The role of propulsive muscles of the shoulder during quadrupedalism in vervet monkeys (Cercopithecus aethiops): implications for neural control of locomotion in primates

In comparative anatomical studies of the shoulder, the humeral retractors are often grouped together as propulsive muscles, which are important in the propulsive stroke of the forelimb during quadrupedal locomotion. Electromyographic (EMG) analyses of these muscles in opossums, cats, and dogs in general have confirmed such conclusions. An EMG study of chimpanzee shoulder muscles during knuckle-walking found, however, that the humeral retractors are either inactive or perform a function unrelated to propulsion (Larson & Stern, 1987). This contrast in muscle recruitment patterns between chimpanzees and more "typical" mammalian quadrupeds was attributed to the derived morphology of the chimpanzee shoulder. The present study examines the activity patterns of the humeral retractors in the vervet monkey, a primate more closely resembling nonprimate mammals in its shoulder morphology. The results of this EMG analysis show that despite the significant differences in anatomy between chimpanzees and vervets, the two species display very similar muscle recruitment patterns during quadrupedalism, and there is evidence for this same pattern in other species of primates. These differences in muscle activity patterns between primates and nonprimate mammals may be related to changes in the neurological control of locomotion in primates due to the evolutionary development of manipulative abilities in the primate forelimb.     

The escape-to-Israel syndrome: Variations on the geographic cure

The author conceptualizes a pattern of thought and behavior that can be called the escape-to-Israel syndrome. This pattern is a contemporary variety, appearing primarily in the Jewish population, of the geographic cure: that is, one can solve one's personal dilemmas by moving from one place to another. The syndrome is characterized by a tendency to idealize life in Israel. This idealization, and the viewers' fantasy of their own future in Israel, deflect solid confrontation with genuine personal problems. If, in fact, they do move to Israel, they may experience shock and trauma at the gap between expected reality and the discovered one. This may only compound their emotional difficulties.The author wishes to express his gratitude to Professor Shamai Davidson, Clinical Director of the Shalvata Mental Health Center, Hod HaSharon, Israel, for his critical comments during the preparation of this article.     

The perceived support network inventory

The development and psychometric investigation of the Perceived Support Network Inventory (PSNI), a measure of perceived social support, is described. A group of 146 introductory psychology students participated in a test-retest study design that collected reliability, internal consistency, and construct, convergent, and discriminant validity data on the scale. In addition, a contrast group of 28 Counseling Center clients was administered the PSNI. Test-retest reliability of the PSNI total score and subscale scores ranged from .72 to .88. Internal consistency for the PSNI was .77. Construct validity estimates ranged from .21 to .57. Convergent validity estimates varied from -.25 to .20. Discriminant validity estimates varied from -.11 to .19. Sample differences between introductory psychology student mean PSNI total and subscale scores and Counseling Center client mean PSNI total and subscale scores proved significant. Recommendations for subsequent research and future application are offered.     

Interaction of emotion and cognition in word recall

Summary Previous research has demonstrated that the emotional properties of words and their imaginability affect their recallability and that verbal material is recalled better when it is related to subjects' current concerns. This study investigates the extent to which this effect of emotion on recall varies as a function of cognitively controllable inference processes and examines the relation of the effects of emotion to those of imaginability and concern-relatedness. Forty different words were presented visually under one of six orienting conditions that varied according to what the subject was asked to rate: their length, pronounceability, concreteness, defineability, the strength of emotion elicited by the word, and the relation of the word to personal concerns. Subjects were then asked to write as many words as they could recall. Words that aroused stronger emotion and were easier to represent in imagery were recalled better than emotionally less arousing and imaginally less evocative words, regardless of the nature of the orienting task. The evidence suggests that the emotional properties of words are evaluated automatically in an early processing stage, without requiring subjects to reflect on word content. Emotional arousal appears to mediate the effects of current concerns on recall. It is correlated with but appears to function independently of word imaginability.     

Hyperactive behavior in english schoolchildren: A questionnaire survey

The differences in apparent prevalence of childhood hyperactivity between England and North America are more than 20-fold. This paper seeks to illuminate the reasons for the difference by applying a standard measure [Conners Teacher Rating Scale] to 437 English schoolchildren, aged 6 to 9 years, and comparing them with published surveys from the United States and Australasia. The rating scale had moderate interrater reliability and stability over time; it distinguished between children referred for psychiatric treatment and normal schoolchildren. Component analysis yielded a factor of hyperactivity-inattentiveness, distinct from conduct disorder. The mean hyperactivity scores of English children were higher than in most U.S. surveys but lower than in New Zealand. The national differences in rates of diagnosed hyperactivity are likely to reflect diagnostic inconsistency rather than true differences in children's behavior.     

Common response processing and psychological refractoriness

This experiment examined whether structural considerations, that is the functional closeness of limb control centres (Kinsbourne and Hicks 1978), have a role to play in common processing models of psychological refractoriness. A typical double stimulation paradigm was used (Kantowitz 1974). On experimental trials, subjects responded with the right hand (RT1) to an auditory signal (0.80 probability). After a varied interstimulus interval (ISI) of 100, 200, 300 or 700 msec, one of three lights corresponding to one of the other limbs provided the signal for the second response (RT2). Control trials for RT1 and RT2 involved both stimuli, but subjects were required to make only one response. Results indicated that experimental RT1 was lengthened considerably over control values. While typical double stimulation effects were found at short ISIs, that is RT2 was lengthened, RT2 at long ISIs was actually faster than double stimulation control values. Although the RT results were not in a pattern that would be predicted by functional distance (Kinsbourne and Hicks 1978), within subject correlations of RT1 and RT2 by limb condition suggest that structural considerations may have a role to play. While within subject correlations were positive at all levels of ISI, they decreased as the interval between the two signals increased. The implications of these results for common processing models are discussed.     

The significance of unusual acts in sexual homicide

In addition to being an unusual form of crime, sexual homicide (SH) sometimes includes unusual crime scene behaviours, such as carving on the victim, evisceration (i.e., removal of internal organs), skinning the victim, cannibalism and vampirism. The current study investigates these unusual crime scene behaviours to better understand their meaning as well as to explore whether such behaviours are associated with a specific crime-commission process. Using a sample of 762 SH cases, the study uses a combination of chi-square and stepwise forward logistic regression analyses to identify the differences between cases with and without unusual acts. Findings reveal that SH cases with unusual acts present a specific crime-commission process. This crime-commission process is characterised by a greater level of sadism—as demonstrated by the presence of mutilation and foreign object insertion—as well as a greater level of organisation from the selection of a contact location where the risk of being seen or heard was low. These findings provide a better understanding of these behaviours and could help investigators facing such cases.     

The relation between hierarchical and euclidean models for psychological distances

In one well-known model for psychological distances, objects such as stimuli are placed in a hierarchy of clusters like a phylogenetic tree; in another common model, objects are represented as points in a multidimensional Euclidean space. These models are shown theoretically to be mutually exclusive and exhaustive in the following sense. The distances among a set ofn objects will be strictly monotonically related either to the distances in a hierarchical clustering system, or else to the distances in a Euclidean space of less thann — 1 dimensions, but not to both. Consequently, a lower bound on the number of Euclidean dimensions necessary to represent a set of objects is one less than the size of the largest subset of objects whose distances satisfy the ultrametric inequality, which characterizes the hierarchical model.This work was supported in part by Grant GB-13588X from the National Science Foundation. I would like to thank L. M. Kelly and A. A. J. Marley for their helpful comments and suggestions.     

Reaction time as a function of the intensity and probability of occurrence of vibrotactile signals

Three Ss made judgments of the presence or absence of a burst of 60-cps vibration onthe index fingertip.The probability of S’s reporting the presence of a signal was found to be influenced by signal probability and signal intensity. Mean reaction time for reporting the presence of a signal decreased as a function of signal intensity and signal probability whereas mean reaction time for reporting the absence of a signal increased as a function of signal intensity and signal probability. On trials where no signal was presented mean R T for reporting a signal decreased with increases in the signal probability whereas mean RT for reporting the absence of a signal increased with increases in signal probability. The results were interpreted as support for the hypothesis that S’s decision time was longer the closer on the sensory continuum a particular observation was to his criterion.     

Psychometric properties and factor structure of the Fear Questionnaire phobia subscale items in two normative samples

Normative data for the Fear Questionnaire (Marks & Mathews, 1979), a popular self-report instrument measuring phobic concerns, were collected from both a community and a collegiate sample. The covariation and internal consistency of the blood-injury phobia (BI), social phobia (SO), and agoraphobia (AG) subscales were assessed in each sample, and the factor structure of the items from these three subscales was examined. Results indicated that, in general, community subjects reported more phobic concerns than did collegiate subjects, and females reported greater phobic concerns than did males. Results from confirmatory factor analyses suggest that the three factors of BI, SO, and AG did not emerge from either data set. Follow-up exploratory factor analyses did identify the general factors of blood-injury phobia and agoraphobia. Normative data from the present study are compared to those obtained previously, and directions for future research are provided.