Processing of memories and knowledge in REM and NREM dreams

Over 4 nights, 16 young-adult males each reported 2 REM and 2 nonREM dreams. They then identified possible sources of dream imagery in their waking memory and/or knowledge. A judge, naive as to conditions of data collection, reliably judged the closeness of correspondence of dream event to identified source. Correspondence was lower for REM than for nonREM reports and for longer than for shorter reports from either stage.     

Daydreams and nap dreams: Content comparisons

Differences between nighttime REM and NREM dreams are well-established but only rarely are daytime REM and NREM nap dreams compared with each other or with daydreams. Fifty-one participants took daytime naps (with REM or NREM awakenings) and provided both waking daydream and nap dream reports. They also provided ratings of their bizarreness, sensory experience, and emotion intensity. Recall rates for REM (96%) and NREM (89%) naps were elevated compared to typical recall rates for nighttime dreams (80% and 43% respectively), suggesting an enhanced circadian influence. All attribute ratings were higher for REM than for NREM dreams, replicating findings for nighttime dreams. Compared with daydreams, NREM dreams had lower ratings for emotional intensity and sensory experience while REM dreams had higher ratings for bizarreness and sensory experience. Results support using daytime naps in dream research and suggest that there occurs selective enhancement and inhibition of specific dream attributes by REM, NREM and waking state mechanisms.     

Strength of German accent under altered auditory feedback.

Borden's (1979, 1980) hypothesis that speakers with vulnerable speech systems rely more heavily on feedback monitoring than do speakers with less vulnerable systems was investigated. The second language (L2) of a speaker is vulnerable, in comparison with the native language, so alteration to feedback should have a detrimental effect on it, according to this hypothesis. Here, we specifically examined whether altered auditory feedback has an effect on accent strength when speakers speak L2. There were three stages in the experiment. First, 6 German speakers who were fluent in English (their L2) were recorded under six conditions--normal listening, amplified voice level, voice shifted in frequency, delayed auditory feedback, and slowed and accelerated speech rate conditions. Second, judges were trained to rate accent strength. Training was assessed by whether it was successful in separating German speakers speaking English from native English speakers, also speaking English. In the final stage, the judges ranked recordings of each speaker from the first stage as to increasing strength of German accent. The results show that accents were more pronounced under frequency-shifted and delayed auditory feedback conditions than under normal or amplified feedback conditions. Control tests were done to ensure that listeners were judging accent, rather than fluency changes caused by altered auditory feedback. The findings are discussed in terms of Borden's hypothesis and other accounts about why altered auditory feedback disrupts speech control.     

Strength of German accent under altered auditory feedback

Borden’s (1979, 1980) hypothesis that speakers with vulnerable speech systems rely more heavily on feedback monitoring than do speakers with less vulnerable systems was investigated. The second language (L2) of a speaker is vulnerable, in comparison with the native language, so alteration to feedback should have a detrimental effect on it, according to this hypothesis. Here, we specifically examined whether altered auditory feedback has an effect on accent strength when speakers speak L2. There were three stages in the experiment. First, 6 German speakers who were fluent in English (their L2) were recorded under six conditions—normal listening, amplified voice level, voice shifted in frequency, delayed auditory feedback, and slowed and accelerated speech rate conditions. Second, judges were trained to rate accent strength. Training was assessed by whether it was successful in separating German speakers speaking English from native English speakers, also speaking English. In the final stage, the judges ranked recordings of each speaker from the first stage as to increasing strength of German accent. The results show that accents were more pronounced under frequency-shifted and delayed auditory feedback conditions than under normal or amplified feedback conditions. Control tests were done to ensure that listeners were judging accent, rather than fluency changes caused by altered auditory feedback. The findings are discussed in terms of Borden’s hypothesis and other accounts about why altered auditory feedback disrupts speech control.     

Another look at dreaming: disentangling Freud's primary and secondary process theories

The Interpretation of Dreams contains Freud's first and most complete articulation of the primary and secondary mental processes that serve as a framework for the workings of mind, conscious and unconscious. While it is generally believed that Freud proposed a single theory of dreaming, based on the primary process, a number of ambiguities, inconsistencies, and contradictions reflect an incomplete differentiation of the parts played by the two mental processes in dreaming. It is proposed that two radically different hypotheses about dreaming are embedded in Freud's work. The one implicit in classical dream interpretation is based on the assumption that dreams, like waking language, are representational, and are made up of symbols connected to latent unconscious thoughts. Whereas the symbols that constitute waking language are largely verbal and only partly unconscious, those that constitute dreams are presumably more thoroughly disguised and represented as arcane hallucinated hieroglyphs. From this perspective, both the language of the dream and that of waking life are secondary process manifestations. Interpretation of the dream using the secondary process model involves the assumption of a linear two-way "road" connecting manifest and latent aspects, which in one direction involves the work of dream construction and in the other permits the associative process of decoding and interpretation. Freud's more revolutionary hypothesis, whose implications he did not fully elaborate, is that dreams are the expression of a primary mental process that differs qualitatively from waking thought and hence are incomprehensible through a secondary process model. This seems more adequately to account for what is now known about dreaming, and is more consistent with the way dream interpretation is ordinarily conducted in clinical practice. Recognition that dreams are qualitatively distinctive expressions of mind may help to restore dreaming to its privileged position as a unique source of mental status information.     

Configuration of the dream in REM sleep

Dreams during REM sleep have a characteristic form. They are, so to speak, "chain dreams, in which the scenes follow consecutively and, although distinctly separate from each other, are welded into a coherent dream by the primary integrating thoughts underlying the dream. The contents of the different scenes are difficult to reconcile with the integrating thought behind the dream because they are not stimulated by the thought alone but, in a certain way, also by past experiences. The author describes a dream which apparently filled the REM phase from beginning to end. It has been possible to explain the background of the integrating thought and the origins of the different scenes. The peculiar character of such dreams should find more attention in scientific research.     

Frequency of Nightmares and Gender Significantly Predict Distressing Dreams of German Athletes Before Competitions or Games

Important sports events are highlights and stressful situations in every athlete's career. This stress might alter the dream content of athletes and consequently evoke disturbed dreaming. In this study, the authors asked 840 German athletes from various sports about distressing dreams on the nights before an important competition or game. About 15% of the athletes stated that they experienced at least 1 distressing dream before an important competition or game during the preceding 12 months. An almost equal number of athletes reported at least 1 distressing dream in their sports career. With respect to the base rate, in about 3% of the events a distressing dream occurred. Reported dream content referred mainly to athletic failure. The main risk factor for an athlete experiencing a distressing dream before a competition appears to be the frequency of experienced nightmares in general. Future research should use diary techniques to study the impact of distressing dreams on the next-day athletic performance in a competition or game.     

Frequency of nightmares and gender significantly predict distressing dreams of German athletes before competitions or games

Important sports events are highlights and stressful situations in every athlete's career. This stress might alter the dream content of athletes and consequently evoke disturbed dreaming. In this study, the authors asked 840 German athletes from various sports about distressing dreams on the nights before an important competition or game. About 15% of the athletes stated that they experienced at least 1 distressing dream before an important competition or game during the preceding 12 months. An almost equal number of athletes reported at least 1 distressing dream in their sports career. With respect to the base rate, in about 3% of the events a distressing dream occurred. Reported dream content referred mainly to athletic failure. The main risk factor for an athlete experiencing a distressing dream before a competition appears to be the frequency of experienced nightmares in general. Future research should use diary techniques to study the impact of distressing dreams on the next-day athletic performance in a competition or game.     

Spoken words in dreams a critique of the views of Otto Isakower.

In 1974 Baudry confirmed Isakower's original and important concept that the spoken word in dreams may be a manifestation of the superego, but found that this is not always true and that there may be important contributions from drive and defense, according to the principle of multiple function. The particular type of dream speech most emphasized by Isakower--that characterized by a portentous, threatening, awe-inspiring, oracular tone--is extremely rare in dreams but may be observed in certain waking phenomena, e.g., psychotic delusions of self-observation or situations of life-threatening stress.     

The language of lies: a preregistered direct replication of Suchotzki and Gamer (2018; Experiment 2)

Is lying in a different language easier or more difficult? The Emotional Distance and the Cognitive Load hypothesis give competing answers. Suchotzki and Gamer measured the time native German speakers needed to initiate honest and deceptive answers to German and English questions. Lie-truth differences in RTs were much smaller for the foreign compared to the native language. In our preregistered replication study in native Dutch speakers, we found that lie-truth differences in RTs were moderately smaller when participants were tested in English than when tested in Dutch. These findings indicate that people struggle with quickly retrieving the truth in another language, and that foreign language use may diminish lie-truth differences.     

The effects of late acquisition of L2 and the consequences of immigration on L1 for semantic and morpho-syntactic language aspects

It has been hypothesized that some aspects of a second language (L2) might be learned easier than others if a language is learned late. On the other hand, non-use might result in a loss of language skills in one's native, i.e. one's first language (L1) (language attrition). To study which, if any, aspects of language are affected by either late acquisition or non-use, long-term German immigrants to the US and English native speakers who are long-term immigrants to Germany as well as two additional control groups of native German speakers were tested with an auditory semantic and morpho-syntactic priming paradigm. German adjectives correctly or incorrectly inflected for gender and semantically associated or not associated with the target noun served as primes. Participants made a lexical decision on the target word. All groups of native German speakers gained from semantically and morpho-syntactically congruent primes. Evidence for language attrition was neither found for semantic nor morpho-syntactic priming effects in the German immigrants. In contrast, English native speakers did not gain from a morpho-syntactic congruent prime, whereas semantic priming effects were similar as for the remaining groups. The present data suggest that the full acquisition of at least some syntactic functions may be restricted to limited periods in life while semantic and morpho-syntactic functions seem to be relatively inured to loss due to non-use.     

Presleep suggestion related to a phobic object: successful manipulation of reported dream affect.

Twenty-four female subjects with a strong dislike of snakes slept for four nonconsecutive nights in the laboratory. They were divided into four groups of six, each group receiving a different presleep suggestion on Nights 3 and 4. On Nights 2, 3, and 4, before sleep, the subjects saw but did not have to touch a live snake and their dreams were collected for each REM period. The results showed that, when compared with the subjects who received the negative affect suggestions, subjects who received positive affect suggestions had significantly higher levels of positive emotions in their dreams, rated their own dreams as more pleasant, and had significantly lower levels of anxiety, sadness, and aggression. These results support the hypothesis that presleep suggestion can be an effective technique in influencing the affective dimension of the dream.     

Presleep Suggestion Related to a Phobic Object: Successful Manipulation of Reported Dream Affect

Twenty-four female subjects with a strong dislike of snakes slept for four nonconsecutive nights in the laboratory. They were divided into four groups of six, each group receiving a different presleep suggestion on Nights 3 and 4. On Nights 2, 3, and 4, before sleep, the subjects saw but did not have to touch a live snake and their dreams were collected for each REM period. The results showed that, when compared with the subjects who received the negative affect suggestions, subjects who received positive affect suggestions had significantly higher levels of positive emotions in their dreams, rated their own dreams as more pleasant, and had significantly lower levels of anxiety, sadness, and aggression. These results support the hypothesis that presleep suggestion can be an effective technique in influencing the affective dimension of the dream.     

Impact of language on development of auditory-visual speech perception

The McGurk effect paradigm was used to examine the developmental onset of inter-language differences between Japanese and English in auditory-visual speech perception. Participants were asked to identify syllables in audiovisual (with congruent or discrepant auditory and visual components), audio-only, and video-only presentations at various signal-to-noise levels. In Experiment 1 with two groups of adults, native speakers of Japanese and native speakers of English, the results on both percent visually influenced responses and reaction time supported previous reports of a weaker visual influence for Japanese participants. In Experiment 2, an additional three age groups (6, 8, and 11 years) in each language group were tested. The results showed that the degree of visual influence was low and equivalent for Japanese and English language 6-year-olds, and increased over age for English language participants, especially between 6 and 8 years, but remained the same for Japanese participants. This may be related to the fact that English language adults and older children processed visual speech information relatively faster than auditory information whereas no such inter-modal differences were found in the Japanese participants' reaction times.     

The reinterpretation of dreams: an evolutionary hypothesis of the function of dreaming

Several theories claim that dreaming is a random by-product of REM sleep physiology and that it does not serve any natural function. Phenomenal dream content, however, is not as disorganized as such views imply. The form and content of dreams is not random but organized and selective: during dreaming, the brain constructs a complex model of the world in which certain types of elements, when compared to waking life, are underrepresented whereas others are over represented. Furthermore, dream content is consistently and powerfully modulated by certain types of waking experiences. On the basis of this evidence, I put forward the hypothesis that the biological function of dreaming is to simulate threatening events, and to rehearse threat perception and threat avoidance. To evaluate this hypothesis, we need to consider the original evolutionary context of dreaming and the possible traces it has left in the dream content of the present human population. In the ancestral environment human life was short and full of threats. Any behavioral advantage in dealing with highly dangerous events would have increased the probability of reproductive success. A dream-production mechanism that tends to select threatening waking events and simulate them over and over again in various combinations would have been valuable for the development and maintenance of threat-avoidance skills. Empirical evidence from normative dream content, children's dreams, recurrent dreams, nightmares, post traumatic dreams, and the dreams of hunter-gatherers indicates that our dream-production mechanisms are in fact specialized in the simulation of threatening events, and thus provides support to the threat simulation hypothesis of the function of dreaming.     

Measuring consciousness in dreams: The lucidity and consciousness in dreams scale

In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its neural correlates during sleep. However, the precise differences between lucid and non-lucid dreams remain poorly understood. The construction of the Lucidity and Consciousness in Dreams scale (LuCiD) was based on theoretical considerations and empirical observations. Exploratory factor analysis of the data from the first survey identified eight factors that were validated in a second survey using confirmatory factor analysis: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors are involved in dream consciousness, realism and negative emotion do not differentiate between lucid and non-lucid dreams, suggesting that lucid insight is separable from both bizarreness in dreams and a change in the subjectively experienced realism of the dream.     

Dreaming and consciousness

Abstract

Research in the second half of the twentieth century may finally have succeeded in constraining the boundaries of reasonable discussion about dreams and dreaming. Largely owing to physiological discoveries and psychophysiological methods for the representative sampling of human dreamlife, we now have a body of observations that delimits plausible explanations and theories.

For example, we now know that neither REM sleep nor its dreaming is a sporadic, fleeting response to intense psychic needs or peripheral organ states, but rather is an autonomous, cyclically recurring process which consumes relatively much of our sleep, indeed of our lives. We also know that the content of representatively sampled dreams of both adults (Snyder, 1970) and children (Foulkes, 1982) is generally realistic and mundane, rather than fantastic and bizarre. From this finding, and from direct com parisons of representatively sampled laboratory-collected dreams with spon taneously remembered home dreams (e.g. Foulkes. 1979). it has become apparent that the idea of dreaming as being full of strange and discontinuous imagery is a stereotype based on limited acquaintance with our own dreamlife. Specifically, our most ordinarily memorable dreams seem to be those relatively few that are particularly emotionally engaging, particularly unrealistic, or particularly odd in their imagery or thematic sequence. This leads us to underestimate the orderliness of a process that typically functions plausibly and coherently, in a similar if not identical manner to that which we believe (perhaps also stereotypically) characterises our non-dreaming experience.

Thus, studies of representatively sampled dreaming have shown that dream imagery itself typically is realistic or plausible (Dorus, Dorus, & Rechtschaffen, 1971). that dream speech typically is both grammatically correct and appropriate to the imagined situation in which it is embedded (Heynick, 1983). that the feelings accompanying dream imagery typically are appropriate to the imagined situations which they accompany (Foulkes, Sullivan, Kerr, & Brown, 1988), and that, overwhelmingly often, dreams progress over time in a continuous rather than a discontinuous way (Foulkes & Schmidt, 1983).

Such data indicate the need to radically revise or replace most older dream theories from the clinical tradition. Given the role that physiologists and physiological methods played in the development of these data, it was perhaps inevitable that dream theories would begin to be framed in reductionist terms. And, since the 19505, there have been many attempts to “explain” dream phenomena through their reduction to neurophysiological processes (e.g. Crick & Mitchison, 1983; Hobson & McCarley, 1977)     

How infants begin to extract words from speech

A crucial step for acquiring a native language vocabulary is the ability to segment words from fluent speech. English-learning infants first display some ability to segment words at about 7.5 months of age. However, their initial attempts at segmenting words only approximate those of fluent speakers of the language. In particular, 7.5-month-old infants are able to segment words that conform to the predominant stress pattern of English words. The ability to segment words with other stress patterns appears to require the use of other sources of information about word boundaries. By 10.5 months, English learners display sensitivity to additional cues to word boundaries such as statistical regularities, allophonic cues and phonotactic patterns. Infants’ word segmentation abilities undergo further development during their second year when they begin to link sound patterns with particular meanings. By 24 months, the speed and accuracy with which infants recognize words in fluent speech is similar to that of native adult listeners. This review describes how infants use multiple sources of information to locate word boundaries in fluent speech, thereby laying the foundations for language understanding.     

Testing the involvement of the prefrontal cortex in lucid dreaming: A tDCS study

Recent studies suggest that lucid dreaming (awareness of dreaming while dreaming) might be associated with increased brain activity over frontal regions during rapid eye movement (REM) sleep. By applying transcranial direct current stimulation (tDCS), we aimed to manipulate the activation of the dorsolateral prefrontal cortex (DLPFC) during REM sleep to increase dream lucidity. Nineteen participants spent three consecutive nights in a sleep laboratory. On the second and third nights they randomly received either 1 mA tDCS for 10 min or sham stimulation during each REM period starting with the second one. According to the participants’ self-ratings, tDCS over the DLPFC during REM sleep increased lucidity in dreams. The effects, however, were not strong and found only in frequent lucid dreamers. While this indicates some preliminary support for the involvement of the DLPFC in lucid dreaming, further research, controlling for indirect effects of stimulation and including other brain regions, is needed.     

Abstraction and the (Misnamed) Language Familiarity Effect

Talkers are recognized more accurately if they are speaking the listeners’ native language rather than an unfamiliar language. This “language familiarity effect” has been shown not to depend upon comprehension and must instead involve language sound patterns. We further examine the level of sound‐pattern processing involved, by comparing talker recognition in foreign languages versus two varieties of English, by (a) English speakers of one variety, (b) English speakers of the other variety, and (c) non‐native listeners (more familiar with one of the varieties). All listener groups performed better with native than foreign speech, but no effect of language variety appeared: Native listeners discriminated talkers equally well in each, with the native variety never outdoing the other variety, and non‐native listeners discriminated talkers equally poorly in each, irrespective of the variety's familiarity. The results suggest that this talker recognition effect rests not on simple familiarity, but on an abstract level of phonological processing.