ASSOCIATION FOR EDUCATION AND
REHABILITATION OF THE BLIND AND VISUALLY IMPAIRED
AER Report Vol. 26, No. 1,
A Perception Basis for Cane
By Daniel Kish, M.A., M.A.,
Perception lies at the center
of our ability to manage ourselves in the world. Other processes, such as
comprehension, psychology, and mutual social engagement, are critical, but
information supports the development and utility of all other neural mechanisms
underlying self management. Without information about the world, what is there
to comprehend, who is there to engage socially and by what means, and with whom
and how do we relate psychologically? We establish and execute intent by
drawing meaning from what our senses register. The more information we can
access, the more adaptive and more varied is our interaction with the world.
Accordingly, humans have
developed integrated, adaptive brain function that anticipates information
through the perceptual process in two principal modes relative to movement - referencing
and preview. Referencing refers to recognizing and discriminating elements
around us which allows us to set a physical goal toward which movement can be
directed, and to maintain orientation with respect to surrounding elements. Preview
refers to awareness of elements and their layout in advance of our position.
This allows us to direct our course efficiently, safely, and gracefully. Both
these modes of gathering information can be divided into near, intermediate, and
We use this information about
what lies ahead and around us to govern interaction. Without this information,
the purposeful flow of movement is disrupted. We struggle to apply other
processes to interact with the environment in a manner that is adaptive and
mutually meaningful to self and others. Broadly speaking, this usually disrupts
the development of grace and confidence to manage ourselves toward achievement.
Tactual Perceptual Extension
Although vision seems to be
the default for gathering this information, the latest in neural research
suggests that, when vision is disrupted, the brain still anticipates and seeks
this information. The mechanisms involved in self management can restore
functioning by restoring these modes of information access despite vision loss.
For both the blind and sighted brain, it is necessary to foster the brain’s
capacity to utilize referencing and preview in order to maintain self
management capacity. For sighted people, this happens relatively naturally in
sighted society. As visual functioning drops, tactual/kinesthetic and auditory
channels must be more intensively applied to restore these modes of information
access. (See “FlashSonar: the next step in
echolocation instruction” for a discussion about audition.) Here, we discuss
tactual/kinesthetic means of restoring near point access through a conductive, haptic, perceptual extension - the long cane.
My long experience as both
cane user and teacher with a background in perception has brought me to regard
the cane, not so much as a tool for probing or shielding, but as an integrated
extension of perception. It should access information naturally to allow an
unconscious flow of movement without conscious need to draw upon or apply a
matrix of skills or techniques. We hardly think about using our hands to read Braille
or put on our clothes, or our eyes to walk or catch a ball. Likewise, the cane
should integrate seamlessly into the perceptual process. I believe the brain
expects this. For this to happen, application of the cane should be fostered in
much the same way that the application of other senses is fostered, through a
developmental process of supported discovery. To facilitate this, we should
look at the characteristics of the cane that most allow it to tap into and
engage perceptual access according to what is native to the nervous system.
Knowing that the nervous system expects to reference and preview, what characteristics
of the cane best facilitate this?
A combination of
biomechanical and perceptual approaches is prudent, since the biomechanics of
our bodies is governed by how we process what we perceive. Modern knowledge of human
perception, neurology, and biomechanics across the lifespan were not available
to the fathers of the long cane. Consequently, the traditional approach to determining
cane length was rooted in the biomechanics of adults with little awareness of
perception or the biomechanics of children. There is now much known in these
areas, but little that pertains to taction guided
movement. So, I combine this knowledge with professional and personal
experience to provide a starting point to address these issues.
Observations and Reflections
My own cane training around
age 12 occurred pretty much according to traditional precepts, which included
mid sternum length. My cane skills were considered exemplary by traditional standards,
and I found no reason to question this approach.
During my thesis project in
my mid-20s, for which I worked with 24 totally blind children, a long time
instructor was orienting several of these students to their middle school campus.
He quickly replaced their canes of sternum length with forehead length,
explaining that increasing the length by about 6 inches generally helped
remediate poor cane skills very quickly. I was politely skeptical.
Later, when my cane broke, an
acquaintance convinced me to try a nose length replacement. I politely agreed.
I hated it at first, because it felt heavy and awkward while my perceptual system
tuned to the extended length, much like someone with new glasses. After a few
days, I found that my travel took on a greater ease and comfort of rhythm, even
faster speed, and fewer unpleasant physical encounters. After some adjustments,
I found that chin length seemed to work best for me.
As I began instructing, I
noticed preschoolers often preferred to use my cane, taking it in both hands
and holding it before them with confident daring. While I conducted most of
their instruction with canes of more manageable length, I noted that the
increased length did seem to facilitate their understanding of the cane’s
purpose, as well as a natural comfort in using it. I never found the need for
One day, a Mexican family
came to me with their 6 year old, non-English speaking son who had refused the
cane despite their insistence. While we spoke, he discovered my cane and began
walking around my office with it. Cautioning his parents not to stop him, I allowed
him to do what should come naturally to children — discover. In short order he
made his way out the door, striding quickly along the walkway with relaxed
poise. His parents were dumbfounded as we hurried along behind him, insisting
they’d never seen him do this. Upon approaching the sounds of children playing,
he happily explored the playground with this very long cane.
On a more recent occasion, it
was brought to my attention that an older gentleman was walking with a
shuffling gait and slightly stooped posture. I handed him my cane. Immediately his
speed increased and his posture straightened. Though he and I had talked about
many things, he couldn’t thank me enough for this one simple suggestion.
Not only are my own
experiences replete with similar examples, but I hear them commonly from
others. One woman recently declared that she’d struggled with one deafblind and one autistic child. Their canes were used for
anything but perception. After providing longer canes to them, she reported that
their cane skills revolutionized in a few days.
After working with nearly one
thousand students of nearly every type and background, I believe that the
reflex to reach physically into the environment is nearly as innate as hand to mouth.
Early man, unable to conjure artificial light, probably used sticks naturally
to improve their reach and balance. I also believe that the referencing and
preview systems are expecting to access near point information at a certain
distance. If this requirement isn’t met, these systems may not be triggered to
engage properly. For now, I can only guess at this magic number, but experience
suggests that sternum length seems to undercut this number for most students,
Children have the same
referencing and preview needs as adults for ambulation. Yet, their
biomechanical properties are not the same with respect to cane use. Due to
their small size, measuring cane length to the sternum may afford half the referencing
and preview capacity as for adults. Though children take shorter strides, their
strides are much more frequent and hurried, keeping their walking speed close
to that of adults.
I have consistently found
that children up to about 6 are most engaged by canes their own height. After 7
or so, it often seems helpful to reduce cane length to about the nose. As they
pass through puberty, about chin length seems optimal.
Obviously, many factors may
influence the student’s decision. What may be natural for the brain will vary
between people and circumstances. Cane weight, length, style of use, environment,
and student physiology must all be balanced.
Here are a few points:
• Heavier cane construction,
especially those with heavy tips may cause a longer cane to feel quite
cumbersome. In general, I recommend canes of lighter construction and smaller
• Longer canes can become
awkward in congested environments. Congested technique usually resolves this,
and I find children accommodate this quite well.
• Concerns are sometimes
raised about the cane getting in people’s way. At the risk of sounding
militant, who’s getting in whose way?
I regard perception as a
sovereign right, not to be infringed upon because it may seem inconvenient. I
have found that blind people and their sighted peers, children and adults
alike, learn to accommodate the longer cane when it is respectfully regarded as
a part of natural function. Blind students learn to consider the presence of
their cane with respect to others, and sighted people learn to respect that
presence. If these concerns persist in a given setting, some education provided
to peers should resolve the matter.