Miranda Occhionero

Time-based prospective remembering: Interference and facilitation in a dual task

The aim of this study was to analyse prospective memory behaviour when people have to fulfil two different intentions whose retention intervals partially overlapped. More specifically, the purpose of the study was to explore the effects of a secondary PM task (either time-based or event-based) on performance of a main time-based PM task. Four embedded conditions were tested: two event-based ones and two time-based ones. The time- and event-based interpolated tasks differed in how closely their target time was to the 20-minute response required by the main time-based task (16th and 19th min., respectively). The results indicated that when a main time-based prospective memory task shares a portion of the retention interval with a second time-based prospective task, this overlapping facilitated performance on the main task. However, the interpolated tasks appeared to be affected by the moment in which they were administered during the execution of the main time-based task. More specifically, a decrease in the interpolated task performance was observed when this was time-based and had to be executed very closely to the target time of the main task. On the contrary, when the two tasks were different (event-based vs. time-based), there was neither interference, nor facilitation.

Autoscopic phenomena and one's own body representation in dreams.

Autoscopic phenomena (AP) are complex experiences that include the visual illusory reduplication of ones own body. From a phenomenological point of view, we can distinguish three conditions: autoscopic hallucinations, heautoscopy, and out-of-body experiences. The dysfunctional pattern involves multisensory disintegration of personal and extrapersonal space perception. The etiology, generally either neurological or psychiatric, is different. Also, the hallucination of Self and own body image is present during dreams and differs according to sleep stage. Specifically, the representation of the Self in REM dreams is frequently similar to the perception of Self in wakefulness, whereas in NREM dreams, a greater polymorphism of Self and own body representation is observed. The parallels between autoscopic phenomena in pathological cases and the Self-hallucination in dreams will be discussed to further the understanding of the particular states of self awareness, especially the complex integration of different memory sources in Self and body representation.

“The people I grew up with”: The role of sociodemographic factors in early memories in an Italian sample

This within-culture study aimed to investigate the age and density of earliest memories in a sample of Italian young adults. The framework of this study is sociocultural, with an emphasis on family reminiscing as contributing to early memories. In this regard Italy is of interest due to the fact that it is a Western but familial oriented culture, where multi-generational family ties are still strong in comparison with other European counterparts, providing for the opportunity to investigate the offset of childhood amnesia as a function of growing up in an extended family structure. Consistent with Mullen (1994), 90 undergraduate students were interviewed about their earliest memory and about sociodemographic factors in their early childhood years: household composition, gender, birth order, presence of family moves, and significant early childhood experiences. Participants who grew up in an extended family situation reported earlier and denser memories in comparison with those from nuclear families. Results are discussed in light of other cross-cultural work on childhood amnesia and with respect to sociocultural theories of the importance of family reminiscing for ones early memories.

Sleep Deprivation and Time-Based Prospective Memory.

STUDY OBJECTIVES To evaluate the effect of sleep deprivation on time-based prospective memory performance, that is, realizing delayed intentions at an appropriate time in the future (e.g., to take a medicine in 30 minutes). DESIGN Between-subjects experimental design. The experimental group underwent 24 h of total sleep deprivation, and the control group had a regular sleep-wake cycle. Participants were tested at 08:00. SETTINGS Laboratory. PARTICIPANTS Fifty healthy young adults (mean age 22 ± 2.1, 31 female). INTERVENTIONS 24 h of total sleep deprivation. MEASUREMENTS AND RESULTS Participants were monitored by wrist actigraphy for 3 days before the experimental session. The following cognitive tasks were administered: one time-based prospective memory task and 3 reasoning tasks as ongoing activity. Objective and subjective vigilance was assessed by the psychomotor vigilance task and a visual analog scale, respectively. To measure the time-based prospective memory task we assessed compliance and clock checking behavior (time monitoring). Sleep deprivation negatively affected time-based prospective memory compliance (P < 0.001), objective vigilance (mean RT: P < 0.001; slowest 10% RT: P < 0.001; lapses: P < 0.005), and subjective vigilance (P < 0.0001). Performance on reasoning tasks and time monitoring behavior did not differ between groups. CONCLUSIONS The results highlight the potential dangerous effects of total sleep deprivation on human behavior, particularly the ability to perform an intended action after a few minutes. Sleep deprivation strongly compromises time-based prospective memory compliance but does not affect time check frequency. Sleep deprivation may impair the mechanism that allows the integration of information related to time monitoring with the prospective intention.

Continuity of the processing of declarative knowledge during human sleep: evidence from interrelated contents of mental sleep experiences.

The positive influence of sleep on memory may partly depend on the processing which transforms items of declarative knowledge into contents of mental sleep experience (MSE). This view implies that the consolidation level should be more enhanced for those items which have been repeatedly processed and transformed into identical or very similar (so-called interrelated) contents of distinct MSEs in the same night. We examined here the occurrence of interrelated contents in the MSEs reported after an awakening provoked in stage 2 at sleep onset and the spontaneous awakening in the morning. Interrelated contents resulted much more frequently than the chance occurrence of contents with the same semantic features, regardless of the sleep stage in which morning awakening occurred. The accessibility of given items for transformation into MSE contents over the night makes it plausible that they are reprocessed, and thus further consolidated, during various stages and cycles of sleep.

Comparison of a wireless dry headband technology for sleep monitoring with actigraphy in healthy adults

The present study aimed to explore the validity of a wireless dry headband technology for long-term home sleep monitoring, through a comparison with concurrent actigraphic recording. Nineteen healthy volunteers (nine females; age range: 22–63 years) slept in their home simultaneously using the wireless dry sensor system (WS) and Basic Mini-Motionlogger® (MML) actigraph. In all we collected 204 valid actigraphic and wireless recordings. We focused on comparisons of these sleep measures: sleep onset latency, wake after sleep onset, total sleep time and sleep efficiency. WS overestimated sleep onset latency and wake after sleep onset in comparison to MML, and underestimated total sleep time and sleep efficiency. On the basis of the present data, WS can be considered a reliable tool for the long-term home sleep monitoring.

Toward a new neuropsychological isomorphism

The deactivation of the dorsolateral prefrontal cortex is likely to be essential for generating some characteristics of the dream. The heterogeneous nature of NREM sleep makes it difficult to assume that there are different NREM dream triggers. Different cortical and subcortical neurophysiological conditions modulate mentation both in waking and in sleeping without any specific direct triggering factor. [Solms]

Such stuff as NREM dreams are made on

The question that we deal with in this commentary is the need to clarify the synergistic role of different non-rapid eye movement (NREM) sleep stages (stages 2 and 3-4) with REM and while awake in elaborative encoding of episodic memory. If the assumption is that there is isomorphism between neuronal and cognitive networks, then more detailed analysis of NREM sleep and dreams is absolutely necessary.

Phenomenal consciousness in dreams and in mind wandering

Abstract Dreaming can be explained as the product of an interaction among memory processes, elaborative processes, and phenomenal awareness. A feedback circuit is activated by this interaction according to the associative links and the requirements of the dream scene. Recently, it has been hypothesized that a partial similarity exists between dreaming and mind wandering and that these two processes may involve the same neural default network. This commentary discusses the differences and similarities between phenomenal consciousness during dreaming and phenomenal consciousness during mind wandering from the perspective of the “continuity” of engagement of cognitive systems. The greatest difference consists in the lack of reality testing during dreaming. Dream imagery is hallucinatory by nature. Consequently, the simulated world in dreams makes dream imagery more akin to perception. In contrast, the imagery of mind wandering is more similar to imagination. The level of meta-awareness is preserved more frequently and to a greater degree in mind wandering.

Mind's eye: a case of out-of-body experiences.

Out-of-body experiences are the phenomena of seeing the image of ones body from an external perspective. We report the case of a patient affected by psychophysiological insomnia who presents hallucinatory phenomenon, successfully treated with haloperidol.We hypothesize that these hallucinations during psychophysiological insomnia are expression of an alteration of specific neurocognitive networks that regulate the cognitive arousal systems.