Clinical neuropsychologist, University Hospital, Geneva

Maître-assistant, University of Geneva

Research interest

• attentionnal control and orienting mechanisms in spatial neglect
• oculomotor disturbances following cortical damage
• optic ataxia
• perceptual and occulomotor learning

1. neglect rehabilitation and plasticity of human attention system

Publications

• Ptak R, Schnider A, Golay L, Müri R (2007) A non spatial-bias favouring fixated stimuli revealed in patients with spatial neglect. Brain, in press.
• Ptak, R. & Golay, L.(2006) Temporal dynamics of attentional control settings in patients with spatial neglect. Brain Research 1092:190-197.
• Gutbrod, K., Krouzel, C., Hofer, H., Müri, R., Perrig, W. & Ptak, R. (2006) Decision-making in amnesia: do advantageous decisions require conscious knowledge of previous behavioural choices? Neuropsychologia,44:1315-1324.
• Ptak, R. & Schnider, A. (2006). Reflexive orienting in spatial neglect is biased towards behaviourally salient stimuli. Cerebral Cortex, 16: 337-345.
• Golay, L., Hauert, C.-A., Greber, C., Schnider, A. & Ptak, R. (2005). Dynamic modulation of visual detection by auditory cues in spatial neglect. Neuropsychologia, 43: 1258-1265.
• Ptak, R. & Valenza, N. (2005). The inferior temporal lobe mediates distracter-resistant visual search of patients with spatial neglect. Journal of Cognitive Neuroscience, 17: 788-799.
• Ptak, R. & Schnider, A. (2005). Visual extinction of similar and dissimilar stimuli: Evidence for level-dependent attentional competition. Cognitive Neuropsychology, 22: 111-127.
• Valenza, N., Murray, M.M., Ptak, R. & Vuilleumier, P. (2004). The space of senses: impaired crossmodal interactions in a patient with Bálint syndrome after bilateral parietal damage. Neuropsychologia, 42: 1737-1748.
• Ptak, R., Bonvallat, J. & Schnider, A. (2004). Rééducation de l'héminégligence. In: Safran, A.B. Neuro-ophtalmologie. Paris: Masson.
• Ptak, R. & Schnider, A. (2004). Disorganised memory after right dorsolateral prefrontal damage. Neurocase, 10: 52-59.
• Annoni, J.-M., Ptak, R., Caldara, A.S., Khateb, A. & Zei Pollermann, B. (2003). Decoupling of autonomic and cognitive emotional reactions after cerebellar stroke: A case report. Annals of Neurology, 53: 654-658.
• Ptak, R., Valenza, N. & Schnider, A. (2002). Expectation-based attentional modulation of visual extinction in spatial neglect. Neuropsychologia, 40: 2199-2205.
• Valenza, N., Ptak, R., Zimine, I., Lazeyras, F., Badan, M. & Schnider, A. (2001). Dissociated active and passive tactile shape recognition: a case study of pure 'tactile apraxia'. Brain, 124: 2287-2298.
• Ptak, R., Gutbrod, K., Perrig, W. & Schnider, A. (2001). Probabilistic learning with limbic or prefrontal damage. Behavioral Neuroscience, 115: 993-1001.
• Ptak, R., Birtoli, B., Imboden, H., Hauser, Ch., Weis, J. & Schnider, A. (2001). Hypothalamic amnesia with confabulations. A clinico-pathological study. Neurology, 56: 1597-1600.
• Schnider, A., Ptak, R., von Däniken, C. & Remonda, L. (2000). Recovery from spontaneous confabulations parallels recovery of temporal confusion in memory. Neurology, 55: 74-83.
• Schnider, A. & Ptak, R. (1999). Spontaneous confabulators fail to suppress currently irrelevant memory traces. Nature Neuroscience, 2: 677-681.
• Ptak, R. & Schnider, A. (1999). Spontaneous confabulations after orbitofrontal damage: The role of self-monitoring and temporal context confusion. Neurocase, 5: 243-250.
• Ptak, R., Gutbrod, K. & Schnider, A. (1998). Association learning in the acute confusional state. Journal of Neurology, Neurosurgery, and Psychiatry, 65: 390-392.

Collaborations

• René Müri (Div. of Neuropsychological Rehabilitation, University Hospital, Bern): Mechanisms of attentional orienting in spatial neglect
• Klemens Gutbrod (Div. of Neuropsychological Rehabilitation, University Hospital, Bern): Decision making in amnesia
• Claude-Alain Hauert (FAPSE, Geneva): Deficits of spatial attention and motor preparation
• Nathalie Valenza: Deficits od somatosensory attention

Grants

• 2003 Swiss National Science Foundation (grant 3100-100 156)
• 2003 De Reuter Foundation (Geneva)

1. 2005 Schmidheiny Foundation (Geneva)
2. 2006 Swiss National Science Foundation (grant 320000-113438)

Ptak Radek, PhD
HUG
Division of NeuroRehabilitation
26 avenue beau-séjour
1211 Genève 14
tel : +41 22 372 35 24
fax : +41 22 3828 338
Radek.Ptak@hcuge.ch