Laverne C. Johnson

The orienting reflex during waking and sleeping

Abstract A 3 sec tone was presented at 30–45 sec intervals to seventeen subjects before sleep and during all night sleep sessions. For twelve of these subjects, 20 tones were presented during a day-awake session. The following components of the orienting reflex to the tone were measured: EEG, heart rate, respiration rate, electro-dermal, and finger plethysmogram. All measures habituated during the awake sessions. With sleep onset there was a return of the OR for all variables, but the magnitude of the restored OR differed for each variable. There was little, if any, habituation of the OR during sleep. While the smallest OR response was generally during 1-REM, heart rate was a striking exception. The presence of a stimulus-evoked K complex was associated with increased responsiveness in all autonomic variables, but presence of eye movement bursts was associated with decreased cardiovascular response to the tone.

Developmental and Psychological Differences between Readers and Nonreaders

This study compared 20 boys with reading disability aged 7-11 to 11-4 with 20 matched controls to examine how nonreaders differ from children who read at age-grade level or better. Significant differences were found between the groups with respect to historical, familial, developmental, and psychological factors. Controls had significantly higher WISC Verbal IQs; higher WISC Information, Vocabulary, Digit Span, Arithmetic, Similarities and Coding subtest scores; and lower mean Bender-Gestalt scores. The groups differed significantly on familial incidence of dyslexia, tested laterality, self-confidence, attentional factors, hyperactivity, birth order, age at crawling, and age at school entry. Significant correlations were found between tested attention and reading proficiency (r = +.67) and between percent righthand dominance and reading proficiency (r = +.48).

Cardiovascular responses to auditory stimuli

Three cardiovascular responses to a moderate tone (about 70 dB) were studied in 25 Ss. Finger-pulse (FP) response was monophasic vasoconstriction. Head-pulse (HP) response was biphasic; vasoconstriction preceded vasodilation. Heart-rate (HR) response usually consisted of an initial small deceleration followed by a more marked acceleration and a secondary deceleration. HP constriction and HR acceleration occurred almost simultaneously; their response magnitudes were highly positively correlated. FP and HP constriction responses were also positively correlated. All responses showed some effect of their prestimulus level.

Electrodermol and Cardiovascular Responses in Nonreaders

Autonomic response patterns of 20 male nonreaders, ranging in age from 7 years 11 months to 11 years 4 months, were compared with those of 20 matched controls. Analyses were made of the onset orienting response, the offset orienting response and anticipatory response as measured for heart rate, finger pulse and electrodermal pheonomena (skin potential and skin resistance). Nonreaders had lower mean skin conductance levels across trials, greater amplitude of skin resistance response to a novel stimulus (75 decibel tone), fewer electrodermal offset responses, fewer negative and diphasic skin potential responses, fewer electrodermal and heart rate anticipatory responses, slower motor reaction times, and a higher degree of sinus arrhythmia. All these differences between the groups were statistically significant. Habituation of the electrodermal, finger pulse, and heart rate onset responses did not differ, and no difference was found between groups as to the magnitude or shape of the heart rate onset response. Both groups showed decreasing skin conductance levels with increasing heart rate levels over trials. Data suggest nonreaders were physiologically less mature, unable to maintain a constant attentional level, and slower in “simple” learning than their matched controls.

Classical conditioning of autonomic responses in alert and drowsy subjects

The primary purpose of this experiment was to study classically conditioned autonomic responses of alert versus drowsy subjects. Sixty-nine subjects in conditioning and pseudo-conditioning groups were subdivided into alert and drowsy groups on the basis of EEG recordings during conditioning trials, giving a total of four groups: conditioning-alert, conditioning-drowsy, pseudoconditioning-alert and pseudoconditioning-drowsy. Using the latency criterion to define responses, significant conditioning occurred only in the conditioning-alert group for the following measures: skin resistance anticipatory and UCS-omission responses, and finger plethysmograph anticipatory response. Both conditioning groups showed evidence of conditioned UCS-omission plethysmograph responses. Discussion centered primarily on (1) the implications of the results on the question of the feasibility of learning during sleep; and (2) the importance of including EEG recordings in studies of classically conditioned autonomic responses. The relationship between the various responses was also evaluated.