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Electrophysiological correlates of change detection and change blindness were studied in 12 observers. The ERP difference between detected changes and undetected changes was considered an electrophysiological correlate of visual awareness. Two distinct electrophysiological responses correlated with the awareness of change. First, awareness was associated(More)
Electrophysiological recordings during visual tasks can shed light on the temporal dynamics of the subjective experience of seeing, visual awareness. This paper reviews studies on electrophysiological correlates of visual awareness operationalized as the difference between event-related potentials (ERPs) in response to stimuli that enter awareness and(More)
Attention and awareness are closely related, but the nature of their relationship is unclear. The present study explores the timing and temporal evolution of their interaction with event-related potentials. The participants attended to specific conjunctions of spatial frequency and orientation in masked (unaware) and unmasked (aware) visual stimuli. A(More)
Humans are able to categorize complex natural scenes very rapidly and effortlessly, which has led to an assumption that such ultra-rapid categorization is driven by feedforward activation of ventral brain areas. However, recent accounts of visual perception stress the role of recurrent interactions that start rapidly after the activation of V1. To study(More)
A "late" period of activity in striate cortex (V1) in response to extrastriate feedback has been proposed to act as a marker of visual awareness. It is not clear, however, whether such recurrent activity is associated exclusively with aware perception or whether it is necessary also for unaware visual processing. We investigated the role of the "late" V1(More)
Event-related potential (ERP) studies have attempted to discover the processes that underlie conscious visual perception by contrasting ERPs produced by stimuli that are consciously perceived with those that are not. Variability of the proposed ERP correlates of consciousness is considerable: the earliest proposed ERP correlate of consciousness (P1)(More)
In order to study whether there exist a period of activity in the human early visual cortex that contributes exclusively to visual awareness, we applied transcranial magnetic stimulation (TMS) over the early visual cortex and measured subjective visual awareness during visual forced-choice symbol or orientation discrimination tasks. TMS produced one dip in(More)
The possible effects of continuous wave (CW) and pulse modulated (PM) electromagnetic field (EMF) on human cognition was studied in 36 healthy male subjects. They performed cognitive tasks while exposed to CW, PM, and sham EMF. The subjects performed the same tasks twice during each session; once with left-sided and once with right-sided exposure. The EMF(More)
We studied the effects of an electromagnetic field (EMF) as emitted by a 902 MHz mobile phone on human short term memory. This study was a replication with methodological improvements to our previous study. The improvements included multi-centre testing and a double blind design. A total of 64 subjects (32 men) in two independent laboratories performed a(More)
Visual masking and visual suppression by transcranial magnetic stimulation (TMS) are both widely utilized in cognitive neuroscience to investigate a wide range of processes. However, the neural processes affected by visual masking and TMS remain unclear. We compared para- and metacontrast masking with TMS-induced suppression of visibility in a(More)