Sense of humor and longevity: older adults' self-ratings compared with ratings for deceased siblings.

33 older adults (mean age = 72.3 yr.) rated themselves and a deceased sibling on the Multidimensional Sense of Humor Scale. A significant mean difference between the two groups on the subscale of Humor appreciation suggested the possibility of a positive relationship between humor appreciation and longevity.

Color-naming and color-matching by preschool children as a function of visual field and sex.

The accuracy for both a color-naming and a color-matching task as a function of visual field and sex was investigated in preschool children. Subjects were 17 boys and 17 girls ranging in age from 4.4 to 5.6 yr. Each subject was tested on both tasks, for which the target stimuli were presented tachistoscopically. Accuracy measures for each task were obtained separately for both left and right visual fields. A two-factor (sex x visual field) analysis of variance with repeated measures on the visual-field factor showed a significant difference between the sexes on the color-naming task only. No significant difference between visual fields was found for either task. However, significant interactions between sex and visual field for both the color-naming and color-matching tasks were obtained. t tests for simple main effects showed a significant right visual-field advantage for girls in naming colors. Conversely, a significant left visual-field advantage for color-matching was found for boys. Also, on the color-matching task, significant sex differences were found for both visual fields when compared separately. Boys were more accurate for left and girls more accurate for right visual field. Boys performed in a more strongly lateralized fashion on the color-matching task than did the girls, supporting the notion of greater lateralization among males.

The relation between sign language skill and spatial visualization ability: mental rotation of three-dimensional objects.

The present study was designed to ascertain whether a relationship exists between the experience of an individual in American Sign Language (ASL) and performance on the Mental Rotations Test. 51 women were divided into three groups on the basis of self-reported ASL skill (years of experience). All subjects then completed the Mental Rotations Test, a paper-and-pencil test of spatial ability. The State-Trait Anxiety Inventory was also administered to examine possible apprehension about evaluation. Significant differences in scores on mental rotations were found, with 18 experienced signers scoring significantly higher than either mean of the two less experienced groups (ns = 16 and 17). It appears that people experienced in ASL perform better on the Mental Rotations Test. No evidence for a difference in anxiety related to the amount of experience a person had in ASL was found.

Effect of verbal interpretation on recall and recognition of ambiguous pictorial stimuli.

66 subjects characterized as either good or poor visualizers were presented ambiguous pictorial stimuli accompanied by either a verbal interpretation or no interpretation. Both recall and recognition measures for the stimuli were obtained. Good visualizers showed superior recall and recognition compared with poor visualizers in the absence of verbal interpretation. Good and poor visualizers did not differ on either measure of memory when an interpretation accompanied the stimuli. Good visualizers performed equally well either with or without an interpretation, while poor visualizers performed significantly better with an interpretation.

Lateralization differences for color-naming and color-matching in men and women.

The relationship between accuracy of color-naming and color-matching in both visual fields (LVF and RVF) as a function of sex was investigated. Subjects were 19 men and 15 women who ranged in age from 18 to 32 yr. Each subject was tested on both a color-naming task and a color-matching task presented tachistoscopically. Accuracy measures for each task were obtained separately for both left and right visual fields. A two-factor analysis of variance with repeated measures on one factor followed by a t test for simple main effects showed significant right visual-field advantage for the color-naming task, a significant sex main effect for the color-matching task (in the left visual field only), and a significant interaction of sex by visual field for the matching task. Men performed in a more strongly lateralized fashion on the color-matching task than did women, supporting the notion of greater lateralization among males.

Breastfeeding and cognitive development in the first 2 years of life.

The relationship between breastfeeding and cognitive development in the first 2 years of life was examined in a cohort of children being followed in a study of risk factors in development. A significant difference between bottlefed children, children breastfed less than or equal to 4 months and those breastfed greater than 4 months was found on the Mental Development Index of the Bayley Scales at ages 1 and 2 years, favoring the breastfed children. At age 6 months, the direction of the relationship was the same but did not reach significance. Supplementary regression analyses examining the strength of the relationship between duration of breastfeeding and cognitive development similarly showed a small but significant relationship between duration of breastfeeding and scores on the Bayley at 1 and 2 years. Alternative explanations for the results are discussed.

Differential visual field-interhemispheric transfer: can it explain sex and handedness differences in lateralization?

104 men and women were tested for visual field-hemispheric transfer of spatial information on a dot-localization task. Right-handed subjects showed significant improvement when stimuli were presented to the left visual field of the right hemisphere (LVF-RH) after practice on the same task presented to the right visual field of the left hemisphere (RVF-LH) first. No improvement was found when the task was presented in the reverse order (LVF-RH first followed by RVF-LH). It was concluded that, for right-handers, transfer of spatial information to the right hemisphere is facilitated while transfer to the left hemisphere is inhibited. Left-handed subjects demonstrated no significant improvement in either condition, suggesting inhibition or lack of transfer of spatial information in either direction. No sex differences were found in either right-handed or left-handed subjects. The findings suggest that there may be different mechanisms underlying the similarities in functional lateralization of women and left-handers.

Preferences for wavelength and intensity in rhesus monkeys: fact or artifact?

10 adult male rhesus monkeys were tested to determine whether systematic preferences existed for specific color or brightness of visual stimuli. In contrast with previous reports no significant preferences for either specific hues or brightness levels were found. Perhaps methodological or subject variables may be responsible for preferential responding in other situations and account for the present inability to confirm prior work on preferences for color and brightness.

Factors affecting perceptual functioning and activity in albino rats.

The effects of crowding and estrus cycling upon visual observing behavior and general activity level in the albino rat were investigated. Experimental groups were composed of non-estrus or estrus females and were subjected to one of three different crowding conditions. Measures of the frequency and duration of observing of photographic slides were taken as well as a measure of general activity. Slides were composed of either geometric patterns or color photographs depicting rats in various social postures. Contrary to previous reports, observing measures did not vary with levels of crowding or stage of estrus. There were, however, differences among the various crowded conditions on a measure of general activity. Relatively short-term crowding was shown to affect estrus based cyclical variation in activity and observing.

Visual field-cerebral hemisphere differences in perception of visual nonverbal stimuli.

16 subjects were tested for differences between left and right visual fields in accuracy of recognition for paired verbal and nonverbal stimuli presented at below threshold duration and at minimal intensity. Performance on the visual recognition task was also compared with scores on a written n-Ach test. The data clearly indicated superior recognition of physiognomic stimuli presented in the left visual field and above-chance-level performance of subjects' manual responses for these below-threshold stimuli. The data also hint at a possible relationship between n-Ach and accuracy of visual recognition in the left hemisphere.

Suppression of visual observing by rhesus monkeys produced by conditioned aversive visual stimuli.

Nine rhesus monkeys were tested in a visual observing situation to determine the influence of conditioned aversive visual stimulation. A set of meaningless visual stimuli was selected on the basis of cumulative frequency and cumulative duration of observing during a pretest phase of the experiment. Three subsets of stimuli (low, medium, high) were formed indicating level of observing during pretesting. A portion of the "medium" category of slides then served as conditioned stimuli in a classical conditioning procedure by being paired with electric shock. Following conditioning the entire set of stimuli was again presented in a visual observing situation. The results showed a significant decrease in both frequency and duration of observing of the slides with conditioned aversive qualities, relative to non-shock control slides. These findings support an aversion-produced suppression of observing relatively unconfounded by methodological, procedural, and other differences existing among previous reports on the role of fear or anxiety in this context.

Visual observing behavior in the albino rat: effects of nature and complexity of visual stimuli and stage of estrus.

The effect of varying levels of complexity within two types of visual stimuli on observing behavior of albino rats (60 females, 30 males, CD Strain, Charles River) was examined. Measures of frequency and duration of looking, as well as measures of general activity, were recorded. Differences in duration of observing as a function of group membership and type of stimuli were obtained. Activity was affected by the level of complexity. A re-examination of the concept of complexity is suggested. Further delineation of variables affecting observing behavior is also needed.

Visual observing by rhesus monkeys: influence of potentially threatening stimuli.

7 rhesus monkeys were afforded the opportunity to observe a series of projected color slides of other monkeys exhibiting five content categories of social-communicative behavior (submission, intense threat, mild threat, grooming, and neutral behavior) combined with two levels of familiarity (familiar vs unfamiliar) with reference to the animals depicted in the slides. Mean duration of observing was significantly influenced by the social-communicative content categories, while mean frequency of observing was significantly affected by the familiarity dimension. The data were discussed in terms of the threat potential or fear-arousing capacity of social stimuli in relation to visual obsrving.

Observing behavior in the albino rat: a within-subjects' comparison of increasing levels of visual complexity.

54 male CD strain Charles River albino rats were tested for complexity preference using a non-locomotor response. Each subject was presented an array of photographic slides containing an incremental series of complexity elements, i.e., 1, 2, 5 and 25 elements. All photographic slides were randomized both within and across subjects. Each photographic slide of each level of complexity was repeated three times. Results of an analysis of covariance, with luminance as the covariate, showed that cummulative viewing time increased with an increase in stimulus complexity. The relationship between looking and level of complexity was shown to be different when covariance procedures were used than without them.