An important vector in our temporal aperture model is scintillation. Our metaphorical model is once again the antenna and electromagnetic wave ("radio wave") propagation.
As one watches DishNetwork TV programs or drives along in the car enjoying a local FM station, one is generally unaware that the receivers are coping with wide swings in signal strength as they work to capture and present your favorite programs. Within design limits the antenna aperture and the receiver's detection aperture do a great job of gathering and integrating the rapid signal variations so as to give the illusion of smooth continuous noise free pictures and sound. If one viewed with a linear receiving system and an instantaneous sensitive signal strength measurement device, one would observe continuous wild signal quality variations. As long as these variations and degradations lie above the receiver's sensitivity and detection thresholds, then the picture and sound presentation remains perfect. Indeed, if one looks at the incoming signal closely enough one would see only a ostensibly random bunch of waves oscillating at a very high rate. These fine electromagnetic scintillations are captured, detected, and finally integrated in the typical receiving equipment.
To get closer to the human mind, consider speech. A wildly variant stream of air pressure pulses - scintillations if looked at very closely with a microphone and oscilloscope - is captured, detected, and integrated by the mind to derive a transmitted meaning. The process typically seems easy and smooth as long as the scintillating pressure pulses collectively are above a threshold of both physical pressure (hearing) and the mind's integrated interpretation abilities (understanding).
The entire body and mind encompasses an enormous array of neurons and neuron structures all of whose intercellular communication is scintillation - a broad dynamic stream of binary on-off switching that is ultimately integrated to form the our convenient illusion of smooth existence. In the case of speech again there are conversion nodes where one scintillation form - the rapid air pressure variations - become an internal neuron scintillation stream, such as at the ear.
Like the radio, a human mind is continuously capturing and detecting streams of many sensual, perceptual, and conceptual types. The mind continuously integrates these within models or constructs to give the illusion of a smooth continuous day-to-day existence. This is convenient and so handy, but the situation has drawbacks in that these models depend on expected inputs just like the physical radio does. Qualitatively and quantitatively the expectation and taking for granted of particular inputs engenders an unfortunate psychological habituation that filters out unexpected or, if you will, undesired inputs. Regrettably, it is this common every day modeling scenario that limits the ultimate extent of any given person's temporal aperture.
The antenna and receiver are defined purpose single purpose devices. The human consciousness shares the essential capture and detection model but in an infinitely more complex scenario. If we consider the potential of such activities beyond the every day 3 dimensional world, then things really become interesting.
All sensation, perception, conceptualization as well as all knowledge and energy present as scintillations with rapid variation in quality and quantity. Our reality comprises a dynamic integration of all those scintillations into expected models. Temporal aperture expansion inevitably involves the shakedown of those primitive models so that nuances - scintillations - can be cognized. Contemplation exercises such as kōans can be used to at least temporarily disable habitual mental cognization constructs.
Once we understand the idea of scintillation in this context, we can take a glance at transcendental implications. By analogy, it can be foreseen that psi events (ESP, spiritual enlightenment, etc.) are scintillating inputs that lie underneath or otherwise beyond the capture and detection threshold of the mind. Or as discussed later, they may go undetected simply for lack of a "key" - analogous to the encryption key typed in to make a computer work on a home wireless network. The home network connection is invisible to the computer until that key is entered. Whatever the situation the exotic scintillated inputs cannot be cognized - most of the time. However, everyone alive can accurately claim having had occasional fleeting ESP or clairvoyant experiences for example. These may be statistical input burst events that temporarily come within our mind's detection, i.e., cognition, systems. Those quick intuitions, brilliant insights, ESP events capture our psychological receivers in the same way that a distant radio station may play in full stereo strength due to an atmospheric perturbation for some period and then never be heard again.
Inspired by this analogical model, we can see that temporal aperture expansion, particularly to more ephemeral or transcendent levels, compels development of a mindset that can cognize barely detectable - fleeting - inputs among the vast noises of daily existence. A first major step lies in realizing that the everyday models we construct and share to give the comfortable illusion of smooth continuity to our collective existence are a primary hindrance to temporal aperture growth- a veritable consciousness jail from wish some persons will choose to escape. Our every-day integration models lend the illusion of stability at the cost of being perpetually incomplete.