Dr Cristiana Cavina Pratesi
(email at firstname.lastname@example.org)
I was born in Faenza (RA- Italy) on February 1971 and I grew up in Marradi, a small village one hundred kilometers north-east of Firenze (where my family still lives – Gamberaldi). I have a degree in Psychology from the University of Padova (1998) and a PhD in Psychological and Psychiatry Sciences (2003) from the University of Verona. I did a two year post-doctoral period at the University of Western Ontario in Canada and I’m currently working as a research associate at Durham University in the UK.
1. Mapping visual features computation along the dorsal stream: grasping. reaching and pointing. On a general basis our experiments measure brain activation using functional MRI while subjects engage in simple visuomotor tasks. Subjects are asked to perform real actions such as reaching, grasping, pointing or avoiding three-dimensional objects.
i. Dissociating the neural correlates of the transport and grip components of reach-to-grasp actions:
• Evidence from event-related fMRI
• Evidences from brain lesioned patients
ii. What exactly is computed in parietal grasping and reaching areas?
iii. Neural correlates of obstacle avoidance;
2. Mapping visual features computation along the ventral stream face and object perception
iv. Computation of objects visual features: shape & texture
v. Face awareness and change blindness
3. Interaction between dorsal and ventral streams
vi. Comparing real and pantomime grasping in magicians!
I study how the brain uses visual information to perceive, recognize and act upon objects.
How do we recognize our cup of coffee from others and how do we accommodate our hand-finger posture to reach and grasp it correctly?
Questions I’m trying to answer:
Does our brain build a single representation of the cup or does it extract the shape, size and location of the cup accordingly to our moment-to-moment goals (perceiving, grasping or pointing)? If different representations do exist, which are the differences between them?
I recently published a paper showing that different areas of the brain come to play when the size of real 3D object has to be extracted for action as compared to perception. I found that while area AIP (in the anterior portion of the Intraparietal sulcus) computes object size for the purpose of action only (i.e. grasping), LOC (in the Lateral portion of the Occipital Cortex) computes object size only for perception only (i.e. button press discrimination task).
What does it mean? It means that the brain does not create one single representation of the world, but it extracts object features accordingly to the specific aim of the moment. For example, we can distinguish between an orange and a small tangerine in a bowl of fruit. We can also grasp the orange and our hand would open wider on approach than when grasping the tangerine. My data show that to distinguish the orange from the tangerine we use LOC but when we open our hand widely to grasp the orange as compared to the tangerine, we use AIP.
These data provide the first unequivocal evidence that visual computation of object to perform real goal-directed actions and to perceive take separate neural pathways in neurologically intact human brains. So far the neuro-functional dissociation between a dorsal action stream and a ventral perception stream in the human cerebral cortex was based largely on neuropsychological case studies
Techniques I use
I use behavioral and kinematics measures to asses specific pattern of visuomotor transformations in healthy subjects and then I use functional imaging and neuropsychological testing to check how they are mapped onto the brain.
I collect kinematic data using two different motion analysis systems: Optotrack 3020 and Minibird 500.
I collect imaging data in York (YNiC - UK) and in London, Ontario (CA Robarts Imaging Center) at the University of Western Ontario.
- Professor Carlo Alberto Marzi (Verona University, IT)
- Professor Jody Culham (University of London Ontario, CA)
- I use behavioural (RT, Accuracy and kinematics), Neuropsychological (patients with selective lesion), and Imaging (fMRI) techniques
- Visual Perception (shape texture and colour of objects)
- Visuomotor transformation for action: grasping and reaching
Journal papers: academic
- Evans C, Milner AD, Humphreys GW & Cavina-Pratesi C (Published). Optic ataxia affects the lower limbs: Evidence from a single case study. Cortex
- Bracci, B, Cavina-Pratesi, C, Ietswaart, I, Caramazza, A & Peelen, MV (2012). Closely overlapping responses to tools and hands in left lateral occipitotemporal cortex. Journal of Neurophysiology 107(5): 1443-1456
- Monaco, S, Cavina-Pratesi, C, Sedda, A, Fattori, P, Galletti, C & Culham, JC (2011). Functional magnetic resonance adaptation reveals the involvement of the dorsomedial stream in hand orientation for grasping. Journal of Neurophysiology 106(5): 2248-2263
- Cavina-Pratesi, C., Kuhn, G., Ietswaart, M. & Milner, A.D. (2011). The Magic Grasp: Motor Expertise in Deception. PLoS ONE 6(2): e16568.
- Stefania Bracci, Magdalena Ietswaart, Marius V. Peelen & Cristiana Cavina-Pratesi (2010). Dissociable Neural Responses to Hands and Nonhand Body Parts in Human Left Extrastriate Visual Cortex. Journal of Neurophysiology 103(6): 3389-3397.
- Cavina-Pratesi, C., Monaco, S., Fattori, P., Galletti, C., McAdam, T.D., Quinlan, D.J., Goodale, M.A. & Culham, J.C. (2010). Functional magnetic resonance imaging reveals the neural substrates of arm transport and grip formation in reach-to-grasp actions in humans. Journal of Neuroscience 30(31): 10306-10323.
- Cavina-Pratesi, C., Kentridge, R.W., Heywood, C.A. & Milner, A.D. (2010). Separate channels for processing form, texture and color: Evidence from fMRI adaptation and visual object agnosia. Cerebral Cortex 20(10): 2319-2332.
- Cristiana Cavina-Pratesi, Magdalena Ietswaart, Glyn W. Humphreys, Vaia Lestou & A. David Milner (2009). Impaired grasping in a patient with optic ataxia: Primary visuomotor deficit or secondary consequence of misreaching?. Neuropsychologia 48(1): 226-234.
- Gallivan, J.P., Cavina-Pratesi, C, & Culham, J.C. (2009). Is that within reach? fMRI reveals that the human superior parieto-occipital cortex encodes objects reachable by the hand. The Journal of Neuroscience 29(14): 4381-4391.
- Cavina-Pratesi C, Kentridge RW, Heywood CA & Milner AD (2009). Separate processing of texture and form in the ventral stream: evidence from fMRI and visual agnosia. Cerebral Cortex 20(2): 433-446.
- Large, M.-E., Cavina-Pratesi, C., Vilis, T. & Culham, J.C. (2008). The neural correlates of awareness in the face perception network. Neuropsychologia
- Valyear, KF, Cavina-Pratesi, C, Stiglick, AJ & Culham, JC (2007). Does tool-related fMRI activity within the intraparietal sulcus reflect the plan to grasp?. Neuroimage 36: T94-T108.
- Cavina-Pratesi, C., Goodale, M.A. & Culham, J. C. (2007). FMRI Reveals a Dissociation between Grasping and Perceiving the Size of Real 3D Objects. PLOS one 2(5): e424.
- Kroliczak, G, Cavina-Pratesi, C, Goodman, DA & Culham, JC (2007). What does the brain do when you fake it? An fMRI study of pantomimed and real grasping. Journal Of Neurophysiology 97(3): 2410-2422.
- Cavina-Pratesi, C, Valyear, KF, Culham, JC, Kohler, S, Obhi, SS, Marzi, CA & Goodale, MA (2006). Dissociating arbitrary stimulus-response mapping from movement planning during preparatory period: Evidence from event-related functional magnetic resonance imaging. Journal Of Neuroscience 26(10): 2704-2713.
- Steeves, JKE, Culham, JC, Duchaine, BC, Pratesi, CC, Valyear, KF, Schindler, I, Humphrey, GK, Milner, AD & Goodale, MA (2006). The fusiform face area is not sufficient for face recognition: Evidence from a patient with dense prosopagnosia and no occipital face area. Neuropsychologia 44(4): 594-609.
- Culham, JC, Cavina-Pratesi, C & Singhal, A (2006). The role of parietal cortex in visuomotor control: What have we learned from neuroimaging?. Neuropsychologia 44(13): 2668-2684.
- Cavina-Pratesi, C, Bricolo, E, Pellegrini, B & Marzi, CA (2004). At what stage of manual visual reaction time does interhemispheric transmission occur: controlled or ballistic?. Experimental Brain Research 155(2): 220-230.
- Cavina Pratesi, C. & Marzi, C.A. (2002). From classic to modern mental chronometry: beyond reaction time. DIPAV 5.
- Forster, B, Cavina-Pratesi, C, Aglioti, SM & Berlucchi, G (2002). Redundant target effect and intersensory facilitation from visual-tactile interactions in simple reaction time. Experimental Brain Research 143(4): 480-487.
- Cavina-Pratesi, C., Bonato, E., Bricolo, E., Prior, M., Posteraro, L. & Marzi, C.A. (2001). Hyperattention in neglect patients: perceptual or pre-motor phenomenon? Cortex 37: 703-705.
- Cavina-Pratesi, C, Bricolo, E, Prior, M & Marzi, CA (2001). Redundancy gain in the stop-signal paradigm: Implications for the locus of coactivation in simple reaction time. Journal Of Experimental Psychology-human Perception And Performance 27(4): 932-941.
Available for media contact about:
- Vision / eye movement: brain, vision, grasping, functional MRI, lesion, hand