Decision making in a case of mixed uncertainty: A normative model

We consider a case of uncertainty which is frequently met in various fields, e.g., in parametric statistics: Events {θ}, θ ∈ ∵, are members of family $\text{E}$ on which the decision maker possesses no information at all; however, conditionally on the realization of {θ}, he is able to affix probabilities to all members of another family of events, $\text{F}$. We assume that the decision maker: (1) has a rational behavior under complete ignorance, for decisions whose results only depend on events of $\text{E}$; (2) with {θ} known, maximizes his conditional expected utility for decisions whose results only depend on events of $\text{F}$; (3) has (unconditional) preferences which are consistent with his conditional ones. These assumptions are shown to be sufficient to ensure an approximate representation of the decision maker's preference by a real-valued function W which has the form $\text{W(f) = v[}\text{Inf}{}_{\mathrm{\theta \in \because }}\text{E}{}_{\mathrm{\theta }}\text{(u°f),}\text{Sup}{}_{\mathrm{\theta \in \because }}\text{E}{}_{\mathrm{\theta }}\text{(u°f)]}$, where u and v, respectively, characterize the decision maker's attitudes toward risk and toward complete ignorance.     

Numerical representations and intuitions of probabilities at 12 months

Recent research shows that preverbal infants can reason about single‐case probabilities without relying on observed frequencies, adapting their predictions to relevant dynamic parameters of the situation (Téglás, Vul, Girotto, Gonzalez, Tenenbaum & Bonatti, 2011 ; Téglás, Girotto, Gonzalez & Bonatti, 2007 ). Here we show that intuitions of probabilities may derive from the ability to represent a limited number of possibilities. After watching a scene containing moving objects of two ensembles, 12‐month‐olds looked longer at an unlikely than at a likely single‐case outcome when the objects were within the parallel individuation range. However, they did not do so when the scene contained the same ratio between ensembles but a larger number of objects. At the same time, they could form rational expectations about single‐case outcomes in scenes containing the same large number of objects when they could exploit subtle physical parameters induced by the objects’ movements and their spatial configuration. Our findings demonstrate that at early stages of development the mental representations involved in probability estimations of future individual situations are powerful and sophisticated, but at the same time they depend on infants’ overall cognitive architecture, being constrained by the numerical representations spontaneously induced by the situations.     

Hypnotic discontinuation in chronic insomnia: impact of psychological distress, readiness to change, and self-efficacy.

OBJECTIVE: To compare individuals who were successful in discontinuing hypnotic medications against those who were not on measures of insomnia severity, medication withdrawal symptoms, psychological symptoms, perceived health, readiness to change and self-efficacy. DESIGN: Secondary analyses of a randomized clinical trial comparing a hypnotic taper intervention with or without self-help treatment for insomnia. MAIN OUTCOME MEASURES: Self-report measures of insomnia severity, medication withdrawal symptoms, depression and anxiety symptoms, physical and mental health, stages of change, readiness to change, decisional balance, and general and situational self-efficacy. RESULTS: There were no significant differences at baseline between medication-free individuals and those still using sleep medication at the end of a taper intervention. Group differences emerged midway through the 8-week withdrawal program and were accentuated after the intervention; participants who remained medication-free during the next six months had less severe insomnia and anxiety symptoms, a more positive perception of their health and higher self-efficacy to refrain from hypnotic use in various situations. Contrary to expectations, there were no differences between drug-free and nondrug-free participants on both readiness to change and stages of change. CONCLUSIONS: Chronic users of hypnotic medications entered a taper intervention with equal levels of psychological distress, health, self-efficacy, and readiness to change. Successful hypnotic discontinuation was associated with overall improvement of insomnia, anxiety and distress symptoms, perceived health and self-efficacy. More intensive and individualized therapeutic attention may be warranted for individuals experiencing worsening of insomnia symptoms, more withdrawal symptoms and psychological distress, and lower self-efficacy during medication discontinuation.     

Visual allesthesia in manual pointing: Some evidence for a sensorimotor cerebral organization

The authors of this paper first summarize some of the theoretical frames put forward to account for allesthesia. Then, pointing performances in a case of visual allesthesia is reported; unexpectedly, pointing behavior for identical targets was different according to hand. The most salient feature was that a same visual target elicited relatively short RTs with adequate pointing using the left hand versus much longer reaction times with allesthesic pointing using the right hand. Discussion is focused on the presented theoretical frames. In view of the results, authors are led to hypothesize that, in sensorimotor cerebral organization, some aspects of signal processing are dependent upon some premotor aspects of response elaboration.     

Remapping versus short-term memory in visual stability across saccades

Saccadic eye movements cause displacements of the image of the visual world projected on the retina. Despite the ubiquitous nature of saccades, subjective experience of the world is continuous and stable. In five experiments, we addressed the mechanisms that may support visual stability: matching of pre- and postsaccadic locations of the target by an internal copy of the saccade, or retention of the visual attributes of the target in short-term memory across the saccade. Healthy human adults were instructed to make a saccade to a peripheral Gabor patch. While the saccade was in midflight, the patch could change location, orientation, or both. The change occurred either immediately or following a 250-ms blank during which no visual stimuli were available. In separate experiments, subjects had to report either whether the patch stepped to the left or right or whether the orientation rotated clockwise or counterclockwise. Consistent with previous findings, we found that transsaccadic displacement discrimination was enhanced by the addition of the blank. However, contrary to previous findings reported in the literature, the feature change did not improve performance. Transsaccadic orientation change discrimination did not depend on either an irrelevant temporal blank or a simultaneous irrelevant target displacement. Taken together, these findings suggest that orientation is not a relevant visual feature for transsaccadic correspondence.     

Using morphology when spelling in a shallow orthographic system: The case of Spanish

Deep orthographies usually represent morphology and phonology simultaneously; both resources are necessary for spelling. In shallow orthographies, such as Spanish, phonology would be enough to spell most words. However, morphological knowledge may also take part in spelling. This study examined how Spanish children in 1st (N = 148), 2nd (N = 155) and 3rd grade (N = 155) use morphological information to spell plural nouns and verbs. A word dictation task was designed. The task included high and low frequency plural nouns ending in “s” (morphological “-s” condition) and verbs in the 2nd person ending in “s” (morphological “-s” condition). A lexical condition including words with a final “s” which was not morphologically motivated was used as a control condition (lexical “-s” condition). The results show that, although Spanish spelling is influenced by phonology, morphological information is also used. These results are discussed in relation to current models of word spelling.     

Inferentialism,degrees of commitment,and ampliative reasoning

Our purpose in this paper is to contribute to a practice-based characterization of scientific inference. We want to explore whether Brandom’s pragmatist–inferentialist framework can suitably accommodate several types of ampliative inference common in scientific reasoning and explanation (probabilistic reasoning, abduction and idealisation). First, we argue that Brandom’s view of induction in terms of merely permissive inferences is inadequate; in order to overcome the shortcoming of Brandom’s proposal, we put forward an alternative conception of inductive, probabilistic reasoning by appeal to the notion of degrees of commitment. Moreover, we examine the sorts of inferential commitments operative in other types of ampliative inferences, such as abduction or reasoning involving idealizations and assumptions. We suggest that agents engaging in these forms of reasoning often undertake restricted inferential commitments, whose scope and reach are more limited that in the case of the commitments associated with full beliefs.

     

A randomized controlled trial of internet-based therapy in depression

Depression is among the most prevalent disorders worldwide. In view of numerous treatment barriers, internet-based interventions are increasingly adopted to “treat the untreated”. The present trial (registered as NCT01401296) was conducted over the internet and aimed to assess the efficacy of an online self-help program for depression (Deprexis). In random order, participants with elevated depression symptoms received program access or were allocated to a wait-list control condition. After eight weeks, participants were invited to take part in an online re-assessment. To compensate for common problems of online studies, such as low completion rates and unclear diagnostic status, reminders and incentives were used, and clinical diagnoses were externally confirmed in a subgroup of 29% of participants. Relative to the wait-list group, program users experienced significant symptom decline on the Beck Depression Inventory (BDI; primary outcome), the Dysfunctional Attitudes Scale (DAS), the Quality of Life scale (WHOQOL-BREF) and the Rosenberg Self-Esteem Scale (RSE). Compared to wait-list participants, symptom decline was especially pronounced among those with moderate symptoms at baseline as well as those not currently consulting a therapist. Completion (82%) and re-test reliability of the instruments (r = .72–.87) were good. The results of this trial suggest that online treatment can be beneficial for people with depression, particularly for those with moderate symptoms.