Roberto Ardigò as a forerunner of George M. Stratton's experiments on inverted vision.

After Johannes Kepler's supposition of inverted and reversed retinal images and Christoph Scheiner's anatomical demonstration of such an inversion, the question arose whether this inversion is necessary and how it is possible to see an upright world based on an inverted image. The answer to this question is commonly attributed to the American psychologist George M. Stratton, who produced, in 1896, upright retinal images by means of lenses and showed that after a phase of inverted perception, upright vision is restored.

The risk of neurodegeneration in REM sleep behavior disorder: A systematic review and meta-analysis of longitudinal studies.

Several studies report an association between REM Sleep Behavior Disorder (RBD) and neurodegenerative diseases, in particular synucleinopathies. Interestingly, the onset of RBD precedes the development of neurodegeneration by several years. This review and meta-analysis aims to establish the rate of conversion of RBD into neurodegenerative diseases.

Repetitive thought is associated with both subjectively and objectively recorded polysomnographic indices of disrupted sleep in insomnia disorder.

Background: Repetitive thought is a hallmark of several psychopathological conditions and in particular a perpetuating and maintaining factor in Insomnia Disorder. Accordingly, one of the primary complaints reported by Insomnia patients is the inability to shut-off or control thoughts. Worry and rumination are the two best-known styles of repetitive thought leading to sleep disturbances.

Evidence of perceptive impairment in OSA patients investigated by means of a visual search task.

Obstructive Sleep Apnoea (OSA) is a common sleep disorder characterized by episodes of complete or partial obstruction of respiratory airways during sleep that leads to hypoxaemia and sleep fragmentation. One relevant daytime consequence of OSA is a negative impact on neurocognitive domain, ranging from psychomotor performance to executive function. In spite of a huge amount of evidence regarding cognitive impairment, little is known about perceptual processing in these patients.

Impaired visual processing in patients with insomnia disorder revealed by a dissociation in visual search.

Insomnia disorder is associated with both subjective and objective daytime impairments. In particular, cognitive impairments are frequently reported. However, little is known about the effects of this pathology on perceptual processes.

The effects of Transcranial Direct Current Stimulation (tDCS) on Idiopathic Hypersomnia: a pilot study.

Idiopathic Hypersomnia (IH) is a rare sleep disorder characterised by excessive daytime sleepiness (EDS) that leads to invalidating daytime consequences. Till now the treatment of IH has mirrored that of sleepiness in narcolepsy, and it is mainly focused on symptoms' management. We employed an anodal transcranic Direct Current Stimulation (tDCS) treatment in order to induce a shift toward arousal in IH patients' cortex during the day.

Restless legs syndrome/Willis Ekbom disease: new diagnostic criteria according to different nosology.

Restless Legs Syndrome/Willis Ekbom Disease (RLS/WED) is a common neurological disorder characterized by uncomfortable and unpleasant sensations in the legs, with an urge to move. The symptoms typically begin or worsen during periods of rest, in particular during the evening and at night, while the activity may typically relieve them. The majority of patients complains of poor sleep.

REM sleep Behaviour Disorder.

Rapid Eye Movement (REM) sleep Behaviour Disorder (RBD) is a REM sleep parasomnia characterized by loss of the muscle atonia that typically occurs during REM sleep, therefore allowing patients to act out their dreams. RBD manifests itself clinically as a violent behaviour occurring during the night, and is detected at the polysomnography by phasic and/or tonic muscle activity on the electromyography channel. In absence of neurological signs or central nervous system lesions, RBD is defined as idiopathic.

Behavioural and Cognitive-Behavioural Treatments of Parasomnias.

Parasomnias are unpleasant or undesirable behaviours or experiences that occur predominantly during or within close proximity to sleep. Pharmacological treatments of parasomnias are available, but their efficacy is established only for few disorders. Furthermore, most of these disorders tend spontaneously to remit with development.

Neurocognitive function in patients with idiopathic Restless Legs Syndrome before and after treatment with dopamine-agonist.

Although a huge amount of clinical evidence for Restless Legs Syndrome (RLS) is present in literature, an exhaustive account of cognitive profile in RLS patients is still lacking. In this study we evaluated the neurocognitive function in RLS patients and the effects of a three-month treatment with a dopamine agonist (pramipexole) at low doses. Clinical and polysomnographic characteristics, cognitive abilities, quality of life and psychological clinical indices were assessed in 20 RLS patients and 15 age-matched controls.

The DCDC2 intron 2 deletion impairs illusory motion perception unveiling the selective role of magnocellular-dorsal stream in reading (dis)ability.

Developmental dyslexia (DD) is a heritable neurodevelopmental reading disorder that could arise from auditory, visual, and cross-modal integration deficits. A deletion in intron 2 of the DCDC2 gene (hereafter DCDC2d) increases the risk for DD and related phenotypes. In this study, first we report that illusory visual motion perception-specifically processed by the magnocellular-dorsal (M-D) stream-is impaired in children with DD compared with age-matched and reading-level controls.

Deeper attentional masking by lateral objects in children with autism.

Autism spectrum disorder (ASD) is often associated with a detail-oriented perception and overselective attention in visual tasks, such as visual search and crowding. These results were obtained manipulating exclusively the spatial properties of the stimuli: few is known about the spatio-temporal dynamics of visual processing in ASD. In this study we employed an attentional masking (AM) paradigm comparing children with ASD and IQ-matched typically developing (TD) controls.

An early history of the Gestalt factors of organisation.

Wertheimer's (1923, Psychologische Forschung 4 301 - 350) idea that the perceptual world is articulated according to factors of organisation is widely acknowledged as one of the most original contributions of Gestalt psychology and stands as a milestone in the history of vision research. An inquiry focused on the forerunners of some of Wertheimer's factors of perceptual organisation is documented here. In fact, in 1900 Schumann described grouping by proximity and by vertical symmetry, and in 1903 G E Müller identified the factors of sameness/similarity and contour.

A new motion illusion based on competition between two kinds of motion processing units: the accordion grating.

Parametric psychophysical investigations are reported for two related illusory effects that occur when viewing an elementary square-wave grating while making "back and forth" head movements along the projection line. Observers report a non-rigid distortion of the pattern, including: (i) an expansion in a direction perpendicular to the stripes, and (ii) a perceived curvature of the stripes. We investigated these two phenomena independently.

The perceptual expansion of a filled area depends on textural characteristics.

According to the Oppel-Kundt illusion, a filled space appears larger than an empty one. In the present research we studied how textural characteristics affect the perceived size of two-dimensional patterns. We investigated the perceived extension of square textures by manipulating spatial frequency and filling microelements' numerosity.

Perceptual compromise between apparent and veridical motion indices: the unchained-dots illusion.

A new motion illusion based on dot-trajectory misperception is presented. The illusory effect can not be explained by the aperture problem unlike some previous illusions characterised by misperception of motion direction. We propose an explanation in terms of 'perceptual compromise' between an original type of apparent motion and the veridical motion.

Measuring the Breathing Light Illusion by means of induced simultaneous contrast.

By blurring the margins of a surface, both its brightness and the perceived contrast against a superimposed figure with sharp boundaries increase. Also, if one approaches a blurred white spot on a grey background, this spot will appear wider and brighter: this phenomenon is known as the Breathing Light Illusion (BLI) (Gori and Stubbs, 2006 Perception 35 1573-1577). We studied the increment of the achromatic contrast of a grey sharp-boundary disk when it was superimposed on the BLI.

Perceptual multistability in figure-ground segregation using motion stimuli.

In a series of experiments using ambiguous stimuli, we investigate the effects of displaying ordered, discrete series of images on the dynamics of figure-ground segregation. For low frame presentation speeds, the series were perceived as a sequence of discontinuous, static images, while for high speeds they were perceived as continuous. We conclude that using stimuli varying continuously along one parameter results in stronger hysteresis and reduces spontaneous switching compared to matched static stimuli with discontinuous parameter changes.

How do painters represent motion in garments? Graphic invariants across centuries.

Western visual art has radically changed throughout the centuries: different techniques, interest in the representation of reality, and use of graphic signs. Indeed, only a few pictorial cues have retained the same meaning and use. These kinds of graphic invariants may play a key role not only in a comparative study of art history, but also for discovering underlying common perceptual mechanisms.

A single "stopwatch" for duration estimation, a single "ruler" for size.

Although observers can discriminate visual targets with long exposures from otherwise-identical targets with shorter exposures, temporally overlapping distracters with an intermediate exposure can produce a striking degradation in performance. This new finding suggests that observers can only estimate one duration at a time. Discrimination on the basis of size, rather than duration, did not degrade as rapidly with the number of distracters but was still worse than predicted by unlimited-capacity models.

Region- and edge-based configurational effects in texture segmentation.

We have found a new configurational effect in texture segmentation. In addition to collinear facilitation at the edge, this effect results from contextual modulation within the texture-region, i.e.

Saliency from orthogonal velocity component in texture segregation.

We found that a moving target line, more-vertical than 45 deg-oriented background lines, pops-out (d'=1.2) although it moves at the same speed of background elements and although it is invisible in static presentation (d'=.7).