eight exploratory cognitive tests. About half of our 123 participants were vegetarians and half were omnivores.

RESULTS

Bayesian evidence supported a small beneficial effect of creatine. The creatine effect bordered significance for BDS (p = 0.064, η2P = 0.029) but not RAPM (p = 0.327, η2P = 0.008). There was no indication that creatine improved the performance of our exploratory cognitive tasks. Side effects were reported significantly more often for creatine than for placebo supplementation (p = 0.002, RR = 4.25). Vegetarians did not benefit more from creatine than omnivores.

CONCLUSIONS

Our study, in combination with the literature, implies that creatine might have a small beneficial effect. Larger studies are needed to confirm or rule out this effect. Given the safety and broad availability of creatine, this is well worth investigating; a small effect could have large benefits when scaled over time and over many people.

TRIAL REGISTRATION

The trial was prospectively registered (drks.de identifier: DRKS00017250, https://osf.io/xpwkc/ ).

The Brain Networks Basis for Deductive and Inductive Reasoning: A Functional Magnetic Resonance Imaging Study

Introduction

Frontoparietal (FPN) and cingulo-opercular network (CON) control cognitive functions needed in deductive and inductive reasoning via different functional frameworks. The FPN is a fast intuitive system while the CON is slow and analytical. The default-interventionist model presents a serial view of the interaction between intuitive and analytic cognitive systems. This study aims to examine the activity pattern of the FPN and CON from the perspective of the default-interventionist model via reasoning.

Methods

We employed functional magnetic resonance imaging (fMRI) to investigate cingulo-opercular and frontoparietal network activities in 24 healthy university students during Raven and Wason reasoning tasks. Due to the different operation times of the CON and FPN, the reaction time was assessed as a behavioral factor.

Results

During Raven's advanced progressive matrices (RAPM) test, both the CON and FPN were activated. Also, with the increase in the difficulty level of the Raven test, a linear increase in response time was observed. In contrast, during the Wason's selection task (WST) test, only the activity of FPN was observed.

Conclusion

The results of the study support the hypothesis that the default-interventionist model of dual-process theory provides an accurate explanation of the cognitive mechanisms involved in reasoning. Thus, the response method (intuitive/analytical) determines which cognitive skills and brain regions are involved in responding.

Highlights

The cingulo-opercular and fronto-parietal networks (FPNs) control cognitive functions and processes.The frontoparietal network is a fast intuitive system that utilizes short-time attention which is compatible with type 1 processing. In contrast, the cingulo-opercular network (CON) is an analytical time-consuming system that utilizes attention and working memory for a longer time, compatible with type 2 processing.The default-interventionist model of a dual-process theory states that our behaviors are controlled by type 1 processing unless we are confronted with novel and complex problems in which we have no prior experiences.

Plain Language Summary

The present study examined the activity of two task-based brain networks through performing diffrent type of reasoning tasks. Fronto-parietal and Cingulo-opercular are the two task-based brain networks that are responsible for cognitive control. These two brain networks direct the way to use cognitive skills and executive functions which are necessary to perform cognitive tasks especially higher-order ones as reasoning tasks. Since the two types of inductive and deductive reasoning tasks requier two different bottom-up and top-down cognitive control respectively, different cognitive skills would be needed which affect the activity of fronto-parietal and cingulo-opercular brain networks. Our results showed that through inductive reasoning task which examined by RAVEN, both of the fronto-parietal and cingulo-opercular brain networks were activated but deductive reasoning task which examined by Wason Selection Card test, just the fronto-parietal brain network was activated. It seems that in the case of deductive reasoninf task, there is a higher probability of errors which lead to giving less correct responses. Based on our results, subjects paid not enough attention to details, so had failure to update informations that leaded to responding with errors. Inactivity of cingulo-opercular network through dedeuctive reasoning task clearly showed that the bottom-up cognitive control did not happen successfully. As a result of that, information processing did not proceed properly.

Both sheep and goats can solve inferential by exclusion tasks

Despite the domestication of sheep and goats by humans for several millennia, we still lack comparative data on their cognitive capacity. Comparing the cognitive skills of farm animals can help understand the evolution of cognition. In this study, we compared the performances of sheep and goats in inference by exclusion tasks. We implemented two tasks, namely a cup task and a tube task, to identify whether success in solving the task could be attributed to either low-level mechanisms (avoiding the empty location strategy) or to deductive reasoning (if two possibilities A and B, but not A, then it must be B). In contrast to a previous study comparing goats and sheep in a cup task, we showed that both species solved the inferential condition with high success rates. In the tube task, performances could not be explained by alternative strategies such as avoiding the empty tube or preferring the bent tube. When applying a strict set of criteria concerning responses in all conditions and controlling for the potential effects of experience, we demonstrate that two individuals, a goat and a sheep, fulfil these criteria. This suggests that sheep and goats are able to make inferences based on deductive reasoning.

Find extra options or reason badly: An investigation of children's reasoning with incompatibility statements

The false dilemma or dichotomy is a logical fallacy that occurs when interlocuters accept the premises in an incompatibility statement as being jointly exhaustive (i.e., leaving no third option), whereas that is in fact not the case. Brisson et al. [Memory & Cognition (2018), Vol. 46, pp. 657-670] investigated this fallacy in an adult sample and discovered a content effect that influenced participants' performance. The current study aimed to elaborate on these findings by establishing whether similar patterns could be observed with children. A number of age-appropriate incompatibility premises were constructed. For every item, four different inferential problems were presented (Affirm First, Affirm Second, Deny First, and Deny Second) with three potential answers to choose from (X, not X, or uncertainty regarding X). A sample of 192 volunteer children, with ages ranging from 8 to 13 years, was collected. Statistical analysis showed no significant effect for participants' age but did reveal main effects for premise validity and the amount of available "third options" (possibilities outside of the presented dichotomy). These results are a clear replication of the general effects on adults found by Brisson et al. Affirm inferences were also easy for children, Deny inferences were difficult (even more so than for adults), and content had a profound effect on participants' performance. Whenever more third options could be generated, children were less likely to fall into the false dilemma fallacy. Our findings thus further support the idea that reasoning with incompatibilities is influenced by the same semantic retrieval processes that have been previously related to human conditional reasoning.

A neuroimaging dataset of deductive reasoning in school-aged children

Here we describe “Brain development of deductive reasoning” a pediatric neuroimaging dataset freely available on OpenNeuro.org. This dataset includes neuroimaging and standardized assessment data from 56 participants aged 8.47–15 years. Functional Magnetic Resonance Imaging (fMRI) data were collected while participants completed both set-inclusion and linear-order deductive reasoning tasks. A subset of participants (n=45) returned two years later for follow-up standardized assessment testing allowing for future research to investigate individual change in cognitive and academic skill. Previous research on this dataset has not examined the relation of skill and demographic measures to the neural basis of reasoning. Moreover, these studies have not examined the relation of the neural basis of reasoning to that of arithmetic or differences between children and adults in the neural basis of reasoning. Therefore, there are many opportunities to extend the research in the published reports on this data.

Reasoning strategies and semantic memory effects in deductive reasoning

Growing evidence supports the dual-strategy model, which suggests that reasoners have access to both a statistical and a counterexample reasoning strategy. In this paper, we explore further the processes underlying strategy use. We report three studies, the aim of which was to clarify the relation between this model and two forms of everyday reasoning. One of the most robust effects found with conditional reasoning with meaningful premises is the effect of alternative antecedents on the endorsement of AC and DA inferences. In a first study, we presented participants with conditional reasoning problems having more or fewer accessible alternatives as well as our dual-strategy diagnostic questionnaire. As hypothesized, results showed that strategy use had an independent effect on the inferences made with the AC and DA forms, over and above the effect of the number of antecedents, but was not related to responding to the MP and the MT forms. In a second study, we found that this relation extended to reasoning from an incompatibility statement. Finally, a third study showed that this relationship did not hold with probabilistic rather than logical response instructions, suggesting that the way reasoners transform a probabilistic evaluation into a dichotomous judgment is a key determinant of strategy use.

Reasoning processes in clinical reasoning: from the perspective of cognitive psychology

Clinical reasoning is considered a crucial concept in reaching medical decisions. This paper reviews the reasoning processes involved in clinical reasoning from the perspective of cognitive psychology. To properly use clinical reasoning, one requires not only domain knowledge but also structural knowledge, such as critical thinking skills. In this paper, two types of reasoning process required for critical thinking are discussed: inductive and deductive. Inductive and deductive reasoning processes have different features and are generally appropriate for different types of tasks. Numerous studies have suggested that experts tend to use inductive reasoning while novices tend to use deductive reasoning. However, even experts sometimes use deductive reasoning when facing challenging and unfamiliar problems. In clinical reasoning, expert physicians generally use inductive reasoning with a holistic viewpoint based on a full understanding of content knowledge in most cases. Such a problem-solving process appears as a type of recognition-primed decision making only in experienced physicians' clinical reasoning. However, they also use deductive reasoning when distinct patterns of illness are not recognized. Therefore, medical schools should pursue problem-based learning by providing students with various opportunities to develop the critical thinking skills required for problem solving in a holistic manner.

Testing the deductive inferential account of blocking in causal learning

The sensitivity of the blocking effect to outcome additivity pretraining has been used to argue that the phenomenon is the result of deductive inference, and to draw general conclusions about the nature of human causal learning. In two experiments, we manipulated participants' assumptions about the additivity of the outcome using pretraining before a typical blocking procedure. Ratings measuring causal judgments, confidence, and expected severity of the outcome were used concurrently to investigate how pretraining affected assumptions of outcome additivity and blocking. In Experiment 1, additive pretraining led to lower causal ratings and higher confidence ratings of the blocked cue, relative to control cues, consistent with the notion that additive pretraining encourages deductive reasoning. However, Experiments 1 and 2 showed that removing additivity assumptions through nonadditive pretraining had no impact on a statistically reliable blocking effect observed in a blocking procedure with no pretraining. We found no evidence that the blocking effect in the absence of pretraining was related to the participants' assumptions about the additivity of the outcome. Although additive pretraining may enhance blocking by encouraging deductive reasoning about the blocked cue, the evidence suggests that blocking in causal learning is not reliant on this reasoning and that humans do not readily engage in deduction merely because they possess the assumptions that permit its use.

Characterizing belief bias in syllogistic reasoning: A hierarchical Bayesian meta-analysis of ROC data

The belief-bias effect is one of the most-studied biases in reasoning. A recent study of the phenomenon using the signal detection theory (SDT) model called into question all theoretical accounts of belief bias by demonstrating that belief-based differences in the ability to discriminate between valid and invalid syllogisms may be an artifact stemming from the use of inappropriate linear measurement models such as analysis of variance (Dube et al., Psychological Review, 117(3), 831-863, 2010). The discrepancy between Dube et al.'s, Psychological Review, 117(3), 831-863 (2010) results and the previous three decades of work, together with former's methodological criticisms suggests the need to revisit earlier results, this time collecting confidence-rating responses. Using a hierarchical Bayesian meta-analysis, we reanalyzed a corpus of 22 confidence-rating studies (N = 993). The results indicated that extensive replications using confidence-rating data are unnecessary as the observed receiver operating characteristic functions are not systematically asymmetric. These results were subsequently corroborated by a novel experimental design based on SDT's generalized area theorem. Although the meta-analysis confirms that believability does not influence discriminability unconditionally, it also confirmed previous results that factors such as individual differences mediate the effect. The main point is that data from previous and future studies can be safely analyzed using appropriate hierarchical methods that do not require confidence ratings. More generally, our results set a new standard for analyzing data and evaluating theories in reasoning. Important methodological and theoretical considerations for future work on belief bias and related domains are discussed.

Inductive reasoning and doubt in obsessive compulsive disorder

BACKGROUND AND OBJECTIVES

Previous studies show that individuals with obsessive compulsive disorder (OCD) accord more importance than healthy controls (HC) to alternative conclusions, resulting in increased doubt regarding an initial conclusion. The goal of the present study was to replicate and extend this finding.

METHODS

Eighteen participants diagnosed with OCD and 16 HC completed the Reasoning with Inductive Arguments Task (RIAT), which operationalizes doubt as change in confidence towards a conclusion after alternative conclusions are presented. To examine conditions that facilitate doubt, the impact of alternative conclusions that both supported and contradicted the initial conclusion was compared, as well as the effect of neutral and OCD-relevant item content.

RESULTS

Both the OCD and HC groups decreased confidence after contradicting conclusions, but only the HC group increased confidence when presented with supporting conclusions. Furthermore, decrease in confidence in the OCD group correlated with OCD symptom severity.

LIMITS

The RIAT could be adapted to better take into account of OCD subtypes.

CONCLUSION

Doubt generation may contribute to obsessional doubting.

Reasoning from an incompatibility: False dilemma fallacies and content effects

In the present studies, we investigated inferences from an incompatibility statement. Starting with two propositions that cannot be true at the same time, these inferences consist of deducing the falsity of one from the truth of the other or deducing the truth of one from the falsity of the other. Inferences of this latter form are relevant to human reasoning since they are the formal equivalent of a discourse manipulation called the false dilemma fallacy, often used in politics and advertising in order to force a choice between two selected options. Based on research on content-related variability in conditional reasoning, we predicted that content would have an impact on how reasoners treat incompatibility inferences. Like conditional inferences, they present two invalid forms for which the logical response is one of uncertainty. We predicted that participants would endorse a smaller proportion of the invalid incompatibility inferences when more counterexamples are available. In Study 1, we found the predicted pattern using causal premises translated into incompatibility statements with many and few counterexamples. In Study 2A, we replicated the content effects found in Study 1, but with premises for which the incompatibility statement is a non-causal relation between classes. These results suggest that the tendency to fall into the false dilemma fallacy is modulated by the background knowledge of the reasoner. They also provide additional evidence on the link between semantic information retrieval and deduction.

When fast logic meets slow belief: Evidence for a parallel-processing model of belief bias

Two experiments pitted the default-interventionist account of belief bias against a parallel-processing model. According to the former, belief bias occurs because a fast, belief-based evaluation of the conclusion pre-empts a working-memory demanding logical analysis. In contrast, according to the latter both belief-based and logic-based responding occur in parallel. Participants were given deductive reasoning problems of variable complexity and instructed to decide whether the conclusion was valid on half the trials or to decide whether the conclusion was believable on the other half. When belief and logic conflict, the default-interventionist view predicts that it should take less time to respond on the basis of belief than logic, and that the believability of a conclusion should interfere with judgments of validity, but not the reverse. The parallel-processing view predicts that beliefs should interfere with logic judgments only if the processing required to evaluate the logical structure exceeds that required to evaluate the knowledge necessary to make a belief-based judgment, and vice versa otherwise. Consistent with this latter view, for the simplest reasoning problems (modus ponens), judgments of belief resulted in lower accuracy than judgments of validity, and believability interfered more with judgments of validity than the converse. For problems of moderate complexity (modus tollens and single-model syllogisms), the interference was symmetrical, in that validity interfered with belief judgments to the same degree that believability interfered with validity judgments. For the most complex (three-term multiple-model syllogisms), conclusion believability interfered more with judgments of validity than vice versa, in spite of the significant interference from conclusion validity on judgments of belief.

The capacity to generate alternative ideas is more important than inhibition for logical reasoning in preschool-age children

There is little consensus about the nature of logical reasoning and, equally important, about how it develops. To address this, we looked at the early origins of deductive reasoning in preschool children. We examined the contribution of two factors to the reasoning ability of very young children: inhibitory capacity and the capacity to generate alternative ideas. In a first study, a total of 32 preschool children were all given generation, inhibition, and logical reasoning measures. Logical reasoning was measured using knowledge-based premises such as "All dogs have legs," and two different inferences: modus ponens and affirmation of the consequent. Results revealed that correctly reasoning with both inferences is not related to the measure of inhibition, but is rather related to the capacity to generate alternative ideas. In a second study, 32 preschool children were given either the generation or the inhibition task before the logical reasoning measure. Results showed that receiving the generation task beforehand significantly improved logical reasoning compared to the inhibition task given beforehand. Overall, these results provide evidence for the greater importance of idea generation in the early development of logical reasoning.

Priming effect in indicative and subjunctive exceptive conditionals

We report the results of three experiments that examine the mental representations underlying the comprehension stages of negative exceptive conditionals using subjunctive mood ('B a menos que A', 'B a no ser que A'; 'B excepto que A'='B unless A') and indicative mood ('B excepto si A' and 'B salvo si A'='B except if A'). The mental representations during the comprehension stage were analyzed using a priming methodology. All experiments showed that participants read the true possibility 'not-B & A' faster when it was primed by exceptive conditionals requiring the subjunctive mood than when it was primed by exceptive conditionals requiring the indicative mood; other possibilities ('B & A', 'B & not-A', 'not-B & not-A') were primed equally by both connectives. The experiments showed that (a) when people understand negative exceptive conditionals using the subjunctive mood, such as 'B a menos que A'/'B a no ser que A'/'B excepto que A', they access the true possibilities 'not-B & A' and 'B & not-A', and (b) when they understand negative exceptive conditionals using the indicative mood, such as 'B excepto si A'/'B salvo si A', they access 'B & not-A', but not 'not-B & A'. We discuss the implications of this for current theories of reasoning.

The modulation of disjunctive assertions

The theory of mental models postulates that disjunctions of the sort, A or B, where A and B are sensible everyday clauses, have a core meaning that allows an inclusive interpretation, referring to three possibilities: A and not-B, not-A and B, and A and B. The meaning of the clauses and knowledge can modulate this meaning by blocking the construction of at least one model of a possibility-for example, "Rui is playing tennis or he is surfing" blocks the model of Rui doing both activities. This theory is implemented in a computer program. Three experiments investigated the core interpretation and interpretations in which the contents of the clauses should block the model of A and B (as in the preceding example), the model of A and not-B, or the model of not-A and B. In Experiment 1, the participants listed the possibilities for each of the four sorts of disjunction. The results corroborated the predicted modulations. In Experiment 2, these predicted interpretations governed the conclusions that participants accepted from disjunctions and categorical premises. In Experiment 3, the predicted interpretations yielded reliable effects on the conclusions that the participants drew for themselves. We relate these results to theories of reasoning.

Additional evidence for a dual-strategy model of reasoning: Probabilistic reasoning is more invariant than reasoning about logical validity

One of the major debates concerning the nature of inferential reasoning is between counterexample-based strategies such as mental model theory and the statistical strategies underlying probabilistic models. The dual-strategy model proposed by Verschueren, Schaeken, and d'Ydewalle (2005a, 2005b) suggests that people might have access to both kinds of strategies. One of the postulates of this approach is that statistical strategies correspond to low-cost, intuitive modes of evaluation, whereas counterexample strategies are higher-cost and more variable in use. We examined this hypothesis by using a deductive-updating paradigm. The results of Study 1 showed that individual differences in strategy use predict different levels of deductive updating on inferences about logical validity. Study 2 demonstrated no such variation when explicitly probabilistic inferences were examined. Study 3 showed that presenting updating problems with probabilistic inferences modified performance on subsequent problems using logical validity, whereas the opposite was not true. These results provide clear evidence that the processes used to make probabilistic inferences are less subject to variation than those used to make inferences of logical validity.

Neural correlates of deductive reasoning: An ERP study with the Wason Selection Task

The Wason Selection Task (WST) is a well-known test of reasoning in which one turns over cards to test a rule about the two faces. Modifications were made to the WST to enable more direct and analytical investigation of reasoning processes. The modifications included extensive training to reduce variations in task interpretation, isolation of working memory in the decision phase, a separate rule for each card and variations in the form of the rule (number-letter as well as letter-number), separate scoring for each card, and inclusion of control cards that could be recognized by features without relational processing. The cognitive complexity of each card was also analyzed to enable investigation of this factor. Behavioral and event-related potential data were recorded. Negative cards differed from positive cards and control cards were differentiated from cards involved in inferences. The N2 component differentiated the negative conditions (not-P, not-Q cards) from the positive conditions (P, Q cards). The P3 component was largest for control and P cards (the simpler conditions). The late slow wave tended to show more sustained processing of not-P, not-Q and Q cards and was little influenced by the simpler control and P cards. Effects were interpreted in terms of cognitive complexity. In particular, the negative conditions had a larger N2 response than the positive conditions, reflecting greater cognitive complexity of the former and their sustained processing.

The interplay of deductive and inductive reasoning in psychoanalytic theorizing

Deductive and inductive reasoning both played an essential part in Freud's construction of psychoanalysis. In this paper, the author explores the happy marriage of empiricism and rationalism in Freud's use of deductive reasoning in the construction of psychoanalytic theory. To do this, the author considers three major amendments Freud made to his theory: (i) infant and childhood sexuality, (ii) the structural theory, and (iii) the theory of signal anxiety. Ultimately, the author argues for, and presents Freud as a proponent of, the epistemological position that he calls critical realism.

Framing deductive reasoning with emotional content: an fMRI study

In the literature concerning the study of emotional effect on cognition, several researches highlight the mechanisms of reasoning ability and the influence of emotions on this ability. However, up to now, no neuroimaging study was specifically devised to directly compare the influence on reasoning performance of visual task-unrelated with semantic task-related emotional information. In the present functional fMRI study, we devised a novel paradigm in which emotionally negative vs. neutral visual stimuli (context) were used as primes, followed by syllogisms composed of propositions with emotionally negative vs. neutral contents respectively. Participants, in the MR scanner, were asked to assess the logical validity of the syllogisms. We have therefore manipulated the emotional state and arousal induced by the visual prime as well as the emotional interference exerted by the syllogism content. fMRI data indicated a medial prefrontal cortex deactivation and lateral/dorsolateral prefrontal cortex activation in conditions with negative context. Furthermore, a lateral/dorsolateral prefrontal cortex modulation caused by syllogism content was observed. Finally, behavioral data confirmed the influence of emotional task-related stimuli on reasoning ability, since the performance was worse in conditions with syllogisms involving negative emotions. Therefore, on the basis of these data, we conclude that emotional states can impair the performance in reasoning tasks by means of the delayed general reactivity, whereas the emotional content of the target may require a larger amount of top-down resources to be processed.