Prior Knowledge Uses Prestimulus Alpha Band Oscillations and Persistent Poststimulus Neural Templates for Conscious Perception.

Prior knowledge has a profound impact on the way we perceive the world. However, it remains unclear how the prior knowledge is maintained in our brains and thereby influences the subsequent conscious perception. The Dalmatian dog illusion is a perfect tool to study prior knowledge, where the picture is initially perceived as noise.

Fate of the second task in dual-task interference is associated with sensory system interactions with default-mode network.

Psychological refractory period (PRP) effect refers to the delay in responding to the second of two tasks occurring in rapid succession. While all the major models of PRP highlight the importance of the frontoparietal control network (FPCN) in prioritizing the neural processing of the first task, the fate of the second task remains poorly understood. Here, we provide novel neural evidence on how the functional connectivity between sensory systems and the default-mode network (DMN) suspends the neural processing of the second task to ensure the efficient completion of the first task in dual-task situation.

Momentary lapses of attention in multisensory environment.

Momentary lapses in attention disrupt goal-directed behaviors, and have been associated with increased pre-stimulus activity in the default mode network (DMN). The human brain often encounters multisensory inputs. It remains unknown, however, whether the neural mechanisms underlying attentional lapses are supra-modal or modality-dependent.

Top-down attention modulates the direction and magnitude of sensory dominance.

Bottom-up inputs from multiple sensory modalities compete to reach perceptual consciousness. The sensory dominance effect refers to the phenomenon that stimuli from one sensory modality are preferentially selected over the other modalities. Top-down attention helps us to select task-relevant information while filtering out task-irrelevant distracting information.

The Simon Effect Based on Allocentric and Egocentric Reference Frame: Common and Specific Neural Correlates.

An object's location can be represented either relative to an observer's body effectors (egocentric reference frame) or relative to another external object (allocentric reference frame). In non-spatial tasks, an object's task-irrelevant egocentric position conflicts with the side of a task-relevant manual response, which defines the classical Simon effect. Growing evidence suggests that the Simon effect occurs not only based on conflicting positions within the egocentric but also within the allocentric reference frame.

Neural practice effect during cross-modal selective attention: Supra-modal and modality-specific effects.

Practice and experiences gradually shape the central nervous system, from the synaptic level to large-scale neural networks. In natural multisensory environment, even when inundated by streams of information from multiple sensory modalities, our brain does not give equal weight to different modalities. Rather, visual information more frequently receives preferential processing and eventually dominates consciousness and behavior, i.

Neural Correlates underlying Size Constancy in Virtual Three-Dimensional Space.

The perceived size of an object remains relatively constant although its retinal size keeps decreasing as the object moves away along the depth dimension of the 3D space, i.e. size constancy.

Neural dynamics underlying varying attentional control facing invariant cognitive task upon invariant stimuli.

Even when performing invariant behavioral task repeatedly on invariant physical stimuli, our behavioral performance always changes as manifested in varying response times (RTs), which is associated with fluctuations in attentional control and thus the underlying self-organization states of the human brain. In a visuospatial task of the present fMRI study, physical stimuli differed across six levels of spatial scope, but were kept invariant within each level. The slower RTs with larger spatial area attended suggested higher demands on visuospatial attention.

The Poggendorff illusion driven by real and illusory contour: Behavioral and neural mechanisms.

The Poggendorff illusion refers to the phenomenon that the human brain misperceives a diagonal line as being apparently misaligned once the diagonal line is interrupted by two parallel edges, and the size of illusion is negatively correlated with the angle of interception of the oblique, i.e. the sharper the oblique angle, the larger the illusion.

Effect of different directions of attentional shift on inhibition of return in three-dimensional space.

When attention is oriented to a peripheral cue, the processing of nearby stimuli is facilitated. This brief period of facilitation is followed by a long-lasting inhibitory effect, during which there is a delayed response to stimuli presented at a previously cued location. Although the mechanisms underlying the facilitatory effect of attentional orienting/reorienting in three-dimensional (3-D) space have been documented, there is not yet consensus as to how attention orients/reorients in depth during the later inhibitory phase (i.

The Simon effect based on the egocentric and allocentric reference frame.

The classic Simon effect refers to the phenomenon that responses are faster when the task-irrelevant egocentric stimulus location is on the same side as the response hand than when not. However, the spatial location of an object often varies according to which reference frame the object location was represented in, e.g.

Interaction between spatial inhibition of return (IOR) and executive control in three-dimensional space.

It has been well documented how spatial inhibition of return (IOR) interacts with executive functions in a two-dimensional plane, i.e., significantly decreased interference at the cued (inhibited) compared to the uncued location.

Multisensory Competition Is Modulated by Sensory Pathway Interactions with Fronto-Sensorimotor and Default-Mode Network Regions.

Multisensory information competes for preferential access to consciousness. It remains unknown what neural processes cause one particular modality to win multisensory competition and eventually dominate behavior. Thus, in a paradigm in which human participants sought to make simultaneous auditory and visual detection responses, we sought to identify prestimulus and poststimulus neural signals that were associated with auditory and visual dominance on each trial.

Enhanced visual dominance in far space.

The Colavita effect refers to the phenomenon that people do not respond to an auditory stimulus in most cases when a visual stimulus is simultaneously presented. Although the Colavita effect remains robust irrespective of many factors, little is known concerning how the visual dominance varies as a function of the depth of sensory inputs. In the present study, visual and auditory stimuli were presented either in the same (in Experiment 1) or in the different spatial distances (in Experiment 2).

Differential contribution of velocity and distance to time estimation during self-initiated time-to-collision judgment.

To successfully intercept/avoid a moving object, human brain needs to precisely estimate the time-to-collision (TTC) of the object. In real life, time estimation is determined conjointly by the velocity and the distance of a moving object. However, surprisingly little is known concerning whether and how the velocity and the distance dimensions contribute differentially to time estimation.

Interaction between allocentric and egocentric reference frames in deaf and hearing populations.

Spatial position of an object can be represented in the human brain based on two types of reference frames: allocentric and egocentric. The perception/action hypothesis of the ventral/dorsal visual stream proposed that allocentric reference frame codes object positions relative to another object/background subserving conscious perception of the external world while egocentric reference frame codes object positions relative to the observer's body/body parts subserving goal-directed actions towards the objects. In three experiments of the present study, by asking congenitally deaf participants and hearing controls to perform allocentric and egocentric judgment tasks on the same stimulus set and by using the spatial congruency effect between allocentric and egocentric positions of the same target object to indicate the extent of influences between the two frames, we aimed to investigate whether the two frames and the potential interaction between them are altered after early deafness.

Neural mechanisms of attentional reorienting in three-dimensional space.

How the human brain reconstructs the three-dimensional (3D) world from two-dimensional (2D) retinal images has received a great deal of interest as has how we shift attention in 2D space. In contrast, it remains poorly understood how visuospatial attention is shifted in depth. In this fMRI study, by constructing a virtual 3D environment in the MR scanner and by presenting targets either close to or far from the participants in an adapted version of the Posner spatial-cueing paradigm, we investigated the behavioral and neural mechanisms underlying visuospatial orienting/reorienting in depth.

Neural interaction between spatial domain and spatial reference frame in parietal-occipital junction.

On the basis of double dissociations in clinical symptoms of patients with unilateral visuospatial neglect, neuropsychological research distinguishes between different spatial domains (near vs. far) and different spatial reference frames (egocentric vs. allocentric).

Altered spatial distribution of visual attention in near and far space after early deafness.

Early deafness results in a redistribution of more attentional resources to the visual periphery in near space, specifically under conditions of selective attention, probably to compensate for the loss of auditory alertness to potentially dangerous stimuli from outside the current attentional focus. It remains poorly understood, however, whether spatial distribution of attention in far space is altered by early deafness as well. In the present study, we investigated whether and how early deafness alters the distribution of visuospatial attention in far space, compared to hearing controls.