Inhibitory Control and Working Memory in Post-Institutionalized Children

Inhibitory control and working memory were examined in post-institutionalized (PI) children adopted into United States families from Russian institutions. The PI sample originated from institutions that were less severely depriving than those represented in previous studies and approximated the level of psychosocial deprivation, which is characterized by adequate physical resources but a lack of consistent and responsive caregiving. PI children (N?=?75; 29 male) ranged in age from 8–17 years (M?=?12.97; SD?=?3.03) and were grouped according to whether they were adopted after 14 months or before 9 months. A non-adopted comparison group (N?=?133; 65 male) ranged in age from 8–17 years (M?=?12.26; SD?=?2.75). PI children adopted after 14 months of age displayed poorer performance on the stop-signal and spatial span tasks relative to PI children adopted before 9 months of age after controlling for age at assessment. The two PI groups did not differ in their performance on a spatial self-ordered search task. Older-adopted PI children also showed poorer spatial span task performance compared to non-adopted children, but younger-adopted PI children did not. Task performance was significantly associated with parent-rated hyperactive-impulsive behavior in everyday contexts. These findings suggest that exposure to prolonged early institutional deprivation may be linked with inhibitory control and working memory difficulties years after adoption.     

Rhesus monkeys (<Emphasis Type="Italic">Macaca mulatta</Emphasis>) remember agency information from past events and integrate this knowledge with spatial and temporal features in working memory

The purpose of the present study was to examine whether rhesus monkeys remember information about their own agency—along with spatial, temporal and contextual properties—from a previously experienced event. In Experiment 1, rhesus monkeys (n = 4) used symbols to reliably indicate whether they had performed or observed an event on a computer screen. In Experiment 2, naïve and experienced monkeys (n = 8) reported agency information when stringent controls for perceptual and proprioceptive cues were included. In Experiment 3, five of the monkeys completed a task in which they reported agency information along with spatial and temporal features of events. Two monkeys performed this agency discrimination when they could not anticipate which memory test they would receive. There was also evidence that these features were integrated in memory. Implications of this research are discussed in relation to working memory, episodic memory and self-awareness in nonhuman animals.     

Place and direction learning in a spatial T-maze task by neonatal piglets

Pigs are a valuable animal model for studying neurodevelopment in humans due to similarities in brain structure and growth. The development and validation of behavioral tests to assess learning and memory in neonatal piglets are needed. The present study evaluated the capability of 2-week old piglets to acquire a novel place and direction learning spatial T-maze task. Validity of the task was assessed by the administration of scopolamine, an anti-cholinergic drug that acts on the hippocampus and other related structures, to impair spatial memory. During acquisition, piglets were trained to locate a milk reward in a constant place in space, as well as direction (east or west), in a plus-shaped maze using extra-maze visual cues. Following acquisition, reward location was reversed and piglets were re-tested to assess learning and working memory. The performance of control piglets in the maze improved over time (P < 0.0001), reaching performance criterion (80 % correct) on day 5 of acquisition. Correct choices decreased in the reversal phase (P < 0.0001), but improved over time. In a separate study, piglets were injected daily with either phosphate-buffered saline (PBS; control) or scopolamine prior to testing. Piglets administered scopolamine showed impaired performance in the maze compared to controls (P = 0.03), failing to reach performance criterion after 6 days of acquisition testing. Collectively, these data demonstrate that neonatal piglets can be tested in a spatial T-maze task to assess hippocampal-dependent learning and memory.     

A test of the reward-value hypothesis

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.     

Deferred imitation and declarative memory in domestic dogs

This study demonstrates for the first time deferred imitation of novel actions in dogs (Canis familiaris) with retention intervals of 1.5 min and memory of familiar actions with intervals ranging from 0.40 to 10 min. Eight dogs were trained using the ‘Do as I do’ method to match their own behaviour to actions displayed by a human demonstrator. They were then trained to wait for a short interval to elapse before they were allowed to show the previously demonstrated action. The dogs were then tested for memory of the demonstrated behaviour in various conditions, also with the so-called two-action procedure and in a control condition without demonstration. Dogs were typically able to reproduce familiar actions after intervals as long as 10 min, even if distracted by different activities during the retention interval and were able to match their behaviour to the demonstration of a novel action after a delay of 1 min. In the two-action procedure, dogs were typically able to imitate the novel demonstrated behaviour after retention intervals of 1.5 min. The ability to encode and recall an action after a delay implies that facilitative processes cannot exhaustively explain the observed behavioural similarity and that dogs’ imitative abilities are rather based on an enduring mental representation of the demonstration. Furthermore, the ability to imitate a novel action after a delay without previous practice suggests presence of declarative memory in dogs.     

Effect of working memory training on working memory,arithmetic and following instructions

Mathematical ability is dependent on specific mathematical training but also associated with a range of cognitive factors, including working memory (WM) capacity. Previous studies have shown that WM training leads to improvement in non-trained WM tasks, but the results regarding transfer to mathematics are inconclusive. In the present study, 176 children with WM deficits, aged 7–15 years performed 5 weeks of WM training. During the training period, they were assessed five times with a test of complex WM (the Odd One Out), a test of remembering and following instructions and a test of arithmetic. The improvements were compared to the performance of a control group of 304 typically developing children aged 7–15 years who performed the same transfer tasks at the same time intervals, but without training. The training group improved significantly more than the control group on all three transfer tests (all p < 0.0001), after correction for baseline performance, age and sex. The effect size for mathematics was small and the effect sizes for the WM tasks were moderate to large. The transfer increased linearly with the amount of training time and correlated with the amount of improvement on the trained tasks. These results confirm previous findings of training-induced improvements in non-trained WM tasks including the ability to follow instructions, but extend previous findings by showing improvements also for arithmetic. This is encouraging regarding the potential role of cognitive training for education, but it is desirable to find paradigms that would enhance the effect of the training on mathematics. One of the future challenges for studying training effects is combining large sample sizes with high quality and compliance, to detect relevant but smaller effects of cognitive training.     

The influence of spatial pattern on visual short-term memory for contrast

Several psychophysical studies of visual short-term memory (VSTM) have shown high-fidelity storage capacity for many properties of visual stimuli. On judgments of the spatial frequency of gratings, for example, discrimination performance does not decrease significantly, even for memory intervals of up to 30 s. For other properties, such as stimulus orientation and contrast, however, such “perfect storage” behavior is not found, although the reasons for this difference remain unresolved. Here, we report two experiments in which we investigated the nature of the representation of stimulus contrast in VSTM using spatially complex, two-dimensional random-noise stimuli. We addressed whether information about contrast per se is retained during the memory interval by using a test stimulus with the same spatial structure but either the same or the opposite local contrast polarity, with respect to the comparison (i.e., remembered) stimulus. We found that discrimination thresholds got steadily worse with increasing duration of the memory interval. Furthermore, performance was better when the test and comparison stimuli had the same local contrast polarity than when they were contrast-reversed. Finally, when a noise mask was introduced during the memory interval, its disruptive effect was maximal when the spatial configuration of its constituent elements was uncorrelated with those of the comparison and test stimuli. These results suggest that VSTM for contrast is closely tied to the spatial configuration of stimuli and is not transformed into a more abstract representation.     

360°-multiple object tracking in team sport athletes: Reliability and relationship to visuospatial cognitive functions

IntroductionIn team sports, the ability to visually track the movements of teammates and opponents simultaneously is a critical aspect of success. In sports psychology, this ability can be examined with the help of the multiple object tracking paradigm. The current study investigated the relationship between task performance in a novel 360°-multiple object tracking task and visuospatial cognitive functions as well as the reliability of the task.MethodsIn a sample of 153 team sport athletes the relationships between performance in the 360°-multiple object tracking task and performance in a spatial attention task, a spatial working memory task, and a fluid intelligence task at a first time of measurement were investigated. Additionally, at a second time of measurement the test-retest reliability of the 360°-multiple object tracking task was measured over a six-week interval in a subsample of 65 athletes.ResultsThe expected significant correlations between the performance in the 360°-multiple object tracking task and the tasks measuring spatial attention and working memory were observed. Test-retest reliability analysis indicated a good reliability of the procedure.ConclusionsThe results of this study demonstrate that the novel 360°-multiple object tracking task allows the reliable assessment of visuospatial cognitive performance of athletes in a dynamic 360°-environment.     

Cognitive Interventions for Cognitively Healthy,Mildly Impaired,and Mixed Samples of Older Adults: A Systematic Review and Meta-Analysis of Randomized-Controlled Trials

Cognitive interventions may improve cognition, delay age-related cognitive declines, and improve quality of life for older adults. The current meta-analysis was conducted to update and expand previous work on the efficacy of cognitive interventions for older adults and to examine the impact of key demographic and methodological variables. EBSCOhost and Embase online databases and reference lists were searched to identify relevant randomized-controlled trials (RCTs) of cognitive interventions for cognitively healthy or mildly impaired (MCI) older adults (60+ years). Interventions trained a single cognitive domain (e.g., memory) or were multi-domain training, and outcomes were assessed immediately post-intervention using standard neuropsychological tests. In total, 279 effects from 97 studies were pooled based on a random-effects model and expressed as Hedges’ g (unbiased). Overall, results indicated that cognitive interventions produce a small, but significant, improvement in the cognitive functioning of older adults, relative to active and passive control groups (g = 0.298, p < .001, 95% CI = 0.248–0.347). These results were confirmed using multi-level analyses adjusting for nesting of effect sizes within studies (g = 0.362, p < .001, 95% CI = 0.275, 0.449). Age, education, and cognitive status (healthy vs. MCI) were not significant moderators. Working memory interventions proved most effective (g = 0.479), though memory, processing speed, and multi-domain interventions also significantly improved cognition. Effects were larger for directly trained outcomes but were also significant for non-trained outcomes (i.e., “transfer effects”). Implications for future research and clinical practice are discussed. This project was pre-registered with PROSPERO (#42016038386).     

Inattentive Behavior in Boys with ADHD during Classroom Instruction: the Mediating Role of Working Memory Processes

Children with ADHD exhibit clinically impairing inattentive behavior during classroom instruction and in other cognitively demanding contexts. However, there have been surprisingly few attempts to validate anecdotal parent/teacher reports of intact sustained attention during ‘preferred’ activities such as watching movies. The current investigation addresses this omission, and provides an initial test of how ADHD-related working memory deficits contribute to inattentive behavior during classroom instruction. Boys ages 8–12 (M = 9.62, SD = 1.22) with ADHD (n = 32) and typically developing boys (TD; n = 30) completed a counterbalanced series of working memory tests and watched two videos on separate assessment days: an analogue math instructional video, and a non-instructional video selected to match the content and cognitive demands of parent/teacher-described ‘preferred’ activities. Objective, reliable observations of attentive behavior revealed no between-group differences during the non-instructional video (d = ?0.02), and attentive behavior during the non-instructional video was unrelated to all working memory variables (r = ?0.11 to 0.19, ns). In contrast, the ADHD group showed disproportionate attentive behavior decrements during analogue classroom instruction (d = ?0.71). Bias-corrected, bootstrapped, serial mediation revealed that 59% of this between-group difference was attributable to ADHD-related impairments in central executive working memory, both directly (ER = 41%) and indirectly via its role in coordinating phonological short-term memory (ER = 15%). Between-group attentive behavior differences were no longer detectable after accounting for ADHD-related working memory impairments (d = ?0.29, ns). Results confirm anecdotal reports of intact sustained attention during activities that place minimal demands on working memory, and indicate that ADHD children’s inattention during analogue classroom instruction is related, in large part, to their underdeveloped working memory abilities.     

Development of egocentric and allocentric spatial representations from childhood to elderly age

Spatial reference frames are fundamental to represent the position of objects or places. Although research has reported changes in spatial memory abilities during childhood and elderly age, no study has assessed reference frames processing during the entire lifespan using the same task. Here, we aimed at providing some preliminary data on the capacity to process reference frames in 283 healthy participants from 6 to 89 years of age. A spatial memory task requiring egocentric/allocentric verbal judgments about objects in peri-/extrapersonal space was used. The main goals were: (1) tracing a baseline of the normal process of development of these spatial components; (2) clarifying if reference frames are differently vulnerable to age-related effects. Results showed a symmetry between children of 6–7 years and older people of 80–89 years who were slower and less accurate than all other age groups. As regards processing time, age had a strong effect on the allocentric component, especially in extrapersonal space, with a longer time in 6- to 7-year-old children and 80- to 89-year-old adults. The egocentric component looked less affected by aging. Regarding the level of spatial ability (accuracy), the allocentric ability appeared less sensitive to age-related variations, whereas the egocentric ability progressively improved from 8 years and declined from 60 years. The symmetry in processing time and level of spatial ability is discussed in relation to the development of executive functions and to the structural and functional changes due to incomplete maturation (in youngest children) and deterioration (in oldest adults) of underlying cerebral areas.     

Is Clinical Anxiety a Risk or a Protective Factor for Executive Functioning in Youth with ADHD? A Meta-regression Analysis

Comorbidity rates between ADHD and anxiety disorders (AD) are high, but little is known about the nature of this co-occurrence. A dominant idea is that AD may intensify some (i.e., attention and working memory) and attenuate other (i.e., inhibition) ADHD symptoms. Results are mixed, potentially because of between-study differences. To investigate this further we performed a meta-regression analysis on 11 studies (n ‘ADHD-only’ = 695; n ‘ADHD + AD’ = 608), containing 35 effect sizes on attention, inhibition and working memory. Main results were: (1) no evidence of a negative effect of AD on attention and working memory; (2) better response inhibition in children with ADHD with AD than those with only ADHD (medium ES g = ? .40); (3) medication moderated this association: the effect seemed limited to studies that included medication-naïve participants; (4) the difference between the two groups increased with age for attention and with proportion of boys for working memory ability. There was no effect of comorbid disruptive behavior disorder. In conclusion, AD seems to be a protective factor for inhibition problems as assessed with laboratory tasks in ADHD, especially in children who are medication naïve. Further, AD may have a protective function for attention in older children, and for working memory in boys with ADHD. It is therefore important to screen for AD when diagnosing ADHD, and to educate those with comorbid AD about the possible positive function of feeling anxious. Potential negative effects of ADHD medication on inhibition in children with comorbid AD should be considered.     

Assessing declarative memory in 12-month-old infants: A test – retest reliability study of the deferred imitation task

This study examined whether declarative memory in infants can be reliably assessed using the deferred imitation task. Twenty-four infants at the age of 12 months were given the same deferred imitation task twice within a short period of time (week-to-week assessment). Replicating the results of former studies the second memory test yielded better memory performances on the group level than the first one, indicating a memory benefit as is typically found in older children as well as in adults. Stability of memory performance level was analysed using two indicators, namely test – retest correlations assessing stability of individual memory performances for the whole sample, as well as corrected test – retest correlations using individual consistency scores. Test – retest reliability was highly significant (r = .52, p = .009), as well as corrected test – retest reliability (r = .62, p = .001), thus demonstrating that the individual memory performance level in infants can reliably be assessed using the deferred imitation task.     

Do as I … Did! Long-term memory of imitative actions in dogs (<Emphasis Type="Italic">Canis familiaris</Emphasis>)

This study demonstrates long-term declarative memory of imitative actions in a non-human animal species. We tested 12 pet dogs for their ability to imitate human actions after retention intervals ranging from 1 to 24 h. For comparison, another 12 dogs were tested for the same actions without delay between demonstration and recall. Our test consisted of a modified version of the Do as I Do paradigm, combined with the two-action procedure to control for non-imitative processes. Imitative performance of dogs remained consistently high independent of increasing retention intervals, supporting the idea that dogs are able to retain mental representations of human actions for an extended period of time. The ability to imitate after such delays supports the use of long-term declarative memory.     

Trace classical conditioning in rainbow trout (Oncorhynchus mykiss): what do they learn?

There are two main memory systems: declarative and procedural memory. Knowledge of these two systems in fish is scarce, and controlled laboratory studies are needed. Trace classical conditioning is an experimentally tractable model of declarative memory. We tested whether rainbow trout (Oncorhynchus mykiss) can learn by trace conditioning and form stimulus–stimulus, as opposed to stimulus–response, associations. We predicted that rainbow trout trained by trace conditioning would show appetitive behaviour (conditioned response; CR) towards the conditioned stimulus (CS; light), and that the CR would be sensitive to devaluation of the unconditioned stimulus (US; food). The learning group (L, N = 14) was trained on a CS + US contingency schedule with a trace interval of 3.4 s. The control group (CtrL, N = 4) was kept on a completely random schedule. The fish that learnt were further trained as either an experimental (L, N = 6) or a memory control (CtrM, N = 3) group. The L group had the US devalued. The CtrM group received only food. No fish in the CtrL group, but nine fish from the L group conditioned to the light. When tested, five L fish changed their CRs after US devaluation, indicating learning by stimulus–stimulus association of the light with the food. CtrM fish retained their original CRs. To the best of our knowledge, this experiment is the first to show that rainbow trout can learn by trace classical conditioning. The results indicate that the fish learnt by ‘facts-learning’ rather than by reflex acquisition in this study.     

Spatial behavior in male and female crayfish (Orconectes rusticus): learning strategies and memory duration

Previous studies have demonstrated that animals use multiple strategies to solve spatial tasks. We used a T-maze to examine spatial behavior in crayfish, using visual and tactile stimuli as place cues and a food-scented escape tank as reinforcement to leave the maze. In trials on a single day and across multiple days, crayfish learned to exit the maze with significantly reduced latency and with fewer turns. In addition, we examined place memory in 40-min periods with the maze closed and found that crayfish spent longer in the vicinity of a previously open exit compared to a closed exit. Probe tests were conducted using a forced-choice procedure to determine whether crayfish remembered the route out of the maze using primarily place cues or response learning. We found that approximately equal numbers of animals used each strategy, and individuals were able to switch from one strategy to the other on different test days. Males and females did not differ significantly in their performance in the place memory test, maze exit task, or probe tests. Both sexes displayed place memory for the exit location and reduced latency to exit during trials 24 h, 48 h, 72 h, and 1 week after initial training trials, suggesting that spatial memories in crayfish are relatively enduring.     

The contribution of private and public information in foraging by Australasian gannets

Predators that forage on foods with temporally and spatially patchy distributions may rely on private or public sources of information to enhance their chances of foraging success. Using GPS tracking, field observations, and videography, we examined potential sites and mechanisms of information acquisition in departures for foraging trips by colonially breeding Australasian gannets (Morus serrator). Analyses of the bill-fencing ceremony between mated pairs of breeding gannets did not detect correlations between parameters of this reciprocal behavior and foraging trips, as would have been predicted if gannets used this behavior as a source of private information. Instead, 60 % of the departing birds flew directly to join water rafts of other conspecific en route to the feeding grounds. The departure of solitary birds from the water rafts was synchronized (within 60 s) with the arrival of incoming foragers and also among departing birds. Furthermore, solitary departing birds from the rafts left in the same directional quadrant (90º slices) as the prior arriving (67 %) and also prior departing forager (79 %). When associated plunge dives of conspecific were visible from the colony, providing a public source of information, gannets more often departed from the water rafts in groups. Our study thus provides evidence for the use of water rafts, but not the nest site, as locations of information transfer, and also confirms the use of local enhancement as a strategy for foraging flights by Australasian gannets.     

Movement of Genetic Counselors from Clinical to Non-clinical Positions: Identifying Driving Forces

A previous study of genetic counselors (GCs) in the state of Indiana identified movement out of clinical positions within the past 2 years. The aims of this study were to determine if this trend is nationwide and identify reasons why GCs are leaving their positions and factors that might help employers attract and retain GCs. An email was sent to members of the American Board of Genetic Counseling with a link to an online confidential survey. There were 939 responses (23.5% response rate). Overall, 52% of GCs report being highly satisfied in their current position, although almost two thirds think about leaving and one third had changed jobs within the past 2 years. Of those who had changed jobs (n =?295), 74.9% had been working in a hospital/clinic setting but only 46.3% currently do, demonstrating a major shift out of the clinic (p <?0.001). The top three reasons cited for leaving a position were work environment/institutional climate, salary/benefits, and a lack of feeling valued/recognized as a professional. These results confirm that GCs are moving out of clinical positions and document elements of job satisfaction. We suggest points for employers to consider when trying to recruit or retain GCs.     

Divine Emotions: On the Link Between Emotional Intelligence and Religious Belief

There have been only few attempts to explore the relationship between emotional intelligence (EI) and religiosity. However, none of them included measures of ability EI. In two studies, we investigated the potential associations between various aspects of religious belief and ability and trait EI. In Study 1 (N = 240), we found that ability EI was positively associated with general level of religious belief. Study 2, conducted among Polish Christians (N = 159), replicated the previous result on the connection between ability EI and religion. Moreover, both trait and ability EI were negatively correlated with extrinsic religious orientation and negative religious coping. Additional analysis showed that extrinsic orientation mediated the relationship between ability EI and religiosity.     

Modification of EEG power spectra and EEG connectivity in autobiographical memory: a sLORETA study

The aim of the present study was to explore the modifications of scalp EEG power spectra and EEG connectivity during the autobiographical memory test (AM-T) and during the retrieval of an autobiographical event (the high school final examination, Task 2). Seventeen healthy volunteers were enrolled (9 women and 8 men, mean age 23.4 ± 2.8 years, range 19–30). EEG was recorded at baseline and while performing the autobiographical memory (AM) tasks, by means of 19 surface electrodes and a nasopharyngeal electrode. EEG analysis was conducted by means of the standardized LOw Resolution Electric Tomography (sLORETA) software. Power spectra and lagged EEG coherence were compared between EEG acquired during the memory tasks and baseline recording. The frequency bands considered were as follows: delta (0.5–4 Hz); theta (4.5–7.5 Hz); alpha (8–12.5 Hz); beta1 (13–17.5 Hz); beta2 (18–30 Hz); gamma (30.5–60 Hz). During AM-T, we observed a significant delta power increase in left frontal and midline cortices (T = 3.554; p < 0.05) and increased EEG connectivity in delta band in prefrontal, temporal, parietal, and occipital areas, and for gamma bands in the left temporo-parietal regions (T = 4.154; p < 0.05). In Task 2, we measured an increased power in the gamma band located in the left posterior midline areas (T = 3.960; p < 0.05) and a significant increase in delta band connectivity in the prefrontal, temporal, parietal, and occipital areas, and in the gamma band involving right temporo-parietal areas (T = 4.579; p < 0.05). These results indicate that AM retrieval engages in a complex network which is mediated by both low- (delta) and high-frequency (gamma) EEG bands.