Maternal aggression in mice: The non-specific nature of the exteroceptive maintenance by young

Five hours of pup removal during early lactation (Postpartum Day 6) reduced maternal aggression in mice, while placement of the dam's entire litter (six pups) or a single pup behind a double wire mesh partition in the homecage maintained aggression at a level identical to that of mothers in direct contact with their young. When placed behind the partition, unfamiliar 6, 13, and 20-day-old pups, but not 30-day-old mice, maintained the behavior as effectively as the dam's own young. The relationship of the findings to communal rearing conditions in the mouse is discussed.     

奖赏刺激的脑电反应特征跨文化差异:一个ERP研究

本研究从文化--社会神经科学的角度出发,采用事件相关电位的方法来探究不同文化背景下的个体对具有进化和社会文化代表性的正性刺激—奖赏刺激的脑电反应特征是否具有差异。本研究采用the Door Task实验范式考察了26名中国人和24名高加索白人对不同反馈反应的脑电特征跨文化差异。结果显示,负性反馈条件下诱发的FRN平均波幅比正性反馈条件诱发的平均脑电波幅更负,这种正负反馈的波幅差异只在中国被试中有体现。在P3成分上,在正性反馈条件下,中国被试诱发的脑电波幅大于西方被试,负性反馈条件下,两组无显著差异。研究结果表明,相对于西方被试,中国被试对奖赏反馈刺激可能具有较高的敏感性。这说明中西方文化下的个体对正负性反馈刺激的加工的脑电反应特征存在显著的差异。     

Development of the Basel Version of the Awareness of Social Inference Test – Theory of Mind (BASIT-ToM) in healthy adults

Impairments of Theory of Mind (ToM) abilities occur in a wide range of brain disorders. Therefore, reliable and ecologically valid examination of these abilities is a crucial part of any comprehensive neuropsychological assessment. An established and ecologically valid, English-language test identifying deficits in ToM abilities is “The Awareness of Social Inference Test – Social Inference Minimal (TASIT-SIM)”. However, no comparable German-language ToM test currently exists. In this study, we aimed to develop the first German-language adaption of TASIT-SIM in healthy adults. We selected 13 scenes [four scenes per message type (i.e., honesty, simple sarcasm, paradoxical sarcasm) and one practice scene] out of the 30 TASIT-SIM scenes. In collaboration with a film institute, we filmed each scene at three different intensities. These intensity version scenes were then administered to 240 healthy adults, equally distributed in sex and age, ranging from 35 to 92 years. By applying Rasch analysis, we selected intensity versions that showed neither floor nor ceiling effects in the majority of ToM questions in participants whose ToM abilities were in the medium range. In conclusion, we have developed the first German-language adaption of TASIT-SIM, i.e., the “Basel Version of the Awareness of Social Inference Test – Theory of Mind (BASIT-ToM)”. The BASIT-ToM incorporates the strengths of TASIT-SIM, while overcoming its limitations such as inconsistencies in cinematic realization and ceiling effects in healthy participants. Next, the BASIT-ToM needs to be validated in healthy people and clinical populations.     

The effects of the stimulus-reinforcer correlation in a discrete-trials IRT>t procedure

The correlation between a keylight and food in a discrete-trials, interresponse-time-greater-than 6-sec (IRT>6-sec) procedure was varied by manipulating the rate of response-independent food presentation in the intertrial interval. When the correlation was positive, the rates of pecking in the IRT>6-sec condition were high and food was obtained on only about 5% of the trials. Likewise, responding was maintained at a high rate in yoked birds that received the same presentations of the light and food as the birds in the IRT>6-sec condition. When the rate of reinforcement between trials was equated to or made greater than the rate of reinforcement within trials, the response rate decreased for all birds, and those decreases were considerably larger for the yoked birds. However, the percentage of trials in which reinforced responses occurred under the IRT>6-sec procedure did not increase substantially when the light and food were either uncorrelated or negatively correlated. The percentage of trials in which a reinforcer was obtained increased when the keylight was left on continuously and the discriminative stimulus was not presented on the key. The results show that the stimulus-reinforcer correlation affects responding in the discrete-trials IRT>6-sec procedure, but that the effects of the stimulus-reinforcer correlation vary as a function of whether reinforcement is response-dependent or response-independent. The differences between the effects of response-independent and response-dependent pairings and nonpairings of the light and food are best accounted for in terms of differences in the control of responding by background stimuli.     

Expansion of arbitrary stimulus classes and function-transfer measured by sorting performances

Sorting (SRT) and matching-to-sample (MTS) tests have measured the formation of arbitrary stimulus classes. This experiment used SRT and MTS tests to document the expansion of class size. Thirty-two participants learned 12 conditional discriminations with a linear series training structure (A➔B➔C➔D➔E). SRT tests documented the formation of 5-member classes by 17 of the participants. Thereafter, 6-member class expansion was implemented by FC training. Nine of these 17 participants showed class expansion when tracked with a sequence of an SRT, MTS, and a final SRT test, and the other 8 showed expansion when tracked with a sequence of MTS and SRT tests. Thus, SRT tests documented class expansion, and the sequence of tests did not influence class expansion. The 15 participants who did not form the 5-member classes learned the baselines for new 3-member classes (A➔B➔C) and formed them as documented by an SRT test. Then, 4-member class expansion was implemented by FB training. Expansion was assessed using the above-mentioned testing sequences. All 15 showed class expansion with 100% correspondence between the SRT and MTS performances. Sorting documented the expansion of arbitrary stimulus classes, while the MTS tests showed that the stimuli also functioned as members of equivalence classes.     

Auditory–Visual stimuli: Effects on derived relations with compound stimuli

This research explored the effect of teaching conditional discriminations with three procedures on the derivation of 36 stimuli relations (derived relations). The stimuli used consisted of three characteristics musical instruments, along with the corresponding picture. In the first experiment six university students were trained with simple stimuli and tested with compound auditory–visual samples; therefore, a one‐to‐many structure was used. In the second experiment, auditory stimuli were replaced by visual stimuli, for the samples used, for new students. A third experiment was implemented with an extra phase of training with compound stimuli for six new students. The structure of the experiments was: pretests (Xbcd–A; Xacd–B; Xabd–C; Xabc–D), training (A–B; A–C; A–D), and posttests (same as pretests). The difference between these conditions was the kind of stimuli used and a new phase of teaching used in condition 3: (Xbcd–A). The results indicate that training with simple stimuli on discriminations that include stimuli that are easy to discriminate from each other (words and sounds) is a sufficient condition for good posttest performance. However, when comparisons are made difficult (words only), participants show better performance on new tests if they have a learning history with compound stimuli.     

An orienting response is not enough: Bivalency not infrequency causes the bivalency effect

When switching tasks, occasionally responding to bivalent stimuli (i.e., stimuli with relevant features for two different tasks) slows performance on subsequent univalent stimuli, even when they do not share relevant features with bivalent stimuli. This performance slowing is labelled the bivalency effect. Here, we investigated whether the bivalency effect results from an orienting response to the infrequent stimuli (i.e., the bivalent stimuli). To this end, we compared the impact of responding to infrequent univalent stimuli to the impact of responding to infrequent bivalent stimuli. For the latter, the results showed a performance slowing for all trials following bivalent stimuli. This indicates a long-lasting bivalency effect, replicating previous findings. For infrequent univalent stimuli, however, the results showed a smaller and shorter-lived performance slowing. These results demonstrate that the bivalency effect does not simply reflect an orienting response to infrequent stimuli. Rather it results from the conflict induced by bivalent stimuli, probably by episodic binding with the more demanding context created by them.     

An experimental investigation of daytime monitoring for sleep-related threat in primary insomnia

An experimental manipulation was conducted to test the hypothesis that monitoring for sleep-related threat during the day triggers a cycle of cognitive processes that includes increased negative thinking, increased use of safety behaviours, increased perceived impairment in functioning, and increased self-reported sleepiness. Forty-seven individuals with primary insomnia were randomly assigned to a monitoring group (instructed to monitor their body sensations), a no-monitoring group (instructed to distract from their body sensations), or a no-instruction group. The manipulations to monitor or not monitor were administered immediately on waking and participants were asked to continue the manipulation throughout the experimental day. The monitoring group reported more negative thoughts, the use of more safety behaviours, and more sleepiness during the day relative to the no-instruction group. These findings offer support to a recent cognitive model, which identifies daytime monitoring for sleep-related threat as a key factor in the maintenance of the daytime distress and difficulty functioning in chronic insomnia.     

Tasks for Assessing Memory for Temporal Order Versus Memory for Items in Aging

Younger and older adults were compared on new tests for item and temporal memory suitable for use in future electrophysiological or neuroimaging studies. Following a series of 10 simple line drawings, 4-choice panels containing two previously seen targets and two novel distractors appeared. Participants identified which pictures had been seen previously (item), or which of the items was presented earliest (temporal order). Performance of younger adults was superior to that of older adults. Memory for item and temporal order were equivalent in the younger group. In contrast, the item memory of the older group was superior to memory for temporal order, confirming previous evidence of differential impairment of memory for temporal order with age.