Editing Iconic memory (section)

===Visible persistence===
Visible persistence is the phenomenal impression that a visual image remains present after its physical offset.  This can be considered a by-product of neural persistence. Visible persistence is more sensitive to the physical parameters of the stimulus than informational persistence which is reflected in its two key properties.:<ref name="Coltheart">{{cite journal|last=Coltheart|first=Max|year=1980|title=Iconic memory and visible persistence|journal=Perception & Psychophysics|volume=27|issue=3|pages=183–228|doi=10.3758/BF03204258|pmid=6992093 |doi-access=free}}<!--| access-date = 2011-03-08 --></ref> 
#The duration of visible persistence is inversely related to stimulus duration.  This means that the longer the physical stimulus is presented for, the faster the visual image decays in memory.
#The duration of visible persistence is inversely related to stimulus [[luminance]]. When the luminance, or brightness of a stimulus is increased, the duration of visible persistence decreases.<ref name="Dick">{{cite journal|last=Dick|first=A. O.|year=1974|title=Iconic memory and its relation to perceptual processing and other memory mechanisms|journal=Perception & Psychophysics|volume=16|issue=3|pages=575–596|doi=10.3758/BF03198590|doi-access=free}}<!--| access-date = 2011-03-08 --></ref> Due to the involvement of the neural system, visible persistence is highly dependent on the physiology of the photoreceptors and activation of different cell types in the [[visual cortex]].  This visible representation is subject to masking effects whereby the presentation of interfering stimulus during, or immediately after stimulus offset interferes with one's ability to remember the stimulus.<ref name="Long">{{cite journal|last=Long|first=Gerald|year=1980|title=Iconic Memory: A Review and Critique of the Study of Short-Term Visual Storage|journal=Psychological Bulletin|volume=88|issue=3|pages=785–820|doi=10.1037/0033-2909.88.3.785|pmid=7003642}}<!--| access-date = 2011-03-08 --></ref>
Different techniques have been used to attempt to identify the duration of visible persistence.  The '''Duration of Stimulus Technique''' is one in which a probe stimulus (auditory "click") is presented simultaneously with the onset, and on a separate trial, with the offset of a visual display. The difference represents the duration of the visible store which was found to be approximately 100-200 ms.<ref name = "Long"/> Alternatively, the '''Phenomenal Continuity''' and '''Moving Slit Technique''' estimated visible persistence to be 300 ms.<ref>{{cite journal|last=Haber|first=R.|author2=L. Standing|year=1970|title=Direct measures of visual short-term visual storage|journal=Quarterly Journal of Experimental Psychology|volume=21|issue=1|pages=216–229|doi=10.1080/14640746908400193|pmid=5777982|s2cid=23042735 }}<!--| access-date = 2011-03-20 --></ref> In the first paradigm, an image is presented discontinuously with blank periods in between presentations.  If the duration is short enough, the participant will perceive a continuous image.  Similarly, the Moving Slit Technique is also based on the participant observing a continuous image.  Only instead of flashing the entire stimulus on and off, only a very narrow portion or "slit" of the image is displayed.  When the slit is oscillated at the correct speed, a complete image is viewed.

====Neural basis====
Underlying visible persistence is neural persistence of the visual sensory pathway. A prolonged visual representation begins with activation of photoreceptors in the [[retina]].  Although activation in both [[rod cell|rods]] and [[cone cell|cones]] has been found to persist beyond the physical offset of a stimulus, the rod system persists longer than cones.<ref name = "Book">{{cite book | last1 = Irwin | first1 = David | last2 = Thomas | first2 = Laura | title = Visual Memory | chapter = Neural Basis of Sensory Memory |editor1= Steven Luck |editor2=Andrew Hollingworth | publisher = Oxford University Press | year = 2008 | location = New York, New York | pages = 32–35 | isbn = 978-0-19-530548-7}}</ref> Other cells involved in a sustained visible image include M and P [[retinal ganglion cells]]. M cells (transient cells), are active only during stimulus onset and stimulus offset.  P cells (sustained cells), show continuous activity during stimulus onset, duration, and offset.<ref name = "Book"/><ref>{{cite journal | title = Responses of cat retinal ganglion cells to brief flashes of light | journal = Journal of Physiology | year = 1970 | first = W. | last = Levick |author2=J. Zacks | volume = 206 | pages = 677–700| pmid = 5498512 | issue = 3 | pmc = 1348672| doi = 10.1113/jphysiol.1970.sp009037 }}</ref> Cortical persistence of the visual image has been found in the primary visual cortex (V1) in the [[occipital lobe]] which is responsible for processing visual information.<ref name = "Book"/><ref name = "Nikolic">{{cite journal|last=Nikolić|first=Danko |author2=S. Häusler |author3=W. Singer |author4=W. Maass|title=Distributed fading memory for stimulus properties in the primary visual cortex|journal=PLOS Biology|year=2009|volume=7|doi=10.1371/journal.pbio.1000260|editor1-last=Victor|editor1-first=Jonathan D.|issue=12|pages=e1000260|pmid=20027205|pmc=2785877 |doi-access=free }}</ref>