A comparison of visual working memory and episodic memory performance in younger and older adults

Item does not contain fulltextWorking memory and episodic memory decline with age.  However, as they are typically studied separately, it is largely unknown whether age-associated differences are similar. A task design was developed in which visual working memory and episodic memory performances were measured using the same stimuli, with both tasks involving context binding. A 2-back working memory task was followed by a surprise subsequent recognition memory task that assessed incidental encoding of object locations of the 2-back task. The study compared performance of younger (N=30; Mage=23.5, SDage=2.9, range=20-29) and older adults (N=29; Mage=72.1, SDage=6.8, range=62-90). Older adults performed worse than younger adults, without an interaction effect. In younger, but not in older adults, performance on the two tasks was related. We conclude that although age differences (Young>Older) are similar in the working memory and incidental associative memory tasks, the relationship between the two memory systems differs as a function of age group.20 p

DEGREES OF COMPETITION, THE RATE OF RETURN AND GROWTH FROM A CLASSICAL/SRAFFIAN PERSPECTIVE

The purpose of the paper is a clarification of the concept of competition from a classical/ Sraffian perspective; including an elucidation of how a classical/Sraffian approach might go about defining the degree of competition. This in turn allows for a sharper contrast between the Sraffian view of competition and mainstream views. The starting point for the analysis is the work of Clifton which interprets the classical/Sraffian view of competition as more general than that of orthodoxy: one which can encompass competition between production units in a given industry as something constrained by more dominant forms of competition such as that between production units across industries for shares of the corporate surplus. Following on from the work of both Clifton and Semmler, and starting from the assumption that multi-divisional corporation is the relevant “firm”, and that the corporate target rate of return is the relevant rate of profit, the question arises as to what determines the latter. And this question has received very little attention outside the more traditional post-Keynesian literature on pricing. The paper explores what is probably the most serious attempt within this literature - in the work of Eichner - to explain the target rate, in terms the desired growth rate of the corporation. This proposition has some interesting implications for a Sraffian approach, not least because it allows a link running from the expected growth of the economy to the target rate and thus the rate of profit. This in turn requires a discussion of the consistency of such a link with the Sraffian critique of the Cambridge growth equation. As well, a link between the target rate of return and the desired corporate growth rate link also has implications for the mechanics by which sectoral profit rates converge and thus for the classical/Sraffian literature on cross-dual dynamics

The mating biology of social insects

Many individuals who sustain moderate-severe traumatic brain injuries (TBI) are poor at recognizing emotional expressions, with a greater impairment in recognizing negative (e.g., fear, disgust, sadness, and anger) than positive emotions (e.g., happiness and surprise). It has been questioned whether this "valence effect" might be an artifact of the wide use of static facial emotion stimuli (usually full-blown expressions) which differ in difficulty rather than a real consequence of brain impairment. This study aimed to investigate the valence effect in TBI, while examining emotion recognition across different intensities (low, medium, and high). METHOD: Twenty-seven individuals with TBI and 28 matched control participants were tested on the Emotion Recognition Task (ERT). The TBI group was more impaired in overall emotion recognition, and less accurate recognizing negative emotions. However, examining the performance across the different intensities indicated that this difference was driven by some emotions (e.g., happiness) being much easier to recognize than others (e.g., fear and surprise). Our findings indicate that individuals with TBI have an overall deficit in facial emotion recognition, and that both people with TBI and control participants found some emotions more difficult than others. These results suggest that conventional measures of facial affect recognition that do not examine variance in the difficulty of emotions may produce erroneous conclusions about differential impairment. They also cast doubt on the notion that dissociable neural pathways underlie the recognition of positive and negative emotions, which are differentially affected by TBI and potentially other neurological or psychiatric disorders. (JINS, 2014, 20, 1-10)

The impact of error frequency on errorless and errorful learning of object locations using a novel paradigm

Item does not contain fulltextErrorless learning (EL) is an approach in which errors are eliminated or reduced as much as possible while learning of new information or skills. In contrast, during trial-and-error - or errorful - learning (TEL) errors are not reduced and are often even promoted. There is a complex and conflicting pattern of evidence whether EL or TEL may result in better memory performance. One major confound in the extant literature is that most EL studies have not controlled for the number of errors made during TEL, resulting in a large variability in the amount of errors committed. This variability likely explains why studies on the cognitive underpinnings of EL and TEL have produced mixed findings. In this study, a novel object-location learning task was employed to examine EL and TEL in 30 healthy young adults. The number of errors was systematically manipulated, allowing us to investigate the impact of frequency of errors on learning outcome. The results showed that recall from memory was significantly better during EL. However, the number of errors made during TEL did not influence the performance in young adults. Altogether, our novel paradigm is promising for measuring EL and TEL, allowing for more accurate analyses to understand the impact of error frequency on a person’s learning ability and style.10 p

Musical mnemonics in cognitively unimpaired individuals and individuals with Alzheimer's dementia: a systematic review

Health and self-regulatio

Executive and attentional functions in chronic pain: Does performance decrease with increasing task load?

Contains fulltext : 107817.pdf (publisher's version ) (Open Access)BACKGROUND: Diminished executive function and attentional control has been reported in chronic pain patients. However, the precise pattern of impairment in these aspects of cognition in chronic pain remains unclear. Moreover, a decline in psychomotor speed could potentially influence executive and attentional control performance in pain patients. OBJECTIVE: To examine different aspects of executive and attentional control in chronic pain together with the confounding role of psychomotor slowing. METHODS: Neuropsychological tests of sustained attention, planning ability, inhibition and mental flexibility were administered to 34 participants with chronic pain and 32 control participants. RESULTS: Compared with the controls, participants with chronic pain took longer to complete tests of sustained attention and mental flexibility, but did not perform worse on inhibition or planning tasks. The decreased performance on the mental flexibility task likely reflects a reduction in psychomotor speed. The pattern of performance on the sustained attention task reveals a specific decline in attention, indicated by a disproportionate decline in performance with an increase in task duration and by increased fluctuations in attention during task performance. No additional effect was noted of pain intensity, pain duration, pain catastrophizing, depressive symptoms, reduced sleep because of the pain or opioid use. CONCLUSIONS: Executive and attention functions are not uniformly affected in chronic pain. At least part of the previously reported decline in executive function in this group may reflect psychomotor slowing. Overall, limited evidence was found that executive and attention performance is indeed lower in chronic pain. Therefore, it can be concluded that in chronic pain sustained attention performance is diminished while mental flexibility, planning and inhibition appear to be intact.7 p

Effects of aging on cerebral oxygenation during working-memory performance: A functional near-infrared spectroscopy study

Contains fulltext : 102484.pdf (publisher's version ) (Open Access)Working memory is sensitive to aging-related decline. Evidence exists that aging is accompanied by a reorganization of the working-memory circuitry, but the underlying neurocognitive mechanisms are unclear. In this study, we examined aging-related changes in prefrontal activation during working-memory performance using functional Near-Infrared Spectroscopy (fNIRS), a noninvasive neuroimaging technique. Seventeen healthy young (21–32 years) and 17 healthy older adults (64–81 years) performed a verbal working-memory task (n-back). Oxygenated and deoxygenated hemoglobin concentration changes were registered by two fNIRS channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition in older adults, but not in young participants. In both young and older adults, prefrontal activation increased with rising working-memory load. Young adults showed slight right-hemispheric dominance at low levels of working-memory load, while no hemispheric differences were apparent in older adults. Analysis of the time-activation curve during the high working-memory load condition revealed a continuous increase of the hemodynamic response in the young. In contrast to that, a quadratic pattern of activation was found in the older participants. Based on these results it could be hypothesized that young adults were better able to keep the prefrontal cortex recruited over a prolonged period of time. To conclude, already at low levels of working-memory load do older adults recruit both hemispheres, possibly in an attempt to compensate for the observed aging-related decline in performance. Also, our study shows that aging effects on the time course of the hemodynamic response must be taken into account in the interpretation of the results of neuroimaging studies that rely on blood oxygen levels, such as fMRI.11 p

Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping

Working memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00429-021-02281-0