Karolinska Cyberball

We have developed a computer software influenced and based on the principles of Williams original 'Cyberball' paradigm (Williams & Jarvis, 2006) our application broadens the perspective in order to study several variables of social psychological interest.

Classical Cyberball Module (CMM):

This module is in priciple the same as the original version used by Williams (Williams & Jarvis, 2006). However, some modifications have been made:

(i) Synchronization via parallell port for use with fMRI, EEG or other physiological recording devices. (ii) extra stimuli can be elicited during game-play (electric shocks or air puffs, sounds like white noise etc.) (iii) option for pre-programmed session sequences with the option to display a message inbetween sessions. (iv) music and sound effects can be added to improve the experience. (v) option to add counters which either add or remove values when the participant recieves or throws the ball and updates this on the screen for the participant to view. (vi) direct computation of measured indexes of the response behavior (different measures of sensitivity and response bias).

Reinforcement Learning Module (RLM):

This module is made for examine choice behavior in a triadic interaction. The user can program schedules of reinforcement by change probabilities for the co-participants behavior across and within sessions. This can either be done with probability arming per throw or by different schedules of reinforcement (fixed interval, variable interval, fixed response ratio, variable response ratio). The behaviors that can be altered are signal probability (the probability that a coparticipant will throw the ball to the participant), probability of direct reciprocity, and change of co-participant's avatar (photo). The change of avatar procedure offers the user the utility to alter emotional expression as a response to the participant’s behavior.