The neurocognitive basis of autism

The cognitive study of the underlying mental abnormalities in autism has advanced rapidly, while the biological study of the underlying brain abnormalities and of putative genetic mechanisms is lagging somewhat behind. However, the linking of cognitive and biological studies has become a real possibility. Developmental cognitive neuroscience has transformed our understanding of this enigmatic disorder, which was once misguidedly thought to be caused by maternal rejection. The hypothesis of a specific theory of mind deficit was a crucial step in this process. It explains the puzzle of the characteristic social and communication impairments of autism and allows for the fact that they can coexist with good general abilities. This hypothesis has been widely accepted and a start has been made at pinpointing the brain basis of theory of mind. The non-social impairments of autism have now become a major focus for cognitive research. One theory proposes dysfunction in executive processes, in an attempt to explain repetitive behaviour and inflexibility. Another theory proposes weak information integration, in an attempt to explain narrow interests and special talents. Autism research has thus stimulated ideas on important mind-brain systems that may be dedicated to the development of social awareness, executive functions and integrative processing.     

On “knowing your partner”: Dangerous illusions in the age of AIDS?

We identified two characteristics of the impression formation process that may cause people to underestimate the riskiness of potential sexual partners. In Study 1, participants were quite confident that they could determine whether someone was lying to them about risk-related behavior when, in reality, they could not. Particularly troubling was a “truth bias” that resulted in relatively high rates of truth detection, but poor lie detection. In Study 2, increased familiarity with a target person (who actually was HIV+) caused participants to lower their estimates of the target's riskiness, despite the fact that we explicitly warned them that the target might be HIV+. We suggest that such processes may foster the illusion of knowing one's partner when one does not.     

Orienting the finger opposition space during prehension movements

Two experiments are reported that examined the act of prehension when subjects were asked to grasp with their thumb and index finger pads an elongated object resting horizontally on a surface and placed at different orientations with respect to the subject. In Experiment 1, the pad opposition preferences were determined for the six angles of orientation examined. For angles of 90 degrees (object parallel to frontal plane) or less, no rotation of the wrist (pronation) was used; for angles 110 degrees or greater, pronation was systematically employed to reorient the finger opposition space. Only one angle, 100 degrees , produced any evidence of ambiguity in how to grasp the object: Approximately 60% of these grasps involved pronation and 40% did not. Using the foregoing grasp preference data, in Experiment 2 we examined the kinematics of the wrist and elbow trajectories during prehension movements directed at an object in different orientations. Movement time, time to peak acceleration, velocity, and deceleration were measured. No kinematic differences were observed when the object orientation either required (110 degrees ) or did not require (80 degrees ) a pronation. By contrast, if the orientation was changed at the onset of the movement, such that an unpredicted pronation had to be introduced to achieve the grasp, kinematics were affected: Movement time was increased, and the time devoted to deceleration was lengthened. These data are interpreted as evidence that when natural prehension occurs, pronation can be included in the motor plan without affecting the movement kinematics. When constraints are imposed on the movement execution as a consequence of a perturbation, however, the introduction of a pronation component requires kinematic rearrangement.     

Rewards and organizational commitment across structural characteristics: A meta-analysis

This article uses meta-analysis to summarize previous empirical studies which examine the relationship between actual income/pay satisfaction and organizational commitment (OC) across different structural settings. Twenty-one studies with correlational data on the relationship between OC and income, and 27 studies dealing with OC and pay satisfaction are examined; these studies include 23 and 31 independent samples, respectively. The findings reveal a moderator effect related to type of occupation in the OC-income relationship, and to sector in the OC-pay satisfaction relationship. The findings also show the moderating effect of measurement of OC on pay satisfaction. Theoretical and methodological considerations pertaining to the OC-rewards relationship are discussed. Directions for future research and practical implications are indicated.The authors would like to thank HelenJane Shawyer and Marion Lupu for their editorial assistance.     

Pharmacological dissociation of memory: anisomycin, a protein synthesis inhibitor, and leupeptin, a protease inhibitor, block different learning tasks

Inhibition of protein synthesis by anisomycin for a short duration impairs memory of a one-trial inhibitory avoidance task in rats. Memory of escape conditioning involving eight trials is disrupted only if the duration of protein synthesis is prolonged by repeated injections. In marked contrast, olfactory memory of rats trained on two odor discriminations is not affected by anisomycin even if the duration of inhibition is prolonged and the number of trials is reduced to a minimum. In previous work, leupeptin, a thiol proteinase inhibitor, was shown to impair olfactory discrimination learning, but left inhibitory and avoidance conditioning intact. Together, these results provide a pharmacological double dissociation of memory, and suggest that the same chemistries, or mixtures of chemistries, may not be involved in all types of memory.     

Differential indications for desipramine--results of a controlled multiclinical study]

The antidepressants desipramine and imipramine were compared within the framework of a multiclinical study performed under the conditions of a controlled clinical experiment. There has been found a time-different remission of affective symptoms, which was not detectable for the inhibition of drive. The tachythymoleptic action of desipramine is discussed with reference to these results. Evaluation of the possibility of controlling affects shows different ranges of activity of desipramine and imipramine, with desipramine influencing especially negative psychoenergetic symptoms in the area of drives and emotions and imipramine, restrictive symptoms in addition to differential phenomena of the psychomotor expression.     

A prospective study of the distribution of illness within the menstrual cycle

The cyclic physiological variations during the menstrual cycle are thought to be associated with change in emotional state, in susceptibility to illness, and in frequency of illness-related behavior. Variations in frequency of illness with the phases of the menstrual cycle were examined using data from a 3-year prospective study of social and psychological antecedents of viral illness in 94 student nurses. Reported illnesses, accidents, medical consultations, and hospital admissions were randomly distributed throughout the menstrual cycle. Subjects took more medication on the 1st day of menses than on any other day of the cycle; howeverreported menstrual symptoms were infrequent, with only 4% of the population reporting two or more such episodes. It was concluded that there was an increase in discomfort on the data of onset of menses which was self-medicated but not defined as illness. There was no discernible relationship of illness or disability to any phase of the cycle.This work was supported in part by Center for Oral Health Research (COHR) grant DEO 2116, and Oral Medicine Training Grant ST01-DE-77. The authors wish to recognize the contribution of Carol Ram, R. N., who was the administrator of this study and responsible for the collection and organization of the large bank of information from which the material for this paper was abstracted. Without her care, diligence, and intelligent management, this study could not have been completed. We also wish to acknowledge the consultive advice of Dr. Larry Laster, Director, Division of Biometrics, School of Dental Medicine, in choice of analytic techniques, and the help of Dr. Arthur Segal in the early stages of data analysis.     

Barriers to Adult Career Change

Adults have unique problems in making career changes. They face crucial economic, educational, and psychological barriers that require special guidance services. In this article, barriers to adult career change are identified and a five-county regional learning service using paraprofessionals is described. Results in working with more than 200 adults making career changes is reported. Suggestions for overcoming some of the problems adults face in making career changes are explained.     

A vector graphic CRT display system

A vector graphic CRT display system for research in visual information processing is described. The vector graphic processor includes a 4K-byte display memory. The processor communicates with the controlling computer via a serial channel. The system is capable of exposure durations below 1 msec, and it allows on-line generation and modification of display files during an experiment. Brightness can be controlled separately for each vector of a picture. A graphic display editor in FORTRAN IV for interactive editing and debugging of display files has been developed.     

Perception of American sign language in dynamic point-light displays

Perception of dynamic events of American Sign Language (ASL) was studied by isolating information about motion in the language from information about form. Four experiments utilized Johansson's technique for presenting biological motion as moving points of light. In the first, deaf signers were highly accurate in matching movements of lexical signs presented in point-light displays to those normally presented. Both discrimination accuracy and the pattern of errors were similar in this matching task to that obtained in a control condition in which the same signs were always represented normally. The second experiment showed that these results held for discrimination of morphological operations presented in point-light displays as well. In the third experiment, signers were able to accurately identify signs of a constant handshape and morphological operations acting on signs presented in point-light displays. Finally, in Experiment 4, we evaluated what aspects of the motion patterns carried most of the information for sign identifiability. We presented signs in point-light displays with certain lights removed and found that the movement of the fingertips, but not of any other pair of points, is necessary for sign identification and that, in general, the more distal the joint, the more information its movement carries.