Differentiated forgetting rates of spatial knowledge in humans in the absence of repeated testing

Spatial knowledge, necessary for efficient navigation, comprises route knowledge (memory of the landmarks along a route) and survey knowledge (map-like). Available data on the retention in humans of spatial knowledge show that this does not decline systematically over months or years. Here, two groups of participants elaborated route and survey knowledge during navigation in a complex virtual environment before performing route and survey tasks. Both groups were tested 5 minutes after learning and 3 months later, while one group was also tested 1 week and 1 month later (repeated testing). Performance was similar in both groups on the first testing session, remained stable in the repeated tested group, but decreased in the non-repeated tested group, especially on route tasks. These results are the first to reveal a substantial and selective decline of spatial knowledge, occurring only if there is no possibility of reactivating knowledge along repeated testing.     

Small-sample characterization of stochastic approximation staircases in forced-choice adaptive threshold estimation

Despite the widespread use of up-down staircases in adaptive threshold estimation, their efficiency and usability in forced-choice experiments has been recently debated. In this study, simulation techniques were used to determine the small-sample convergence properties of stochastic approximation (SA) staircases as a function of several experimental parameters. We found that satisfying some general requirements (use of the accelerated SA algorithm, clear suprathreshold initial stimulus intensity, large initial step size) the convergence was accurate independently of the spread of the underlying psychometric function. SA staircases were also reliable for targeting percent-correct levels far from the midpoint of the psychometric function and performed better than classical up-down staircases with fixed step size. These results prompt the utilization of SA staircases in practical forced-choice estimation of sensory thresholds.     

Linguistic constraints on statistical computations: the role of consonants and vowels in continuous speech processing

Speech is produced mainly in continuous streams containing several words. Listeners can use the transitional probability (TP) between adjacent and non-adjacent syllables to segment "words" from a continuous stream of artificial speech, much as they use TPs to organize a variety of perceptual continua. It is thus possible that a general-purpose statistical device exploits any speech unit to achieve segmentation of speech streams. Alternatively, language may limit what representations are open to statistical investigation according to their specific linguistic role. In this article, we focus on vowels and consonants in continuous speech. We hypothesized that vowels and consonants in words carry different kinds of information, the latter being more tied to word identification and the former to grammar. We thus predicted that in a word identification task involving continuous speech, learners would track TPs among consonants, but not among vowels. Our results show a preferential role for consonants in word identification.     

Word length effect in early reading and in developmental dyslexia

Vocal reaction times were measured in Italian dyslexics and in proficient readers while they read single words. Three groups of control participants (for a total of 79) were tested. All were in the first, second or third grade of elementary school. Nine third graders with a low level of reading ability when assessed by standard reading procedures were also tested. Results indicated that vocal RTs of control participants were faster and less sensitive to word length as a function of age; also, there was a particularly marked change between first and second graders. Dyslexics' vocal RTs and errors were much worse than those of peer control participants and resembled those of first grade controls. It is suggested that normal readers in an orthographically transparent language (Italian) adopt a lexical strategy quite early in their learning. On the contrary, dyslexics seem unable to learn this mode of processing and continue to use a sub-lexical reading procedure.     

High cost helping scenario: The role of empathy,prosocial reasoning and moral disengagement on helping behavior

This study aimed to investigate the process that leads people to offer or omit help in response to an explicit request for assistance, taking into account both emotional and cognitive factors. Specifically, a hypothetical scenario methodology was used in a sample of 174 Italian youths (50% males) to examine whether and how factors such as empathy, prosocial moral reasoning and moral disengagement influence the propensity to help when providing assistance is not in the individual’s personal interest. While a few previous studies have included moral disengagement as an antecedent of prosocial decision making, we highlight the significance of this factor in the avoidance of moral responsibility towards others in need. The results highlight two ways in which differences in emotional tendencies and moral-cognitive processes may operate in prosocial decision making in high personal cost situations. First, high empathy levels could promote an altruistic response which in turn fosters mature prosocial moral reasoning. Second, personal distress may enhance moral disengagement mechanisms that may facilitate self-centred behaviors.     

Time perspective as a predictor of problematic Internet use: A study of Facebook users

Time perspective (TP) has been related to different problematic human behaviors. The work presented in this paper assesses the role of time perspective in predicting problematic Internet use (PIU) by studying a sample (n = 149) of Facebook users. Participants (79 male, 70 female, mean age = 32.40, SD = 11.80) completed electronic versions of the Zimbardo Time Perspective Inventory (ZTPI) to assess their TP, and the Generalized Problematic Internet Use Scale 2 (GPIUS2) to assess their PIU. Results show that Past Negative and Present Fatalistic temporal frames are predictors of problematic Internet use, suggesting that time perspective is an individual difference construct that should be taken into consideration in the context of PIU.