Prof. Christian Ruff, PhD

 

Main Goals, Keywords

Neural mechanisms of human decision-making: top-down control of perception, emotion, and action; effects of motivational factors (attention, rewards, social context) on perception and action selection.

Non-invasive brain stimulation: Causal inference about brain-behavior relations; studying causal functional interactions between interconnected brain areas with brain stimulation and neuroimaging.

Group Members

1 professor, 4 postdoctoral fellows, 6 PhD students, 1 administrator

Previous and current research

Humans do not react to the environment in a reflex-like manner, but can freely choose which action to perform in response to a given situation. We study the neural mechanisms that enable such flexible decision-making, ranging from influences of intention and motivation on sensory processing to the effects of affective and social contexts on choice behavior. A particular focus of our work is on using non-invasive brain stimulation techniques (TMS, tDCS), alone or on conjunction with neuroimaging techniques (fMRI, EEG), to identify truly causal links between activity patterns in brain networks and behavior.

Future research

We will characterize the neural processes underlying various forms of decision-making (perceptual, affective, economic, social) with combinations of brain stimulation and neuroimaging, to identify core mechanisms that instantiate top-down control across all these different contexts. One focus of these projects will be to explain how individual differences in decision-making may be causally rooted in differences in neural processing.

Techniques and Equipment

Techniques: Behavioral experiments (psychophysics, behavioral economics), fMRI, computational modeling of brain responses (SPM, DCM), TMS, tDCS, concurrent TMS-fMRI, concurrent tDCS-fMRI, psychophysiological responses (eye movements, SCR, breathing, heart rate).

Equipment at the SNS-Lab: 3T fMRI scanner, 128 channel EEG system, Magstim Rapid2 TMS, Brainsight frameless stereotaxy, Neuroconn 16-channel tDCS, Behavioral and psychophysics laboratory with eye tracker and psychophysiology measurement devices.

Selected Publications

• Denison RN, Driver J, Ruff CC. Temporal structure and complexity affect audio-visual correspondence detection. Front Psychol. 2012;3:619. doi: 10.3389/fpsyg.2012.00619. Epub 2013 Jan 22.

• Morishima Y, Schunk D, Bruhin A, Ruff CC, Fehr E. Linking brain structure and activation in temporoparietal junction to explain the neurobiology of human altruism. Neuron. 2012 Jul 12;75(1):73-9. doi: 10.1016/j.neuron.2012.05.021.

• Gerits A*, Ruff CC*, Guipponi O, Wenderoth N, Driver J, Vanduffel W. Transcranial magnetic stimulation of macaque frontal eye fields decreases saccadic reaction time. Pierre Pouget PhD, Nicolas Wattiez MSc and Antoni Valero-Cabre MDPhD. Exp Brain Res. 2012 Apr;218(1):157-8. doi: 10.1007/s00221-012-3022-y. Epub 2012 Feb 7.*Shared First Authorship
  

• Marchant JL, Ruff CC, Driver J. Audiovisual synchrony enhances BOLD responses in a brain network including multisensory STS while also enhancing target-detection performance for both modalities. Hum Brain Mapp. 2012 May;33(5):1212-24. doi: 10.1002/hbm.21278. Epub 2011 Sep 23.

Funding

UZH Research Priority Program "Foundations of Human Social Behaviour”, NCCR Affective Sciences

URL

http://www.econ.uzh.ch/faculty/groupruff.html