Reaction times of pigeons on a wavelength discrimination task

After extensive pretraining, three pigeons were exposed in 2-second trials to a random series of 14 light wavelengths, ranging in one nanometer (nm) steps from 575 nanometers to 589 nanometers. Responses to one of the wavelengths, 582 nanometers, were intermittently reinforced. The relative frequency of response approached 1.0 at 582 nanometers, and decreased with progressively higher and lower wavelengths. Reaction times shorter than about 0.2 second occurred with a low frequency that was largely independent of wavelength. Wavelength controlled the frequency of longer reaction times, but did not affect the distribution of these reaction times. Consequently, receiver-operating characteristic curves constructed by using reaction time as a rating measure did not conform to the signal-detection model, in contrast to such conformity when response rate is used in a similar way. The data suggest that stimulus onset as such triggers early response emission with some small probability; the probability of responses with longer latency is controlled by wavelength, but their time of emission is controlled by some independent process.     

Reaction times of younger and older men and temporal contingencies of reinforcement

Influences of extended training and temporal contingencies on reaction time were studied in relation to developmental differences. Older and younger men were trained on a chained schedule in which completion of a variable interval produced a terminal link in which reaction time was measured. The reaction-time procedure involved a conditional discrimination with matching to sample in one component and oddity matching in the other. During baseline training, no time limit was placed on the response to the discrimination choice stimuli. Subsequently, increasingly severe time limits were imposed over a series of sessions. Older and younger men showed increased speeds (decreased reaction times) when temporal contingencies were imposed, and these changes were maintained during post-training baseline sessions when there was unlimited time in which to respond. The younger men generally responded faster than the older ones, and age differences were not appreciably reduced during the course of the experiment. The results indicated the feasibility of studying reaction time in human subjects using operant procedures analogous to those developed for the study of nonverbal organisms.     

The ventromedial hypothalamus and aggressive behaviour in rats

Male rats were given bilateral lesions in either the anterior or posterior ventromedial hypothalamus (VMH). The intermale aggressive behaviour of these animals within their own territory was observed before and after the surgical procedure and compared with the behaviour of sham-operated animals. The effects of anterior VMH lesions include an increased tendency to respond with frontal threatening upon approach of a conspecific male. This behaviour closely resembles the aggressive responses described in “shock-induced aggression” tests. Posterior VMH lesions facilitate territorial aggressive behaviour characterized by approaching the opponent followed by lateral threatening and fighting. It is suggested that 2 distinct neural substrates exist, which serve to inhibit defensive (anterior-VMH) and offensive (posterior-VMH) intermale aggression, respectively.     

Marx and Russia

I present the scope andcharacteristics of Marx's interest in Russiaand review its evolution. Initially, Marx'sattitudes were marked by russophobia,pronounced anti-panslavism, assessments ofRussia as an outpost of European reaction andcounterrevolution, and even as the head of aconspiracy to block the world revolution. Withtime, however, Marx came to consider Russia asthe country in which the outbreak of theRevolution was most likely. In his research forsucessive volumes of Capital, he readRussian theoretical works by, among others, V.Bervi-Flerovskij and A. Koshelev. Marx'sattitudes to the anticipated peasant revolutionin Russia remained ambivalent; to a certaindegree he feared its occurrence suspecting thatit could take on an `asiatic' hue.     

Probing the Time Course of Nonlinear Discriminations during Human Electrodermal Conditioning

Animal-based theories of Pavlovian conditioning propose that patterning discriminations are solved using unique cues or immediate configuring. Recent studies with humans, however, provided evidence that in positive and negative patterning two different rules are utilized. The present experiment was designed to provide further support for this proposal by tracking the time course of the allocation of cognitive resources. One group was trained in a positive patterning schedule (A−, B−, AB+) and a second in a negative patterning schedule (A+, B+, AB−). Electrodermal responses and secondary task probe reaction time were measured. In negative patterning, reaction times were slower during reinforced stimuli than during nonreinforced stimuli at both probe positions while there were no differences in positive patterning. These results support the assumption that negative patterning is solved using a rule that is more complex and requires more resources than does the rule employed to solve positive patterning.     

Proactive and reactive aggression in early adolescence as precursors to anti- and prosocial behavior in young adults

Three groups of adolescents who were 14 years old in 1974 were formed on the basis of peer nominations and teacher ratings in an ongoing longitudinal study: 1) reactively aggressive (REA) individuals who displayed reactive, that is, self-defensive aggression but not proactive aggression (43 boys, 35 girls); 2) proactively aggressive (PROA) individuals who attacked another person without a reason (56 boys, 35 girls); and 3) nonaggressive (NONA) individuals who were low in proactive and reactive aggression (48 boys, 45 girls). The groups were compared at ages 8, 14, and 27 in variables representing the constructs of a two-dimensional model of emotional and behavioral regulation. The REA Ss were characterized by higher self-control, especially constructiveness, at each age and better adult adjustment than the PROA Ss. The PROA males were prone to externalizing problems and criminality in adulthood, whereas the PROA females were prone to internalizing problems and neuroticism in adulthood. Both exhibited conduct problems in adolescence, and became heavy users of alcohol in adulthood. The PROA Ss had more children at age 27 than the other Ss. © 1996 Wiley-Liss, Inc.     

Effects of ritanserin on offense and defense in male mice

Effects of ritanserin on agonistic behavior of isolated mice exhibiting aggressive or nonaggressive behavioral strategies were studied in pair-wise encounters with group-housed opponents. An ethological approach to behavioral scoring is adopted, which allows for examination of the profiles of individual subjects. Although the data generally support the view that ritanser in has little effect on offense or defense in male mice, the stimulation of pre-aggressive behavior (threats, alerts, tail rattles) was detected in some nonaggressive mice. © 1995 Wiley-Liss, Inc.     

自控摄入小剂量酒精影响熟练驾驶行为的实验研究

一个小样本受试者内设计实验,受试者在实验允许的酒精剂量范围内自由选择摄入量。实验安排饮酒前,酒后３０分钟、１１０分钟和１７０分钟四个测试阶段,分别检验受试者在模拟驾驶和实际驾驶两项任务中的认知行为。酒后３０分钟实际驾驶的技能与其他三个测试期相比存在有意义的差别显著性;模拟测试任务中酒后对红、黄两种信号灯的认知反应时之间呈现显著性差别,酒后１１０分钟对黄色信号灯的反应明显延迟。研究提示：受试对酒精感受性的估计是不可靠的,小剂量酒精也能对驾驶行为构成伤害。     

“组织学习障碍”研究

组织要进行真正的学习 ,就必须克服“组织学习障碍”。“组织学习障碍”分为“单环学习障碍”和“双环学习障碍”两大类。为了克服“组织学习障碍”,首先必须消除组织的习惯性防御机制 ,然后进行“学习型组织”的各项修炼。     

Immobility reaction at birth in newborn infant

Objective

To describe an immobility reaction (IR) that was not previously reported at or immediately after birth in human newborns.

Method

We analyzed 31 videos of normal term vaginal deliveries recorded from Time 0 of birth defined as the as the moment that lies between the birth of the thorax and the pelvis of the infant. We searched for perinatal factors associated with newborn's IR.

Results

IR at birth was observed in 8 of the 31 newborns. The main features of their behavior were immobilization, frozen face, shallow breathing and bradycardia. One of the 8 newborns had sudden collapse 2 h after birth. We found significant relationships between maternal prenatal stress (PS) and IR (p = .037), and a close to significant one between infants’ lividness at Time 0 and IR (p = .053). The first breath of the 31 newborns occurred before and was not associated with the first cry (p < .001).

Discussion

The main features of IR at birth are similar to those of the universal most severe response to severe stress or danger. The relationship with PS suggests that children who had IR at birth might be at risk for similar disorders as those associated with PS. Sudden neonatal collapse of one of the IR newborns needs further research to determine if they are at risk for sudden infant death syndrome.

Conclusion

This first report of an IR reaction at birth in human infants could open up new paths for improving early neonatal care. Further research is needed for maternal PS, stress hormones, umbilical cord blood pH measurements in IR newborns. The challenge of education and support for parents of IR newborns is outlined.