Social and Behavioral Sciences Commons^™

A Selective Impairment Of Perception Of Sound Motion Direction In Peripheral Space: A Case Study., Lore Thaler, Joseph Paciocco, Mark Daley, Gabriella D Lesniak, David W Purcell, J Alexander Fraser, Gordon N Dutton, Stephanie Rossit, Melvyn A Goodale, Jody C Culham

Brain and Mind Institute Researchers' Publications

It is still an open question if the auditory system, similar to the visual system, processes auditory motion independently from other aspects of spatial hearing, such as static location. Here, we report psychophysical data from a patient (female, 42 and 44 years old at the time of two testing sessions), who suffered a bilateral occipital infarction over 12 years earlier, and who has extensive damage in the occipital lobe bilaterally, extending into inferior posterior temporal cortex bilaterally and into right parietal cortex. We measured the patient's spatial hearing ability to discriminate static location, detect motion and perceive motion direction in …

Visual Acceleration Perception For Simple And Complex Motion Patterns., Alexandra S Mueller, Brian Timney

Brain and Mind Institute Researchers' Publications

Humans are able to judge whether a target is accelerating in many viewing contexts, but it is an open question how the motion pattern per se affects visual acceleration perception. We measured acceleration and deceleration detection using patterns of random dots with horizontal (simpler) or radial motion (more visually complex). The results suggest that we detect acceleration better when viewing radial optic flow than horizontal translation. However, the direction within each type of pattern has no effect on performance and observers detect acceleration and deceleration similarly within each condition. We conclude that sensitivity to the presence of acceleration is generally …

Changes In Visual And Sensory-Motor Resting-State Functional Connectivity Support Motor Learning By Observing., Heather R Mcgregor, Paul L Gribble

Brain and Mind Institute Researchers' Publications

Motor learning occurs not only through direct first-hand experience but also through observation (Mattar AA, Gribble PL. Neuron 46: 153-160, 2005). When observing the actions of others, we activate many of the same brain regions involved in performing those actions ourselves (Malfait N, Valyear KF, Culham JC, Anton JL, Brown LE, Gribble PL. J Cogn Neurosci 22: 1493-1503, 2010). Links between neural systems for vision and action have been reported in neurophysiological (Strafella AP, Paus T. Neuroreport 11: 2289-2292, 2000; Watkins KE, Strafella AP, Paus T. Neuropsychologia 41: 989-994, 2003), brain imaging (Buccino G, Binkofski F, Fink GR, Fadiga L, …

Sharp Emergence Of Feature-Selective Sustained Activity Along The Dorsal Visual Pathway., Diego Mendoza-Halliday, Santiago Torres, Julio C Martinez-Trujillo

Brain and Mind Institute Researchers' Publications

Sustained activity encoding visual working memory representations has been observed in several cortical areas of primates. Where along the visual pathways this activity emerges remains unknown. Here we show in macaques that sustained spiking activity encoding memorized visual motion directions is absent in direction-selective neurons in early visual area middle temporal (MT). However, it is robustly present immediately downstream, in multimodal association area medial superior temporal (MST), as well as and in the lateral prefrontal cortex (LPFC). This sharp emergence of sustained activity along the dorsal visual pathway suggests a functional boundary between early visual areas, which encode sensory inputs, …

Lifting Without Seeing: The Role Of Vision In Perceiving And Acting Upon The Size‐Weight Illusion, Gavin Buckingham, Melvyn A. Goodale

Psychology Presentations

Our expectations of an object’s heaviness not only drive our fingertip forces, but also our perception of heaviness. This effect is highlighted by the classic size-weight illusion (SWI), where different‐sized objects of identical mass feel different weights (Charpentier, 1891) long after any initial errors in the application of fingertip forces have been corrected (Flanagan & Beltzner, 2000).

Here, we examined whether our expectations about the weight of an upcoming lift are sufficient to induce the SWI in a single wooden cube when lifted without visual feedback, by varying the size of the object seen prior to the lift during a …

Laterality, Perception, And Action During The Size-Weight Illusion, Gavin Buckingham, Nathalie S. Ranger, Melvyn A. Goodale

Psychology Presentations

In the classic size-weight illusion (SWI), a small object will feel heavier than an larger object of equal weight (Charpentier, 1891). Individuals continue to perceive this illusory difference in weight long after their gripping and lifting forces have scaled to the actual, identical, mass of the illusion-inducing stimuli (Flanagan & Beltzner, 2000).

The independence of our weight perception and fingertip force application has only been quantified in the right hand of right-handers. The immunity to this perceptual illusion may be affected by manual asymmetries (e.g., Gonzalez, Ganel & Goodale, 2006).

We examined perception of heaviness and fingertip force scaling in …

A Contralateral Preference In The Lateral Occipital Area: Sensory And Attentional Mechanisms., Matthias Niemeier, Herbert C Goltz, Anil Kuchinad, Douglas B Tweed, Tutis Vilis

Brain and Mind Institute Researchers' Publications

Here we examined the level of the lateral occipital (LO) area within the processing stream of the ventral visual cortex. An important determinant of an area's level of processing is whether it codes visual elements on both sides of the visual field, as do higher visual areas, or prefers those in the contralateral visual field, as do early visual areas. The former would suggest that LO, on one side, combines bilateral visual elements into a whole, while the latter suggests that it codes only the parts of forms. We showed that LO has a relative preference for visual objects in …

The Lateral Occipital Complex Subserves The Perceptual Persistence Of Motion-Defined Groupings., Susanne Ferber, G Keith Humphrey, Tutis Vilis

Brain and Mind Institute Researchers' Publications

How are the bits and pieces of retinal information assembled and integrated to form the coherent objects that we see? One long-established principle is that elements that move as a group are linked together. For instance a fragmented line-drawing of an object, placed on a background of randomly distributed short lines, can be impossible to see. But if the object moves relative to the background, its shape is instantly recognized. Even after the motion stops, the percept of the object persists briefly before it fades into the background of random lines. Where in the brain does the percept of the …