Effects of linear and angular velocity on 2-, 4-, and 6-month-olds'' visual pursuit behaviors

We report on a study with 12 infants at each of 2, 4, and 6 months of age which examines the effects on infant visual pursuit of varying the target linear velocity (m/s) and the target angular velocity (deg/s) independently. Tracking performance is described in terms of five behaviors which characterize infant performance as a tracking trial unfolds: time to initial capture, duration of initial tracking, duration of initial break in tracking, frequency of interruptions in tracking, and mean duration of all tracking intervals. Interruptions in tracking become more frequent as linear velocity increases but less frequent as angular velocity increases. The mean duration of later tracking intervals is diminished relative to the duration of earlier tracking intervals in 4- and 6-month-olds, but not in the 2-month-olds. Differences in angular velocity may account for the conflicting reports of disruptions in object permanence studies relying on a visual tracking paradigm.     

Control of responding by the location of sound: role of binaural cues.

In auditory localization experiments, where the subject observes from a fixed position, both relative sound intensity and arrival time at the two ears determine the extent of localization performance. The present experiment investigated the role of binaural cues in a different context, the sound-position discrimination task, where the subject is free to move and interact with the sound source. The role of binaural cues was investigated in rats by producing an interaural imbalance through unilateral removal of the middle auditory ossicle (incus) prior to discrimination training. Discrete trial go-right/go-left sound-position discrimination of unilaterally incudectomised rats was then compared with that of normal rats and of rats with the incus of both sides removed. While bilateral incus removal affected binaural intensity and arrival times, the symmetry of sound input between the two ears was preserved. Percentage of correct responses and videotaped observations of sound approach and exploration showed that the unilateral rats failed to localize the sounding speaker. Rats with symmetrical binaural input (normal and bilaterally incudectomised rats) accurately discriminated sound position for the duration of the experiment. Previously reported monaural localization based upon following the intensity gradient to the sound source was not observed in the unilaterally incudectomised rats of the present experiment. It is concluded that sound-position discrimination depends upon the use of binaural cues.     

Note on aversion learning to the shape of food by monkeys

Vervet and grivet monkeys were repeatedly tested eating bar- and circle-shaped cookies. One subject was always injected with lithium immediately after eating cookies with the circle shape and learned to avoid the circular cookies while continuing to eat the bar-shaped cookies. Another subject received similar treatment except that lithium injections were always delayed 30 minutes after access to the circle-shaped cookies. She also acquired a discriminative aversion. Aversion learning was not observed with 60-minute delayed toxicosis or with lithium injections administered unpaired with access to the cookies. The two types of cookies differed only in shape, and conditioning and test sessions were conducted in total darkness to preclude the use of visual cues. Therefore, the avoidance observed in subjects conditioned with immediate and 30-minute delayed toxicosis represents a conditioned aversion to the shape of the cookies as revealed by tactile cues. These findings illustrate that monkeys can learn to select food on the basis of tactile stimuli when such stimuli are conditioned with delayed aversive stimulation.     

PROGRAMMING PARTICIPATION IN FAMILY ACTIVITIES FOR CHILDREN WITH AUTISM: PARENTS' USE OF PHOTOGRAPHIC ACTIVITY SCHEDULES

The parents of 3 boys with autism were taught to help their children follow photographic activity schedules depicting a variety of home-living tasks. A multiple baseline across participants showed that the home-based intervention produced increases in children's engagement and social initiations and decreases in disruptive behavior, which were maintained for as long as 10 months.     

Species differences in temporal control of behavior II: human performance

Human subjects responded on two panels. A differential-reinforcement-of-low-rate schedule with a limited-hold contingency operated on Panel A. In Condition 1, responses on Panel B produced a stimulus on the panel that signalled whether reinforcement was available on Panel A. In Condition 2, responses on Panel B briefly illuminated a digital clock. In both conditions, performance on Panel A was very efficient; with few exceptions, Panel A was pressed only when reinforcement was available. Thus, in effect, a fixed-interval schedule operated on Panel B. In Condition 1, a “break-and-run” response pattern occurred on Panel B; with increasing temporal parameters, the duration of the postreinforcement pause on Panel B increased linearly while overall response rate and running rate (calculated by excluding the postreinforcement pauses) remained approximately constant. In Condition 2, the response pattern on Panel B was scalloped; the postreinforcement pause was a negatively accelerated increasing function of schedule value, while overall response rate and running rate were negatively accelerated decreasing functions of schedule value. The performance of subjects in Condition 2, but not in Condition 1, was highly sensitive to the contingencies in operation, and resembled that of other species on the fixed-interval schedule.     

Communication accommodation in text messages: Exploring liking,power, and sex as predictors of textisms

This mixed-methods study applies Communication Accommodation Theory to explore how liking, power, and sex predict one’s likelihood for using textisms in digital interpersonal interactions. Textisms are digital cues that convey nonverbal meaning and emotion in text communication. The main experiment used a hypothetical texting scenario to manipulate textism amounts (none/many) and participant’s perceived power levels (low/equal/high) during texting interactions to examine the number of textisms participants used in subsequent responses in comparison to the number of textisms they viewed. Primary results show that (1) participants moderately converged to use similar amounts of textisms, and (2) those with low power who viewed many textisms were more likely to use textisms themselves during subsequent responses. Through the examination of adaption behaviors in text messaging, scholars can better understand the contexts in which users will include textisms to intentionally convey nonverbal meaning and emotion in digital communication.     

无意识目标追求的行为特征、机制及影响因素

无意识目标追求是指个体自动地追求由情境线索激活的目标, 而全然不知目标对自己行为的导向作用。无意识目标追求具有灵活性、抑制性和坚持性。无意识目标追求经由行动的无意识准备和目标价值的自动评估与努力过程实现。积极情绪、内隐态度和人际关系影响无意识目标追求。未来研究需要进一步探讨无意识目标追求的影响因素, 完善无意识目标追求的机制, 探究无意识目标追求结果对个体心理和行为的影响, 提高研究结果的生态效度, 拓展应用研究。     

社交线索对害羞者社交行为倾向的影响

以89名高害羞者和84名低害羞者为被试,以基于虚拟社交情境中的愤怒面孔线索、愉快面孔线索和中性面孔线索为刺激材料,采用线索暴露范式探讨了社交线索对害羞者社交行为倾向的影响。实验结果表明,相对于中性面孔线索,愤怒面孔线索对高害羞者的社交退缩行为倾向具有显著的诱发作用,而愉快面孔线索对其社交行为倾向具有促进作用。该研究为解释高害羞者社交障碍的特征提供了实验证据,并为如何减少高害羞者的退缩行为进而消除其社交障碍提供了一定的思路。     

小学儿童空间物体位置编码(I)

采用找物范式研究小学 7、9、11岁儿童利用点与点之间的关系对目标物位置进行编码的认知发展。结果表明 :两点距离编码和三点共线编码认知成绩的年龄效应显著 ,9岁组和 11岁组儿童的认知成绩显著好于 7岁组儿童的认知成绩。两个不同实验任务对儿童认知成绩的影响不同 ,7岁组儿童两点距离编码认知成绩显著好于三点共线编码认知成绩 ,9岁组和 11岁组两个任务的认知成绩差异不显著。提供编码线索后 ,认知成绩有了较大的改善。