Manual performance asymmetries and motor control processes: Subject-generated changes in response parameters

Performance asymmetries between the hands have recently been explained in terms of differences in the nature of motor control processes between the hands. If performance asymmetries between the hands on a serial tapping task are due to differences in motor control processes, the degree of asymmetry should be sensitive to changes in the manipulated response parameter, speed of tapping. The results strongly supported this prediction. The differences in control processes observed here seem to be explained by the feedback model proposed by Flowers. Alternate models to that of Flowers (1975) are, however, presented.     

Pastoral considerations on abortion and sterilization

Concerns over sterlization and abortion typify our current moral dilemma. These matters begin as individual problems but rapidly expand to become pressing social concerns. The ethical, psychological, and physical factors related to sterilization in men and women are examined and a careful scrutiny of the meaning of the decision to the parties is advised. Abortion is an even more complex issue. The counselor's value system is always a part of the counseling process. Rigidity is not helpful in attempts to adjudicate conflicting rights among the child, the mother, and the father. Four alternative approaches to counseling with persons considering abortion are described.     

Psychological reactivity to discrepant events: Support for the curvilinear hypothesis

80 male and 60 female infants were observed under 5 a priori judged levels of discrepancy to assess whether sustained attention was linearly or curvilinearly related to degree of discrepancy from an experimental standard. Following habituation, $\text{7}\text{1}\text{2}$-month-old infants were exposed to either the repetition of the standard, a minimal, first- or second-level moderate discrepancy, or a novel stimulus having no relation to the standard. The related stimuli, varying in elongation, were sphere, pear, club, and cylinder-shaped objects; the novel stimulus was a different colored, tooth-like object. 80 infants observed the sphere as the standard and the cylinder as the second-level moderate discrepancy; 60 infants were exposed to the reverse order with the cylinder as the standard. The use of different stimuli at each discrepancy level controlled for specific stimulus effects. Habituation and recovery of responding were observed in an operant paradigm. Lever pressing, fixation, and vocalization increased most to the second-level moderate stimuli and decreased most to the familiar and novel objects; fretting was highest to the redundant stimuli and lowest to the moderate objects. There were no stimulus main effects or interactions. The results support the hypothesis of a curvilinear relation between stimulus discrepancy and sustained attention, excitement, and preference.     

Temporal order: The effect of single versus repeated presentations,practice, and verbal feedback

Whereas Hirsh and Sherrick (1961) found that experienced Os could judge correctly the temporal order of a sound and a light presented repeatedly when the interval separating them was 20 msec, Hirsh and Fraisse (1964) found that naive Os required about 60 msec for the same accuracy of performance with single presentations of the same pair. This experiment examined the effects of single vs repeated presentations, practice, and verbal feedback on performance in the judgment of temporal order. The results indicate that performance under repeated presentation is significantly better than under single presentation, that learning effects are most pronounced during the first 4 of 16 sessions, and that the effects of feedback appear to depend on the precise wording given the S on how he is to perform.     

Attractiveness of Occupations to High School Students

Information was obtained by questionnaire from a sample of approximately 3,100 Washington high school juniors and seniors concerning career aspirations and whether they would like or dislike each of 61 selected occupations. Analysis of the responses shows (1) that a wide range of occupations, including many nonprofessional occupations, would be attractive even though 67 per cent of the boys and 59 per cent of the girls aspired to professions, (2) that students tend to reject occupations traditionally followed primarily by the opposite sex as well as a number of other occupations, and (3) that the prestige ranking of a specific occupation is not a very good predictor of occupational likes and dislikes of students. The implications of these findings are discussed.     

Recording puff volume in smoking

Recent research on nicotine self-administration has highlighted the need to accurately assess within-cigarette topography in order to estimate changes in puff profiles that occur in response to varying nicotine content. This paper describes equipment and techniques that may be used to record puff volume in the laboratory and discusses methods used by other researchers to study puff volume with an emphasis on methodological advantages of the present technique.