Respiratory and Vascular Responses to Simple Visual Stimuli in Autistics, Retardates and Normals

Abstract

Experiment 1 examined changes in respiratory period, peripheral pulse amplitude and cephalic pulse amplitude in autistic, retarded and normal children as a function of stimulus novelty. The respiratory measure showed habituation in the retardates and normals but not in the autistic group. Measures of peripheral and cephalic pulse amplitude showed no habituation in any group, but a higher mean response level for autistics. Autistic children thus differed from both retarded and normal children in two respects: a failure to habituate phasic respiratory responses, and enhanced response magnitude in the vascular systems. This experiment was replicated using groups of preschool children and university students. Results indicated significant age effects in the vascular systems, with preschoolers showing enhanced response magnitude. It was thus argued that autistics may display a general developmental lag in phasic vascular response measures, and an additional specific deficit indicated by failure to habituate respiratory responses. The implications of these group differences were discussed in relation to the etiology of autistic psychopathology.

Electrodermal activity to auditory stimuli in autistic, retarded, and normal children

“…In some respects, their patterns of reactivity showed tendencies toward overarousal, providing partial support for earlier findings (James & Barry, 1980a. Levels of skin conductance tended to be slightly higher and showed increases over time.…”

“…Similarly, research into autism has embraced three possible arousal dysfunctions: underarousal (Rimland, 1964), overarousal (Hutt, Hutt, Lee, & Ounsted, 1964), and perceptual inconstancy or faulty modulation of arousal (Ornitz & Ritvo, 1968). A recent review (James & Barry, 1980a) has indicated a marked paucity of data on the psychophysiological functioning of autistic children. Early studies suggested, on the one hand (Bernal, 1965;Bernal & Simmons, 1969), that autistic children were hyperresponsive and slower to habituate and, on the other (Bernal & Miller, 1971), that physiological responsivity was diminished and correlated with behavioral unresponsiveness.…”

Assessment of Emotionally Disturbed Preschoolers

“…Autistic children will also avoid focusing on complex, novel, or socially threatening stimuli (for reviews, see Hermelin & O'Connor, 1970;Hutt & Ounsted, 1968). The fact that autistic children demonstrate greater physiological responsiveness to novel stimuli and failure to habituate relative to normal and retarded children (individually matched for age, sex, and IQ) may explain their preference for familiar, nonthreatening stimuli (Hermelin & O'Connor, 1968;James & Barry, 1980;Palkovitz & Wiesenfeld, 1980). Autistic children also respond to learning tasks with overly selective motor responses (perseveration, position, and pattern preferences) and with delayed responses to previous task stimuli more than both retarded and mental-age controls (Boucher, 1977;Hermelin & Frith, 1971;Prior, 1977).…”

Event-related brain potential correlates of the processing of novel visual and auditory information in autism

“…The disorder seems to include defects in recognizing or making classifications (Hermelin, 1976;Rutter, 1978;Hoffmann & Prior, 1982) and defects in mechanisms of attention and orienting to novel stimulation (Gold & Gold, 1975;James & Barry, 1980;Kootz & Cohen, 1981). Opinions remain divided as to whether the defects in orienting are principally characterized by increased or decreased sensitivity to events, or both.…”