Difficult Turned Easy: Suggestion Renders a Challenging Visual Task Simple

Suggestions can cause some individuals to miss or disregard existing visual stimuli, but can they infuse sensory input with nonexistent information? Although several prominent theories of hypnotic suggestion propose that mental imagery can change our perceptual experience, data to support this stance remain sparse. The present study addressed this lacuna, showing how suggesting the presence of physically absent, yet critical, visual information transforms an otherwise difficult task into an easy one. Here, we show how adult participants who are highly susceptible to hypnotic suggestion successfully hallucinated visual occluders on top of moving objects. Our findings support the idea that, at least in some people, suggestions can add perceptual information to sensory input. This observation adds meaningful weight to theoretical, clinical, and applied aspects of the brain and psychological sciences

Exploring the relation between Metacognition, Multi-tasking and stress

When people do multiple tasks at the same time, it is often found that their performance is worse relative to when they do those same tasks in isolation. Indeed, error rates and response times (the Type 1 performance) have been repeatedly found to increase when multitasking. However, one aspect that has received little empirical attention in comparison, is whether observers are aware of these effects (their Type 2 performance). In a previous study, using a simple dual-task visual paradigm, we found that metacognition was unaffected by multitasking. In order to understand if this result could be generalised to other types of multitasking, we further developed a multi-modal paradigm, involving a motor tracking task, a visual detection task, and an auditory n-back task. We made participants perform these tasks in different combinations of single-, dual-, and tripletasking, and asked them to assess their own performance on a trial-by-trial basis. Comparing these different conditions, we discuss our results in the light of the influence that multitasking, and the specific type of task, has both on type 1 and type 2 performance, as well as on participants’ metacognitive bias. Finally, we explore how stress impact these different measures

Attention or instruction: do sustained attentional abilities really differ between high and low hypnotisable persons?

Previous research has suggested that highly hypnotisable participants (‘highs’) are more sensitive to the bistability of ambiguous figures—as evidenced by reporting more perspective changes of a Necker cube—than low hypnotisable participants (‘lows’). This finding has been interpreted as supporting the hypothesis that highs have more efficient sustained attentional abilities than lows. However, the higher report of perspective changes in highs in comparison to lows may reflect the implementation of different expectation-based strategies as a result of differently constructed demand characteristics according to one’s level of hypnotisability. Highs, but not lows, might interpret an instruction to report perspective changes as an instruction to report many changes. Using a Necker cube as our bistable stimulus, we manipulated demand characteristics by giving specific information to participants of different hypnotisability levels. Participants were told that previous research has shown that people with similar hypnotisability as theirs were either very good at switching or maintaining perspective versus no information. Our results show that highs, but neither lows nor mediums, were strongly influenced by the given information. However, highs were not better at maintaining the same perspective than participants with lower hypnotisability. Taken together, these findings favour the view that the higher sensitivity of highs in comparison to lows to the bistability of ambiguous figures reflect the implementation of different strategies

The Confidence Database

Understanding how people rate their confidence is critical for the characterization of a wide range of perceptual, memory, motor and cognitive processes. To enable the continued exploration of these processes, we created a large database of confidence studies spanning a broad set of paradigms, participant populations and fields of study. The data from each study are structured in a common, easy-to-use format that can be easily imported and analysed using multiple software packages. Each dataset is accompanied by an explanation regarding the nature of the collected data. At the time of publication, the Confidence Database (which is available at https://osf.io/s46pr/) contained 145 datasets with data from more than 8,700 participants and almost 4 million trials. The database will remain open for new submissions indefinitely and is expected to continue to grow. Here we show the usefulness of this large collection of datasets in four different analyses that provide precise estimations of several foundational confidence-related effects

Mind wandering at the fingertips: automatic parsing of subjective states based on response time variability

Research from the last decade has successfully used two kinds of thought reports in order to assess whether the mind is wandering: random thought-probes and spontaneous reports. However, none of these two methods allows any assessment of the subjective state of the participant between two reports. In this paper, we present a step by step elaboration and testing of a continuous index, based on response time variability within Sustained Attention to Response Tasks (N = 106, for a total of 10 conditions). We first show that increased response time variability predicts mind wandering. We then compute a continuous index of response time variability throughout full experiments and show that the temporal position of a probe relative to the nearest local peak of the continuous index is predictive of mind wandering. This suggests that our index carries information about the subjective state of the subject even when he or she is not probed, and opens the way for on-line tracking of mind wandering. Finally we proceed a step further and infer the internal attentional states on the basis of the variability of response times. To this end we use the Hidden Markov Model framework, which allows us to estimate the durations of on-task and off-task episodes

Can hypnosis displace the threshold for visual consciousness?

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OPERATION ET DESCRIPTION (LA CRITIQUE PAR WITTGENSTEIN DES THEORIES DE LA PROPOSITION DE RUSSELL)

LE BUT DE CE TRAVAIL EST DE DETERMINER LE ROLE DU CONCEPT D'OPERATION DANS LA PHILOSOPHIE DE LUDWIG WITTGENSTEIN (1889-1951) (DANS LE TRACTATUS ET JUSQU'AU DEBUT DE LA PERIODE INTER♭ MEDIAIRE), AU MOYEN D'UNE CONFRONTATION AVEC LA PENSEE DE BERTRAND RUSSELL (1872-1970). ON MONTRE D'ABORD QU'UNE DES CONSTANTES DE LA PENSEE DE RUSSELL EST SON INSISTANCE SUR LES DES♭ CRIPTIONS EN TERMES DE RELATIONS. IL S'AGIT POUR LUI D'UNE QUESTION DE METAPHYSIQUE FONDATRICE, ET CELA A POUR CONSEQUENCE QUE SCIENCE ET PHILOSOPHIE S'ATTACHENT TOUTES DEUX, A DES NIVEAUX DE GENERALITE DIFFERENTS, A LA DESCRIPTION D'UN MONDE DE CHOSES EN RELATION. IL EST ALORS MONTRE PAR CONTRASTE, COMMENT WITTGENSTEIN DANS LE TRACTATUS A DECOUVERT L'IMPOSSIBILITE DE RENDRE COMPTE EN CES TERMES DES CALCULS DE L'ARITHMETIQUE, LESQUELS EXIGENT DES CONCEPTS OPERATOIRES. L'OBJECTION FAITE ALORS A RUSSELL EST D'AUTANT PLUS VIOLENTE QUE LA REDUCTION DE L'ARITHMETIQUE A LA LOGIQUE ETAIT UN DES PREMIERS BUTS AFFICHES DE LA NOUVELLE PHILOSOPHIE RUSSELLIENNE. ON MONTRE COMMENT WITTGENSTEIN EN TIRE LA CONCLUSION QU'UNE LANGUE ANALYTIQUE UNIVERSELLE EST IMPOSSIBLE. DANS LA SECONDE PARTIE DU TRAVAIL ON MONTRE QUE WITTGENSTEIN A REDECOUVERT PAR UN BIAIS DIFFERENT L'IMPORTANCE DE L'OPERATION, APRES LE TOURNANT EPISTEMOLOGIQUE DE SA PENSEE (APRES 1929). ON SUIT ALORS LES VICISSITUDES DU PROJET DE DESCRIPTION PHENOMENOLOGIQUE DE L'EXPERIENCE PURE JUSQU'A SON ABANDON DANS LE CAHIER BLEU. MAIS C'EST ALORS QUE L'ON DECOUVRE UN NOUVEAU CONCEPT OPERATOIRE : LE JEU DE LANGAGE, ET NON PLUS LE CALCUL. ON PRESENTE LES JEUX DE LANGAGE COMME DES POINTS DE JONCTION ENTRE LES OPERATIONS QUE NOUS EFFECTUONS DANS L'EXPERIENCE ET LE LANGAGE DE LA DESCRIPTION. CE SONT CES OPERATIONS ELEMENTAIRES ET LANGAGIERES QUI RENDENT POSSIBLE UNE DESCRIPTION CONCRETE DE L'EXPERIENCE, DONT LES EFFETS SONT CRITIQUES.PARIS1-BU Pierre Mendès-France (751132102) / SudocPARIS-SORBONNE-BIU Centrale (751052105) / SudocSudocFranceF

Introspection during short-term memory scanning

International audienceThe literature in metacognition has argued for many years that introspective access to our own mental content is restricted to the cognitive states associated with the response to a task, such as the level of confidence in a decision or the estimation of the response time; however, the cognitive processes that underlie such states were deemed inaccessible to participants’ consciousness. Here, we ask whether participants could introspectively distinguish the cognitive processes that underlie two short-term memory tasks. For this purpose, we asked participants, on a trial-by-trial basis, to report the number of items that they mentally scanned during their short-term memory retrieval, which we have named “subjective number of scanned items.” The subjective number of scanned items index was evaluated, in Experiment 1, immediately after a judgment of recency task and, in Experiment 2, after an item recognition task. Finally, in Experiment 3, both tasks were randomly mixed. The results showed that participants’ introspection successfully accessed the complexity of the decisional processes