Two experiments extend the ecological validity of tests of hemispheric interaction in three novel ways. First, we present a broad class of naturalistic stimuli that have not yet been used in tests of hemispheric interaction. Second, we test whether probable differences in complexity within the class of stimuli are supported by outcomes from…

Objective: The goal of the present study was to examine distributed attentional functions in long-term but currently abstinent methamphetamine (MA) abusers using a task that measures attentional alertness, orienting, and conflict resolution. Methods: Thirty currently abstinent MA abusers (1 month-5 years) and 22 healthy non-substance using adults…

An issue of continued debate in the visuomotor control literature surrounds whether a 2D object serves as a representative proxy for a 3D object in understanding the nature of the visual information supporting grasping control. In an effort to reconcile this issue, we examined the extent to which aperture profiles for grasping 2D and 3D objects…

In this study we quantify for the first time electrophysiological components associated with incorporating long-term semantic knowledge with visuo-spatial information using two variants of a traditional matrix patterns task. Results indicated that the matrix task with greater semantic content was associated with enhanced accuracy and RTs in a…

Integration of simultaneous auditory and visual information about an event can enhance our ability to detect that event. This is particularly evident in the perception of speech, where the articulatory gestures of the speaker's lips and face can significantly improve the listener's detection and identification of the message, especially when that…

Developmental studies have demonstrated that cognitive processes such as attention, suppression of interference and memory develop throughout childhood and adolescence. However, little is currently known about the development of top-down control mechanisms and their influence on cognitive performance. In the present study, we used functional…

Category training can induce category effects, whereby color discrimination of stimuli spanning a newly learned category boundary is enhanced relative to equivalently spaced stimuli from within the newly learned category (e.g., categorical perception). However, the underlying mechanisms of these acquired category effects are not fully understood.…

The role of frontal cortex in selective attention to visual distractors was examined in an attentional capture task in which participants searched for a unique shape in the presence or absence of an additional colour singleton distractor. The presence of the additional singleton was associated with slower behavioural responses to the shape target,…

A number of human brain areas showing a larger response to faces than to objects from different categories, or to scrambled faces, have been identified in neuroimaging studies. Depending on the statistical criteria used, the set of areas can be overextended or minimized, both at the local (size of areas) and global (number of areas) levels. Here…

In two behavioral experiments involving lateralized stimulus presentation, we tested whether one of the most commonly used measures of holistic face processing--the composite face effect--would be more pronounced for stimuli presented to the right as compared to the left hemisphere. In experiment 1, we investigated the composite face effect in a…

Ambiguous (or bistable) figures are visual stimuli that have two mutually exclusive perceptual interpretations that spontaneously alternate with each other. Perceptual reversals, as compared with non-reversals, typically elicit a negative difference called reversal negativity (RN), peaking around 250 ms from stimulus onset. The cognitive…

Learning movement sequences is thought to develop from an initial controlled attentive phase to a more automatic inattentive phase. Furthermore, execution of sequences becomes faster with practice, which may result from changes at a general motor processing level rather than at an effector specific motor processing level. In the current study, we…

Studies have suggested that supramodal attentional resources are biased rightward due to asymmetric spatial fields of the two hemispheres. This bias has been observed especially in right-handed subjects. We presented left and right-handed subjects with brief uniform grey visual stimuli in either the left or right visual hemifield. Consistent with…

Watching a rubber hand being stroked by a paintbrush while feeling identical stroking of one's own occluded hand can create a compelling illusion that the seen hand becomes part of one's own body. It has been suggested that this so-called rubber hand illusion (RHI) does not simply reflect a bottom-up multisensory integration process but that the…

In this study of the project DyAdd, three aspects of visual attention were investigated in adults (18-55 years) with dyslexia (n = 35) or attention deficit/hyperactivity disorder (ADHD, n = 22), and in healthy controls (n = 35). Temporal characteristics of visual attention were assessed with Attentional Blink (AB), capacity of visual attention…