Object permanence in lemurs

Object permanence, the ability to mentally represent objects that have disappeared from view, should be advantageous to animals in their interaction with the natural world. The objective of this study was to examine whether lemurs possess object permanence. Thirteen adult subjects representing four species of diurnal lemur (Eulemur fulvus rufus, Eulemur mongoz, Lemur catta and Hapalemur griseus) were presented with seven standard Piagetian visible and invisible object displacement tests, plus one single visible test where the subject had to wait predetermined times before allowed to search, and two invisible tests where each hiding place was made visually unique. In all visible tests lemurs were able to find an object that had been in clear view before being hidden. However, when lemurs were not allowed to search for up to 25-s, performance declined with increasing time-delay. Subjects did not outperform chance on any invisible displacements regardless of whether hiding places were visually uniform or unique, therefore the upper limit of object permanence observed was Stage 5b. Lemur species in this study eat stationary foods and are not subject to stalking predators, thus Stage 5 object permanence is probably sufficient to solve most problems encountered in the wild.     

Concept of uprightness in baboons: assessment with pictures of realistic scenes

How nonhuman primates process pictures of natural scenes or objects remains a matter of debates. This issue was addressed in the current research by questioning the processing of the canonical orientation of pictures in baboons. Two adult guinea baboons were trained to use an interactive key (IK) on a touch-screen to change the orientation of target pictures showing humans or quadruped mammals until upright. In experiment 1, both baboons successfully learned to use the IK when that key induced a 90 degrees rightward rotation of the picture, but post-training transfer of performance did not occur to novel pictures of natural scenes due to potential motor biases. In Experiment 2, a touch on IK randomly displayed the pictures in any of the four cardinal orientations. Baboons successfully learned the task, but transfer to novel pictures could only be demonstrated after they had been exposed to 360-480 pictures in that condition. Experiment 3 confirmed positive transfers to novel pictures, and showed that both the figure and background information controlled the behavior. Our research on baboons therefore demonstrates the development and use of an "upright" concept, and indicates that picture processing modes strongly depend on the subject's past experience with naturalistic pictorial stimuli.     

Can we understand why cognitive function predicts mortality? Results from the Caerphilly Prospective Study (CaPS)

The association between cognitive function and mortality is of increasing interest. We followed 1870 men aged 55–69 years at cognitive assessment for 16 years to establish associations with all case and cause specific mortality. Cognitive assessment included AH4, 4 choice reaction time (used as estimates of mid-life cognition) and the National Adult Reading Test (used as an estimate of early-life cognition). Causal models were tested for the effects of a) early-life cognition, b) confounding through mid-life disease, and c) the effects of sociodemographic and lifestyle factors. A fully adjusted model was also tested. Age adjusted associations with mid-life cognitive function were found with mortality from circulatory, coronary, respiratory and digestive disease but not from cancer mortality. Age adjusted associations were attenuated and in some cases nullified by further adjustment for each of early-life cognition, mid-life disease risk and sociodemographic and lifestyle factors. These associations cannot be assumed to be unbiased estimates of effect due to the complex confounding structures that exist in these data. Future studies should explore natural experiments, use different populations where the confounding structures may be different and evaluate more complex methods that may be able to deal with the inherent complexities of a life course perspective.     

The Role of Natural Class Features in the Acquisition of Phonotactic Regularities

Previous research has shown that phonotactic regularities can be acquired through recent production or auditory experience (e.g., Dell et  al., Journal of Experimental Psychology: Learning, Memory, and Cognition, 26(6), 1355–1367, 2000; Onishi et al., Cognition, 83(1), B13–B23, 2002). However, little is known about the role of phonological natural classes in this learning process. This study addressed this question by investigating the acquisition of a contingency relationship between onsets and medial glides by Mandarin speakers. The experiments involved the manipulation of three types of phonotactic regularities. In the Laryngeal version, onsets that preceded the same glide shared a voicing feature. In the Place version, onsets that preceded same glide shared a place feature. In the Neither version, onsets associated with the same glide shared neither a voicing feature nor a place feature. Results showed the Place version and the Laryngeal version were more easily acquired than the Neither version in terms of the amount of exposure needed to acquire the experimentally manipulated phonotactic schema and the sustainability of the acquired schema. The results suggest that the statistical learning mechanism that guides our processing of speech input prefers phonological regularities that follow certain natural class features. This preference may account for the way natural languages are structured phonologically. An erratum to this article can be found at     

The Role of Cognitive Control in Cocaine Dependence

While hedonic and reward-related processes are central to drug use and dependence, this article focuses on the contribution that cognitive processes may make to addiction. In particular, attention is drawn to those processes involved in exercising control over behavior as drug dependence is characterized by risky, impulsive behavior. Functional neuroimaging implicates prefrontal deficits in cocaine dependence with an emerging picture of cocaine users having attentional biases towards drug-related stimuli, poor performance in laboratory tests of inhibitory control, and compromised monitoring and evaluation of their behavior. Combined, these deficits may contribute to the continuation of use in dependent individuals and may qualify as important targets for therapeutic interventions.     

Effects of the menstrual cycle on looking preferences for faces in female rhesus monkeys

Fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors in primates. For example, female rhesus monkeys exhibit heightened interest for males and increased agonistic interactions with other females during periods of high estrogen levels. In the present study, we hypothesized that females’ preference for males during periods of high estrogen levels is also expressed at the level of face perception. We tested four intact females on two face-tasks involving neutral portraits of male and female rhesus monkeys, chimpanzees and humans. In the visual preference task (VP), monkeys had to touch a button to view a face image. The image remained on the screen as long as the button was touched, and the duration of pressing was taken as an index of the monkey's looking time for the face stimulus. In the Face-Delayed Recognition Span Test (Face-DRST), monkeys were rewarded for touching the new face in an increasing number of serially presented faces. Monkeys were tested 5 days a week across one menstrual cycle. Blood was collected every other day for analysis of estradiol and progesterone. Two of the four females were cycling at the time of testing. We did not find an influence of the cycle on Face-DRST, likely due to a floor effect. In the VP however, the two cycling individuals looked longer at conspecific male faces than female faces during the peri-ovulatory period of the cycle. Such effects were absent for human and chimpanzee faces and for the two noncycling subjects. These data suggest that ovarian hormones may influence females’ preferences for specific faces, with heightened preference for male faces during the peri-ovulatory period of the cycle. Heightened interest for stimuli of significant reproductive relevance during periods of high conception risk may help guide social and sexual behavior in the rhesus monkey.     

Octopuses (Octopus bimaculoides) and cuttlefishes (Sepia pharaonis, S. officinalis) can conditionally discriminate

In complex navigation using landmarks, an animal must discriminate between potential cues and show context (condition) sensitivity. Such conditional discrimination is considered a form of complex learning and has been associated primarily with vertebrates. We tested the hypothesis that octopuses and cuttlefish are capable of conditional discrimination. Subjects were trained in two maze configurations (the conditions) in which they were required to select one of two particular escape routes within each maze (the discrimination). Conditional discrimination could be demonstrated by selecting the correct escape route in each maze. Six of ten mud-flat octopuses (Octopus bimaculoides), 6 of 13 pharaoh cuttlefish (Sepia pharaonis), and one of four common cuttlefish (S. officinalis) demonstrated conditional discrimination by successfully solving both mazes. These experiments demonstrate that cephalopods are capable of conditional discrimination and extend the limits of invertebrate complex learning.     

Group cognition,membership change,and performance: Investigating the benefits and detriments of collective knowledge

This study analyzes the effects of group membership change on group cognition and performance to determine how groups can simultaneously leverage oldtimers’ collective knowledge and a newcomer’s expertise. Our analysis focuses specifically on the interrelated effects of the two components of a transactive memory system (TMS)—TMS structure and TMS processes—to explain the cognitive mechanisms through which membership change affects group performance. Results from a laboratory study show that groups that experience partial membership change tend to rely on the TMS structure that oldtimers developed in their original group, and that doing so is ultimately detrimental to performance because it creates inefficient TMS processes. Results from a supplemental study indicate that these TMS process inefficiencies can be avoided when oldtimers are instructed to reflect upon their collective knowledge prior to task execution. We discuss the implications for managing group cognition in organizations where membership change is prevalent.     

Suppression-induced hyperaccessibility of thoughts in abstinent alcoholics: a preliminary investigation

Abstinent alcoholics were compared to a non-alcoholic control group on a modified Stroop color-naming task. Alcoholics took significantly longer to name the color of the word "alcohol" than to name the color of non-alcohol words (i.e., they showed an interference effect) after they had first tried to suppress thoughts of alcohol. Alcoholics who had freely expressed thoughts about alcohol prior to the Stroop did not show such interference. Control participants who had suppressed thoughts of alcohol showed no interference effect. The results overall suggest that when alcoholics try to suppress thoughts of alcohol, these thoughts may become hyperaccessible immediately afterward.     

走向整合的智力研究 ——Demetriou的经验结构式认知发展理论述评

基于经验结构式认知发展理论的智力结构包含环境指向系统、超认知系统和加工系统三个层次。环境指向系统用于表征和加工不同领域的信息,加工系统是个体加工信息的操作平台,超认知系统负责监控和调节其他两个系统的认识活动。三个层次的发展既具有各自的特点又相互影响。因此,该理论指出智力结构的发展是一个动态平衡过程,存在三种发展变化模式：自下而上、自上而下和平行变化。智力结构层次内和层次间的发展都要遵循四种变化的机制。该理论作为整合型智力理论有自己的优势,但在概念使用、超认知概念的提出以及执行功能在结构中定位等问题有待商榷