Steady State Topography

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The Steady State Topography ( SST ) is a method developed by the Australian brain researcher Richard Silberstein to measure human brain activity. The procedure is a further development of the electroencephalogram (EEG).

Procedure

Non-invasive measurements of human brain activity record either ongoing spontaneous activity of the brain (also electroencephalogram, EEG) or event-related activity in which the change in cortical activity is associated with a sensory or cognitive event ( event-related potential , EKP). SST is based on the measurement of EKPs. To collect the data, the person being examined wears an electrode cap (SST headset) and special glasses (SST visor). In accordance with current EEG practices, the electrodes are attached to standardized positions on the head in order to guarantee that the results can be compared. Based on the principles of the EEG method, a measurement records electrical changes in the examined brain region, as even processes that take place far inside the brain are reflected on the surface of the head. Changes in activity in a specific brain region can be used to B. draw conclusions as to whether a certain stimulus activates a function in the brain.

Measurement methodology

At the core of the measurement is a weak, continuous oscillating stimulus , which is presented in the periphery of the visual field during the measurement with the help of the SST visor . This continuously flickering light stimulus triggers a rhythmic sinusoidal brain response, which is called ' steady-state visually evoked potential ' (SSVEP). The Steady State Potential is characterized by its characteristic amplitude and the phase difference between the stimulus and the SSVEP. Different characteristics of the phase difference reflect different latency times between the SSVEP and the visual stimulus. These latencies are associated with a shortened or lengthened synaptic transmission due to inhibition and excitation processes. While a decrease in latency indicates an increase in synaptic excitation (or a reduction in synaptic inhibition ), an increase in latency indicates a decrease in synaptic excitation. This enables an analysis of the brain activity based on neuronal processing speed as an alternative to the conventional analysis of the EEG data, in which the measured amplitudes are used as indicators of human brain activity. The benefits of the method both for cognitive neuroscience and for neural communication research result primarily from three properties:

High temporal resolution
The SST method is able to continuously record rapid changes in brain activity over a longer period of time. This property is of central importance because the characteristics of human brain activity can change in fractions of a second.
High signal-to-noise ratio and resistance to interference and noise
Using SST measurements, a high degree of interference and noise signal can be tolerated, which can be caused by muscle contractions , head and eye movements , among other things .
One test run per person is sufficient
Due to the high signal-to-noise ratio, it is possible to work with data that are obtained from just one test run per person. In conventional EEG evaluations of event-related potentials, it is necessary to average numerous test runs of a single person due to a stronger noise signal in order to obtain an adequate signal-to-noise ratio and consequently sufficiently good data quality .

application areas

The SST method is able to record the brain activities in the brain areas to be examined with millisecond precision, which is of great benefit in the context of neurological examinations. SST is used in many areas of clinical research. Areas of application include on the one hand cognitive functions of the brain such as B. attention , acoustic perception , memory or the basics of decision-making and emotional processes . The method is also recommended to examine malfunctions of the brain, for example in schizophrenia , ADHD or as a result of the influence of drugs .
SST is also used to research various communication phenomena. The focus is on neuromarketing and neural market research, where SST is used in studies of advertising impact research. The procedure offers the possibility of illuminating advertising material and its placement in detail and can help explain changes in purchasing behavior .

Individual evidence

  1. ↑ a b c R. B. Silberstein, MA Schier, A. Pipingas, J. Ciorciari, SR Wood, DG Simpson: Steady state visually evoked potential topography associated with a visual vigilance task. In: Brain Topography. 3, 1990, pp. 337-347.
  2. ↑ a b c R. B. Silberstein: Steady state visually evoked potentials, brain resonances and cognitive processes. In: PL Nunez: Neocortical dynamics and human EEG rhythms . Oxford University Press. New York 1995, pp. 272-303.
  3. ↑ a b R. B. Silberstein, MA Farrow, F. Levy, A. Pipingas, DA Hay, FC Jarman: Functional brain electrical; activity mapping in boys with attention deficit hyperactivity disorder. In: Archives of General Psychiatry . 55, 1998, pp. 1105-1112.
  4. ^ D. Regan: Human Brain Electrophysiology: Evoked Potentials and Evoked Magnetic Fields in Science and Medicine. Elsevier, New York 1989.
  5. ↑ F. Vialatte, M. Maurice, J. Dauwels, A. Cichocki: Steady-state visually evoked potentials: Focus on essential paradigms and future perspectives. In: Prog. Neurobiol. 90, 2010, pp. 418-438.
  6. ^ A b R. B. Silberstein, P. Line, A. Pipingas, D. Copolov, P. Harris: Steady-state visually evoked potential topography during the continuous performance task in normal controls and schizophrenia. In: Clinical Neurophysiology. 111, 2000, pp. 850-857.
  7. ^ M. Gray, AH Kemp, RB Silberstein, PJ Nathan: Cortical neurophysiology of anticipatory anxiety: an investigation utilizing steady state probe topography (SSPT). In: Neuroimage. 20, 2003, pp. 975-986.
  8. ^ G. Nield, RB Silberstein, A. Pipingas, DG Simpson, G. Burkitt: Effects of visual vigilance task on gamma and alpha frequency range steady state potential (SSVEP) topography. In: Y. Koga, K. Nagata, H. Hirata (Eds.): Brain Topography Today. Elsevier Science, 1998, pp. 189-194.
  9. ^ PG Harris, RB Silberstein, GE Nield, A. Pipingas: Frontal lobe contributions to perception of rhythmic group structure. An EEG investigation. In: Annals of the New York Academy of Sciences. 930, 2001, pp. 414-417.
  10. ^ RB Silberstein, PL Nunez, A. Pipingas, P. Harris, F. Danieli: Steady state visually evoked potential (SSVEP) topography in a graded working memory task. In: International Journal of Psychophysiology. 42, 2001, pp. 125-138.
  11. ^ KA Ellis, RB Silberstein, PJ Nathan: Exploring the temporal dynamics of the spatial working memory n-back task using steady state visual evoked potentials (SSVEP). In: Neuroimage. 31, 2006, pp. 1741-1751.
  12. ^ RB Silberstein, PG Harris, GA Nield, A. Pipingas: Frontal steady-state potential changes predict long term recognition memory performance. In: International Journal of Psychophysiology . 39, 2000, pp. 79-85.
  13. ↑ H. Macpherson, A. Pipingas, RB Silberstein: A steady state visually evoked potential investigation of memory and aging In: Brain and Cognition. 69, 2009, pp. 571-579.
  14. ↑ RB Silberstein, J. Ciorciari, A. Pipingas: steady-state visually evoked potential topography during the Wisconsin card sorting test. EEG and Clin. In: Neurophysiol. 96, 1995, pp. 24-35.
  15. ↑ AH Kemp, MA Gray, P. Eide, RB Silberstein, PJ Nathan: Steady-state visually evoked potential topography during processing of emotional valence in healthy subjects In: Neuroimage. 17, 2002, pp. 1684-1692.
  16. ↑ A. Kemp, M. Gray, RB Silberstein, PJ Nathan: Augmentation of serotonin enhances pleasant and suppresses unpleasant electrophysiological responses to visual emotional stimuli. In: Neuroimage. 22, 2004, pp. 1084-1096.
  17. ^ P. Line, RB Silberstein, JJ Wright, D. Copolov: Steady State Visually Evoked Potential Correlates of Auditory Hallucinations in Schizophrenia. In: Neuroimage. 8, 1998, pp. 370-376.
  18. ^ J. Thompson, C. Stough, K. Tzambazis, K. Nagata, RB Silberstein: The effects of nicotine on the 13Hz steady-state visually evoked potential. In: Clinical Neurophysiology. 111, 2000, pp. 1589-1595.
  19. ^ JR Rossiter, RB Silberstein, PG Harris, G. Nield: Brain-imaging detection of visual scene encoding in long-term memory for TV commercials. In: Journal of Advertising Research. 41, 2001, pp. 13-21.
  20. ↑ a b R. B. Silberstein, GE Nield: Brain activity correlates of consumer brand choice shift associated with television advertising. In: Int. Journal of Advertising. 27, 2008, pp. 359-380.