Role or dominance in macaque response to novel objects

Forty-four juvenile rhesus, 30 stumptailed, and 6 pigtailed monkeys were tested individually and in stable quadrads for time to contact slightly and highly novel objects. When peer-group tested, dominant monkeys were the first to contact the slightly novel but not the highly novel objects, unlike preferences found when they were tested individually. A role analysis revealed better contact-order prediction, most groups having their habitual first contactor. When this contactor was overtly punished or covertly trained to avoid the object, group response was altered. The use of the termrole is discussed in detail, concluding that a role involves a particular individual who is expected to interact with others while in certain groups to complete some beneficial function.     

The generality of overselectivity in developmentally disabled children

A growing body of research suggests that low Mental Age (MA) autistic and retarded children show a unique stimulus control deficit, one that may cause many or most of their behavioral deficiencies. This problem, stimulus overselectivity, is evidenced when a child responds only to a restricted portion of the stimulus environment when compared with normal children. The purpose of this study was to assess whether this overselectivity is general across situations or whether it is restricted to certain stimulus/task conditions. Eight autistic children, who evidenced overselectivity on a preassessment task, and 8 normal children with similar MA levels participated. All children were trained on 3 tasks to determine if overselectivity varied as a function of different stimulus conditions. Each of the 3 tasks involved training a child to respond to (i.e., touch) a card containing a circle (S +) and to avoid a blank (S ?) card. In each case, the circle comprised a series of dots. The difference between the 3 circles (tasks) was the distance between the successive dots making up each circle. Also, in the minimal separation condition the dots were smaller in size and greater in number than in the larger separation conditions. Of concern was whether autistic children learned about the gestalt (i.e., the circle), which required attention to multiple cues, or whether children would overselect and respond to the dots. The results showed that (1) stimulus overselectivity was found not to be a generalized deficit in autistic subjects; instead, it varied as a function of the stimulus variables; and (2) the stimulus variables manipulated in this study similarly influenced the responding of both normal and autistic children. The implications of these data for a theory of overselectivity are discussed.     

Personality patterns of adolescent poor and good sleepers

To determine whether poor sleepers have a unique personality constellation significantly different from that of good sleepers, a sample of 162 emotionally disturbed adolescent poor sleepers was compared to a sample of 153 emotionally disturbed adolescent good sleepers on standardized personality instruments. Poor sleepers were found to have a high incidence of neurotic psychopathology with personality patterns characterized by depression, fearfulness, inhibition, anxiety, and rumination. In contrast, good sleepers showed quasi healthy and/or characterological patterns. While this study does not resolve cause and effect relationships, it does establish a highly significant relationship between neuroticism and sleep disturbance for adolescent boys and girls, and also demonstrates a similarity of personality dynamics and patterns between adult and adolescent samples of patients with sleep disturbances.     

Cardiac autonomic reactivity and recovery in predicting carotid atherosclerosis: the cardiovascular risk in young Finns study.

The present study examined the association of cardiac autonomic task-induced reactivity and recovery to preclinical atherosclerosis. Thirty-three men and 33 women aged 24-39 years participated in the ongoing epidemiological Cardiovascular Risk in Young Finns study. The authors measured heart rate (HR), respiratory sinus arrhythmia (RSA), and preejection period (PEP) during the mental arithmetic and speech tasks in 1999. Carotid atherosclerosis was assessed by measuring the thickness of the common carotid artery intima-media complex (IMT) with ultrasound in 2001. Higher HR, RSA, and PEP reactivity were associated with lower IMT values even after adjusting for cardiovascular risk factors (lipid levels, obesity, and blood pressure). In addition, better HR recovery after the mental arithmetic task was associated with lower IMT values, and this association persisted after all adjustments. Thus, higher task-induced cardiac autonomic reactivity and better HR recovery were related to less preclinical atherosclerosis. The authors concluded that cardiac pattern of reactivity and quick recovery may be associated with better cardiovascular health, and therefore all reactivity occurring in challenging situations should not automatically be considered as potentially pathological.