The perception of visible speech: estimation of speech rate and detection of time reversals.

Four experiments investigated the perception of visible speech. Experiment 1 addressed the perception of speech rate. Observers were shown video-clips of the lower face of actors speaking at their spontaneous rate.

Detecting temporal reversals in human locomotion.

An experiment investigated the ability by human observers to detect temporal reversals in dynamic displays of human locomotion. We video-taped the lower portion of the body of actors walking at their preferred speed either in the normal, forward direction (FW) or in the backward direction (BW). The videos were presented in a random order either as recorded (N) or in reverse (R).

Determining priority between attentional and referential-coding sources of the Simon effect through optokinetic stimulation.

The "Simon effect" is the performance advantage for spatially corresponding target-response ensembles that is observed when coding of target position is irrelevant for the selection of motor responses. The "attentional-shift" account of the Simon effect holds that it arises from the congruency between response location and the direction of the last shift of attention toward the target. The "referential-coding" account traces the origin of the Simon effect back to the congruency between the response location and the position of the target with respect to a spatial reference frame.

The influence of distracters, stimulus duration and hemianopia on first saccade in patients with unilateral neglect.

The aim of the present study was to assess the influence of visual distracters, stimulus duration and the presence of contralesional hemianopia on direction of the first saccade in right brain damaged (RBD) patients affected by left unilateral neglect (UN). During a visual search task we recorded eye movements in five RBD patients with UN and hemianopia (N+H+), nine RBD patients with UN but no hemianopia (N+H-), four RBD patients with neither neglect nor hemianopia and four normal controls. Two task variables were orthogonally manipulated: (a) presence or absence of distracters and (b) short or long stimulus duration.

The "ways" we look at dreams: evidence from unilateral spatial neglect (with an evolutionary account of dream bizarreness).

Despite decades of research, the question of whether the rapid eye movements (REMs) of paradoxical sleep (PS) are equivalent to waking saccades and whether their direction is congruent with visual spatial events in the dream scene is still very controversial. We gained an insight into these questions through the study of a right brain damaged patient suffering attentional neglect for the left side of space and drop of the optokinetic nystagmus (OKN) with alternating rightward slow/leftward fast phases evoked by rightward optic flow. During PS the patient had frequent Nystagmoid REMs with alternating leftward slow/rightward fast phases and reported dreams with visual events evoking corresponding OKN such as a train running leftward.

Effects of vestibular rotatory accelerations on covert attentional orienting in vision and touch.

Peripheral vestibular organs feed the central nervous system with inputs favoring the correct perception of space during head and body motion. Applying temporal order judgments (TOJs) to pairs of simultaneous or asynchronous stimuli presented in the left and right egocentric space, we evaluated the influence of leftward and rightward vestibular rotatory accelerations given around the vertical head-body axis on covert attentional orienting. In a first experiment, we presented visual stimuli in the left and right hemifield.

Underestimation of contralateral space in neglect: a deficit in the "where" task.

Space perception was investigated in right brain damaged patients with ( N=13) and without neglect ( N=5; control group). Patients were requested to localise a target tachistoscopically flashed at various eccentricities along the horizontal meridian. All patients had an intact visual field and spared ability to manually point to a target.