Editing Perception (section)

=== Vision ===
{{main|Visual perception}}
[[File:Cerebrum lobes.png|thumb|400px|Cerebrum lobes]]
In many ways, vision is the primary human sense. Light is taken in through each eye and focused in a way which sorts it on the retina according to direction of origin. A dense surface of photosensitive cells, including rods, cones, and [[intrinsically photosensitive retinal ganglion cells]] captures information about the intensity, color, and position of incoming light. Some processing of texture and movement occurs within the neurons on the retina before the information is sent to the brain. In total, about 15 differing types of information are then forwarded to the brain proper via the optic nerve.<ref>{{cite journal|last1=Gollisch|first1=Tim|last2=Meister|first2=Markus|date=28 January 2010|title=Eye Smarter than Scientists Believed: Neural Computations in Circuits of the Retina|journal=Neuron|volume=65|issue=2|pages=150–164|doi=10.1016/j.neuron.2009.12.009|pmc=3717333|pmid=20152123}}</ref>

The timing of perception of a visual event, at points along the visual circuit, have been measured. A sudden alteration of light at a spot in the environment first alters photoreceptor cells in the [[retina]], which send a signal to the [[retina bipolar cell]] layer which, in turn, can activate a retinal ganglion neuron cell. A retinal ganglion cell is a bridging neuron that connects visual retinal input to the visual processing centers within the central nervous system.<ref name="pmid34093409">{{cite journal |vauthors=Kim US, Mahroo OA, Mollon JD, Yu-Wai-Man P |title=Retinal Ganglion Cells-Diversity of Cell Types and Clinical Relevance |journal=Front Neurol |volume=12 |pages=661938 |date=2021 |pmid=34093409 |pmc=8175861 |doi=10.3389/fneur.2021.661938 |doi-access=free }}</ref> Light-altered neuron activation occurs within about 5–20 milliseconds in a rabbit retinal ganglion,<ref name="pmid9144251">{{cite journal |vauthors=Berry MJ, Warland DK, Meister M |title=The structure and precision of retinal spike trains |journal=Proc Natl Acad Sci U S A |volume=94 |issue=10 |pages=5411–6 |date=May 1997 |pmid=9144251 |pmc=24692 |doi=10.1073/pnas.94.10.5411 |bibcode=1997PNAS...94.5411B |doi-access=free }}</ref> although in a mouse retinal ganglion cell the initial spike takes between 40 and 240 milliseconds before the initial activation.<ref name="pmid31641196">{{cite journal |vauthors=Tengölics ÁJ, Szarka G, Ganczer A, Szabó-Meleg E, Nyitrai M, Kovács-Öller T, Völgyi B |title=Response Latency Tuning by Retinal Circuits Modulates Signal Efficiency |journal=Sci Rep |volume=9 |issue=1 |pages=15110 |date=October 2019 |pmid=31641196 |pmc=6806000 |doi=10.1038/s41598-019-51756-y |bibcode=2019NatSR...915110T}}</ref> The initial activation can be detected by an [[action potential]] spike, a sudden spike in neuron membrane electric voltage.

A perceptual visual event measured in humans was the presentation to individuals of an anomalous word. If these individuals are shown a sentence, presented as a sequence of single words on a computer screen, with a puzzling word out of place in the sequence, the perception of the puzzling word can register on an electroencephalogram (EEG). In an experiment, human readers wore an elastic cap with 64 embedded electrodes distributed over their scalp surface.<ref name="pmid23515395">{{cite journal |vauthors=Kim AE, Gilley PM |title=Neural mechanisms of rapid sensitivity to syntactic anomaly |journal=Front Psychol |volume=4 |pages=45 |date=2013 |pmid=23515395 |pmc=3600774 |doi=10.3389/fpsyg.2013.00045 |doi-access=free }}</ref> Within 230 milliseconds of encountering the anomalous word, the human readers generated an event-related electrical potential alteration of their EEG at the left occipital-temporal channel, over the left occipital lobe and temporal lobe.