Yes,they can! Efficient physical effort mobilization according to task difficulty in schizophrenia

The current literature has largely highlighted a deficit of effort-based decision-making for reward in schizophrenia. However, not all studies have dissociated effort from reward, while other studies emphasize that difficulty is the main determinant of effort rather than reward. In this study, 33 individuals with schizophrenia and 32 healthy controls were recruited to perform a decision-making isometric force task. According to motivational intensity theory, task difficulty (i.e., required force) but not reward was manipulated from easy to impossible. Accuracy between force exerted and force required, and choice to perform a task or not were our effort measures. Clinical variables including depression, defeatist beliefs, and apathy were assessed. Our results demonstrated that the schizophrenia group chose to perform easy, moderate, and difficult tasks and exerted the necessary effort to succeed similarly to the non-clinical group. No association between effort and clinical variables was found. Our findings provide new understandings related to effort mechanisms in schizophrenia.

     

Gaze-following behind barriers in domestic dogs

Although gaze-following abilities have been demonstrated in a wide range of species, so far no clear evidence has been available for dogs. In the current study, we examined whether dogs follow human gaze behind an opaque barrier in two different contexts, in a foraging situation and in a non-foraging situation (food involved vs. food not involved in the situation). We assumed that dogs will spontaneously follow the human gaze and that the foraging context will have a positive effect on dogs’ gaze-following behaviour by causing an expectation in the dogs that food might be hidden somewhere in the room and might be communicated by the experimenter. This expectation presumably positively affects their motivational and attentional state. Here, we report that dogs show evidence of spontaneous gaze-following behind barriers in both situations. According to our findings, the dogs gazed earlier at the barrier in the indicated direction in both contexts. However, as we expected, the context also has some effect on dogs’ gaze-following behaviour, as more dogs gazed behind the barrier in the indicated direction in the foraging situation. The present results also support the idea that gaze-following is a characteristic skill in mammals which may more easily emerge in certain functional contexts.     

Structural properties of spatial representations in blind people: Scanning images constructed from haptic exploration or from locomotion in a 3-D audio virtual environment

When people scan mental images, their response times increase linearly with increases in the distance to be scanned, which is generally taken as reflecting the fact that their internal representations incorporate the metric properties of the corresponding objects. In view of this finding, we investigated the structural properties of spatial mental images created from nonvisual sources in three groups (blindfolded sighted, late blind, and congenitally blind). In Experiment 1, blindfolded sighted and late blind participants created metrically accurate spatial representations of a small-scale spatial configuration under both verbal and haptic learning conditions. In Experiment 2, late and congenitally blind participants generated accurate spatial mental images after both verbal and locomotor learning of a full-scale navigable space (created by an immersive audio virtual reality system), whereas blindfolded sighted participants were selectively impaired in their ability to generate precise spatial representations from locomotor experience. These results attest that in the context of a permanent lack of sight, encoding spatial information on the basis of the most reliable currently functional system (the sensorimotor system) is crucial for building a metrically accurate representation of a spatial environment. The results also highlight the potential of spatialized audio-rendering technology for exploring the spatial representations of visually impaired participants.     

Speaking two languages with different number naming systems: What implications for magnitude judgments in bilinguals at different stages of language acquisition?

Differences between languages in terms of number naming systems may lead to performance differences in number processing. The current study focused on differences concerning the order of decades and units in two-digit number words (i.e., unit-decade order in German but decade-unit order in French) and how they affect number magnitude judgments. Participants performed basic numerical tasks, namely two-digit number magnitude judgments, and we used the compatibility effect (Nuerk et al. in Cognition 82(1):B25–B33, 2001) as a hallmark of language influence on numbers. In the first part we aimed to understand the influence of language on compatibility effects in adults coming from German or French monolingual and German–French bilingual groups (Experiment 1). The second part examined how this language influence develops at different stages of language acquisition in individuals with increasing bilingual proficiency (Experiment 2). Language systematically influenced magnitude judgments such that: (a) The spoken language(s) modulated magnitude judgments presented as Arabic digits, and (b) bilinguals’ progressive language mastery impacted magnitude judgments presented as number words. Taken together, the current results suggest that the order of decades and units in verbal numbers may qualitatively influence magnitude judgments in bilinguals and monolinguals, providing new insights into how number processing can be influenced by language(s).     

When one-two-three beats two-one-three: Tracking the acquisition of the verbal number sequence

Psychonomic Bulletin & Review - Learning how to count is a crucial step in cognitive development, which progressively allows for more elaborate numerical processing. The existing body of...     

Working memory components and imagery instructions in the elaboration of a spatial mental model

The paper investigates the involvement of verbal and visuo-spatial working memory during the processing of spatial texts via a dual-task paradigm. Subjects were presented with three texts describing locations from a route perspective, and had either to imagine themselves moving along a route in surroundings or to rehearse verbal information. Concurrently they had to perform a spatial tapping task, an articulatory task, or no secondary task. Performance on a verification test used to assess the product of comprehension showed that the concurrent tapping task impaired performance in the imagery instructions group but not in the repetition instructions group, and caused the beneficial effect of imagery instructions to vanish. This result was not observed with the articulatory task, where interference effects were similar in both instructions groups. Performance on the concurrent tasks confirmed the pattern obtained with the verification test. In addition, results seem partly dependent on the capacity of spatial working memory as measured by the Corsi Blocks Test. We argue that these results clarify the processes of the construction of a spatial mental model, and confirm that the visuo-spatial working memory is involved in mental imagery.