PMID- 16504094
OWN - NLM
STAT- MEDLINE
DCOM- 20060711
LR  - 20181113
IS  - 1471-2202 (Electronic)
IS  - 1471-2202 (Linking)
VI  - 7
DP  - 2006 Feb 23
TI  - Human sensory-evoked responses differ coincident with either "fusion-memory" or 
      "flash-memory", as shown by stimulus repetition-rate effects.
PG  - 18
AB  - BACKGROUND: A new method has been used to obtain human sensory evoked-responses 
      whose time-domain waveforms have been undetectable by previous methods. These 
      newly discovered evoked-responses have durations that exceed the time between the 
      stimuli in a continuous stream, thus causing an overlap which, up to now, has 
      prevented their detection. We have named them "A-waves", and added a prefix to 
      show the sensory system from which the responses were obtained (visA-waves, 
      audA-waves, somA-waves). RESULTS: When A-waves were studied as a function of 
      stimulus repetition-rate, it was found that there were systematic differences in 
      waveshape at repetition-rates above and below the psychophysical region in which 
      the sensation of individual stimuli fuse into a continuity. The fusion phenomena 
      is sometimes measured by a "Critical Fusion Frequency", but for this research we 
      can only identify a frequency-region [which we call the STZ (Sensation-Transition 
      Zone)]. Thus, the A-waves above the STZ differed from those below the STZ, as did 
      the sensations. Study of the psychophysical differences in auditory and visual 
      stimuli, as shown in this paper, suggest that different stimulus features are 
      detected, and remembered, at stimulation rates above and below STZ. CONCLUSION: 
      The results motivate us to speculate that: 1) Stimulus repetition-rates above the 
      STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ 
      show neuronal processing in which "flash-memory" occurs. 2) These two memories 
      differ in both duration and mechanism, though they may occur in the same cell 
      groups. 3) The differences in neuronal processing may be related to "figure" and 
      "ground" differentiation. We conclude that A-waves provide a novel measure of 
      neural processes that can be detected on the human scalp, and speculate that they 
      may extend clinical applications of evoked response recordings. If A-waves also 
      occur in animals, it is likely that A-waves will provide new methods for 
      comparison of activity of neuronal populations and single cells.
FAU - Jewett, Don L
AU  - Jewett DL
AD  - Abratech Corporation, Sausalito, CA, USA. don.jewett@ucsf.edu
FAU - Hart, Toryalai
AU  - Hart T
FAU - Larson-Prior, Linda J
AU  - Larson-Prior LJ
FAU - Baird, Bill
AU  - Baird B
FAU - Olson, Marram
AU  - Olson M
FAU - Trumpis, Michael
AU  - Trumpis M
FAU - Makayed, Katherine
AU  - Makayed K
FAU - Bavafa, Payam
AU  - Bavafa P
LA  - eng
GR  - MH054922/MH/NIMH NIH HHS/United States
GR  - NS36880/NS/NINDS NIH HHS/United States
GR  - RR014002/RR/NCRR NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20060223
PL  - England
TA  - BMC Neurosci
JT  - BMC neuroscience
JID - 100966986
SB  - IM
MH  - Acoustic Stimulation/methods
MH  - Adolescent
MH  - Adult
MH  - Aged
MH  - Electric Stimulation/methods
MH  - *Evoked Potentials, Auditory
MH  - Evoked Potentials, Auditory, Brain Stem
MH  - *Evoked Potentials, Somatosensory
MH  - *Evoked Potentials, Visual
MH  - Female
MH  - Humans
MH  - Male
MH  - *Memory
MH  - Middle Aged
MH  - Models, Psychological
MH  - Photic Stimulation/methods
MH  - Psychophysics
MH  - Time Factors
PMC - PMC1483834
EDAT- 2006/03/01 09:00
MHDA- 2006/07/13 09:00
PMCR- 2006/02/23
CRDT- 2006/03/01 09:00
PHST- 2005/09/05 00:00 [received]
PHST- 2006/02/23 00:00 [accepted]
PHST- 2006/03/01 09:00 [pubmed]
PHST- 2006/07/13 09:00 [medline]
PHST- 2006/03/01 09:00 [entrez]
PHST- 2006/02/23 00:00 [pmc-release]
AID - 1471-2202-7-18 [pii]
AID - 10.1186/1471-2202-7-18 [doi]
PST - epublish
SO  - BMC Neurosci. 2006 Feb 23;7:18. doi: 10.1186/1471-2202-7-18.