Pursuit gain and saccadic intrusions in first-degree relatives of probands with schizophrenia

Oculomotor functioning of 26 probands with schizophrenia, 12 spectrum and 46 nonspectrum first-degree relatives, and 38 nonpsychiatric control subjects was evaluated. Spectrum relatives had more anticipatory saccades (ASs) and lower pursuit gain than nonspectrum relatives, who had more ASs and lower pursuit gain than control subjects. Probands also had lower pursuit gain than nonspectrum relatives and control subjects but did not differ from other groups on AS frequency. Control subjects had more globally accurate pursuit tracking (root mean square [RMS] error deviation) than both relative groups, whereas probands had the poorest RMS scores. Square wave jerk frequency did not differentiate the groups. Attention enhancement affected the frequency of ASs but did not affect either the other intrusive saccadic event or RMS scores. These results offer evidence that eye-movement dysfunction may serve as a biological marker for schizophrenia.     

The Influence of Source Physical Attractiveness on Advertising Effectiveness: A Functional Perspective1

High and low self-monitors heard either a physically attractive or unattractive source promote a new product with either strong or weak arguments. High self-monitors were persuaded by the physically attractive source only when she presented strong arguments. In contrast, low self-monitoring individuals were persuaded by the physically attractive source regardless of argument strength. Neither high nor low self-monitors were persuaded by the physically unattractive source, regardless of the quality of the arguments she offered. Cognitive response and recall data suggest that high self-monitors may have been systematically processing the physically attractive source's message and low self-monitors may have been more heuristically processing her message. Results are discussed in terms of their implications for advertising strategies.     

Younger and older adolescents' thinking about commitments

One hundred and sixty-three adolescents listed factors they consider or would consider when choosing a career and a romantic partner, and defined "commitment" in an open-ended essay. Male and female ninth graders, twelfth graders, and college juniors, from public and private schools served as subjects. Gender, grade, and type of school differences were found in the types and number of different types of factors listed for the above commitments, but not in the number of factors listed. Conceptions of the nature of commitment became more complex with grade, and differed as a function of gender and of type of school. Females listed more "internal" factors than did males for romantic commitments. Males described commitment more contractually, women more affectively. Older students focused more upon long-term and internal concerns, and defined "commitment" more in terms of cognitive processing and emotional attachment than younger students. Implications for related areas of work are discussed.     

Subsyllabic units in computerized reading instruction: onset-rime vs. postvowel segmentation

Previous studies suggest that adults and children divide spoken syllables into subsyllabic onset-rime units more readily than into any other kind of subsyllabic unit. We asked whether this same onset-rime segmentation might also be beneficial in teaching children to read. That is, can children learn more words segmented at the onset-rime boundary (e.g., CL-AP, D-ISH) than words segmented after the vowel (CLA-P, DI-SH)? In three experiments, first-grade students studied single words presented by a computer connected to a high-quality speech synthesizer. Experiment 1 used words of four letters but only three phonemes apiece (e.g., WHIP, DISH). In some of these words the onset-rime segmentation corresponded to the initial bigram (e.g., WH-IP); in some it did not (e.g., D-ISH). Experiments 2 and 3 used words of four letters and four phonemes (e.g., CLAP, CORN). In all three experiments, onset-rime segmentation proved more helpful than postvowel segmentation in short-term learning of the words.     

The interaction of criterion and feedback information in learning a drawing task

Experiments were designed to examine the influence of criterion and feedback information in the learning of a two-dimensional drawing task. Experiment 1 showed that when the task criterion is well known to the subject, the combined presentation of criterion information and information feedback facilitates the rate of acquisition of the skill but not its overall performance level of achievement. Experiment 2 showed that when the task criterion information is not well known to the subject, presentation of criterion information facilitates both the rate of acquisition and the overall performance level and, furthermore, is essential if configuration information feedback is to be utilized effectively. Experiment 3 showed that it is the combined presentation of criterion and configuration information feedback rather than the isolate presentation of either type of information alone, that facilitates learning and performance. Collectively, the findings from the three experiments suggest an interactive effect of prior knowledge by the learner and type of augmented information in facilitating the acquisition of skill, according to the constraints imposed in the task. The data are consistent with the proposal that the degrees of freedom in the information available to support motor skill learning must match the degrees of freedom to be constraint in the perceptual-motor workspace.     

Temporal regularity of tapping by the left and right hands in timed and untimed finger tapping

The temporal characteristics of repetitive finger tapping by the left and right hands were examined in two experiments. In the first experiment, interresponse intervals (IRIs) were recorded while right-handed male subjects tapped in synchrony with an auditory timing pulse (the synchronization phase) and then attempted to maintain the same tapping rate without the timing pulses (the continuation phase). The left and right hands performed separately, at four different rates (interpulse intervals of 250, 500, 750, and 1500 ms). There was no asymmetry of the asynchronies of the timing pulses and the associated responses in the synchronization phase or of the IRIs in either phase, but there was an asymmetry of chronization phase or of the IRIs in either phase, but there was an asymmetry in the temporal dispersion of the responses in both phases. in the second experiment, right-handed males tapped separately with each hand at three different speeds: as quickly as possible, at a fast but steady rate, and at a slow rhythmical rate. The speed asymmetry present when tapping as quickly as possible (with the preferred hand tapping more quickly ) was reduced when tapping at the fast steady rate and was absent when tapping at the slow rhythmical rate. The temporal dispersion of the IRIs produced by the nonpreferred hand was greater than the temporal dispersion of those produced by the preferred hand in all speed conditions. These results show smaller temporal dispersion of tapping by the preferred hand in right-handed males under different conditions, including submaximal speeds at which both hands respond at the same rate. This suggests that the motor system controlling the preferred hand in right-handers had more precise timing of response output than that controlling the nonpreferred hand.     

The effect of motor preparation on changes in h reflex amplitude during the response latency of a warned reaction time task

Monosynaptic Hoffman reflexes (H reflexes) were recorded from the soleus muscle during the response latency of a warned reaction time (RT) task that required plantarflexion of the foot. The task was done under four conditions of predictability of the response signal (RS), created by the factorial combination of foreperiod duration (1 and 4 s) and variability (fixed and variable). RT varied systematically with RS predictability and was facilitated in conditions that favored prediction of the RS. The response latency was divided into two successive phases by the onset of reflex augmentation: a premotor phase of constant reflex amplitude and a succeeding motor phase marked by progressively increasing reflex amplitude. Reflex augmentation during the motor phase was coupled more closely to the imminent movement than to the preceding signal to respond. The duration of the premotor phase was unaffected by RS predictability, but the duration of the motor phase (like RT) was shorter when the RS was more predictable. The maximum H reflex amplitude reached during the motor phase was greater when the RS was more predictable. The tonic level of H reflex amplitude during the premotor phase was greater in conditions that made prediction of the RS difficult. A second experiment showed that this difference was present throughout the foreperiod. These results suggest that conditions that favor prediction of the RS enhance motor preparation. changes in motor preparation (which affect RT) affect the processes underlying reflex amplitudes in the premotor phase and throughout the preceding foreperiod, in conditions that make prediction of the RS difficult, appear to reflect heightened general arousal.     

Preload and isometric force variability

Two experiments are reported, which examined the relative contributions of preload (resting force level), change of force, and the time taken to achieve the force in determining isometric force variability. The findings showed that change of force is the strongest determiner of peak force variability but that preload and time to peak force have smaller though systematic effects. A formula that predicts peak force variability is proposed, with preload as an additive effect to the ratio between the change of force level and the square root of time to peak force. These findings confirm that these three impulse variables are significant in predicting force variability and that the impact of rate of force on peak force variability is nonlinear.     

Relationships between study organization, retrieval organization, and general and strategy-specific memory knowledge in young children

The present study examined relationships between young children's memory knowledge and their use of taxonomic and color memory organization. Forty-eight 5-, 6-, and 7-year-olds were administered metamemory tests of organization-strategy knowledge and general memory knowledge, and were tested on two study-recall tasks before, and two study-recall tasks after, training in the use of color or taxonomic organization. Study organization (grouping) scores were low before training, but improved significantly in post-training tasks. Training effects were less pronounced for retrieval organization (clustering) and did not occur for item recall. Relationships between taxonomic study and retrieval organization were apparent only for the 7-year-olds, while relationships between color organization at study and retrieval were not apparent at any age level. Relationships between metamemory, strategy-use, and recall proficiency were evident on some tasks for 7-year-olds, but not for younger children. Although teacher ratings of the children's mastery orientations were also found to be related to recall proficiency for the older subjects, specific strategy knowledge was a more consistent correlate of strategy use and amount recalled.