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Learning results from online (within-session) and offline (between-sessions) changes. Heterogeneity of age-related effects in learning may be ascribed to aging differentially affecting these two processes. We investigated the contribution of online and offline consolidation in visuo-spatial working memory (vWM). Younger and older participants performed a vWM task on day one and after nine days, allowing us to disentangle online and offline learning effects. To test whether offline consolidation needs continuous practice, two additional groups of younger and older adults performed the same vWM task in between the two assessments. Similarly to other cognitive domains, older adults improved vWM through online (during session one) but not through offline learning. Practice was necessary to improve vWM between sessions in older participants. Younger adults instead exhibited only offline improvement, regardless of practice. The findings suggest that while online learning remains efficient in aging, practice is instead required to support more fragile offline mechanisms.

It is believed that the approximate estimation of large sets and the exact quantification of small sets (subitizing) are supported by two different systems, the Approximate Number System (ANS) and Object Tracking System (OTS), respectively. It is a current matter of debate whether they are both impaired in developmental dyscalculia (DD), a specific learning disability in symbolic number processing and calculation. Here we tackled this question by asking 32 DD children and 32 controls to perform a series of tasks on visually presented sets, including exact enumeration of small sets as well as comparison of large, uncountable sets. In children with DD, we found poor sensitivity in processing large numerosities, but we failed to find impairments in the exact enumeration of sets within the subitizing range. We also observed deficits in visual short-term memory skills in children with dyscalculia that, however, did not account for their low ANS acuity. Taken together, these results point to a dissociation between quantification skills in dyscalculia, they highlight a link between DD and low ANS acuity and provide support for the notion that DD is a multifaceted disability that covers multiple cognitive skills.

This study analyses the categorical ambiguity between visual appearances that belong in different categories, such as Oriental Calligraphy and certain Abstract Paintings selected from the works of Klee. In particular, the aim of our research was to identify whether there exist abstract features at the basis of purely visual configurations that determine the way in which they are categorized. Specifically, the intention was to determine whether, and to what extent, two artistic forms that display documented shared graphic and conceptual characteristics differ, or do not differ, visually, and whether certain features exist that identify them as a specific type of graphic work. The assumption that both categories had shared characteristics that made them graphically and conceptually similar and that resulted in categorical ambiguity, was confirmed. Moreover, the presence of some constituent features specific to one or the other was also confirmed. The results show that a Calligraphic Image and an Abstract Painting by Klee can be ‘exchanged’, but the tendency to confuse Calligraphy with an Abstract Painting is greater than that of confusing an Abstract Painting with Calligraphy.

This article presents an experimental study on the naturally biased association between shape and color. For each basic geometric shape studied, participants were asked to indicate the color perceived as most closely related to it, choosing from the Natural Color System Hue Circle. Results show that the choices of color for each shape were not random, that is, participants systematically established an association between shapes and colors when explicitly asked to choose the color that, in their view, without any presupposition, they saw as the most naturally related to a series of given shapes. The strongest relations were found between the triangle and yellows, and the circle and square with reds. By contrast, the parallelogram was connected particularly infrequently with yellows and the pyramid with reds. Correspondence analysis suggested that two main aspects determine these relationships, namely the "warmth" and degree of "natural lightness" of hues.

A number of studies in recent years have suggested that exogenous and endogenous attention might enhance the perceived magnitude of various perceptual attributes, such as contrast and motion speed. Those studies have generally used comparative judgments as a measure to assess the point of subjective equality; however, similarity judgments have been proposed as possibly less prone to decision biases (Schneider & Komlos, 2008). In three experiments, using a similarity judgment task, we did not find any evidence of motion speed enhancement by exogenous attention. We suggest that the effect revealed by comparative judgments arises at the decisional, rather than the perceptual, stage. © 2010 The Psychonomic Society, Inc.

Humans' ability to recognize static images of self body-parts can be lost following a lesion of the right hemisphere [Frassinetti, F., Maini, M., Romualdi, S., Galante, E., & Avanzi, S. (2008). Is it mine? Hemispheric asymmetries in corporeal self-recognition. Journal of Cognitive Neuroscience, 20, 1507-1516]. Here we investigated whether the visual information provided by the movement of self body-parts may be separately processed by right brain-damaged (RBD) patients and constitute a valuable cue to reduce their deficit in self body-parts processing. To pursue these aims, neurological healthy subjects and RBD patients were submitted to a matching-task of a pair of subsequent visual stimuli, in two conditions. In the dynamic condition, participants were shown movies of moving body-parts (hand, foot, arm and leg); in the static condition, participants were shown still images of the same body-parts. In each condition, on half of the trials at least one stimulus in the pair was from the participant's own body ('Self' condition), whereas on the remaining half of the trials both stimuli were from another person ('Other' condition). Results showed that in healthy participants the self-advantage was present when processing both static and dynamic body-parts, but it was more important in the latter condition. In RBD patients, however, the self-advantage was absent in the static, but present in the dynamic body-parts condition. These findings suggest that visual information from self body-parts in motion may be processed independently in patients with impaired static self-processing, thus pointing to a modular organization of the mechanisms responsible for the self/other distinction.

Transient spatial attention has been shown to alter different stimulus properties, such as perceived contrast and speed of motion. Interestingly, recent studies seem to suggest that involuntary shifts of spatial attention can also occur on the basis of the contents of Working Memory (WM). According to the biased competition model of visual attention, stimuli in the visual field that match those currently maintained in working memory receive the highest attentional priority. In a series of five experiments we addressed whether WM-based attention shifts alter perception, and specifically speed of motion. We found that response times for target discrimination were shorter at the location where an object matching the one held in WM was presented, thus confirming WM-based attention shifts. In contrast, results from other experiments, in which a speed-discrimination task was used, failed to reveal any modulation of motion speed perception by the content of WM. At present these data suggest that WM-based attention operates at different (later) stages of visual analysis than transient attention. © ARVO.

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.

Although it is well established that attention affects visual performance in many ways, by using a novel paradigm [Carrasco, M., Ling, S., & Read. S. (2004). Attention alters appearance. Nature Neuroscience, 7, 308-313.] it has recently been shown that attention can alter the perception of different properties of stationary stimuli (e.g., contrast, spatial frequency, gap size). However, it is not clear whether attention can also change the phenomenological appearance of moving stimuli, as to date psychophysical and neuro-imaging studies have specifically shown that attention affects the adaptability of the visual motion system. Here, in five experiments we demonstrated that attention effectively alters the perceived speed of moving stimuli, so that attended stimuli were judged as moving faster than less attended stimuli. However, our results suggest that this change in visual performance was not accompanied by a corresponding change in the phenomenological appearance of the speed of the moving stimulus. © 2006.