Recovery of Locomotion in Monkeys With Spinal Cord Lesions

This study reanalyzes kinematically (via film) the pre- and postoperative locomotor behavior of 4 of the 10 monkeys with partial spinal cord lesions (T8) briefly described by Eidelberg, Walden, and Nguyen (1981). The behavior of the remaining 6 monkeys is qualitatively described. The analysis reveals that 5 of the animals initially exhibited unilateral hind limb stepping. Hind and forelimb cycle durations often differed postoperatively; the hind limbs commonly showed increased values, whereas forelimb cycle durations were reduced: ipsilateral interlimb phase values were usually inconsistent. A review of prior studies of primate spinal cord lesions indicates that sparing of the ventrolateral quadrant may not be essential for locomotor recovery (cf. Eidelberg, Walden, & Nguyen, 1981). Furthermore, this review as well as the kinematic analysis indicates that primates with very significant spinal lesions can stilI exhibit locomotor movements. Thus, although the primate's spinal cord seems less able than other mammals' to readily organize locomotor movements (Eidelberg, Walden, & Nguyen, 1981), the total absence of stepping in primates with completely transected cords is unexpected and warrants further research.     

Stimulus recognition and the mere exposure effect.

A meta-analysis of research on Zajonc's (1968) mere exposure effect indicated that stimuli perceived without awareness produce substantially larger exposure effects than do stimuli that are consciously perceived (Bornstein, 1989a). However, this finding has not been tested directly in the laboratory. Two experiments were conducted comparing the magnitude of the exposure effect produced by 5-ms (i.e., subliminal) stimuli and stimuli presented for longer durations (i.e., 500 ms). In both experiments, 5-ms stimuli produced significantly larger mere exposure effects than did 500-ms stimuli. These results were obtained for polygon (Experiment 1), Welsh figure (Experiment 2), and photograph stimuli (Experiments 1 and 2). Implications of these findings for theoretical models of the mere exposure effect are discussed.     

Repression at encoding: discrete appraisals of emotional stimuli.

In previous research, the emotions associated with repressors' memorial representations were found to be more discrete than those associated with nonrepressors'. In each of the 3 experiments reported here, repressive discreteness was apparent in repressors' appraisals of emotional stimuli at the time they were encoded. In 1 experiment, Ss appraised individual facial expressions of emotion. Repressors judged the dominant emotions in these faces as no less intense than did nonrepressors, but they appraised the blend of nondominant emotions as less intense than did nonrepressors. In the remaining 2 experiments, Ss appraised crowds of emotional faces as well as crowds of geometric shapes. In both crowd experiments, the repressive discreteness was evident in appraisals of crowds of emotional faces but not in appraisals of crowds of geometric shapes. The repressive discreteness effect did not appear to reflect a general repressor-nonrepressor difference in the appraisal of stimulus features. Rather, the results suggested that repressive discreteness may be constrained to appraisals of emotions.     

Mothers with hostile, Type A predisposing child-rearing practices.

The authors examined characteristics of Finnish mothers (N = 924) who use hostile child-rearing practices (i.e., they ignore the child, are punitive and irritable, and perceive the child as a burden), practices that have been shown (R?ikk?nen & Keltikangas-J?rvinen, 1992) to predispose children to Type A behavior. The results of this study indicate that two factors--Type A behavior in the mothers and the mothers' sociodemographic background (low occupational status, low educational level and young age)--increase the probability of the mothers' treating their children in a hostile manner. Also, the mothers of boys in this study reported more hostile child-rearing practices than the mothers of girls did.     

Concrete operational thought in children with learning disabilities and children with normal achievement.

This study compared Piagetian cognitive development in normal achieving children and two groups of children with learning disabilities designated as either auditory-linguistic or visual-spatial on the basis of Verbal-Performance IQ differences on the Wechsler Intelligence Scale for Children-Revised (WISC-R; 1974). The two groups with learning disabilities were matched with normal achieving controls on intelligence, socioeconomic status, sex, race, and age. Piagetian tasks measuring conservation, seriation, and classification were administered to each child to determine level of operative thought. The auditory-linguistic group scored significantly below normal controls in operativity, and significantly fewer were at a concrete operational level on a conservation of length task than were normal achieving children. The visual-spatial group did not differ significantly from normal controls. These results suggest that auditory-linguistic disabilities may be more detrimental than visual-spatial disabilities to development of operativity.     

Early memories and the criminally dangerous.

We demonstrated the efficacy of using early memory (EM) data to distinguish postdictively criminally dangerous from nondangerous psychiatric patients. Dangerous patients (n = 30) had been adjudicated not criminally responsible (NCR) for felonies, whereas nondangerous psychiatric patients (n = 30) had no convictions for aggressive offenses. Groups were comparable in age, IQ, socioeconomic status (SES), marital status, and diagnoses. Group racial compositions, however, were significantly different. Statistical analyses were thus performed to clarify the potential effect of this racial confound. Overall, 73% of the dangerous and nondangerous patients were accurately classified via a newly developed EM scoring system, the Early Memory Aggressiveness Potential Score System (EMAPSS). Of those classified as dangerous, 15 of 16 (94%) were actually dangerous. The false-positive rate was an impressively low 6%, suggesting EM aggression is highly predictive of dangerousness postdictively.     

An assessment of the Edwards Personal Preference Schedule from the perspective of the five-factor model.

We examined the validity of need scales of the Edwards Personal Preference Schedule (EPPS) by correlating them with a measure of the five basic factors of personality; we also considered test format as a possible source of invalidity. Three hundred thirty (223 women, 107 men) undergraduate students completed both the NEO Personality Inventory (NEO-PI)--a measure of the five factors--and one of two versions of the EPPS. Results show that both ipsative and normative versions of the EPPS could be meaningfully interpreted within the five-factor model, although the ipsative, forced-choice format of the standard EPPS apparently lowered validity coefficients and decreased convergent and discriminant validity. We argue that the five-factor model can provide a useful interpretive context for evaluating many clinical measures.     

Effects of Pointing Rate and Availability of Visual Feedback on Visual and Proprioceptive Components of Prism Adaptation

While looking through laterally displacing prisms, subjects pointed 60 times straight ahead of their nose at a rate of one complete movement every 2 or 3 s, with visual feedback available early in the pointing movement or delayed until the end of the movement. Sagittal pointing was paced such that movement speed covaried with pointing rate. Aftereffect measures (obtained after every 10 pointing trials) showed that when the limb became visible early in a pointing movement, proprioceptive adaptation was greater than visual, but when visual feedback was delayed until the end of the movement, the reverse was true. This effect occurred only with the 3-s pointing rate, however. With the 2-s pointing rate, adaptation was predominately proprioceptive in nature, regardless of feedback availability. Independent of the availability of visual feedback, visual adaptation developed more quickly with 3-s pointing, whereas proprioceptive adaptation developed more rapidly with 2-s pointing. These results are discussed in terms of a model of perceptual-motor organization in which the direction of coordinative (guidance) linkage between eye-head (visual) and hand-head (proprioceptive) systems (and consequently the locus of discordance registration and adaptive recalibration) is determined jointly by pointing rate and feedback availability. An additional effect of pointing rate is to determine the rate of discordant inputs. Maximal adaptive recalibration occurs when the input (pointing) rate matches the time constant of the adaptive encoder in the guided system.