If information overload is not diffused in time, it can result in temporal sensory agnosia – an inability to process touch, sound or visual information.
The consequence of being unable to filter sensory information and being flooded with sensory stimuli at the rate the person cannot cope, is being able to sense (see, hear, etc.), but unable to attach the meaning to (i.e. to interpret) the sensations. The person is ‘blind while seeing’, ‘deaf while hearing’, etc. Donna Williams calls these experiences ‘meaning-blind/meaning-deaf/touch-dead’. She compares this condition with being deaf-blind, the main difference being, the blind get meaning without seeing, while the meaning-blind see without meaning. The deaf-blind may have lost their sense but the meaning-blind/deaf lost the sense (meaning).
Though they can see adequately, some autistic people may often have limited comprehension of what is seen when they are focused on something else. For example, they may be able to recognize the location of pieces of furniture in space to avoid bumping into them, but may not be able to identify what these objects are unless some cues (verbal or other- wise) are provided. Sometimes they cannot even identify people as people and may be startled by unexpected movements of ‘noisy objects’. For example:
“My lack of interest and involvement in the outside world did not protect my mind from the flood of unwanted information that continually assaulted my senses. The unmodulated sensory input often overwhelmed me, causing me mental torture, and I would begin feeling mentally confused and sluggish. My head would feel fogged so that I could not think. My vision would blur, and the speech of those around me would become gibberish. My whole body buzzed…My hands would feel detached from my body, as if they were foreign objects. I would be paralyzed, unable to comprehend my own movements unless I could see them. I could not tell where my hand started and the table ended, or what shape the table was, or even if it was rough or smooth. I felt like I was in a cartoon world. Indeed, I often felt more in common while with the furniture around me than I did with other people. I felt lifeless, dazed, and had difficulty refocusing on anything” (Hawthorne).
Sensory agnosia is sort of ‘literal perception’; for example, they may see things without interpretation and understanding (literal vision), hear sounds without comprehension (literal hearing), etc. The difference between ‘literal perception’ and ‘sensory agnosia’ is about permanence and temporality. Here we apply ‘literal perception’ to describe those so-called low-functioning autistic individuals who have not yet moved from the stage of literal perception to verbal conceptualisation, while the term ‘sensory agnosia’ refers to a temporary state of literal perception caused by sensory overload.
Too much sensory overload may result in systems shutdowns, in which the person loses some or all of the normal functioning. The difference between sensory agnosia and shutdown is the first is involuntary, the latter is more conscious (voluntary). If it is used early in life it leads to self-imposed sensory deprivation.
In the state of sensory agnosia, interpretation of any sense can be lost; they often act as if they were really blind, deaf, numb, sometimes – ‘dead’. It is a very frightening experience. Each individual develops his/her own strategies to cope with it.
References
Hawthorne, D. (2002) ‘My common sense approach to autism.’ Autism Today.
Williams, D. (1999) Somebody Somewhere. London: Jessica Kingsley Publishers.
Written on behalf of Integrated Treatment Services by Olga Bogdashina
