Socially mediated learning in male Betta splendens. III: Rapid acquisitions

In four experiments with male Siamese fighting fish, the classical conditioning of visual/spatial cues with elicitors of aggression was demonstrated. These studies show that this type of socially mediated learning is more rapidly conditioned than was previously known. One 15-min training session is adequate to condition a preference for those cues that had recently been paired with conspecific images. Finally, behavior occurring during acquisition, in the presence of aggression-eliciting cues, was uncorrelated with the magnitude of the learned preferences that were assayed during extinction tests and in the absence of social stimuli.     

Instrumental conditioning of aggressive behavior in rats

A method has been developed for bringing an aggressive response under stimulus control. It was found that the number of conditioned aggyessive responses was maximal when low-weight target rats were used. The latencies of the conditioned responses toward target animals of 124 gm were significantly lower than those toward animals of 221 and 284 gm. The application of an extinction procedure on the conditioned aggressive response substantially increased the total number of emitted aggressive responses.     

预期错误在恐惧记忆更新中的作用与机制

依据错误驱动的学习理论,行为预期结果与实际结果之间的不匹配即预期错误(Predictionerror,PE)是学习产生的驱动因素。作为显著性信息中的一种,预期错误和物理显著性、惊讶、新异性等存在信息加工阶段的不同,与记忆更新的关系也有差异。近年来,记忆再巩固干预范式(reconsolidation interference)被证明可用于人类条件性恐惧记忆的更新,其中记忆提取激活阶段所包含的预期错误起到了引发记忆“去稳定”、开启记忆再巩固的关键作用。在促进恐惧记忆更新的行为机制上,PE被认为是记忆去稳定的必要非充分条件。记忆提取必须包含适量的PE,但其引发的是记忆去稳定、消退还是中间状态,还需结合记忆本身性质确定。在促进恐惧记忆更新的神经机制上,杏仁核、导水管周围灰质(PAG)、海马均在PE探测和计算过程中具有重要作用;前额叶皮层(PFC)及其亚区在PE开启记忆再巩固过程中扮演了重要角色。上述过程又受到神经系统中特定神经递质的重要调节,尤其是多巴胺能和谷氨酸能。未来研究应进一步探索基于PE计算模型的量化研究,整合PE与其他边界条件的交互作用,考察不同类型显著性在记忆再巩固中的作用等;并亟...     

Affective-Evaluative Learning in Humans: A Form of Associative Learning or Only an Artifact?

The status of evaluative conditioning (EC) as a distinct form of associative learning was called in question by Field and Davey (1997, 1998, 1999), who argued that in the typical visual EC paradigm, nonassociative visual concept learning is responsible for the evaluative changes observed. Especially, the use of only within-subject control conditions instead of independent control groups was criticized. The present three experiments show (a) that EC effects can be demonstrated within another sensory modality than visual perception and (b) that EC effects are demonstrable in a between-subject design (including a successful replication attempt). A further result was that these EC effects do not require participants' conscious awareness. The data provide no support for an artifactual account of EC but suggest an interpretation of EC as a form of associative learning.     

Differential Conditioning Based on a Difference in the Predictability of Reinforcement

A Pavlovian procedure containing a set of several alternative reliable trial stimuli and a set of several alternative unreliable trial stimuli was used to determine if reliability of outcome, per se, would differentially condition additional trial stimuli that either preceded or followed those original trial stimuli in a serial conditioning paradigm. The reinforcing effectiveness of the antecedent stimuli themselves was later tested in a higher-order conditioning design. It was found that different rates could be established to the different antecedent stimuli in the absence of a difference in the probability of reinforcement. Further, stimuli paired with those antecedent stimuli in the higher-order conditioning test also exhibited a difference in rate. It was concluded that a combination of a stimulus that is always followed by food and another that is never followed by food are, in net, a more effective reinforcer than a common stimulus that has the same overall probability of reinforcement but which is followed by both outcomes.     

Revisiting the learning-without-awareness question in human pavlovian autonomic conditioning: Focus on extinction in a dichotic listening paradigm

Numerous studies have indicated that, consistent with current “cognitive” accounts of information processing, human Pavlovian autonomic discrimination acquisition cannot occur without awareness of the CS-US relationship. However, extinction studies have suggested that awareness is not necessary, findings that, in information-processing terms, have been explained by assuming that the processing by the extinction stage is parallel (automatic) rather than serial (controlled). This explanation was tested in an 80-subject study. The first, acquisition phase was a standard semantic differential conditioning arrangement with a 96-db white noise as US, and a “long” CS-US interval of 8 s, with ten trials each of CS+ (paired with US) and CS− (unpaired) trials. In extinction (USs omitted), in order to obtain non-autonomic indices of processing and thereby test the information-processing account of “unaware” autonomic conditioning during extinction, a dichotic listening task was implemented, with the CSs presented in the unattended channel (ear), while the subject had to perform a semantic differential reaction task in an attended-to channel (other ear). In early extinction, the electrodermal response occurring at an interval of 9–15 s after CS onset (i.e., following placement of the US during acquisition) and the finger-pulse-volume response occurring at an interval of 4–11 s after CS onset both showed reliable conditioning, but reaction-time and subjective-report data for the recognized critical words indicated serial rather than parallel processing of the CSs during extinction.     

Functional analysis and operant treatment of food guarding in a pet dog

The present study extended functional analysis (FA) methodology to human-directed resource guarding in a dog in an in-home setting. The subject underwent four conditions including control, attention, escape, and tangible, arranged in a modified FA. The results indicated multiply controlled resource guarding (i.e., escape, attention, and tangible functions). The experimenter then conducted a treatment evaluation involving three function-based treatments in a concurrent multiple baseline design. Resource guarding decreased to zero levels in treatments for each maintaining contingency. Treatment effects were maintained when the subject was tested with an owner, with an untrained handler, a highly preferred treat, in an untrained setting, as well as after 2 weeks in the absence of training. Behavior analytic techniques may hold promise for lasting behavior change for resource guarding in domestic dogs, and should be examined in other populations and with other canine problem behavior.     

Using hippocampal‐dependent eyeblink conditioning to predict individual differences in spatial reorientation strategies in 3‐ to 6‐year‐olds

The hippocampus is a subcortical structure in the medial temporal lobe involved in cognitive functions such as spatial navigation and reorientation, episodic memory, and associative learning. While much is understood about the role of hippocampal function in learning and memory in adults, less is known about the relations between the hippocampus and the development of these cognitive skills in young children due to the limitations of using standard methods (e.g., MRI) to examine brain structure and function in developing populations. This study used hippocampal‐dependent trace eyeblink conditioning (EBC) as a feasible approach to examine individual differences in hippocampal functioning as they relate to spatial reorientation and episodic memory performance in young children. Three‐ to six‐year‐old children (N = 50) completed tasks that measured EBC, spatial reorientation, and episodic memory, as well as non‐hippocampal‐dependent processing speed abilities. Results revealed that when age was held constant, individual differences in EBC performance were significantly related to individual differences in performance on the spatial reorientation test, but not on the episodic memory or processing speed tests. When the relations between hippocampal‐dependent EBC and different reorientation strategies were explored, it was found that individual differences in hippocampal function predicted the use of geometric information for reorienting in space as opposed to a combined strategy that uses both geometric information and salient visual cues. The utilization of eyeblink conditioning to examine hippocampal function in young populations and its implications for understanding the dissociation between spatial reorientation and episodic memory development are discussed.     

Children's implicit attitude acquisition: Evaluative statements succeed,repeated pairings fail

From the earliest ages tested, children and adults show similar overall magnitudes of implicit attitudes toward various social groups. However, such consistency in attitude magnitude may obscure meaningful age‐related change in the ways that children (vs. adults) acquire implicit attitudes. This experiment investigated children's implicit attitude acquisition by comparing the separate and joint effects of two learning interventions, previously shown to form implicit attitudes in adults. Children (N = 280, ages 7–11 years) were taught about novel social groups through either evaluative statements (ES; auditorily presented verbal statements such as ‘Longfaces are bad, Squarefaces are good’), repeated evaluative pairings (REP; visual pairings of Longface/Squareface group members with valenced images such as a puppy or snake), or a combination of ES+REP. Results showed that children acquired implicit attitudes following ES and ES+REP, with REP providing no additional learning beyond ES alone. Moreover, children did not acquire implicit attitudes in four variations of REP, each designed to facilitate learning by systematically increasing verbal scaffolding to specify (a) the learning goal, (b) the valence of the unconditioned stimuli, and (c) the group categories of the conditioned stimuli. These findings underscore the early‐emerging role of verbal statements in children's implicit attitude acquisition, as well as a possible age‐related limit in children's acquisition of novel implicit attitudes from repeated pairings.     

普萘洛尔修复即刻消退产生的二次创伤

恐惧消退能力的受损是创伤后应激障碍(posttraumatic stress disorder, PTSD)的标志之一。以往的研究表明, 相较于延迟消退, 恐惧获得后短时间内进行的消退训练不能形成长时程的消退记忆, 这一现象被称为即刻消退缺损。然而, 目前并不清楚这种缺损是一次性的, 还是会继续影响其后的重消退。实验1中, 大鼠在恐惧习得后1小时(即刻消退)或24小时(延迟消退)开始进行消退训练, 24小时后进行重消退, 再24小时后进行消退记忆的测试。结果显示, 与延迟消退相比, 即刻消退效果缺损, 并引起第二天的重消退也出现效果缺损。实验2中, 恐惧获得后立即给予大鼠盐水或β-肾上腺素受体阻断剂普萘洛尔(10 mg/kg, i.p.), 然后测试即刻消退和重消退的效果。结果显示, 普萘洛尔虽没有阻止即刻消退的缺损, 但避免了重消退出现缺损。总之, 严重创伤后的即刻消退不但无法有效抑制恐惧反应, 还可能造成二次创伤, 会损害恐惧消退能力, 而普萘洛尔可修复即刻消退引起的重消退缺损。这些结果将有助于我们加深对PTSD病理机制和早期干预后果的认识。