Children's reports of the sources of self-knowledge

Nursery schoolers and first- and third-graders participated in an interview which assessed recall, comprehension, and perceived importance of three sources of self-knowledge: social feedback, self-observation, and social comparison. For recall measures, these sources were embedded in stories about a child making a self-discovery. Recall of all three sources improved with grade level, and feedback was the best remembered self-validational process. Comprehension was defined as the ability to identify the sources as depicted in line drawings, and it, too, increased with grade level. All three sources were well understood by older children, but preschoolers had difficulty with the concept of social comparison. Ratings of importance, also assessed using line drawings, were independent of grade level. When selecting their own “very best” source of self-knowledge, children cited self-observation most frequently. A supplementary sample of preschoolers nominated the best source of self-knowledge for other children rather than for themselves; under these instructions, feedback from others emerged as the preferred source.     

One Frog, Two Frog, Red Frog, Blue Frog: Factors Affecting Children's Syntactic Choices in Production and Comprehension

Two experiments are reported which examine children's ability to use referential context when making syntactic choices in language production and comprehension. In a recent on-line study of auditory comprehension, Trueswell, Sekerina, Hill, and Logrip (1999) examined children's and adults' abilities to resolve temporary syntactic ambiguities involving prepositional phrases (e.g., “Put the frog on the napkin into ¨”). Although adults and older children used the referential context to guide their initial analysis (pursuing a destination interpretation in a one-frog context and a modifier interpretation in a two-frog context), 4 to 5-year olds' initial and ultimate analysis was one of destination, regardless of context. The present studies examined whether these differences were attributable to the comprehension process itself or to other sources, such as possible differences in how children perceive the scene and referential situation. In both experiments, children were given a language generation task designed to elicit and test children's ability to refer to a member of a set through restrictive modification. This task was immediately followed by the “put” comprehension task. The findings showed that, in response to a question about a member of a set (e.g., “Which frog went to Mrs. Squid's house?”), 4- to 5-year-olds frequently produced a definite NP with a restrictive prepositional modifier (e.g., “The one on the napkin”). These same children, however, continued to misanalyze put instructions, showing a strong avoidance of restrictive modification during comprehension. Experiment 2 showed that an increase in the salience of the platforms that distinguished the two referents increased overall performance, but still showed the strong asymmetry between production and comprehension. Eye movements were also recorded in Experiment 2, revealing on-line parsing patterns similar to Trueswell et al.: an initial preference for a destination analysis and a failure to revise early referential commitments. These experiments indicate that child–adult differences in parsing preferences arise, in part, from developmental changes in the comprehension process itself and not from a general insensitivity to referential properties of the scene. The findings are consistent with a probabilistic model for uncovering the structure of the input during comprehension, in which more reliable linguistic and discourse-related cues are learned first, followed by a gradually developing ability to take into account other more uncertain (or more difficult to learn) cues to structure.     

Self-concept and psychosocial adjustment in adolescence

This study analyses the relationship between a multidimensional measure of self-concept, Self-concept Form-5 Questionnaire (AF5), and a broad set of adolescents' psychosocial adjustment indicators. From the responses of 1,281 participants (53.7% females) aged 12 to 17 years ( M = 14.98 years, SD = 1.74 years), results indicated that higher self-concept scores corresponded to better psychological adjustment, good personal skills and fewer behavioral problems. Although a positive relationship between social self-concept and drug use was found, this significant relationship disappeared once the adolescent's age and sex was controlled for. These results support the idea that the self-concept is a basic theoretical construct closely related to the psychosocial adjustment in adolescence. Also this study helps explain some contradictory results reported in the literature (i.e., a positive relationship between social self-concept and drug use), by showing how the statistical control of a third variable effect (i.e., age) avoids reaching conclusions based on spurious relationships.     

Time-dependent transformations of memory representations differ along the long axis of the hippocampus

Research has shown that sleep is beneficial for the long-term retention of memories. According to theories of memory consolidation, memories are gradually reorganized, becoming supported by widespread, distributed cortical networks, particularly during postencoding periods of sleep. However, the effects of sleep on the organization of memories in the hippocampus itself remains less clear. In a 3-d study, participants encoded separate lists of word–image pairs differing in their opportunity for sleep-dependent consolidation. Pairs were initially studied either before or after an overnight sleep period, and were then restudied in a functional magnetic resonance imaging (fMRI) scan session. We used multivariate pattern similarity analyses to examine fine-grained effects of consolidation on memory representations in the hippocampus. We provide evidence for a dissociation along the long axis of the hippocampus that emerges with consolidation, such that representational patterns for object–word memories initially formed prior to sleep become differentiated in anterior hippocampus and more similar, or overlapping, in posterior hippocampus. Differentiation in anterior hippocampal representations correlated with subsequent behavioral performance. Furthermore, representational overlap in posterior hippocampus correlated with the duration of intervening slow wave sleep. Together, these results demonstrate that sleep-dependent consolidation promotes the reorganization of memory traces along the long axis of the hippocampus.

The hippocampus has long been considered critical for encoding new memories; however, the effects of consolidation on hippocampal memory traces has remained an area of active research. Memories are thought to be stabilized for the long term as they become distributed across neocortical networks (Buzsáki 1989; Alvarez and Squire 1994; McClelland et al. 1995), a process supported by mechanisms during sleep (Diekelmann and Born 2010; Rasch and Born 2013). Whereas much research has been devoted to understanding the hippocampal contributions to the long-term retention of memories, open questions remain in considering how sleep-dependent consolidation affects the organization of hippocampal traces.The hippocampus has previously been shown to be critical for binding disparate elements of an experience together (Cohen and Eichenbaum 1993; Davachi 2006). Theories suggest that the hippocampus quickly encodes new experiences, while the cortex, with a slower learning rate, gradually comes to represent the central features from this hippocampal trace, resulting in abstracted memories that can be integrated into long-term cortical stores (McClelland et al. 1995). Prior research has demonstrated evidence for a coordinated hippocampal–cortical dialogue during sleep (Andrade et al. 2011; Bergmann et al. 2012; Ngo et al. 2020) as well as enhanced hippocampal–cortical functional connectivity after learning, facilitating the retention of memories (Tambini et al. 2010; Tompary et al. 2015; Murty et al. 2017; Cowan et al. 2021). Reports suggest consolidation results in more integrated cortical memory traces in the cortex (Richards et al. 2014; Tompary and Davachi 2017; Cowan et al. 2020); however, it remains an open question whether the active consolidation processes that support memory reorganization across hippocampal–cortical networks also transform hippocampal memory traces.Research on the fate of the hippocampal trace with consolidation has often focused on questions about the permanence of memories in the hippocampus. Theories of systems consolidation have classically debated whether the hippocampal trace is time-limited (Alvarez and Squire 1994), or, rather, whether the hippocampus continues to represent memories in perpetuity (Nadel and Moscovitch 1997; Winocur and Moscovitch 2011; Moscovitch et al. 2016; Sekeres et al. 2018a). Another theory posits that while the original hippocampal trace is transient, during retrieval the hippocampus reconstructs details of an experience from cortical traces (Barry and Maguire 2019). Much research in this vein has focused on investigating changes in hippocampal blood-oxygenation level-dependent (BOLD) univariate activation with time (Bosshardt et al. 2005a,b; Takashima et al. 2006, 2009; Gais et al. 2007; Sterpenich et al. 2007, 2009; Yamashita et al. 2009; Milton et al. 2011; Watanabe et al. 2012; Ritchey et al. 2015; Baran et al. 2016; Dandolo and Schwabe 2018) and the effects of hippocampal lesions in animals and humans (Winocur et al. 2001; Frankland and Bontempi 2005; Winocur and Moscovitch 2011; Moscovitch et al. 2016) with mixed results. Interestingly, pinpointing these effects along the long axis of the hippocampus has also proven unclear. Some reports have found that only the anterior hippocampus exhibits time-dependent changes in retrieval-related univariate activation, with evidence of decreases with delay (Takashima et al. 2006; Milton et al. 2011; Dandolo and Schwabe 2018), but also evidence of greater activation for more remote, compared with recent, memories (Bosshardt et al. 2005a,b). At the same time, other studies have found decreases in univariate activation only in the posterior hippocampus (Bosshardt et al. 2005b; Takashima et al. 2009; Yamashita et al. 2009; Milton et al. 2011; Watanabe et al. 2012; Ritchey et al. 2015; Sekeres et al. 2018b).Because of these conflicting findings, instead of asking just about dependence or overall changes in activation in the hippocampus, theories and empirical research have instead increasingly considered the organization of memory representations in the hippocampus (Robin and Moscovitch 2017; Sekeres et al. 2018a). Broadly, using representational similarity analyses, several studies have shown that hippocampal memory representations tend to become differentiated over learning, particularly for memories with overlapping content (LaRocque et al. 2013; Schlichting et al. 2015; Chanales et al. 2017; Brunec et al. 2020). Furthermore, it has been suggested that information is represented at different scales or “granularity” along the long axis of the hippocampus, in line with place field size differences (Kjelstrup et al. 2008; Komorowski et al. 2013), with anterior hippocampus representing more similar, coarse-grained, or gist-like information, while the posterior hippocampus represents fine-grained, detail-oriented representations (Evensmoen et al. 2013; Poppenk et al. 2013; Robin and Moscovitch 2017; Brunec et al. 2018, 2020). However, limited work has investigated whether this representational organization is altered with consolidation. Reports have shown that memory representations sharing overlapping content become more similar over a delay (Tompary and Davachi 2017; Audrain and McAndrews 2020), yet other work has found that hippocampal representations were not modulated by time (Ritchey et al. 2015; Ezzyat et al. 2018). Intriguingly, reports indicating greater differentiation in memories in anterior compared with posterior hippocampus with consolidation (Tompary and Davachi 2017; Dandolo and Schwabe 2018; Ezzyat et al. 2018) raise the possibility that the representational granularity along the anteroposterior axis may be transformed with consolidation. Thus, more work is needed to understand how consolidation influences the representational structure of memories in the hippocampus. In particular, despite much research connecting sleep to consolidation (Diekelmann and Born 2010; Rasch and Born 2013), it remains unknown whether sleep-dependent processes facilitate such delay-dependent transformations to the hippocampus.Active processes in the sleeping brain seem to be optimized for systems consolidation. Currently, the best mechanistic evidence for sleep-dependent consolidation comes from studies on hippocampal replay showing the repeated reactivation of encoding-related patterns of hippocampal activity (Buzsáki 1989; Wilson and McNaughton 1994; Girardeau and Zugaro 2011), which seems to be coordinated with replay in areas of the cortex (Ji and Wilson 2007; Peyrache et al. 2009; Wierzynski et al. 2009). It is thought that the coupling between oscillations during non-REM sleep stages (particularly slow wave sleep [SWS])—including sharp wave ripples that support replay, thalamocortical spindles, and slow oscillations—facilitates the hippocampal–cortical dialogue and information transfer to the cortex (Buzsáki 1996; Sirota et al. 2003; Steriade 2006; Clemens et al. 2011; Mölle and Born 2011; Staresina et al. 2015). Indeed, our previously published work from the present study provided supporting evidence that the density of thalamocortical sleep spindles (11–16 Hz) during overnight sleep is related to enhanced hippocampal–cortical functional connectivity measures, and increased similarity, or greater representational overlap, among memories in the ventromedial prefrontal cortex (vmPFC) (Cowan et al. 2020). Yet, while some prior work has shown that features of sleep, including spindle density and the duration of non-REM SWS, are related to decreased retrieval-related hippocampal activation for memoranda learned prior to sleep (Takashima et al. 2006; Baran et al. 2016; Hennies et al. 2016), it remains unclear how the reactivation of hippocampal traces during replay may impact the way memories are organized along the long axis of the hippocampus.To examine the effects of sleep-dependent consolidation on the neural representation of memories in the hippocampus, we designed a within-participant 3-d study using overnight polysomnography (PSG), functional magnetic resonance imaging (fMRI), and behavioral measures of memory (Fig. 1). In this study, aspects of which have been previously published (Cowan et al. 2020), participants first studied a list of word–image pairs before sleeping overnight (Sleep List), during which PSG was recorded. Upon waking in the morning, participants studied a new list of pairs (Morning List). The word–image pairs from these two lists were then restudied while undergoing an fMRI scan, intermixed with a third, novel list of pairs (Single Study List). Associative memory was tested immediately after the scan and again 24 h later. We compared measures of multivariate pattern similarity and univariate BOLD signal for the lists learned prior to, or after, sleep to probe how modulating the opportunity for sleep-dependent consolidation impacts the way memories are organized across the long axis of the hippocampus. Furthermore, our design allowed us to examine how features of overnight sleep are related to the representational organization of memories learned prior to the sleep period, as well as the behavioral benefit of changes to the organization of these memories. Thus, our study provides a novel examination of the effects of sleep-dependent consolidation on the representation of memories along the long axis of the hippocampus.Open in a separate windowFigure 1.Study design. For all encoding and restudy sessions, participants were asked to form an association between a word and an image. Participants first encoded the Sleep List (blue) before sleeping overnight while polysomnography was recorded. The next morning (day 2), participants encoded a second set of novel word–image pairs (Morning List). After a short delay (∼2 h), participants restudied these two sets of pairs, intermixed with novel pairs (Single Study List) in the functional magnetic resonance imaging (fMRI) scanner. Source memory was tested immediately after the scan and after a 24-h delay (day 3).     

Frequency illusions and other fallacies

[Cosmides and Tooby, 1996] increased performance using a frequency rather than probability frame on a problem known to elicit base-rate neglect. Analogously, [Gigerenzer, 1994] claimed that the conjunction fallacy disappears when formulated in terms of frequency rather than the more usual single-event probability. These authors conclude that a module or algorithm of mind exists that is able to compute with frequencies but not probabilities. The studies reported here found that base-rate neglect could also be reduced using a clearly stated single-event probability frame and by using a diagram that clarified the critical nested-set relations of the problem; that the frequency advantage could be eliminated in the conjunction fallacy by separating the critical statements so that their nested relation was opaque; and that the large effect of frequency framing on the two problems studied is not stable. Facilitation via frequency is a result of clarifying the probabilistic interpretation of the problem and inducing a representation in terms of instances, a form that makes the nested-set relations amongst the problem components transparent.     

Children’s orientation judgments: Retinally or environmentally determined?

Attention, Perception, & Psychophysics - Children between the ages of 3 and 9 years judged the uprightness of pictures of realistic figures under three conditions: tilt of the visual surround,...