“The view that perception starts with a stimulus impinging upon a sensory 
organ “is totally wrong,” he says. “If it starts anywhere, it starts with 
the motor movement and not with the sensory reception.” - 
—­Ehud Ahissar, Weizmann Institute of Science, 

I think that his experiments support my view that sense isn’t a passive 
receptivity to collisions, it is participation.  Perception is no less than 
the experienced entanglement of the perceiver and the perceived. Sense is 
not a local model or simulation. Sense is physics itself.



> While it’s generally easy for humans to describe the color of an object or 
> the feel of a fabric, neurobiologists have struggled to articulate the 
> psychophysical mechanics of perception. Movement is nearly always part of 
> sensing the world around us—we scan a room with our eyes or step back from 
> a painting to get a different perspective; we tilt our heads to sniff; we 
> lean in for a better listen; we stroke our babies’ heads to learn their 
> contours. A central question, however, has been whether these physical 
> movements are influenced by what they perceive. In other words, does 
> perception shape our information-seeking activity or do we rely on 
> predetermined data-gathering motions? 
> In vision, at least on a superficial level, it appears obvious that the 
> movement of the eyes and the images they perceive can have an effect on one 
> another. Michele Rucci, the director of the Active Perception Laboratory at 
> Boston University, offers this example: when you walk into a room, you 
> select the location you want to examine based on the visual information 
> you’ve gathered—your perception altered your behavior, and in response, 
> “this behavior is now instructing vision,” he says.
>  If [perception] starts anywhere, it starts with the motor movement and 
> not with the sensory reception.—­Ehud Ahissar, Weizmann Institute of 
> Science,
> Rehovot, Israel
>  “For touch, the assumption is that the processes leading to perception 
> are only sensory processes,” says Ehud Ahissar, a professor at the Weizmann 
> Institute of Science in Rehovot, Israel. That is, sensations of touch 
> don’t, according to the conventional wisdom, feed back and influence our 
> motor movements that are involved in gathering tactile information. But 
> there isn’t much evidence to back up this assumption. Ahissar and his 
> colleagues designed a simple 
> experiment<http://www.the-scientist.com/?articles.view/articleNo/34225/title/Testing-for-Whisker-Sense/>to
>  test whether motor movements are influenced by what the body feels: they 
> equipped humans with whisker-like appendages. The “whiskers” were attached 
> to the fingertips of eight adults who were blindfolded and earplugged. 
> Ahissar’s group asked the subjects to determine which of two nearby poles 
> was closer.
> The researchers found that all the participants chose the same strategy, 
> says Ahissar: “They tried to keep their hands as coordinated as possible 
> and use a temporal cue to judge [distance].” The people would move both 
> hands at the same time, and the first hand to touch a pole with its whisker 
> indicated that that pole was closer. In repeated trials, the difference 
> between the poles’ distances was gradually shrunk to measure each subject’s 
> tactile acuity.
> On a subsequent day, the subjects got better at judging the poles’ 
> distances—not in how quickly they responded, but in their acuity. Whereas 
> on day 1 they could accurately pick out the closer pole if the distances 
> were set apart by about 8 cm, on day 2 they could feel a difference between 
> the placement of the poles separated by only a little more than 3 cm. It 
> turned out that the improvement in acuity was due to a change in behavior: 
> the subjects had slowed down their hand movements as the task became more 
> difficult, lengthening the delay between contact with the closer and more 
> distant poles and thus enabling them to perceive a smaller spatial 
> difference. The experience of previous trials had enabled them to refine 
> their strategy.
> “It does suggest that active movement is crucial in the way we integrate 
> sensory information,” says Hillel Chiel, a professor at Case Western 
> Reserve University, who was not part of the study. Chiel says he’s not 
> surprised by the results, but is gratified to see them come out of a 
> controlled experiment. “The reality is, any organism that depends on a 
> sense almost always uses active movement to sense,” he says. Take, for 
> instance, a bloodhound, which moves its nose—if not its whole body—around a 
> scent, or an owl that turns its head to hear.
> Ahissar says he can imagine ways in which the whisker-based sense, adopted 
> so quickly by the humans in the experiments, might be helpful to people 
> with visual impairments. Sensory substitution devices convert images to 
> tactile sensations, allowing blind people to feel what others can see. But 
> Ahissar says these devices have often relied on the assumption that moving 
> the body would not enhance perception, and are designed so that the user 
> just passively receives the information from the machine. If, instead, 
> visually impaired people could engage their motor movements with the 
> tactile stimulation, perhaps they could learn faster, and it would be a 
> richer and more user-friendly experience.
> To develop such a device would take some technical ingenuity (“it’s now a 
> little bit of a fantasy,” says Ahissar) and an understanding that movement 
> is just as important in perception as is sensation itself. The view that 
> perception starts with a stimulus impinging upon a sensory organ “is 
> totally wrong,” he says. “If it starts anywhere, it starts with the motor 
> movement and not with the sensory reception.”

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