visual evoked potential auditory evoked potential

STIM

A complete software environment for custom stimulus and task design as well as presentation, the STIM system can be integrated in FMRI, MEG, and other functional neuroimaging applications. The software provides a familiar menu-driven interface in which to design and present visual and auditory simulation paradigm. When coupled with MARI-compatible visual and auditory stimulus presentation system, STIM becomes a powerful part of your functional imaging system.

STIM’s powerful and intuitive design translated into a short learning curve and quick implementation. Utilities make it easy to design and execute your stimuli with the greatest precision and the wide array of pre-packaged stimuli ensure fast integration into your search.

Specifications:

Digital Sound Editor: a program for recording, editing, and presenting digital sound segments. SOUND has programmable attenuation in .75 dB steps, a dynamic range from 0 to 130 dB, 16 bit CD quality digital sampling (see Audio System, Options next page), customizable digital filtering, spectral analysis, noise masking, mono or stereo processing, and a variety of windowing options. Sounds can be synthesized (i.e. pure tone, noise, click) or digitally sampled from a microphone or line input. Precise triggering is also provided for external devices such as SCAN EP/ERP system. Commonly used to present click stimuli for ABR or BAER recording and to create sound files used in other STIM modules.
Graphics Editor: a draw and paint program that allows you to create and edit visual stimuli for use in other STIM visual tasks (i.e. GENTASK, NAMING, VISCPT, SPR, and TRACK). DRAW includes special features such as visual noise masking and precise image degradation. Additional images can be scanned and edited within DRAW.
Generalized Task Editor: an interface for creating and presenting almost any type of visual, auditory, or combined task and recording behavioral responses. Here are just a few of the features GENTASK provides that make designing complex tasks simple: calibration to ensure precise timing of stimulus presentation and EP/ERP acquisition system triggering; 256 color PCX image support; 16 bit sound support (see Audio System, Options next page); present pictures and sounds in the same task, even simultaneously; display pictures for as little as one screen refresh; flip between pictures with virtually no delay; plus many more too numerous to name. Has been used for a variety of experiments including auditory N400, MMN, CNV, picture memory, and many more.
Motor Tasks
Tap: a motor performance task modeled after the finger tapping test commonly employed in neuropsychological assessment.
Track: a visual tracking task useful in measuring visual-motor tracking ability. Precise triggering is provided for neurophysiological recording systems such as SCAN.
Perceptual Tasks
Contrast: a unique interface for performing contrast reversal stimulation with evoked potential recording systems such as SCAN. CONTRAST features a simultaneous fixation task to ensure foveation, repositioning of pattern relative to fixation, vertical/horizontal bars, selective masking, task suspension during inattentive periods, and user definable keys for rapid assessment of visual acuity.
Naming: a flexible interface for presenting visual stimuli and recording verbal responses. NAME allows you to configure tasks with almost any visual stimuli (including text and pictures), digitally record verbal responses, and score responses for both accuracy and latency. Precise triggering is also provided for neurophysiological recording systems such as SCAN.
Stroop: a version of the Stroop neuropsychological test modified for evoked potential recordings.
Attentional Tasks
Cued: a visual cued attention switching task. CUED provides central “arrow” and peripheral “highlighted box” cues and is commonly used as an index of ability to release and reorient visual attention. Triggering is provided for external devices such as SCAN ER/ERP system.
Concpt: a “go/no-go” visual continuous performance task in which the subject’s response to the target should be contingent upon the appearance of a cue stimulus. CONCPT also provides triggering for evoked potential recording systems.
Viscpt: a visual continuous performance task widely used in the assessment of sustained attention. VISCPT provides precise triggering for evoked potential recording systems such as SCAN and is an appropriate interface for visual P300 and related experiments.
Audcpt: an auditory continuous performance task. AUDCPT provides an interface similar to VISCPT, wherein you assign probabilities to up to 10 different auditory events. Provides precise triggering for evoked potential recordings and is perfect for P300 and MMN experiments.
Memory Tasks
Spatial Memory: a battery designed to assess static and sequential visual spatial memory.
Vlt: a flexible interface for presenting a variety of verbal learning, verbal memory, and other language paradigms. VLT provides precise triggering for ERP systems and is well suited to N400 and other language-related ERPs.
Spr: a visual memory task that can be used in a variety of experiments in which serial position effects are of interest. SPR can be used with provided “normed” pictures or your own. SPR provides precise triggering for ERP systems and is well suited to Sternberg memory scanning experiments.
Cognitive Tasks
Card Sorting: similar to the card sorting test used in neuropsychological batteries, CARDSORT is widely used in behavioral and imaging research studies on concept formation.
Categories: CATEGORY is similar to the widely used neuropsychological test, and is useful as an activation task in imaging studies or as a behavioral measure of problem solving ability.
The STIM Audio System and Response Interface
Each STIM system is provided with precision hardware for recording sounds from a microphone or line input with 16 bit A/D conversion, playing back mono or stereo sounds at SPL calibrated levels (HL also possible), recording manual responses with push buttons or optional finger-lift LED photocells, recording verbal responses with millisecond accuracy, and measuring reaction time with an independent clock in case stimulus and response occur simultaneously. Other features of the STIM AUDIO SYSTEM include anti-aliasing filters, audiometric quality insert earphones, independent left and right channel gain levels, and more.