Journal of VisionJanuary 5, 2026Cemre Yilmaz, Kerstin Maitz, Maximilian Gerschütz et al.
Binocular rivalry occurs when two eyes are presented with two conflicting stimuli. Although the physical stimulation stays the same, the conscious percept changes over time. This property makes it a unique paradigm in both vision science and consciousness research. Two key parameters, contrast and attention, were repeatedly shown to affect binocular rivalry dynamics in a similar manner. This...
In visual perception, an effect known as surround suppression occurs wherein the apparent contrast of a center stimulus is reduced when it is presented within a higher-contrast surrounding stimulus. Many key aspects of visual perception involve surround suppression, yet the neuromodulatory processes involved remain unclear. Psilocybin is a serotonergic psychedelic compound known for its robust...
Perceptual reality monitoring refers to the ability to distinguish internally triggered imagination from externally triggered reality. Such monitoring can take place at perceptual or cognitive levels-for example, in lucid dreaming, perceptual experience feels real but is accompanied by a cognitive insight that it is not real. We recently developed a paradigm to reveal perceptual reality...
Three findings motivated this study. First, "decision to shoot" research has provided robust evidence of visual racial bias in police officers and the US population (Payne & Correll, 2020). In threat detection experiments, patterns of hit rates, false alarm rates, and reaction times show that typical participants "shoot" an armed target more frequently and quickly when that visual target is...
Previous studies have shown that spontaneous fluctuations in prestimulus fMRI activity can predict trial-by-trial fluctuations in the perception of identical stimuli (Boly et al., 2007; Hesselmann et al., 2008, 2010; Sadaghiani et al., 2009; Rahnev et al., 2012; Pajani et al., 2015), yet such activity on its own does not seem to lead to conscious perception, even when awareness is carefully...
A main question in the scientific study of conscious perception is the nature of the dissociation between conscious and non-conscious perception. That is, it is crucial to use bias-free measures to evaluate perceptual sensitivity and response criterion of participants in the conscious and non-conscious tasks to evaluate this dissociation. The aim of this study is to evaluate sensitivity and...
An eyeblink has a clear effect on low-level information processing because it temporarily occludes all visual information. Recent evidence suggests that eyeblinks can also modulate higher level processes (e.g., attentional resources), and vice versa. Despite these putative effects on different levels of information processing, eyeblinks are typically neglected in vision and in consciousness...
ABSTRACT Introduction: The question of how spatially-organized activity in the visual cortex behaves during eyes-closed, LSD-induced, visual psychedelic imagery has never been empirically addressed, although it has been proposed that under psychedelics the brain may function "as if" there is visual input when there is none (de Araujo, et al., 2012). We suspected that eyes-closed psychedelic...
How do expectations influence transitions between unconscious and conscious perceptual processing? According to the influential predictive processing framework, perceptual content is determined by predictive models of the causes of sensory signals. On one interpretation, conscious contents arise when predictive models are verified by matching sensory input (minimizing prediction error). On...
In visual search, context information can serve as a cue to guide attention to the target location. When observers repeatedly encounter displays with identical target-distractor arrangements, reaction times (RTs) are faster for repeated relative to nonrepeated displays, the latter containing novel configurations. This effect has been termed "contextual cueing." The present study asked whether...
Journal of VisionSeptember 23, 2011Marcia Grabowecky, L. Ortega, C. Nwosu et al.
Attention and emotion are linked in critical ways. Emotionally salient objects attract and capture attention. Attention to emotional stimuli influences emotion processing and regulation. Meditation techniques have been used for millennia both to train attention and to regulate emotion. A common meditation practice involves sustained attention on the breath. Slagter and colleagues (2007,...
There has been considerable interest recently in using multivariate decoding techniques applied to functional MRI signals in order to decode the contents of a person’s consciousness. The use of such signals has inherent disadvantages due to the delay of the hemodynamic response. Moreover to date it has not been shown possible to generalize the decoding of brain signals from one individual to...
Meditative practices can enhance visuospatial working memory (Kozhevnikov et al., 2009) and sensory acuity (Kerr et al., 2005). It is thought that these effects are caused by enhanced attention to a given task, due to meditation. However, it is not clear whether meditation facilitates other forms of implicit processing that do not directly relate to attention. Here we investigated the effects...
Liberal acceptance, overconfidence, and increased activity of the neurotransmitter dopamine have been proposed to account for abnormal sensory experiences, for instance, hallucinations in schizophrenia. In normal subjects, increased sensory experience in Yoga Nidra meditation is linked to striatal dopamine release. We therefore hypothesize that the neurotransmitter dopamine may function as a...
Whether active and passive, top-down and bottom-up, or endogenous and exogenous, attention is typically divided into two types. To show the relationship between attention and other functions (sleep, memory, learning), one needs to show whether the type of attention in question is of the active or passive variety. However, the division between active and passive is not sharp in any area of...
Introduction Current theories suggest that prefrontal cortex (PFC) plays an important role in visual awareness (Dehaene 2003). This hypothesis has been supported by a number of brain imaging studies (Rees 2002). However, critics have challenged that there has been a lack of neuropsychological demonstration of the essential role of PFC in visual awareness: PFC damage does not seem to result in...
Binocular rivalry refers to the fluctuations in visual awareness/suppression that occur when different images are simultaneously presented to each eye. To explore the role of serotonin (5-HT) in binocular rivalry, this study investigated the affects of the hallucinogenic 5-HT1A&2A receptor agonist psilocybin (the active compound in “magic mushrooms”), alone and after pretreatment with the...
Increasing evidence suggests a link between attention, working memory, serotonin (5-HT) and prefrontal cortex activity. In an attempt to tease out the relationship between these elements, this study tested the effects of the hallucinogenic 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin on multiple object tracking and spatial working...