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.     

Future-event schemas and certainty about the future: automaticity in depressives' future-event predictions.

The proposition was tested that depressives make predictions about the future based on a pessimistic future-event schema. Participants varying in depression predicted whether positive and negative events would happen to them (or to an average person) in the future by pressing yes or no at a computer terminal as quickly as possible, either under a concurrent attentional load or under no such load. As hypothesized, depressives predicted more negative events and fewer positive events than did mild depressives or nondepressives and showed greater automaticity in their predictions. That is, the attentional load did not increase depressives' response latencies for either negative or positive events, even though it did so reliably for both mildly depressed and nondepressed individuals. Depressives may thus possess a highly developed future-event schema that operates efficiently in enabling future-event predictions.     

Why do people need self-esteem? Converging evidence that self-esteem serves an anxiety-buffering function.

Three studies were conducted to assess the proposition that self-esteem serves an anxiety-buffering function. In Study 1, it was hypothesized that raising self-esteem would reduce anxiety in response to vivid images of death. In support of this hypothesis, Ss who received positive personality feedback reported less anxiety in response to a video about death than did neutral feedback Ss. In Studies 2 and 3, it was hypothesized that increasing self-esteem would reduce anxiety among individuals anticipating painful shock. Consistent with this hypothesis, both success and positive personality feedback reduced Ss' physiological arousal in response to subsequent threat of shock. Thus, converging evidence of an anxiety-buffering function of self-esteem was obtained.     

Does memory contaminate test-retest reliability?

The Wonderlic Personnel Test (1983) was administered twice over a 3-week period under conditions in which the activity of the second test was experimentally manipulated. Data from 302 undergraduates were analyzed. The standard test-retest reliability coefficient, .872, was not significantly different from the coefficients obtained from three other groups that, on the second test, were each given specific instructions: (a) to reason out the answers (pure reassess condition); (b) to use reasoning, memory of their initial responses, or both (reassess and memory); or (c) to take an alternate form of the test (parallel). However, the standard test-retest reliability coefficient was higher, p less than .10, than the coefficient obtained from a condition (pure memory) in which subjects were instructed to duplicate their previous responses, using only memory. Although the subjects in the test-retest and combined reassess and memory conditions reported recalling previous answers for 20-25% of the items on the second test, it was concluded that conscious repetition of specific responses did not seriously inflate the estimate of test-retest reliability.     

Self-report, peer-report, and teacher-report measures of childhood depression: an analysis by item.

We explored the low correlation among different types of childhood depression measures at the item level. The items from the Children's Depression Inventory (CDI), Peer Nomination Inventory of Depression (PNID), and the Child Behavior Checklist-Teacher Report Form (CBCL-T) were combined, and both first- and second-order factor analyses were conducted. Results indicate that self-report, peer-report, and teacher-report assessments of depression measure generally uncorrelated constructs. Second-order analysis suggests that depression as a global construct is being measured to some degree by items from all three instruments. Canonical analysis was employed to identify items that best predicted CDI, PNID, and CBL-T summary scores simultaneously. Also, the relationship between specific items with similar content was investigated. Results from these analyses generally supported a conclusion that the three types of measures yield scores that are primarily independent and that the use of summary scores is not masking stronger relationships within measures. These findings have implications for clinical practice and construct elaboration.     

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.     

Factors and Taxa, Traits and Types, Differences of Degree and Differences in Kind

ABSTRACT A taxon is a nonarbitrary class whose existence is conjectured as an empirical question, not a mere semantic convenience. Numerous taxa are known to exist in nature and society (chemical elements, biological species, organic diseases, geological strata, kinds of stars, elementary particles, races, cultures, Mendelizing mental deficiencies, major psychoses, vocations, ideologies, religions). What personality types, if any, occur in the nonpathological population remains to be researched by sophisticated methods, and cannot be settled by fiat or "dimensional" preference. The intuitive concept of taxonicity is to be explicated by a combination of formal-numerical and causal criteria. Taxometric methods should include consistency tests that provide Popperian risk of strong discorroboration. In social science, latent class methods are probably more useful than cluster algorithms.     

Reliability and validity of the Coolidge Axis II Inventory: a new inventory for the assessment of personality disorders.

This group of studies describes the development of a 200 item, self-report, 4-point true-false inventory (Coolidge Axis II Inventory [CATI]) to assess personality disorders according to the criteria established in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev. [DSM-III-R]; American Psychiatric Association, 1987). The 13 personality disorder scales of the CATI had a mean test-retest reliability of .90 and a median internal consistency (Cronbach's alpha) of .76. There was a 50% concordance rate with clinician's diagnosis for 24 personality disordered patients. The median concurrent validity (raw score sums) between the CATI and the Millon Clinical Multiaxial Inventory-II for the 13 personality disorder scales was .58. Preliminary studies also support the reliability and validity of Depression, Anxiety, and Brain Dysfunction scales.