Tracking Eye Movements during Spontaneous and Directed Refreshing

There is a growing interest in specifying the mechanisms underlying refreshing, i.e., the use of attention to keep working memory (WM) contents accessible. Here, we examined whether participants’ visual fixations during the retention interval of a WM task indicate the current focus of internal attention, thereby serving as an online measure of refreshing. Eye movements were recorded while participants studied and maintained an array of colored dots followed by probed recall of one (Experiments 1A and 1B) or all (Experiment 2) of the memoranda via a continuous color wheel. Experiments 1A and 2 entailed an unfilled retention interval in which refreshing is assumed to occur spontaneously, and Experiment 1B entailed a retention interval embedded with cues prompting the sequential refreshment of a subset of the memoranda. During the retention interval, fixations revisited the locations occupied by the memoranda, consistent with a looking-at-nothing phenomenon in WM, but the pattern was only evident when placeholders were onscreen in Experiment 2, indicating that these fixations may largely reflect random gaze. Furthermore, spontaneous fixations did not predict recall precision (Experiments 1A and 2), even when ensuring that they did not reflect random gaze (Experiment 2). In Experiment 1B, refreshing cues increased fixations to the eventually tested target and predicted better recall precision, which interacted with an overall benefit of target fixations. These results suggest that fixations during instructed, but not spontaneous, refreshing conditions account for additional variance in recall precision. Eye movements, however, do not seem suitable as an online measure of refreshing.

Optimizing song retention through the spacing effect

The spacing effect refers to the improvement in memory retention for materials learned in a series of sessions, as opposed to massing learning in a single session. It has been extensively studied in the domain of verbal learning using word lists. Less evidence is available for connected discourse or tasks requiring the complex coordination of verbal and other domains. In particular, the effect of spacing on the retention of words and music in song has yet to be determined. In this study, university students were taught an unaccompanied two-verse song based on traditional materials to a criterion of 95% correct memory for sung words. Subsequent training sessions were either massed or spaced by two days or one week and tested at a retention interval of three weeks. Performances were evaluated for number of correct and incorrect syllables, number of correctly and incorrectly pitched notes, degree notes were off-pitch, and number of hesitations while singing. The data revealed strong evidence for a spacing effect for song between the massed and spaced conditions at a retention interval of three weeks, and evidence of no difference between the two spaced conditions. These findings suggest that the ongoing cues offered by surface features in the song are strong enough to enable verbatim recall across spaced conditions, as long as the spacing interval reaches a critical threshold.

Long Retention Intervals Impair the Confidence-Accuracy Relationship for Eyewitness Recall

A growing body of research suggests that confidence judgements can provide a useful indicator of memory accuracy under some conditions. One factor known to affect eyewitness accuracy, yet rarely examined in the confidence-accuracy literature, is retention interval. Using calibration analyses, we investigated how retention interval affects the confidence-accuracy relationship for eyewitness recall. In total, 611 adults watched a mock crime video and completed a cued-recall test either immediately, after 1 week, or after 1 month. Long (1 month) delays led to lower memory accuracy, lower confidence judgements, and impaired the confidence-accuracy relationship compared to shorter (immediate and 1 week) delays. Long-delay participants who reported very high levels of confidence tended to be over-confident in the accuracy of their memories compared to other participants. Self-rated memory ability, however, did not predict eyewitness confidence or the confidence-accuracy relationship. We discuss the findings in relation to cue-utilization theory and a retrieval-fluency account.

The Effects of Retrieval Practice Across Levels of Thinking and Retention Interval on Reading Comprehension

The present study examined the effect of different types of retrieval practice on reading comprehension across levels of thinking and retention interval in a classroom setting. One hundred undergraduates divided into two retention interval groups (short- and long-retention interval) were asked to read a passage on a topic in Cognitive Psychology and were then required to engage in a retrieval practice learning strategy using the two types of question format (production test and recognition test) and different levels of thinking (lower-order thinking and higher-order thinking). A three-way mixed ANOVA statistical test was used to analyse the data and found no significant differences in reading comprehension across the different types of retrieval practice, suggesting that the performance when using the recognition test is equivalent to when using the production test. The difference in reading comprehension between the different types of retention interval also was not observed, indicating that students in the short-retention interval group retained just as much information as those in the long-retention interval group. Additionally, the present study observed a significant difference in students’ reading comprehension between different levels of thinking, signifying that the students’ performance for the lower-level thinking questions was better than that for the higher-level thinking questions. The present finding contributed to the existing body of knowledge in which it suggested that the performance in reading comprehension when using a recognition test, particularly a well-constructed one, with competitive alternatives was equivalent to when using a production test. Keywords: Levels of thinking, Question format, Reading comprehension, Retention interval, Retrieval practice

Is Pupil Activity Associated With the Strength of Memory Signal for Words in a Continuous Recognition Memory Paradigm?

Research on pupillometry provides an increasing evidence for associations between pupil activity and memory processing. The most consistent finding is related to an increase in pupil size for old items compared with novel items, suggesting that pupil activity is associated with the strength of memory signal. However, the time course of these changes is not completely known, specifically, when items are presented in a running recognition task maximizing interference by requiring the recognition of the most recent items from a sequence of old/new items. The sample comprised 42 healthy participants who performed a visual word recognition task under varying conditions of retention interval. Recognition responses were evaluated using behavioral variables for discrimination accuracy, reaction time, and confidence in recognition decisions. Pupil activity was recorded continuously during the entire experiment. The results suggest a decrease in recognition performance with increasing study-test retention interval. Pupil size decreased across retention intervals, while pupil old/new effects were found only for words recognized at the shortest retention interval. Pupillary responses consisted of a pronounced early pupil constriction at retrieval under longer study-test lags corresponding to weaker memory signals. However, the pupil size was also sensitive to the subjective feeling of familiarity as shown by pupil dilation to false alarms (new items judged as old). These results suggest that the pupil size is related not only to the strength of memory signal but also to subjective familiarity decisions in a continuous recognition memory paradigm.

Misinformation effects in an online sample: results of an experimental study with a five day retention interval

Traditional face-to-face laboratory studies have contributed greatly to our understanding of how misinformation effects develop. However, an area of emerging concern that has been relatively under-researched is the impact of misinformation following exposure to traumatic events that are viewed online. Here we describe a novel method for investigating misinformation effects in an online context. Participants (N = 99) completed the study online. They first watched a 10-min video of a fictional school shooting. Between 5 and 10 days later, they were randomly assigned to receive misinformation or no misinformation about the video before completing a recognition test. Misinformed participants were less accurate at discriminating between misinformation and true statements than control participants. This effect was most strongly supported by ROC analyses (Cohen’s d = 0.59, BF10 = 8.34). Misinformation effects can be established in an online experiment using candid violent viral-style video stimuli.

In for a penny, in for a pound: examining motivated memory through the lens of retrieved context models

When people encounter items that they believe will help them gain reward, they later remember them better than others. A recent model of emotional memory, the emotional context maintenance and retrieval model (eCMR), predicts that these effects would be stronger when stimuli that predict high and low reward can compete with each other during both encoding and retrieval. We tested this prediction in two experiments. Participants were promised £1 for remembering some pictures, but only a few pence for remembering others. Their recall of the content of the pictures they saw was tested after 1 min and, in experiment 2, also after 24 h. Memory at the immediate test showed effects of list composition. Recall of stimuli that predicted high reward was greater than of stimuli that predicted lower reward, but only when high- and low-reward items were studied and recalled together, not when they were studied and recalled separately. More high-reward items in mixed lists were forgotten over a 24-h retention interval compared with items studied in other conditions, but reward did not modulate the forgetting rate, a null effect that should be replicated in a larger sample. These results confirm eCMR's predictions, although further research is required to compare that model against alternatives.

Observational Spatial Memory in North Island Robins (Petroica Longpies)

<p>Observational spatial memory is employed by members of food-hoarding species to pilfer caches created by other individuals more effectively. North Island robins (Petroica australis) experience high levels of reciprocal cache pilferage within mate pairs. These circumstances were hypothesised to produce conditions under which advanced pilferage strategies such as observational spatial memory may evolve. Here I tested the ability of North Island robins to use observational spatial memory to discriminate between varying prey rewards. Three experiments were conducted which differed in the maximum number of prey items offered as a reward. Additional variables of retention interval, number of cache sites and a variable reward were included to assess how the birds’ memory was affected by small-scale factors. Results showed that North Island robins performed above chance expectations in most treatment combinations, indicating that they were able to utilize observational spatial memory. They were equally able to discriminate between different combinations of prey numbers that were hidden in 2, 3 and 4 caches sites from between 0, 10 and 60 seconds. Overall results indicate that North Island robins can solve complex numerical problems involving more than two parameters and up to one minute long retention intervals without training.</p>

Observational Spatial Memory in North Island Robins (Petroica Longpies)

<p>Observational spatial memory is employed by members of food-hoarding species to pilfer caches created by other individuals more effectively. North Island robins (Petroica australis) experience high levels of reciprocal cache pilferage within mate pairs. These circumstances were hypothesised to produce conditions under which advanced pilferage strategies such as observational spatial memory may evolve. Here I tested the ability of North Island robins to use observational spatial memory to discriminate between varying prey rewards. Three experiments were conducted which differed in the maximum number of prey items offered as a reward. Additional variables of retention interval, number of cache sites and a variable reward were included to assess how the birds’ memory was affected by small-scale factors. Results showed that North Island robins performed above chance expectations in most treatment combinations, indicating that they were able to utilize observational spatial memory. They were equally able to discriminate between different combinations of prey numbers that were hidden in 2, 3 and 4 caches sites from between 0, 10 and 60 seconds. Overall results indicate that North Island robins can solve complex numerical problems involving more than two parameters and up to one minute long retention intervals without training.</p>

Visual Short-Term Memory for Coherent and Sequential Motion: A rTMS Investigation

We investigated the role of the human medio-temporal complex (hMT+) in the memory encoding and storage of a sequence of four coherently moving random dot kinematograms (RDKs), by applying repetitive transcranial magnetic stimulation (rTMS) during an early or late phase of the retention interval. Moreover, in a second experiment, we also tested whether disrupting the functional integrity of hMT+ during the early phase impaired the precision of the encoded motion directions. Overall, results showed that both recognition accuracy and precision were worse in middle serial positions, suggesting the occurrence of primacy and recency effects. We found that rTMS delivered during the early (but not the late) phase of the retention interval was able to impair not only recognition of RDKs, but also the precision of the retained motion direction. However, such impairment occurred only for RDKs presented in middle positions along the presented sequence, where performance was already closer to chance level. Altogether these findings suggest an involvement of hMT+ in the memory encoding of visual motion direction. Given that both position sequence and rTMS modulated not only recognition but also the precision of the stored information, these findings are in support of a model of visual short-term memory with a variable resolution of each stored item, consistent with the assigned amount of memory resources, and that such item-specific memory resolution is supported by the functional integrity of area hMT+.