Hypnotizing Libet: Readiness potentials with non-conscious volition

The readiness potential (RP) is one of the most controversial topics in neuroscience and philosophy due to its perceived relevance to the role of conscious willing in action. Libet and colleagues reported that RP onset precedes both volitional movement and conscious awareness of willing that movement, suggesting that the experience of conscious will may not cause volitional movement (Libet, Gleason, Wright, & Pearl, 1983). Rather, they suggested that the RP indexes unconscious processes that may actually cause both volitional movement and the accompanying conscious feeling of will (Libet et al., 1983; pg. 640). Here, we demonstrate that volitional movement can occur without an accompanying feeling of will. We additionally show that the neural processes indexed by RPs are insufficient to cause the experience of conscious willing. Specifically, RPs still occur when subjects make self-timed, endogenously-initiated movements due to a post-hypnotic suggestion, without a conscious feeling of having willed those movements.     

Influencing choice without awareness

Forcing occurs when a magician influences the audience’s decisions without their awareness. To investigate the mechanisms behind this effect, we examined several stimulus and personality predictors. In Study 1, a magician flipped through a deck of playing cards while participants were asked to choose one. Although the magician could influence the choice almost every time (98%), relatively few (9%) noticed this influence. In Study 2, participants observed rapid series of cards on a computer, with one target card shown longer than the rest. We expected people would tend to choose this card without noticing that it was shown longest. Both stimulus and personality factors predicted the choice of card, depending on whether the influence was noticed. These results show that combining real-world and laboratory research can be a powerful way to study magic and can provide new methods to study the feeling of free will.     

Unconscious manipulation of free choice by novel primes

The extent to which non-conscious perception can influence behaviour has been a topic of considerable controversy in psychology for decades. Although a challenging task, convincing empirical demonstrations have emerged suggesting that non-consciously perceived ‘prime’ stimuli can influence motor responses to subsequent targets. Interestingly, recent studies have shown that the influence of masked primes is not restricted to target-elicited responses, but can also bias free-choices between alternative behaviours. The present experiment extends these findings by showing that free-choices could also be biased by novel primes that never appeared as targets and therefore could not trigger acquired stimulus–response (S–R) mappings. This new evidence suggests that free-choice behaviour can be influenced by non-consciously triggered semantic representations. Furthermore, the results reported here support accounts of masked priming that posit an automatic semantic categorisation of non-consciously perceived visual stimuli.     

免除伦理审查制度及其应用实践建议

2023年发布的《涉及人的生命科学和医学研究伦理审查办法》（以下简称《办法》）首次设立了免除伦理审查制度。该制度设计旨在提升伦理审查效率,但也面临一系列的应用实践挑战。从澄清免除伦理审查的概念入手,简要分析免除伦理审查制度设计的初衷和必要性,同时,以美国为例,介绍了免除伦理审查制度的国际进展以及既往实践的经验教训。最后,针对《办法》提出的免除伦理审查相关要求的重点和难点进行了探讨,并就免除伦理审查的决定主体、标准操作程序,以及免除伦理审查的研究的跟踪审查等应用实践细节提出初步建议。

     

Free recall and retrieval speed of categorized items by kindergarten children

Kindergarten Ss were presented with 16 pictorial items in four category sets or a partially random ordem with one item from each category composing the four presentation sets. The pictures were presented either on conceptually related background pictures or on white backgrounds. The categorically grouped presentation facilitated free recall performance, both in terms of number of items recalled and the speed with which the items were recalled, and increased the amount of clustering in recall. Categorical clustering in recall was associated with shorter within- than between-category intervals and for those Ss who recalled items from each of four categories successively, the over-all temporal pattern in recall closely approximated that found with adults. No background effects were found.     

Satisfiability Decay along Conjunctions of Pseudo-Random Clauses

k-SAT is a fundamental constraint satisfaction problem. It involvesS(m), the satisfaction set of the conjunction of m clauses,each clause a disjunction of k literals. The problem has manytheoretical, algorithmic and practical aspects. When the clauses are chosen at random it is anticipated (butnot fully proven) that, as the density parameter m/n (n thenumber of variables) grows, the transition of S(m) to beingempty, is abrupt: It has a "sharp threshold", with probability1 – o(1). In this article we replace the random ensemble analysis by apseudo-random one: Derive the decay rule for individual sequencesof clauses, subject to combinatorial conditions, which in turnhold with probability 1 – o(1). This is carried out under the big relaxation that k is not constantbut k = log n , or even r log log n . Then the decay of S isslow, "near-perfect" (like a radioactive decay), which entailssharp thresholds for the transition-time of S below any givenlevel, down to S = .     

Effects of language dominance on item and order memory in free recall,serial recall and order reconstruction

Spanish–English bilinguals (N = 144) performed free recall, serial recall and order reconstruction tasks in both English and Spanish. Long-term memory for both item and order information was worse in the less fluent language (L2) than in the more fluent language (L1). Item scores exhibited a stronger disadvantage for the L2 in serial recall than in free recall. Relative order scores were lower in the L2 for all three tasks, but adjusted scores for free and serial recall were equivalent across languages. Performance of English-speaking monolinguals (N = 72) was comparable to bilingual performance in the L1, except that monolinguals had higher adjusted order scores in free recall. Bilingual performance patterns in the L2 were consistent with the established effects of concurrent task performance on these memory tests, suggesting that the cognitive resources required for processing words in the L2 encroach on resources needed to commit item and order information to memory. These findings are also consistent with a model in which item memory is connected to the language system, order information is processed by separate mechanisms and attention can be allocated differentially to these two systems.     

How Do Children Restrict Their Linguistic Generalizations? An (Un‐)Grammaticality Judgment Study

A paradox at the heart of language acquisition research is that, to achieve adult‐like competence, children must acquire the ability to generalize verbs into non‐attested structures, while avoiding utterances that are deemed ungrammatical by native speakers. For example, children must learn that, to denote the reversal of an action, un‐ can be added to many verbs, but not all (e.g., roll/unroll; close/*unclose). This study compared theoretical accounts of how this is done. Children aged 5–6 (N = 18), 9–10 (N = 18), and adults (N = 18) rated the acceptability of un‐ prefixed forms of 48 verbs (and, as a control, bare forms). Across verbs, a negative correlation was observed between the acceptability of ungrammatical un‐ prefixed forms (e.g., *unclose) and the frequency of (a) the bare form and (b) alternative forms (e.g., open), supporting the entrenchment and pre‐emption hypotheses, respectively. Independent ratings of the extent to which verbs instantiate the semantic properties characteristic of a hypothesized semantic cryptotype for un‐ prefixation were a significant positive predictor of acceptability, for all age groups. The relative importance of each factor differed for attested and unattested un‐ forms and also varied with age. The findings are interpreted in the context of a new hybrid account designed to incorporate the three factors of entrenchment, pre‐emption, and verb semantics.