Preschoolers' use of eye contact while speaking: The influence of sex,age, and conversational partner

The influences of sex, age, and conversational, partner (mother vs. stranger) on eye contact during verbalizations were examined in a longitudinal study of 33 children at 2 and 4 years of age. A free-play sample was obtained of each child interacting with mother and with a male or female experimenter. The amount of eye contact in conjunction with verbalization was analyzed. Significant main effects were found for sex (females engaged in a higher percent of eye contact than males) and conversational partner (more eye contact while speaking exhibited to experimenter than to mother). There was an interaction between age and conversational partner, in that mother received more and experimenter relatively less percent of eye contact during verbalizations as children got older. Notably, there was no main effect for age. These results revealed sex differences at an age (2–2 1/2 years) and in a context (free-play setting) not previously studied, demonstrating the robustness of the effect. Further, age findings seem indicative of unique developmental trends for eye contact during verbalizations for the ages between 2 and 4 years.Mount Saint Vicent University     

Visual stimulation affects the perception of voluntary leg movements during walking

When a limb is used for locomotion, patterns of afferent and efferent activity related to its own motion are present as well as visual, vestibular, and other proprioceptive information about motion of the whole body. A study is reported in which it was asked whether visual stimulation present during whole-body motion can influence the perception of the leg movements propelling the body. Subjects were tested in conditions in which the stepping movements they made were identical but the amount of body displacement relative to inertial space and to the visual surround varied. These test conditions were created by getting the subjects to walk on a rotatable platform centered inside a large, independently rotatable, optokinetic drum. In each test condition, subjects, without looking at their legs, compared, against a standard condition in which the floor and drum were both stationary, their speed of body motion, their stride length and stepping rate, the direction of their steps, and the perceived force they exerted during stepping. When visual surround motion was incompatible with the motion normally associated with the stepping movements being made, changes in apparent body motion and in the awareness of the frequency, extent, and direction of the voluntary stepping movements resulted.     

Short-term memory for Chinese characters and radicals

Short-term memory for Chinese radicals and characters, varying in orthographic complexity, frequency, and—for radicals—intercharacter frequency (the number of compound characters that contain the radical), was studied using an immediate free-recall task. When radicals or characters are relatively frequent, so that their pronunciations are well known by literate Chinese, they seem to be maintained in verbal form in short-term memory. For these stimuli, intercharacter frequency and complexity have relatively small influences on memory span. Stimuli low in frequency, with pronunciations that are not apt to be known, seem to be maintained in visual form in short-term memory. Memory span is much smaller for these stimuli and is influenced by both intercharacter frequency and complexity. Furthermore, short-term memory for relatively high-frequency characters is interfered with more by a verbal than by a visual intervening task, whereas the opposite is true for low-frequency characters.     

Familiar idiom comprehension

Sentences containing idioms used either literally or figuratively were presented repeatedly for 100 msec per presentation. Half of the sentences were preceded by a paragraph. The number of presentations required to read the sentences and cued recall of the sentences were recorded. The serial brief presentations method provided predictable and meaningful results. Sentences containing idioms used literally required more presentations than those containing idioms used figuratively. Cued recall was better for idioms used literally than for those used figuratively. These results are interpreted as support for the Idiomatic Processing Model of idiom comprehension, which suggests that the figurative meaning is processed first; only if that one is inappropriate is the literal meaning processed.     

Age-related changes in working and reference memory performance and locomotor activity in the Wistar rat

Wistar rats of three age groups were tested in an automated tunnel-maze system of variable geometry to investigate whether changes in spontaneous locomotor activity and in learning and memory develop differentially or in a correlated fashion as a function of age. Senescent (30 months) as well as mature-adult (17 months) rats showed an age-correlated decline of locomotor activity as compared to the mature-young (5 months) group. Both working-memory (measured as within-trial arm discrimination performance) and reference-memory (measured as avoidance of "blind alley" visits) were severely affected in the senescent group, whereas the middle-aged animals suffered only from a working-memory deficit. The findings provide evidence that locomotor deficits do not necessarily interfere in the assessment of age-related changes in cognitive performance. Furthermore the results support the hypothesis that working and reference memory have different underlying physiological correlates and that these neuronal systems are differentially affected by the aging process.     

Dissociation of data-based and expectancy-based memory following hippocampal lesions in rats

Sham-operated and nonoperated animals or animals with hippocampal lesions were presented with sets of trials to test both expectancy-based and data-based memory within the same task. During the study phase of each trial the animals were presented with a constant sequence of five arms on an eight-arm radial maze followed by a test phase in which a recognition test requiring a win-stay rule was used. Expectancy-based memory was measured during the study phase of the trials as a pattern of correct or incorrect orienting responses in anticipation of the ensuing doors in the constant sequence. Both groups of animals acquired correct orienting responses at the same rate, emitted the same pattern of correct orienting responses, and made the same number and pattern of intralist and extralist intrusion errors. Data-based memory was measured during the test phase of the trial as correct recognition test performance. During the test phase the animals with hippocampal lesions were impaired relative to controls on both immediate and 24-h recognition tests. These results suggest that the hippocampus might mediate only data-based, but not expectancy-based, memory and imply a possible dissociation between expectancy-based and data-based memory systems.     

Emotional experiences during engagement in intrinsically and extrinsically motivated tasks

Previous theories of intrinsic motivation have traditionally ignored the experiential or subjective aspects of engagement in intrinsically and extrinsically motivated tasks. Part of the reason for the lack of research in this area was our ignorance of which emotions to study. Data are presented here from two studies designed to produce the first systematic evidence of changes in basic emotional states during task engagement. Our findings suggest that intrinsic and extrinsic tasks can be differentiated according to the emotional changes subjects retrospectively report about their engagement with these tasks, and point the way to future research incorporating emotion as an important variable to consider.The first author was supported in part by a Minority Fellowship administered by the American Psychological Association under a Clinical Training Grant from the National Institute of Mental Health (5 T01 MH13833), and by a Regents Fellowship from the University of California, Berkeley.