Stimulus-governance and the hyperkinetic syndrome

The hypothesis that hyperkinetic children are stimulusgoverned was tested. In a sample of 39 nonmedicated hyperkinetic boys 26 were found to be stimulus-governed. In a control sample of 20 nonmedicated boys 6 were found to be stimulus-governed. An association was found between the hyperkinetic syndrome and stimulusgovernance. The hypothesis is raised that response to methylphenidate is related to stimulusgovernance. Several issues raised by the research are discussed.This research was supported in part by a grant from Bloemendaal Psychiatric Hospital, The Hague, The Netherlands. The authors wish to thank Mr. E. M. Ockhorst, for constructing the KFA-testing equipment, and Mr. R. Reyneart, for helping with the computer analysis. An earlier draft of the paper was presented at the European Conference of Neuropsychology, sponsored by the International Neuropsychology Society, at Oxford University, England.     

The multiple vigilance test

The multiple vigilance test is a 30-min signal detection task designed to assess performance. Sixty target and 180 nontarget stimuli are presented with random interstimulus intervals ranging from 4 to 11 sec. Subjects respond by pressing the spacebar (or microswitch in an alternate version of the program) when they see the masking pattern transformed into the target. This vigilance test is used in conjunction with measures of physiological sleepiness (Multiple Sleep Latency Test) and subjective sleepiness (Stanford Sleepiness Scale). This behavioral information concerning manifest sleepiness provides a more complete picture of a subject’s state of alertness. The assessment of vigilance during long, monotonous, nonstimulating tasks is clinically important in patients with disorders of sleep and arousal.     

Traumatic Brain Injury in School-Age Children Academic and Social Outcome

School-aged children with a traumatic brain injury (TBI) require extraordinary effort and energy from individuals in their school, home, and community. The purpose of this study was to examine the academic, behavioral, and social outcomes of a cohort of children and adolescents following TBI. A comprehensive assessment of cognitive functioning, achievement, and adaptive behavior was administered to 43 school-aged children 2 years after their TBI. Premorbid functioning for each participant was obtained from state-mandated test scores assessed prior to the TBI. The predictive utility of premorbid functioning, TBI severity, and age at injury were examined. Findings revealed that premorbid functions were significant predictors of reading and spelling achievement and adaptive functioning. Severity of injury was predictive of adaptive functioning. Implications of findings include program development, reintegration into school, and educating parents and teachers.     

The auditory motionaftereffect: Its tuning and specificity in the spatial and frequency domains

In this paper, the auditory motion aftereffect (aMAE) was studied, using real moving sound as both the adapting and the test stimulus. The sound was generated by a loudspeaker mounted on a robot arm that was able to move quietly in three-dimensional space. A total of 7 subjects with normal hearing were tested in three experiments. The results from Experiment 1 showed a robust and reliable negative aMAE in all the subjects. After listening to a sound source moving repeatedly to the right, a stationary sound source was perceived to move to the left. The magnitude of the aMAE tended to increase with adapting velocity up to the highest velocity tested (20°/sec). The aftereffect was largest when the adapting and the test stimuli had similar spatial location and frequency content. Offsetting the locations of the adapting and the test stimuli by 20° reduced the size of the effect by about 50%. A similar decline occurred when the frequency of the adapting and the test stimuli differed by one octave. Our results suggest that the human auditory system possesses specialized mechanisms for detecting auditory motion in the spatial domain.     

The costs and benefits of undoing egocentric responsibility assessments in groups

Individuals working in groups often egocentrically believe they have contributed more of the total work than is logically possible. Actively considering others' contributions effectively reduces these egocentric assessments, but this research suggests that undoing egocentric biases in groups may have some unexpected costs. Four experiments demonstrate that members who contributed much to the group outcome are actually less satisfied and less interested in future collaborations after considering others' contributions compared with those who contributed little. This was especially true in cooperative groups. Egocentric biases in responsibility allocation can create conflict, but this research suggests that undoing these biases can have some unfortunate consequences. Some members who look beyond their own perspective may not like what they see.     

A Temporal Logic for Sortals

With the past and future tense propositional operators in its syntax, a formal logical system for sortal quantifiers, sortal identity and (second order) quantification over sortal concepts is formulated. A completeness proof for the system is constructed and its absolute consistency proved. The completeness proof is given relative to a notion of logical validity provided by an intensional semantic system, which assumes an approach to sortals from a modern form of conceptualism.