Oculomotor programming disturbances in the dementia syndrome

Three types of oculomotor programming disturbances are described in patients with the dementia syndrome. This report describes two of these abnormalities, poorly regulated gaze patterns and a programming type of gaze perseveration. All patients showed poorly regulated gaze patterns in contrast to the normal controls, whereas on the whole only the moderately affected patients showed the programming type of gaze perseveration. The third type of oculomotor programming disturbance is efferent perseveration of gaze (a hypokinetic, "staring" type of gaze pattern) and can be seen with severe dementia. The possible significance of these findings is discussed.     

Handedness of handedness researchers.

This study tested the hypothesis that laterality and handedness researchers are more likely than other researchers to be left-handed. A questionnaire assessing hand preference was sent to authors of articles which either dealt with handedness (N = 50) or other aspects of laterality (N = 100) or did not concern laterality (N = 50). The proportion of left-handers was highest in the handedness group (12.9%) and lowest in the non-laterality group (5.0%), but this difference did not reach significance.     

Long-term retention of a visually cued poison-based aversion in monkeys.

Retention of a poison-based aversion after a 3-yr. period by 8 vervet monkeys (Cercopithecus aethiops) was found. The color of the visual cue appeared to effect the retention of the aversion.     

Communication patterns in pedodontics.

This investigation examined communication patterns between 16 randomly selected senior dental students and their child patients. Interactions were videotaped during a regular treatment appointment and analyzed according to four Practitioner Communication categories and four Child Cooperation categories. Communication categories included Directive Guidance Behavior, Permissive Behavior, Coercive Behavior, and Other Behavior. Child behavior categories included Cooperation, Resistance, Noncooperation, and Other. The probability that a given category of child's behavior would follow a given category of practitioner's behavior was calculated. Results indicated a .85 probability that Directive Guidance would be followed by Cooperation; a .67 probability that Permissiveness would lead to Noncooperation; and a .97 likelihood that Coerciveness would lead to either Noncooperation or Resistance. Practitioners' confidence was also considered; less confident operators account for 95% of the Coercive behaviors, 86% of Permissive behaviors and 87% of Uncooperative behaviors.     

Temporal and intensitive factors in comparative judgments of tactile space.

Temporal imbalances between the successive stimulation of pairs of loci on each forearm altered judgments of the equality of the spatial extents between sets of loci. The spatial judgments became increasingly inaccurate as the temporal imbalance was increased, i.e., the Tau effect. Changes in stimulus intensity also influenced the dependency of spatial judgments on temporal factors. The data suggest that concomitant variations of spatial, temporal, and intensitive components of a vibrotactile stimulus "package" can produce systematic perceptual effects of potential significance in the design of vibrotactile sensory substitution systems.     

Cognitive flexibility-rigidity, repetition effects, and memory

This experiment examined the role of cognitive flexibility-rigidity in memory. On the basis of several personality tests, subjects were classified as flexible, intermediate, or rigid, using a postexperimental blocking procedure. All subjects were given a perceptual grouping task, which masks the meaningful structure of the material. Subjects have the option of discovering the more meaningful structure consisting of word pairs, or alternatively, processing less meaningful chunks of letters. Results were that flexible subjects recalled substantially more items than intermediate and rigid subjects, in that order. In addition, subjects given different (varied) groupings of the letter chunks recalled substantially more than subjects given repeated presentations of the same grouping structure. Transfer tests indicated that subjects acquired different coding strategies under varied and constant input. Repetitious input led subjects to adopt inefficient strategies in processing the material to be remembered, whereas varied input led subjects to adopt efficient encoding strategies.     

Fact and fantasy: the roles of accuracy and variability in confusing imaginations with perceptual experiences

In Experiment 1, pictures were presented to subjects two, five, or eight times, and subjects were asked to imagine each pciture two, five, or eight times. Subsequently, subjects estimated the number of times each picture had been presented. Their estimates of the frequency of these external events were influenced by imagination trials; this effect was greater for good imagers than for poor imagers. Experiment 2 involved a similar design in which subjects were asked either to imagine the same referent for a word or to imagine a different referent for a word on successive imagination trials. Consistency (same referent) did not increase the influence of imaginations on immediate judgments of external frequency. Thus, the results of Experiment 1 were attributed to the greater accuracy (as opposed to greater consistency) of good imagers' internal generations of the stimuli. Furthermore, variation (imagining different referents), like greater accuracy, increased the effects of imagination trials on immediate but not on delayed judgments of frequency. Possible mechanisms underlying these effects are discussed. In general, the two studies show that qualitative characteristics of completely covert generations influence their impact on estimates of the frequency of external events.     

Response versus place learning by human infants

Two cross-setional studies examined how infants learn the location of visual events. In Experiment 1, infants of 4, 8, and 12 mo of age learned to turn one way to view a novel pattern. In a subsequent transfer task, they were rotated to face the opposite side of the room. The 4-mo-old infants tended to err by repeating their previously learned response, but within 16-20 trials their performance was comparable to the higher levels maintained by the older infants. These results suggest that young infants learn the location of the pattern primarily in terms of response cues, whereas older infants employ both response cues and place cues. Experiment 2 was designed to independently assess the use of response cues and place cues by infants of 4, 8, 12, and 16 mo of age. All infants were able to rapidly learn and remember the location of the novel pattern when they were given response cues. There was a gradual emergence of place-cue use associated with age. It is suggested that the decrease in infant egocentricity in such spatial localization tasks may in fact reflect an age-related increase in the variety of reliable cues responded to by infants.     

Coactor's behavior and imitative aggression

After being exposed to either an aggressive or a nonaggressive filmed model, four- and five-year-old boys were tested for imitation while either alone or with a confederate who had also seen the film. The confederate's behavior was either inactive, the same as that in the film, the same as that in the film the child had not seen, novel but of the same category (aggressive or nonaggressive) as that in the film seen, or novel but in the category of the film not seen. These conditions conformed to the dimensions of a 2 × 6 factoral design. According to prediction, the imitation of subjects exposed to the aggressive model was greatest when the confederate's behavior was similar to the model's. No difference in imitation was produced by the confederate's actions if the boy had watched the nonaggressive model. The results were interpreted within the context of social comparison theory.This project was facilitated by the senior author's Margaret Bosshardt Pace and Paul David Pace Research Fellowship.     

Visual-geometric illusions: unisex phenomena

The possibility of sex differences in responses to visual-geometric illusions was investigated with the use of forty-five illusion variants and a sample of 221 observers. No difference in illusion magnitude as a function of sex was found. A second experiment measured illusion decrement and transfer of decrement to other illusion configurations. Again there were no significant differences between male and female observers.