熟悉嗓声识别中猴脑的事件相关电位

在四只三岁龄雄性猕猴(Macaca mulatta)中,研究了识别熟悉人与陌生人、熟悉猴与陌生猴嗓声中的脑事件相关电位(ERPs)。结果表明,对熟悉猴和陌生猴的噪声“er”所诱发的ERPs在左颞区和左、右两顶区存在着显著差异。熟悉猴嗓声在左颞区诱发的P200波潜伏期长,左顶区N100波幅值大,在左、右顶区P300波潜伏期短。熟悉人与陌生人嗓声“pa”诱发的ERPs在左、右顶区P200波潜伏期有显著性差异,熟悉“Pa”诱发反应潜伏期短。熟悉人与陌生人噪声“ba”诱发的ERPs没有差异。熟悉猴嗓声与熟悉人嗓声加“pa”诱发的ERPs相比,在右颞区的P300波幅值显著变大,两顶区N100波幅值也增大,在右顶区P200和P300波的潜伏期也明显变短。顶问区N100波潜伏期短、幅值高。陌生人与陌生猴“pa”嗓声诱发的ERPs间没有差异。熟悉猴嗓声和陌生猴嗓声出现的概率不同,并不引起ERPs的明显差异。     

Case study of a one‐sided attack by multiple troop members on a nontroop adolescent male and the death of Japanese macaques (Macaca fuscata)

An adolescent wild male Japanese macaque (Macaca fuscata), following Kinkazan A troop, was attacked one‐sidedly by multiple members of the troop. The victim was identified as PI, and was estimated to be seven±one year old. The aggressive interaction was recorded by video camera until the end. Although at least 16 troop members approached PI more than once, only three males (one adult, two adolescents) of A troop attacked him. PI kept crouching throughout the attack, then escaped to the shore and dived into the sea. The interaction continued for more than one hour. PI was found dead a few hours after the end of interaction. The damage caused by the assailants was not the direct cause of PI's death; it was due to hypothermia caused by drifting in the sea. PI's life history was reconstructed from past records. PI was a normal adolescent male who migrated from an all‐male group around B₁ troop and started ranging around A troop. The aggressive interaction is believed to be a typical example of conflict between troop males and a nontroop male. The interaction period was very long compared with previous reports on such conflicts among Japanese macaques. PI kept crouching in open areas, exposing himself as a potential competitor for the resources of the troop, and did not show any submissive or reconciliatory behavior toward the troop males. This may be why the troop males did not stop the attack. Aggr. Behav. 35:334–341, 2009. © 2009 Wiley‐Liss, Inc.     

Effects of short-term crowding on aggression in captive groups of pigtail monkeys (macaca nemestrina)

Agonistic behaviors of 14 groups of pigtail monkeys were monitored under 2 spatial conditions, normal living space and half that amount of space. Aggression occurred less frequently in the crowded than in the relatively less crowded condition. The results of this study resemble those of some analogous research on human children, and they suggest that nonhuman primate models of crowding stress and aggression may be especially appropriate.     

Performance in a computerized self-control task by rhesus macaques (Macaca mulatta): The combined influence of effort and delay

The variables of delay and effort have been found to influence self-control predictably and in similar fashion when tested independently, but it is unclear how they influence self-control interactively. In the present study, I tested these two variables simultaneously to gain better understanding of their combined influence on self-control. A computerized task was employed in which monkey participants could sequence 1 or more digital images before “cashing-out,” after which they would receive their accumulated rewards. Delay was manipulated by adjusting the speed of the cursor used to select images. Cognitive effort was manipulated by presenting image sets that appeared in either a constant or a randomized configuration. For most monkeys, an interaction was found between the effects of delay and effort on the number of images selected before cashing-out. The results suggest that, when combined, these two variables have a complex influence on self-control.