I have been using Functional Magnetic Resonance Imaging to study the brain areas in adults which are responsible for processing visual form and motion information. We have shown that form and motion are processed by separate but closely related systems (top figure). In more recent parametric studies, we have characterised the response of form sensitive areas to different levels of form coherence. Middle occipital and fusiform gyri show a linear response to form coherence, while more medial ventral foci and intra parietal foci show an unusual non-linear response (bottom figure)

Download this Current Biology paper for a summary.

• OJ Braddick, T Hartley, J O'Brien, J Atkinson, J Wattam-Bell,R Turner "Brain Areas Differentially Activated by Coherent Visual Motion and Dynamic Noise" NeuroImage 7 S322 (1998) [HBM'98]
• JMD O'Brien, OJ Braddick, T Hartley, J Atkinson, J Wattam-Bell, R Turner "Areas within and beyond the visual cortex differentially activated by coherent motion and dynamic noise" Perception 1998 [ECVP 98]
• OJ Braddick, JMD O'Brien, J Wattam-Bell, J Atkinson, T Hartley "Brain areas sensitive to coherent visual motion" (2001) Perception 30 61:72 [PDF 288Kb]
• OJ Braddick, JMD O'Brien, J Wattam-Bell, J Atkinson, R Turner "Form and motion coherence activate independent, but not dorsal/ventral segregated networks in the human brain" (2000) Current Biology 10 731:734 [PDF 336Kb]
• O J Braddick, J O'Brien, J Wattam-Bell, J Atkinson, C Hutton (2001) Sensitivity to global form coherence lies outside retinotopically ordered brain areas. Perception 30 S [ECVP 2001]
• O.J. Braddick, J. O'Brien, G. Rees, J. Wattam-Bell, J. Atkinson, R. Turner. Quantitative neural responses to form coherence in human extrastriate cortex. Program No. 721.9. 2002 Washington, DC: Society for Neuroscience, 2002. Online. [Abstract]
• Braddick OJ, Atkinson J, Wattam-Bell J, Aspell J & O’Brien JMD (2004) Brain systems processing global form and motion. Perception 33 [ECVP 2004]
• Benton CP & O'Brien JMD (2005) Fractal Rotating Stimulus Activates Human MT/V5 Vision Sciences Society
• Braddick OJ, O'Brien JMD, Rees G, Wattam-Bell J, Atkinson J & Turner R (coming soon) Quantitative neural responses to form coherence in human extra-striate cortex

Developmental Disorders
We have found that there is a deficit in motion processing and object recognition in Autistic Spectrum Disorder, but not in Asperger Syndrome. Children with dyspraxia exhibit an object recognition deficit, but not a motion processing deficit. We are continuing our research into sensory processing in children with developmental disorders as well developing an fMRI program too look at the underlying neural basis of these deficits in adults with developmental disorders.

The figure on the right shows a field of random dots containing a Glass Pattern. this is a circular region defined by dot pairs rotated around a central point. It is easy to detect the circular patch in this display which is 100% coherent. But we show the display for only 250 milliseconds, and gradually reduce the coherence of the display. This means that the circular patch is filled with more and more random dots and is more difficult to see. We have found that children with autism have particular difficulty spotting the circle. This is a deficit in global integration.

• Spencer J.V. & O'Brien JMD (in press) Visual Form Processing Deficits in Autism. Perception (email me for further info)
• O’Brien JMD, Spencer JV & Tsermenstelli S (2005) Form and Motion Processing in Dyslexia Vision Sciences Society
• Spencer JV & O’Brien JMD (2005) Imaging Visual Deficits in Autistic Spectrum Disorder Vision Sciences Society
• O'Brien JMD & Spencer J (2004) Perceptual deficits in autism and Asperger syndrome: form and motion processing. Perception 33 [ECVP 2004]
• O’Brien J. M. D, Spencer J., Atkinson J., Braddick O., & Wattam-Bell, J. (2002) Form and motion coherence processing in dyspraxia: evidence of a global spatial processing deficit. NeuroReport 13:1399-1402 [PDF 165Kb]
• Spencer, J., O’Brien, J. M. D., Riggs, K., Braddick, O. J., Atkinson, J, & Wattam-Bell, J. Dorsal Stream Deficit in Autism. (2000) NeuroReport 11:2765-2767 [PDF 121Kb]
• Spencer J & O’Brien, J. M. D. Form and Motion Processing in Autism. (2000) Perception 29 S98 [ECVP 2000]

Visual Development References:

Texture and Motion Research
In collaboration with Graham Edgar and Mark Williams at BAe Sowerby Research Centre, and with Alan Johnston at UCL, I completed a three year PhD project on the use of texture and motion cues in computer generated displays. Advances in computer graphics technology have resulted in a wide range of visual cues being used in displays such as flight simulators, so research is now focusing on how the human visual system integrates information about the visual environment from these different sources. We determined the circumstances in which the visual system puts a greater weight on information from texture mapping, than from the motion of the scene itself. A summary of this research can be found in the first chapter of my doctoral thesis, which is available in PDF format below.

Texture and Motion References: