All these findings converge on the claim that the perceptual contents of both online and offline forms of perception are subserved by a common system of neural representations. The existence of this common system of neural representations of perceptual content lends empirical support to the philosophical thesis that the phenomenal similarities between perceiving and visualising is underlain by a similarity between the content of these two different mental states (Nanay, 2015). Csörnyei, Marianna - mathematician, won a 2002 Whitehead Prize and a Royal Society Wolfson Research Merit Award that same year

Sandberg, K., Timmermans, B., Overgaard, M., & Cleeremans, A. ( 2010). Measuring consciousness: Is one measure better than the other? Consciousness and Cognition, 19( 4), 1069– 1078. Subjective intensity versus subjective specificity. Here, subjective intensity varies along its contrast sub-dimension, whereas subjective specificity varies along its blurriness sub-dimension (the illustration is based on Fazekas & Overgaard, 2018). Detailedness versus blurriness. From left to right, subjective specificity decreases along the detailedness sub-dimension, whereas from top to bottom subjective specificity decreases along the blurriness sub-dimension (the illustration is based on the decreased quality photos that were used to study the visual appearance of dreams; see Antrobus et al., 1987; Rechtschaffen & Buchignani, 1983). Nir, Y., & Tononi, G. ( 2010). Dreaming and the brain: From phenomenology to neurophysiology. Trends in Cognitive Sciences, 14( 2), 88– 100. Such knowledge about the characteristics of the corresponding neural representations can even teach us an important lesson about how the perceptual apparatus attributes properties to the perceived scene.

Additionally, and in line with the analysis above (Section 3.2), VVIQ-measured vividness has been found to covary with the extent of overlap between the activity in visual areas during mental imagery and perception (Albers et al., 2013; Cui et al., 2007; Dijkstra, Bosch, & van Gerven, 2017) and also with the strength of top-down recruitment of early visual areas (Dijkstra et al., 2019; Dijkstra, Zeidman, et al., 2017). These findings indicate that experienced vividness changes along the subjective specificity dimension as well. Miyazono, K. ( 2018). Vivid representations and their effects. Rivista Internazionale di Filosofiae Psicologia, 9( 1), 73– 80. Fazekas, P. ( 2021). Hallucinations, as intensified forms of mind-wandering. Philosophical Transactions of the Royal Society B, 376, 20190699. We conducted a systematic search of PubMed and EMBASE databases up to July 2022 using keywords or Medical Subject Heading terms (“cerebral small‐vessel diseases,” “leukoaraiosis,” “microbleed,” “enlarged perivascular space,” “recent small subcortical infarct,” “atrophy,” “lacune,” and “thrombectomy”). The assessed clinical outcomes were a good functional outcome, 90‐day mortality, symptomatic intracranial hemorrhage, and early neurologic improvement after EVT.

In a multicenter registry study, we enrolled patients with EVT for anterior-circulation LVO-stroke. In 3.0-T MR imaging, we assessed 4 CSVD imaging markers, lacunes, white matter hyperintensities, cerebral microbleeds, and enlarged perivascular spaces, each assigned a score of 0 or 1 and summed up to an overall CSVD burden score of 0-4. We dichotomized the overall CSVD severity as none to mild (score 0-2) and moderate to severe (3-4). Primary outcome was 90-day functional dependence or death (modified Rankin Scale (mRS) 3-6). Secondary outcomes included increase in NIH Stroke Scale ≥ 4 within 24 h (early neurological deterioration (END)) and within 7 days, symptomatic intracranial hemorrhage, 90-day mRS 2-6, and 90-day mortality.Amedi, A., Malach, R., & Pascual-Leone, A. ( 2005). Negative BOLD differentiates visual imagery and perception. Neuron, 48( 5), 859– 872. Halpern, A. R. ( 2015). Differences in auditory imagery self-report predict neural and behavioral outcomes. Psychomusicology: Music, Mind, and Brain, 25( 1), 37– 47. This study revealed that cognitive function in the infratentorial stroke patients with WMH was significantly lower compared to with no-WMH. General cognitive function measured by K-MMSE was significantly lower in the infratentorial stroke patients with WMH, compared to no-WMH. Sustained and selective attention assessed by auditory CPT and verbal learning was also lower in the infratentorial stroke patients with WMH. These results suggest that WMH should be considered in the pathophysiology of the cognitive dysfunction, in the infratentorial stroke patients. Therefore, the management for cognitive dysfunction with WMH can be applied for infratentorial stroke patients in the cognitive rehabilitation [ 4].

D'Esposito, M., & Postle, B. ( 2015). The cognitive neuroscience of working memory. Annual Review of Psychology, 66, 115– 142. As it has recently been argued, consciousness can gradually change along many dimensions. For instance, consciousness can be degraded in the sense of gating, that is, what range of perceptually represented information can enter consciousness (Bayne et al., 2016a, 2016b), as in the case of prosopagnosia when one is in a condition that only lower-level features can enter one's consciousness like oriented edges, or simple shapes like ovals and cylinders, but not higher-level features like faces (Milner & Goodale, 2006). Consciousness can also be degraded in the sense of cognitive capacities, that is which cognitive processes can access the information entering consciousness (Bayne et al., 2016a, 2016b), as in the case of mild sedation (Bayne et al., 2016a) or dreaming (Fazekas et al., 2019; Nemeth & Fazekas, 2018; Nir & Tononi, 2010) when certain cognitive functions are not in operation. Most importantly from our present perspective, consciousness can also be degraded in the sense of its quality, that is how the features that can enter consciousness appear in one's conscious experience (Fazekas et al., 2020; Fazekas & Overgaard, 2016, 2018; Nemeth, 2022) . For instance, even if one's consciousness is not degraded in the gating sense regarding faces, one can still have a degraded conscious experience of a face if the face is experienced as low in contrast, or as having not enough details. It is degradation in this sense, we propose, that the notion of vividness tries to capture. 2.2 The dimensions of vividness White matter changes known as leukoaraiosis are commonly referred to as a periventricular white matter disease, or white matter hyperintensities (WMH), due to their bright white appearance on T2-weighted MRI scans [ 1]. Cerebral white matter disease is frequently reported on brain imaging, predominantly in older patients [ 2]. Previously, it was regarded as an incidental finding with no therapeutic consequences. It is now becoming increasingly clear that WMH is associated with cognitive decline especially in attention, executive function, and process speed domains [ 2, 3]. In recent years, due to its apparent clinical relevance, there has been a growing interest in white matter changes, its pathology, epidemiology, risk factors, and treatment options. The pathogenesis of WMH is poorly understood. Hypoxic injury due to hypoperfusion caused by atherosclerosis has been proposed as an etiological factor [ 4]. This is similar to clinical ischemic stroke or lacunar infarction, especially in the infratentorial lesions [ 5]. To see why, consider that perceptual content, according to a straightforward way of thinking about it, is the sum of the different properties that the perceptual apparatus attributes to various parts of the perceived scene (Nanay, 2010, p. 265). Nanay ( 2015) argues that the content of mental imagery is similar to the content of perception with the important difference that the content of mental imagery can contain determinables without their determinates. On the one hand, this claim is nicely in line with the proposal of the present article, as precision, blurriness and detailedness are different ways in which determinacy might manifest itself. Less precise colours (like red) are the quintessential textbook cases of determinables (with particular shades as determinates e.g., vermillion in the case of red), but both more blurry and less detailed (due to e.g., over and underexposure) images can be seen as determinables as well (with less blurry and more detailed determinates; see Nanay, 2015, 2018). Fazekas's prestigious reputation is linked to special mathematics classes which were started in 1962, when Imre Rábai gathered some promising talent who went on to achieve world fame for the school in the subject. Ever since, numerous Fazekas alumni have excelled on the world stage, particularly in mathematics and the natural sciences.Dijkstra, N., Bosch, S. E., & van Gerven, M. A. J. ( 2017). Vividness of visual imagery depends on the neural overlap with perception in visual areas. The Journal of Neuroscience, 37( 5), 1367– 1373. Fazekas, P., & Overgaard, M. ( 2016). Multidimensional models of degrees and levels of consciousness. Trends in Cognitive Sciences, 20( 10), 715– 716. Knowledge about the specific details regarding how the features that constitute the content of perception are encoded by the neural ensembles in question is able to shed new light on the similarities and differences between the contents of distinct experiences. The issue of vividness is an example of this. By knowing the relevant characteristics of the neural representations, it becomes possible to turn the task of exploring the dimensions of vividness, finding their neural bases and comparing them across experiences a viable empirical research programme. Phillips, I. ( 2020). Blindsight is qualitatively degraded conscious vision. Psychological Review, 128( 3), 558–584.