Working memory is a cognitive process that involves maintaining and manipulating information for a short period of time. WM is central to many cognitive processes and declines rapidly with age. Deficits in WM are seen in older adults and in patients with dementia, schizophrenia, major depression, mild cognitive impairment, Alzheimer’s disease, etc. The frontal, parietal, and occipital cortices are significantly involved in WM processing and all brain oscillations are implicated in tackling WM tasks, particularly theta and gamma bands. The (...) theta/gamma neural code hypothesis assumes that retained memory items are recorded via theta-nested gamma cycles. Neuronal oscillations can be manipulated by sensory, invasive- and non-invasive brain stimulations. Transcranial alternating-current stimulation and repetitive transcranial magnetic stimulation are frequency-tuned non-invasive brain stimulation techniques that have been used to entrain endogenous oscillations in a frequency-specific manner. Compared to rTMS, tACS demonstrates superior cost, tolerability, portability, and safety profile, making it an attractive potential tool for improving cognitive performance. Although cognitive research with tACS is still in its infancy compared to rTMS, a number of studies have shown a promising WM enhancement effect, especially in the elderly and patients with cognitive deficits. This review focuses on the various methods and outcomes of tACS on WM in healthy and unhealthy human adults and highlights the established findings, unknowns, challenges, and perspectives important for translating laboratory tACS into realistic clinical settings. This will allow researchers to identify gaps in the literature and develop frequency-tuned tACS protocols with promising safety and efficacy outcomes. Therefore, research efforts in this direction should help to consider frequency-tuned tACS as a non-pharmacological tool of cognitive rehabilitation in physiological aging and patients with cognitive deficits. (shrink)

Difficulties understanding speech form one of the most prevalent complaints among older adults. Successful speech perception depends on top-down linguistic and cognitive processes that interact with the bottom-up sensory processing of the incoming acoustic information. The relative roles of these processes in age-related difficulties in speech perception, especially when listening conditions are not ideal, are still unclear. In the current study, we asked whether older adults with a larger working memory capacity process speech more efficiently than peers with (...) lower capacity when speech is presented in noise, with another task performed in tandem. Using the Eye-tracking of Word Identification in Noise Under Memory Increased Load an adapted version of the “visual world” paradigm, 36 older listeners were asked to follow spoken instructions presented in background noise, while retaining digits for later recall under low or high memory load. In critical trials, instructions directed listeners’ gaze to pictures of objects whose names shared onset or offset sounds with the name of a competitor that was displayed on the screen at the same time. We compared listeners with different memory capacities on the time course for spoken word recognition under the two memory loads by testing eye-fixations on a named object, relative to fixations on an object whose name shared phonology with the named object. Results indicated two trends. For older adults with lower working memory capacity, increased memory load did not affect online speech processing, however, it impaired offline word recognition accuracy. The reverse pattern was observed for older adults with higher working memory capacity: increased task difficulty significantly decreases online speech processing efficiency but had no effect on offline word recognition accuracy. Results suggest that in older adults, adaptation to adverse listening conditions is at least partially supported by cognitive reserve. Therefore, additional cognitive capacity may lead to greater resilience of older listeners to adverse listening conditions. The differential effects documented by eye movements and accuracy highlight the importance of using both online and offline measures of speech processing to explore age-related changes in speech perception. (shrink)

Using the Remember/Know procedure, we compared the impact of a reflective repetition by refreshing and a perceptual repetition on subjective experience during recognition memory. Participants read aloud words as they appeared on a screen. Critical words were presented once , immediately repeated , or followed by a dot signalling the participants to think of and say the just-previous word . In Experiments 1 and 2, Remember responses benefited from refreshing a word . In Experiment 2, this benefit (...) disappeared when participants had to refresh one of three active items. Perceptual repetition increased Remember responses in Experiment 1, but not in Experiment 2 regardless of whether participants had just previously seen 1- or 3-items. These findings indicate that under some circumstances, reflective and perceptual repetition may have different consequences for later subjective experience during remembering, suggesting differences in their underlying functional mechanisms. (shrink)

When pandemics hit communities, women are bound to suffer as most of the responsibilities of ensuring food security lie on them. This article assesses the impact of the COVID-19 pandemic on the role that church-going women play in food provision. The qualitative study used interviews and focus group discussions to examine the toll of the pandemic-induced restrictions, especially with regard to their disruption of activities that ensure the provision of food for the family. They sought to identify how an environment (...) as restrictive as the one that was imposed during the COVID-19 pandemic affects those largely responsible for food provision in urban Marondera – the women, in this case. The focus was extended to factor in how disasters and pandemics affect women and detract from their normative food procurement and provision roles in marginal societies and how these effects can be mitigated to allow women to carry on with their roles even in restrictive environments. This research was motivated by the recent COVID-19-imposed regulations that restricted the movement of people, restrictions that have only recently been relaxed and (in some cases) removed. We also sought to establish how gender roles are played out, together with whether they are exacerbated by pandemics, and in what ways these pandemics result in higher workloads on women. By utilising the Africana womanist theory, the study analysed women roles in food provision and food security in their societies within the restrictive environments of the pandemics.Contribution: This study concluded that there are gender inequalities that are exacerbated by these pandemics that result in higher workloads for women. It foregrounded how existing gender inequalities were exacerbated by the pandemic, resulting in higher workloads on women. It therefore recommended that women should form empowerment groups to help focus attention on food provision to mitigate challenges women face in this role. Finally, we averred that there ought to be consultation and participation of women on issues to do with pandemics to allow for their full and productive participation in critical roles of providing food. (shrink)

Motor learning is the process of updating motor commands in response to a trajectory error induced by a perturbation to the body or vision. The brain has a great capability to accelerate learning by increasing the sensitivity of the memory update to the perceived trajectory errors. Conventional theory suggests that the statistics of perturbations or the statistics of the experienced errors induced by the external perturbations determine the learning speeds. However, the potential effect of another type of error perception, (...) a self-generated error as a result of motor command updates, on the learning speeds has not been examined yet. In this study, we dissociated the two kinds of errors by controlling the perception of the aftereffect using a channel-force environment. One group experienced errors due to the aftereffect of the learning process, while the other did not. We found that the participants who perceived the aftereffect of the memory updates exhibited a significant decrease in error-sensitivity, whereas the participants who did not perceive the aftereffect did not show an increase or decrease in error-sensitivity. This suggests that the perception of the aftereffect of learning attenuated updating the motor commands from the perceived errors. Thus, both self-generated and externally induced errors may modulate learning speeds. (shrink)

Miller (1956) summarized evidence that people can remember about seven chunks in short-term memory (STM) tasks. However, that number was meant more as a rough estimate and a rhetorical device than as a real capacity limit. Others have since suggested that there is a more precise capacity limit, but that it is only three to five chunks. The present target article brings together a wide variety of data on capacity limits suggesting that the smaller capacity limit is real. Capacity (...) limits will be useful in analyses of information processing only if the boundary conditions for observing them can be carefully described. Four basic conditions in which chunks can be identified and capacity limits can accordingly be observed are: (1) when information overload limits chunks to individual stimulus items, (2) when other steps are taken specifically to block the recoding of stimulus items into larger chunks, (3) in performance discontinuities caused by the capacity limit, and (4) in various indirect effects of the capacity limit. Under these conditions, rehearsal and long-term memory cannot be used to combine stimulus items into chunks of an unknown size; nor can storage mechanisms that are not capacity-limited, such as sensory memory, allow the capacity-limited storage mechanism to be refilled during recall. A single, central capacity limit averaging about four chunks is implicated along with other, noncapacity-limited sources. The pure STM capacity limit expressed in chunks is distinguished from compound STM limits obtained when the number of separately held chunks is unclear. Reasons why pure capacity estimates fall within a narrow range are discussed and a capacity limit for the focus of attention is proposed. Key Words: attention; enumeration; information chunks; memory capacity; processing capacity; processing channels; serial recall; short-term memory; storage capacity; verbal recall; working memory capacity. (shrink)

There are many ways to assess face perception skills. In this study, we describe a novel task battery FEAST (Facial Expression Action Stimulus Test) developed to test recognition of identity and expressions of human faces as well as stimulus control categories. The FEAST consists of a neutral and emotional face memory task, a face and object identity matching task, a face and house part-to-whole matching task, and a human and animal facial expression matching task. The identity and part-to-whole matching (...) tasks contain both upright and inverted conditions. The results provide reference data of a healthy sample of controls in two age groups for future users of the FEAST. (shrink)

BackgroundRegularity effect can affect performance in prospective memory, but little is known on the cognitive processes linked to this effect. Moreover, its impacts with regard to aging remain unknown. To our knowledge, this study is the first to examine regularity effect in PM in a lifespan perspective, with a sample of young, intermediate, and older adults.Objective and designOur study examined the regularity effect in PM in three groups of participants: 28 young adults, 16 intermediate adults, and 25 older adults. (...) The task, adapted from the Virtual Week, was designed to manipulate the regularity of the various activities of daily life that were to be recalled. We examine the role of several cognitive functions including certain dimensions of executive functions, short-term memory, and retrospective episodic memory to identify those involved in PM, according to... (shrink)

Topics include sources of schematic effects on memory; the M. Ross and M. Conway model; E. R. Hirt's model of reconstructive memory; and moderators of the relative weighting of expectancy vs memory trace.

Research on sequence effects on learning visual categories has shown that interleaving (i.e., studying the categories in a mixed manner) facilitates category induction as compared to blocking (i.e., studying the categories one by one), but learners are unaware of the interleaving effect and prefer blocking. However, little attention has been paid to sequence effects in perceptual learning across further sensory modalities. The present (preregistered) research addresses this shortcoming by using auditory (birdcalls), olfactory (tealeaves), gustatory (ingredient mixtures), and (...) tactile (stones) stimuli across four analog experiments. The number of participants per experiment was determined based on a medium effect size of interleaving. Participants studied six categories (with six exemplars, respectively) either interleaved or blocked. No single experiment showed a significant effect of interleaving. We ran a comprehensive meta‐analysis based on the data from all experiments, which revealed a significant small effect of interleaving, demonstrating its applicability to perceptual learning across all sensory modalities. Learners in the interleaved condition underestimated their classification performance. Overall, learners did not rate interleaving as less effective than blocking, which is at odds with previous studies that consistently demonstrated a metacognitive preference of blocking. Our findings suggest that learners rely less on conventional beliefs about the effectivity of study sequence when dealing with unfamiliar (blindfolded) perceptual learning tasks. (shrink)

The ability to integrate information from diverse texts and to detect logical implications of the integrated information is fundamental to the understanding process. This paper shows that identifying and configuring relevant facts in order to support hypothesized inferences is extremely difficult unless the facts have been committed to memory. Simply reading relevant texts for familiarization and then referring to them as needed provides an inadequate basis for deductive logic. Further, apprehension of the logical configuration of fads underlying a particular (...) inference can be an essentially automatic process for the reasoner who has structured the facts appropriately in memory. A model of search and memory mechanisms is proposed. It accounts for accuracy and reaction time data, as well as individual differences in inference evaluation. The implications of the superiority of memorization over familiarization‐plus‐referencing as a basis for learning and reasoning are discussed. (shrink)

The ability to integrate information from diverse texts and to detect logical implications of the integrated information is fundamental to the understanding process. This paper shows that identifying and configuring relevant facts in order to support hypothesized inferences is extremely difficult unless the facts have been committed to memory. Simply reading relevant texts for familiarization and then referring to them as needed provides an inadequate basis for deductive logic. Further, apprehension of the logical configuration of fads underlying a particular (...) inference can be an essentially automatic process for the reasoner who has structured the facts appropriately in memory. A model of search and memory mechanisms is proposed. It accounts for accuracy and reaction time data, as well as individual differences in inference evaluation. The implications of the superiority of memorization over familiarization‐plus‐referencing as a basis for learning and reasoning are discussed. (shrink)

A variant of the process dissociation procedure was coupled with a manipulation of response signal lag to assess whether manipulations of context affect one or both of the familiarity and search processes described by the dual process model of recognition. Participants studied a list of word pairs followed by a recognition test with target words presented in the same or different context, and in the same or different form as study . Participants were asked to recognize any target word regardless (...) of changes to form , or to only recognise words that were presented in the same form . The standard context reinstatement effect was evident even at the short response lags. Analyses of the estimates of the contributions of familiarity and search processes suggest that the context effect demonstrated here can be attributed in part to the influence of familiarity on recognition, whereas the effect on recollection was less clear. (shrink)

It has been claimed that the ability to remember the past and the ability to project oneself into the future are intimately related. We sought support for this proposition by examining whether individual differences in dimensions that have been shown to affect memory for past events similarly influence the experience of projecting oneself into the future. We found that individuals with a higher capacity for visual imagery experienced more visual and other sensory details both when remembering past events (...) and when imagining future events. In addition, individuals who habitually use suppression to regulate their emotions experienced fewer sensory, contextual, and emotional details when representing both past and future events, while the use of reappraisal had no effect on either kind of events. These findings are consistent with the view that mental time travel into the past and into the future relies on similar mechanisms. (shrink)