The Ketamine Model of the Near-Death Experience: A Central Role for the N-Methyl-D-Aspartate Receptor

Near-death experiences (NDEs) can be reproduced by ketamine via blockade of receptors in the brain for the neurotransmitter glutamate, the N-methyl-D-aspartate (NMDA) receptors. Conditions that precipitate NDEs, such as hypoxia, ischemia, hypoglycemia, and temporal lobe epilepsy, have been shown to release a flood of glutamate, overactivating NMDA receptors and resulting in neurotoxicity. Ketamine prevents this neurotoxicity. There are substances in the brain that bind to the same receptor site as ketamine. Conditions that trigger a glutamate flood may also trigger a flood of neuroprotective agents that bind to NMDA receptors to protect cells, leading to an altered state of consciousness like that produced by ketamine.     

Social desirability in the bedroom: Role of approval motivation in sexual relationships

One-hundred and twelve unmarried participants completed a questionnaire that examined the relationship between gender and approval motivation (assessed by the Marlowe—Crowne Social Desirability Scale) and college students' stereotypes of and experiences with power in sexual encounters. Regardless of approval motivation, students described men as using power predominantly to have sex and women as using power predominantly to avoid having sex. However, interactions between need for approval and gender suggested that high-need-approval women might be having more experiences with sex and power in the bedroom than high-need-approval men. These results are discussed in light of Elkind's hypothesis that adolescent behavior conforms to an imaginary audience of peers and the Crowne-Marlowe model of approval motivation.An earlier version of this article was presented in the symposium Gender and Power Strategies: Contrasting Models and Applications, at the meeting of the American Psychological Association, Los Angeles, August 24–28, 1981. The authors wish to express appreciation to J. W. McCormick for his assistance with data analysis and to E. Allgeier for her helpful comments on a previous draft.     

Learned helplessness: Not dependent upon cognitions, attributions, or other such phenomenal experiences

Subjects shot a light gun at a target with a photorecepter cell in the bull's-eye, with the only information regarding their accuracy being provided by reinforcing tone signals. Half the subjects received reinforcers contingent upon their hits. The others were yoked to the contingent subjects, receiving non-contingent reinforcers in the same patterns. Experiment 1 compared contingent or noncontingent positive or aversive reinforcers in their effect on subsequent anagrams performance. Phenomenal experiences, such as cognitive awareness, attributions, and moods, were assessed. Subjects exhibited a strong helplessness effect independent of their phenomenal experiences. In Experiment 2 the independent variables of contingent/noncontingent reinforcement and awareness of noncontingency were manipulated orthogonally by informing half the subjects that their reinforcement had been noncontingent in the target-shooting. Actual noncontingency produced a strong helplessness effect whereas “awareness of noncontingency” did not.     

Apparent movement and metacontrast: A note on Kahneman’s formulation

Recently metacontrast has been described as a case of “impossible” apparent motion. Kahneman (J 967) has supported this hypothesis with a study showing that apparent motion and metacontrast functions resemble one another. However, when visual angle, luminance, and duration vary from the values used in the Kahneman study, the resemblance between the two effects breaks down. Since the apparent motion explanation for metacontrast assumes an identity between apparent motion and metacontrast, these present results indicate that the apparent motion hypothesis for metacontrast is untenable. Metacontrast and apparent motion may not be unrelated, however; they might both have something to do with single units in the visualcortex. For each effect, however, different functional units would be involved.     

The crossword puzzle paradigm: The effectiveness of different word fragments as cues for the retrieval of words

We investigated the internal structure of words in the mental lexicon by using a crossword puzzle paradigm. In two experiments, subjects were presented with word fragments along with a semantic cue, and were asked to retrieve the whole word that contained the presented fragment and was compatible with the semantic information. In Experiment 1, we found that any cluster of three adjacent letters facilitated retrieval better than dispersed letters. Moreover, syllabic clusters had a greater facilitative effect than nonsyllabic pronounceable clusters or nonpronounceable clusters. In Experiment 2, we found that syllable units facilitated retrieval better than morphemic units. The results are interpreted as evidence for the existence of lexical subunits that are larger than the letter but smaller than the word, and that are organized according to phonologic principles. We propose an interactive model for how crossword puzzles are solved.     

Mood and fluency: The case of pronunciation ease,liking and trust

We explored the impact of mood on the judgemental consequences of word pronounceability in six Experiments (1 preregistered, total N = 1183). Positive and negative mood was induced via video clips (all but Experiment 4) and subliminal affective primes (Experiment 4). Additionally, participants were presented with easy- and difficult-to-pronounce letter strings. These were framed as target words to be judged for liking (Experiments 1–2), as names of eBay sellers to be judged for trustworthiness (Experiments 3–5), or as either seller names or passwords to provoke opposing interpretations of pronunciation fluency (Experiment 6). While pronounceability showed a robust effect across experiments, mood did not modulate the judgemental use of (Experiments 1–4), the correction for (Experiment 5) and the interpretation (Experiment 6) of word pronounceability. In conclusion, the judgemental effects of pronounceability persist despite the presence of more objective and task-pertinent cues, resist judgemental correction and remain unaffected by affective states.