Intracranial self-stimulation improves memory consolidation in rats with little training

Post-training intracranial electrical self-stimulation can improve learning and memory consolidation in rats. However, the molecular mechanisms involved are not known yet. Since previous paradigms of this kind of facilitation are relatively unsuitable to try a molecular approach, here we develop a single and short model of learning and memory facilitation by post-training self-stimulation that could make easier the research of its neural and molecular basis. Thus, three consecutive experiments were carried out to ascertain whether post-training self-stimulation is able to facilitate memory when learning consists of only a brief (5 trials) two-way active avoidance conditioning session. The results of Experiment 1 showed that it is actually possible, and that 48 h after the acquisition session is a very good time to observe the memory improvement. As a way to probe the retroactive effect of self-stimulation, in Experiment 2 we observed that the same self-stimulation treatment given to the subjects not post-training but 48 h before a single two-way active avoidance session does not improve the acquisition of conditioning. In Experiment 3, we showed that the SS facilitative effect observed 48 h after the acquisition session in Experiment 1 was still maintained one week later. We concluded that post-training intracranial self-stimulation can consistently improve memory consolidation even when little acquisition training is given to the animals in a single training session.     

Persistent effects of subliminal stimulation: sex differences and the effectiveness of debriefing

Persistent and non-trivial effects of unconscious stimuli have been reported (Sohlberg & Birgegard, 2003). This raises the ethical question of whether informing participants about such stimuli effectively returns them to a normal state. Two experiments (sex-mixed, N = 70 and 118) tested two kinds of debriefing to participants following subliminal (tachistoscopic) attachment-related or control stimulation. Measures were the Beck Depression Inventory, Structural Analysis of Social Behavior, and Retrospective Attachment. Results showed persistent effects. Simple debriefing about the stimulus was effective in preventing these, while more elaborate debriefing also describing the effects and mechanisms for them was less effective. Persistent effects were also strongly related to participant sex, but debriefing effects were similar in men and women with regard to the purpose of debriefing. The findings have implications for ethical recommendations for subliminal research, and suggest that this unexplored area requires more attention.     

Intersensory Redundancy Guides the Development of Selective Attention, Perception, and Cognition in Infancy

Abstract— That the senses provide overlapping information for objects and events is no extravagance of nature. This overlap facilitates attention to critical aspects of sensory stimulation, those that are redundantly specified, and attenuates attention to nonredundantly specified stimulus properties. This selective attention is most pronounced in infancy and gives initial advantage to the perceptual processing of, learning of, and memory for stimulus properties that are redundant, or amodal (e.g., synchrony, rhythm, and intensity), at the expense of modality-specific properties (e.g., color, pitch, and timbre) that can be perceived through only one sense. We review evidence supporting this hypothesis and discuss its implications for theories of perceptual, cognitive, and social development.     

Making Group Brainstorming More Effective: Recommendations From an Associative Memory Perspective

Much literature on group brainstorming has found it to be less effective than individual brainstorming. However, a cognitive perspective suggests that group brainstorming could be an effective technique for generating creative ideas. Computer simulations of an associative memory model of idea generation in groups suggest that groups have the potential to generate ideas that individuals brainstorming alone are less likely to generate. Exchanging ideas by means of writing or computers, alternating solitary and group brainstorming, and using heterogeneous groups appear to be useful approaches for enhancing group brainstorming.     

Imagery and olfactory stimulation

The purpose of the present study was to investigate a possible odor-emotion interaction by determining whether humans could differentially detect other humans' odor collected under varying emotional conditions. Odorants were collected from the axillary apocrine glands of four female donors, each of whom underwent different imagery induction procedures of anxiety, relaxation, and sexual arousal. The odorants were chemically preserved and later evaluated by 16 naive white male judges as to the presence of discriminatory odor cues. Judges' imagery was differentially related to the anxiety imagery-produced odorants but only for those produced by the most imaginative donors. The relaxation odorants of all donors were correlated. The judges were unable to detect the sexual imagery arousal odorants.     

ATTENTION TRAINING: THE USE OF OVERCORRECTION AVOIDANCE TO INCREASE THE EYE CONTACT OF AUTISTIC AND RETARDED CHILDREN

A crucial first step in teaching and training the retarded and autistic is to develop and maintain eye contact with the therapist. Functional movement training (an overcorrection procedure) plus edibles and praise were compared with edibles and praise alone as a method of developing eye contact in three such children. In both conditions, the child was given food and praise when eye contact occurred within 5 sec of the therapist's verbal prompt: “Look at me.” Functional movement training avoidance plus edibles and praise produced about 90% attention for the three children, while edibles and praise alone were less effective (eye contact never exceeded 55%). Functional movement training avoidance combined with edibles and praise appears to be an effective method of teaching eye contact and possibly other forms of instruction-following to behaviorally disordered children who are not always responsive to positive consequences.     

Food and intracranial stimulation responding suppressed with regular-interval shock.

Attenuation of conditioned suppression during intracranial stimulation was compared with that during food reinforcement. Response rates controlled by food and by brain stimulation were equalized on a multiple schedule by adjusting the stimulating current. When foot shock was delivered during timeout periods separating response components, responding for food was significantly more suppressed than responding for brain stimulation. When components were shortened from 10 to 2 minutes, responding maintained by either food or brain stimulation showed a similar temporal pattern of suppression preceding each shock, but responding in the component involving food remained significantly more suppressed. Explanations for the attenuated suppression during brain stimulation based on neural disruption, stimulus blocking, and analgesic properties were questioned. The increased responding during brain stimulation seemed to reflect greater response strength relative to food reinforced responding.     

“生生”、“感通”、“偕行”——《易传》的天人共生哲学

天人问题是中国哲学的基本问题,天人的基本含义之一相当于我们现在通常说的自然与人;基本含义之二是视天人为有德性(道德)的、有能动性的动态的、协调的存在。中国哲学中的这种天人观在《易传》中表现为"生生"——"感通"——"偕行"的天人共生态。《易传》既将天人视为一个"生生不息"的自然的生命有机体,又充分发掘天人的德性,并使二者相资相长,"日新之谓盛德,生生之谓易",天地人各有其位,各尽其能,各循其道,"各正性命",一体偕行,共生共存共荣。     

Input-specific long-term potentiation in the rat lateral amygdala of horizontal slices

Long-term potentiation (LTP) at input synapses to the lateral nucleus of the amygdala (LA) is a candidate mechanism for memory storage during fear learning. Cellular mechanisms of LTP have been nearly exclusively investigated in coronal brain slices. In our experiments, we used a horizontal brain slice preparation of rats that preserved most of the connections to cortical areas and the hippocampus. The stimulation electrodes were located either within the external capsule (EC) or the LA. The aim of the present study was to investigate the mechanisms of LTP induced either by weak theta burst stimulation (TBS) or strong high frequency stimulation (HFS) using the two different stimulation sites. Whereas both TBS and HFS of afferences running through the LA induced stable LTP, TBS failed to induce LTP of EC-inputs to the LA. The present findings also show that LTP in the LA exhibits vulnerability at different time windows after induction. The time window was dependent on the kind of stimulated afferences. Later LTP becomes resistant to disruption by low frequency stimulation. We could show that both used inputs depended on NMDA receptors for LTP-induction. LTP induced by stimulation of fibers within the LA was not altered by nifedipine (10 microM). In contrast, EC-induced LTP was dependent on L-type voltage-gated calcium channels (VGCC). Finally, we found a higher magnitude of LTP in females using TBS, whereas HFS did not cause gender-specific differences. Our study supports the conclusion that the form of LA-LTP depend on which afferences are activated and what pattern of stimulation is used to induce LTP.