短时距知觉中的面积效应

初步探讨了短时距（１─５ｓ）下时距刺激的面积大小和立体框架大小对时距知觉的影响及其成因。结果表明：刺激的面积大小对短时距知觉的影响极其显著;存在两种不同反应类型的被试─－大小依存者与非大小依存者,在不同反应类型的被试中刺激的立体框架大小对短时距知觉的影响不同,刺激的立体框架大小对大小依存者的短时距知觉的影响极其显著,但对非大小依存者的影响不显著。     

Short-component multiple schedules: effects of relative reinforcement duration

Pigeons were exposed to multiple variable-interval 2-min variable-interval 2-min schedules of food presentation in which relative duration of food presentation was manipulated. When components alternated every 5 sec and were scheduled on separate response keys, relative response rates closely matched relative reinforcement duration in three of four pigeons. On the other hand, relative response rates were insensitive to relative reinforcement duration when components scheduled on a single response key alternated every 5 sec, and when components scheduled on separate response keys alternated every 2 min. Thus, both rapid alternation and spatial separation of components were necessary to produce approximate matching of relative responding to relative reinforcement duration. This finding contrasts with previous findings that only rapid component alternation is necessary for matching when relative rate of reinforcement is manipulated.     

Concurrent schedules: Interaction of reinforcer frequency and reinforcer duration

Six pigeons were trained on concurrent variable-interval schedules with unequal reinforcer durations for the two responses. The schedules arranged on the two keys were kept equal while they were varied in absolute size. As the overall reinforcer rate was increased, both response-allocation and time-allocation measures of choice showed a trend toward indifference, and measures of sensitivity to reinforcer-duration ratios significantly decreased. Recent reports have shown that the generalized matching law cannot describe the changes in behavior allocation under constant delay-, duration-, or rate-ratios when changes are made in the absolute levels of each of these variables. The present results complement these findings by demonstrating that the concatenated generalized matching law cannot describe the interactions of two reinforcer variables on behavior allocation.     

Sequential effects of interval duration on fixed-interval performance

The bar pressing of rats was reinforced on a multiple fixed-interval schedule. The schedule intervals were 1 and 5 min long, and the sequence was such that intervals of either duration were equally likely to be followed by intervals of the same or of the other duration. Rates were higher during 1-min and after 5-min intervals. Best fit equations for cumulative responses during the 5-min intervals produced very similar exponents regardless of preceding duration. It was concluded that preceding duration may have affected the subjects' performances through direct effects on temporal discrimination.     

Choice, relative reinforcer duration, and the changeover ratio

Relative reinforcer duration was varied in concurrent schedules with a fixed-ratio four changeover requirement. The schedule in effect after each reinforcer was randomly chosen. For all three pigeons, relative response rates overmatched relative reinforcer durations. Time allocation was less extreme and, on the average, matched relative reinforcer duration. In a subsequent manipulation, the level of preference was shown to depend on the size of the changeover requirement. These results are similar to those from related unequal reinforcement-frequency procedures.     

Amount consumed varies as a function of feeder design.

Studies of pigeon behavior in which magazine-cycle duration is varied suggest that many researchers assume that feeders of different designs dispense food at roughly the same rate. However, Epstein (1981) showed that, with a commonly used feeder, the amount of grain a pigeon consumes is a negatively accelerated function of magazine-cycle duration. The present experiment shows that, with a different commonly used feeder, amount consumed is roughly a linear function of magazine-cycle duration. At a duration of 60 seconds, the second feeder dispenses roughly 10 times as much food as the first. Thus, reports of studies in which magazine-cycle duration is varied should identify the design of the feeder employed, and in some cases, authors should consider determining the feeding functions for those feeders.     

母亲消极教养、同伴侵害与FKBP5基因对青少年抑郁的影响

累积压力假说与匹配-不匹配假说均可解释远端和近端逆境对个体抑郁的影响,但鲜有研究考察遗传基因在其中的调节作用。采用问卷法和DNA分型技术,对970名青少年进行间隔3年的追踪调查。分别以母亲消极教养、同伴侵害为远端和近端压力指标, FKBP5基因多位点累加得分为遗传指标,考察三者对青少年抑郁的交互作用及性别差异。结果发现,在男青少年中, E×E×G显著。当累加得分较高、同伴侵害水平较高时,母亲消极教养显著负向预测抑郁,符合匹配-不匹配假说;累加得分较低时, E×E不显著,但倾向于以累积压力假说的方式发挥作用。女青少年中, E×E×G不显著。研究结果提示,在男青少年中,累积压力假说与匹配-不匹配假说均可阐明抑郁的发生机制,分别适用于携带不同FKBP5基因多位点累加得分的个体。     

Peer victimization and subsequent disruptive behavior in school: The protective functions of anger regulation coping

Peer victimization is linked to adjustment problems in youth, including aggressive behavior, yet not all victimized youth are aggressive. The present study investigated whether youth’s anger regulation coping might attenuate the positive association between peer victimization and subsequent aggressive behavior. Longitudinal data from 485 7th-grade students (55% female, mean age = 12.84 years) and their teachers were collected in the fall and six months later. Teacher ratings of youth aggressive behavior at follow-up were the primary outcome, with statistical adjustments for baseline aggressive behavior and demographics. Results from multilevel models showed significant interactive effects of baseline anger regulation and peer victimization on residualized teacher-rated aggressive behaviors that were consistent with the hypothesis that anger regulation played a protective role: under high levels of peer victimization, youth with higher levels of anger regulation displayed lower levels of aggressive behavior than their counterparts with lower levels of anger regulation. These findings suggest that targeting and improving students’ ability to regulate their anger may be protective in the face of peer victimization and reduce subsequent aggressive behavior.     

Homophobic bullying victimization trajectories: The roles of perpetration,sex assigned at birth,and sexuality

There is a paucity of research on developmental trajectories of bias-based aggression. We examined homophobic bullying victimization trajectories among high school students (N = 3,064; M age = 13.67; Girls = 50.2%) and how these developmental pathways vary as a function of factors like homophobic bullying perpetration, sex assigned at birth, and sexuality. Using data from a 3-wave longitudinal investigation over a 2-year period, we utilized latent growth mixture modeling to explore the aforementioned trajectories. Findings suggested that there were three distinct classes characterized by high initial rates and declines over time, low initial rates, and increases over time, and low, stable, rate across time. Furthermore, results indicated that homophobic bullying perpetration, sex assigned at birth, and sexuality all predicted class membership.