Switch to english language  Passa alla lingua italiana  
Random quote

The Autism Paradox; Stimulus Seeking/Stimulus Avoidance

November 22nd, 2011 by Robert DePaolo | Posted in Psychology | No Comments » | 420 views | Send article | Print this Article |

By Robert DePaolo


This article discusses an apparent contradiction in the sensory behaviors of autistic children, specifically their tendency to both avoid input and seek it out. An explanation is put forth that this apparent conflict can help explain the nature of autism as well as future prospects for treatment.

Most autistic individuals have significant language deficits and as a result can’t tell us very much about their “take” on experience, their awareness of having a developmental disorder, the ways in which they cope or their views of the outside world. While some people diagnosed with autism have written books and given speeches (the so-called high functioning group), their accounts might be less than definitive. That is not necessarily because they have been misdiagnosed but because by definition their involvement is mild. Otherwise they could not integrate and/or conceptualize their world enough to write and talk about their experiences in the first place.

The presumption that high-functioning autistic persons can tell us something about the experiences of more severely impaired clients (one that permeates autistic research) presents a significant problem with respect to gaining a true understanding of the disorder. Since high-functioning autistic persons can communicate, label objects and experiences, compartmentalize and express emotion through words rather than motion that would, if for no other reason than that they expend far less energy in adapting to their environment, distinguish them from their less verbal and nonverbal counterparts.

To understand the experiences of the classically autistic person can only resort to observations of nonverbal behavior in drawing inferences about the functions of brain and body. One of the more fascinating as well as diagnostically indicative features of non-verbal, autistic persons is the way in which they deal with sensory input. There is a plethora of research devoted to this topic. For example Rosenhall, Johannson et. al. (1988), Scharre, Creedon et. al. (1992) and Takarae, Minshew, (2004) and Belmonte, M (2000) have shown that autistics have a delayed reaction to input which interferes their timing with regard to responsiveness, memory consolidation and social interaction. Dawson (1989) has shown that this delay in processing creates problems with arousal levels such that the autistic individual often feels overwhelmed, unable to make sense of sensory inputs (unless the patterns are over-learned) and therefore learns to be generally stimulus avoidant. Notwithstanding research findings most of the above trends can be discerned through simple observation. In fact observation and inference are in some instances the most accurate ways to determine cause-effect patterns in autistic development.

Talents in Camouflage

Many so-called non verbal autistic individuals actually have language, but it is too dyspraxic, atonal and detached from the interactive rhythm to be understood. For example it is not uncommon for an autistic individual to be asked a question, then duck his head, gather himself, flap his hands, and moments later issue a fuzzy language response under his breath. Because language entails multiple use of faculties, including oral motor, acoustic, cognitive, auditory and cadence, and because the autistic person is unable to “package” multiple faculties into a focal response– due most likely to highly sequestered brain neural columns (Casanova & Buxhoeveden, 2002) the minimally verbal autistic has to economize in his language responses. That often leaves the impression that he can’t speak

Also since delayed processing precludes spontaneous processing and responsiveness he will take longer to respond. Since he cannot effectively weave together the integrative motor, auditory, rhythmic and cognitive components of language he has to engage in a bit of language economizing.

The result is often oblique language. For example the words might be accurate but the tone will be subdued. Or perhaps the tone and the words will be accurate while cognition is sacrificed, in which case an echolalic pattern of speech might emerge. In still other instances a Herculean attempt so integrate all language components can result in exhaustive faculty-gathering and temporarily appropriate speech, followed by fatigue-induced “burn-out” typified by repetitive non contextual statements (DePaolo, 2011)Such a ‘rob from Peter to pay Paul”, compartmental response style probably influences other types of behavior as well, such that all perceptions and behaviors are similarly parsed.

On one hand that suggests a dramatic functional deficit. Yet the fact that the autistic individual is inclined to make this type of adjustment suggests he is aware of the parameters of his syndrome. That in turn suggests that, despite cognitive and language deficits, he is much more intelligent than many of us might assume. (In fact it might not be outrageous to suppose that on a test measuring functional self awareness (not… “who I am” but “what I can and cannot do”), the autistic individual might score higher than the aging athlete who plays beyond his years, the middle aged woman who dresses provocatively to compensate for diminishing sex appeal, or the politician who runs for office without a clue as to the issues before him.

Input Approach and Avoidance

The way in which autistic individuals process input is particularly interesting in light of the above presumptions. For somewhat mysterious reasons they will alternately avoid and seek out or induce stimulation. They seem to abhor loud noises (particularly the choppy, fragmented topography of human language, with its discontinuous, stop and start sequences). On the other hand in extremely quiet conditions an autistic child will try to up the stimulus ante; prompting others to act by creating a problem for them to “fix” – thereby forcing them to provide input through their corrective actions. Or, if that doesn’t work, they might provide their own stimulation through noise making, paper ripping, compulsive engagement in tasks or hyperactivity. All of which seem to suggest They are averse to both high stimulus and low stimulus conditions.

If it were simply a question of finding a stimulus middle ground then educators might be able to develop an optimal sensory milieu – as discussed in the Son Rise program – perhaps featuring some pre-determined sound level, or light intensity that could facilitate the exploratory, information seeking behaviors (i.e curiosity) that typifies normal children.

Unfortunately that might be impossible to do. Autistics do not readily habituate to sensory inputs, or selectively attend in general (Remington, Swettenham et. al. 2009). That might be due in part to lack of memory access resulting from a vertically dominant arrangement of neurons in their brain, and lack of horizontal, integrative connections that provide multi-access in the normal brain. It might also have something to do with cerebellar hypoplasia (cellular immaturity in the cerebellum, a hindbrain structure that provides automaticity and allows one to take certain skills and movements for granted – thus making new learning, closure, anxiety control and new, cumulative learning possible (Courchesne, Yeung-Courchesne et. al. 1988).

The question of why autistic persons are both stimulus avoidant and stimulus hungry is not easy to answer. Obviously all brains need input and it would be inconceivable that any brain in nature – let alone the ravenous human brain – could accommodate a stimulus vacuum for any length of time. However, autistic persons don’t require a stimulus vacuum to seek stimulation. They do so in a variety of circumstances.
Perhaps this question can be addressed – if not totally answered – by looking at the regulatory functions of the brain through the prism of physical laws.

This writer has previously written about something called a “shield” mechanism in the central nervous system. This is a metaphor used to describe an energy-based prerequisite for learning and it can be explained via the following experiment.

Inputs, Shields and Stability

Place two beacons side by side. Place a small rubber tube through a small hole in each beacon. Leave one beacon empty and fill the other to the brim. Within a few moments the water from the filled beacon will begin to flow rapidly into the empty beacon. That is because energy moves toward a vacuum as per the second law of thermodynamics. The empty beacon – now assaulted by input/flow will become highly unstable and will exhibit a low level of self regulation. It is virtually at the whim amd mercy of input flow. By way of analogy, It has no systemic anchor point – no sense of “self.”

Next, half-fill both beacons. In this instance the flow of water will be much slower. The interaction between the two beacons as well as the movement and dynamics within each beacon will be more stable – perhaps too stable. At that point the beacons can be said to have a greater capacity for internal regulation but since outside stimuli no longer has much of an impact, few if any changes in either beacon will occur. In that case there is not enough tension for change or stimulus resolution to ensue.

Now comes the final stage of the experiment. Fill one beacon to three quarters and the other to one quarter. The flow will now increase. The flow will be faster and more impactful than the half to half beacon relationship but slower than in the full to empty relationship. In this instance, there is a degree of internal regulation but it is incomplete and only semi-stable. Ironically that semi-stability is what renders it capable of learning (a concept implied in Piaget’s notion of disequilibrium and assimilation). Some flow will occur but not enough to overwhelm the receptor beacon. The net effect of this skewed stability would be to allow for both stability and change – precisely the dual mechanisms needed to process memory and make sense out of one’s environment. To personify a bit, differentially filled or “permeably shielded” information/energy units are well suited to compute two very important bits of data; the state of the outside world and the state of the inside world.

Absent that rather precise information/energy ratio learning and self awareness – alternately referred to as meta-cognition (Flavell, 1979) or a theory of mind (Baron-Cohen, Leslie et. al. 1985) – normal cognition becomes extremely difficult.
As arcane as this might sound, autistic individuals are probably well aware of it, at least on an existential level. Out of necessity they dwell more in the domain of physics and energy-apportionment life than most of us. Thus their muted, occasionally splintered speed patterns and fractionated behavior patterns might belie a capacity for surprisingly informed, strategic maneuvers for purposes of compensating for lack of an adequate shield mechanism.

Since we are proposing that autistics have an extraordinarily functional, if not symbolic sense of self it might be reasonable to assume they are more cognizant of various aspects of their social environment than many of us have assumed. To some this will seem overly optimistic. Yet the proof is in the pudding.

For instance, it is well known that autistics see without directly looking at objects and people – that they can be highly proficient in the use of peripheral vision, often picking up on visual cues that slide right past the normal individual.
It is also well known that autistics have an extraordinary capacity to memorize small details and to react emotionally as though they can predict events from even meager past experience. (Bashoun 2011)

Thus we know that they process and learn many things in oblique fashion, and that in such instances they are clearly using a sensory and/or behavioral economy to respond to circumstances. If they can do that in one response domain it stands to reason they can do it in others – including, as discussed earlier, the language domain,.
Thus one might surmise that their level of awareness is much deeper than has been assumed and that they do engage in thought patterns couched in para-verbal ideas such as… “ I know something is coming up. Some task, some expectation, some aversive or rewarding experience is about to occur and in the absence of a stimulus shield mechanism I must prepare for any and all possibilities through self arousal.”

Doing so prevents overload, the threat of immediacy (especially important for a brain with a penchant for processing delays) and emotional aversion. By creating differential arousal levels needed to modulate between internal state and external input the autistic person is “partially filling the beacon.” It is the only way for him to learn, tolerate and do all those things that normal do with ease.

Internal regulation vis a vis outside input might not be the sole reason for self stimulation – the latter also occurs for purposes of expressing/releasing arousal levels as a neuro-behavioral after-effect) However it appears to be a central functional, purposeful adaptation as well.

In light of the above discussion, it is ironic that autistics are typically described as having little or no capacity for self regulation (Loveland 20050). In fact it could just as easily be stated that they are ingenious when it comes to self regulation; that practice makes perfect and that they must engage in this very activity every moment of the day, every day of their lives.


If one of the core problems in autism is a shield deficiency one might expect resting arousal levels to be atypical. Research has indeed shown that to be the case. (Polleux, 2004). One might also expect energy levels to be low – analogous to the empty beacon that lacks energy and is thus vulnerable to high energy transfers. Research on mitochondrial function tends to support that argument as well (Pons, Andrew et. al. 2004). One might also expect arousal levels to be delayed and disorganized due to the confusion-induced inability to interpret input signals. Research tends to support that assumption, (Hutt, Hutt et. al. 1964),

If any of these assumptions is valid then one might expect certain forms of treatment to be effective with autistic individuals. For example, the shield mechanism can be likened to catecholamine arousal levels. More specifically to the presence and moment to moment maintenance of pleasure chemicals in the brain as input-filtering, preparatory learning facilitators. In that context, the question could be asked as to whether stimulation of the limbic system, specifically pleasure (catecholamine releasing) centers in the septum and hypothalamus might enhance the autistic person’s input/output modulating capacities, bolster the shield mechanism and facilitate more integrative functions. That might obviate to some extent, the need to economize on behaviors and also ameliorate the feelings of aversion and concomitant behaviors that seem pervasive in autism.

One of the more intriguing, indeed agonizing questions arising from this assumption is that medication (which tends to have a mostly generic affect on the brain) might not target precisely enough the exact brain centers needed to create a shield. At that point, parents, educators and clinicians would have to ask if the potential benefits of, say, a computer chip in the brain would outweigh the risk and inhumane connotations of such a procedure, especially since factors other than shield mechanisms appear to be involved in autism.
Physicians often implant pacemakers, artificial hearts and other prosthetic devices but typically only in dire medical circumstances. In less than urgent circumstances such a method could no doubt be called into question. Indeed the use of such methods even in research projects by Delgado and others has been widely criticized. It is not easy to reconcile the ethical, moral and functional elements of such a hypothetical approach. Fortunately this is a question at best far off into the future.


Baron-Cohen, S. Leslie, AM. Frith, U. (1988) Does the Autistic Child Have a Theory of Mind? Cognition 21 (1); 37-46

Bashoun, P. Article in LA Special Education Examiner. Research Emphasizes Autism’s Advantages over Deficits. Retrieved 11/211

Belmonte, MK. (2000) Abnormal Attention in Autism Shown by Steady-State Visual Evoked Potentials. Autism 4; 269-285

Casanova, MF. Buxhoeveden, DP (2002) Minicolumnar Pathology in Autism. Neurology 58; 428-432

Dawson, G. Lewy, A. (1989) Arousal, Attention and the Social-Emotional Impairment of Individuals with Autism. In G Dawson (Ed) Autism; Nature Diagnosis and Treatment. New York, Guilford

DePaolo, R. (2011) Teaching the Autistic Student: A Method Based on Arousal Modulation and Neural Asynchrony. Education Articles

Flavell, JH. (1979) Metacognition and Cognitive Monitoring: A New Area of Cognitive-Developmental Inquiry. American Psychologist 34; 906-911

Hirstein, W. Iversen, P. Ramachandran, US. (2001) Autonomic Response of Autistic Children to People and Objects. Proceedings. Biological Sciences/The Royal Society.

Hutt, C. Hutt, J. Lee, D. Ounstead, C (1964) Arousal and Childhood Autism. Nature, 204; 908-909

Loveland, KA. (2005) Social-Emotional Impairment and Self-Regulation in Autism Spectrum Disorder. Emotional Development Research Advances. 365-382

Polleux, F. Lauder, IM. (2004) Toward a Developmental Neurobiology of Autism. Mental Retardation, Developmental Disabilities Research Review. 10 (4); 303-317

Pons, R. Andrew, AL. Chicarelli, N. Vila, MR. Engelstad, K. Sue, CM. Shunger, D. Haggerty, R. deVivo, DC. & DiMauro, S. (2009) Mitochondrial Disorder and Autism Spectrum Disorder. Journal of Pediatrics 144 (1) 81-85

Press, GA. Hesselink, JR. Jemigan, TL. (1988) Hypoplasia of Cerebellar Vernal Lobules VI and VII in Autism. New England Journal of Medicine. 318; 1349-1354

Remington, A. Swettenham, J. Campbell, R. Coleman, M (2009) Selective Attention and Perceptual Load in Autism Spectrum Disorder. Psychological Science. Vol. 20 (11) 1388-1383

Rosenhall, U. Johannson, E. Gilberg, C. (1988). Oculomotor Findings in Autistic Children. Journal of Laryngology and Otology. 102; 435-439

Scharre, JE. Creedon, MP. (1992) Assessment of Visual Function in Autistic Children. Optometry and Vision Science 69; 433-439

Takarae, Y. Minshew, NJ. Luna, B. Krisky, CM. Sweeney, JA. (2004) Pursuit Eye Movement Deficits in Autism. Brain 127; 2584-2594

PDF Creator    Send article as PDF   

Bookmark and Share

Leave a Reply