Neuropsychologia
May 1, 2019
Chiara Mazzi, Silvia Savazzi, Juha Silvanto
Blindsight has been central to theories of phenomenal awareness; that a lesion to primary visual cortex (V1) abolishes all phenomenal awareness while unconscious visual functions can remain has led to the view that this region plays a crucial role in generating visual consciousness. However, since the early 20th century, there have been reports, many of which controversial, of phenomenal...
Frontiers in Psychology
October 19, 2015
Jane Jacob, Christianne Jacobs, Juha Silvanto
What is the role of top-down attentional modulation in consciously accessing working memory (WM) content? In influential WM models, information can exist in different states, determined by allocation of attention; placing the original memory representation in the center of focused attention gives rise to conscious access. Here we discuss various lines of evidence indicating that such...
Trends in Neurosciences
November 2014
Juha Silvanto
Influential models propose that conscious experience of extrastriate activity requires the integrity of primary visual cortex (V1). A new study challenges this view by demonstrating that when V1 is lesioned, visual qualia can be induced when transcranial magnetic stimulation (TMS) is applied over the patients' ipsilesional hemisphere.
Frontiers in Psychology
January 20, 2011
Juha Silvanto, Geraint Rees
The complete loss of visual awareness resulting from a lesion to the primary visual cortex (V1) suggests that this region is indispensable for conscious visual perception. There are however a number cases of conscious perception in the absence of V1 which appear to challenge this conclusion. These include reports of patients with bilateral V1 lesions sustained at an early age whose conscious...
Journal of Visualized Experiments
December 28, 2010
Umer Najib, Jared C Horvath, Juha Silvanto et al.
Transcranial magnetic stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized magnetic field pulses. Within the field of TMS, the term state dependency refers to the initial, baseline condition of the particular neural region targeted...
Neuropsychologia
November 5, 2007
Juha Silvanto, Alan Cowey, Nilli Lavie et al.
A lesion of striate cortex, area V1, produces blindness in the retinotopically corresponding part of the visual field, although in some cases visual abilities in the blind field remain that are paradoxically devoid of conscious visual percepts ("blindsight"). Here we demonstrate that the blindsight subject GY can experience visual sensations of phosphenes in his blind field induced by...