Psychophysiology

Bio pac

The Core psychophysiology suite includes a shielded subject room with video surveillance to the control booth outside for continual subject monitoring during experiments.  Collection of physiological measures are done using the Biopac MP150 system. The MP150 system provides high resolution (16 bit), variable sample rates for analog and calculation channels, 16 analog inputs and two analog outputs, digital I/O lines, and 16 online calculation channels. The MP150 System provides high-speed acquisition (400 kHz aggregate) via an Ethernet connection to a host computer.  AcqKnowledge, the Biopac control and analysis software package, is used to control the acquisition and can be used for data analysis.

Electrodermal activity is acquired using the Biopac amplifier and two 6mm Ag-AgCL non-polarizable electrodes placed on the tips of the second and third fingers.

Facial electromyography is recorded using the Biopac amplifier and two 3mm Ag-AgCL non-polarizable electrodes placed over the right or left zygomaticus major cheek muscle, with a third electrode applied over the ipsilateral mastoid to serve as an electrical ground; corrugator muscle activity is acquired via two electrodes placed over the right or left corrugator supercilli muscle (small narrow pyramidal muscle at the medial end of the eyebrow beneath the frontalis and obicularis oculi); eyeblink reflex magnitude is recorded through two electrodes placed beneath the left or right eye (lower orbicularis oculi muscle).

Respiration data is acquired using the Biopac amplifier and a respiration transducer to measure abdominal or thoracic expansion and contraction.

Eyetracking data can be acquired via the Tobii 120 Hz eyetracker.  This eyetracker is incorporated into a computer monitor and is therefore completely non-intrusive to study participants. It is capable of performing quick and automatic calibration, track eye movements at a fast acquisition rate of 120 Hz while allowing and compensating for considerable head movement, and measure absolute pupil diameter all without the need for a headholder, headmount, or chinrest. Finally, the Tobii is able to respond based on subjects' eye fixation, waiting to start a trial until fixation is achieved. Because of its flexibility and non-intrusiveness, it is the ideal eyetracking system for use when studying children and patient populations who may have difficulty keeping their head still or who may be slower to return to a fixation point.