Probing the Dual-Route Model of the SNARC Effect by Orthogonalizing Processing Speed and Depth.

The dual-route model explains the SNARC (Spatial-Numerical Association of Response Codes) effect assuming two routes of parallel information processing: the unconditional route (automatic activation of pre-existing links) and the conditional route (activation of task-specific links). To test predictions derived from this model, we evaluated whether response latency in superficial number processing modulates the SNARC effect in a color task (participants judged the color of a number). In Experiment 1, participants performed a parity task, an easy color task (short RTs), and a difficult color task (RTs similar to those of the parity task). A SNARC effect emerged only in the parity task. In Experiment 2, participants performed a color task and a secondary task under four conditions chosen to orthogonally manipulate response latency (short vs. long) and processing depth (semantic vs. perceptual). Only the long-latency perceptual-processing condition elicited a SNARC effect. To explain these results, we suggest that the cognitive resources required by a secondary task might dilute the SNARC effect. Our results indicate that the dual-route model should be modified to take into account additional factors (e.g., working memory load) that influence the level of activation of the unconditional route.

Parietal alpha-based inhibitory abilities are causally linked to numerosity discrimination.

Processing numerosities relies on the innate capacity to understand and manipulate the number of items in a set, and to additional abilities such as inhibitory skills -which are known to be linked to brain oscillations in the alpha range. Whether these inhibitory skills are causally linked to numerosity processing and critical for it is unclear. To address this question, we used alpha-based brain stimulation (transcranial alternate current stimulation, tACS) to target inhibitory abilities in the context of numerosity discrimination. Twenty-nine young adults received bilateral tACS to the parietal lobe, a brain region critical for numerical processes. tACS at target (alpha, 10 Hz), control oscillation frequencies (theta, 4 Hz; beta, 22 Hz; sham, no stimulation), and control areas (bilateral frontal regions) was paired to an established numerosity paradigm that allows distinguishing between congruent and incongruent numerosity trials, the latter requiring to inhibit task-irrelevant information. Performance significantly and specifically worsened in incongruent numerosity trials following bilateral parietal alpha-tACS relative to sham and to the other stimulations used, possibly due to the desynchronization of parietal neuronal oscillations in the alpha range. No significant changes in performance were observed in parietal beta and theta-tACS, relative to sham, nor in frontal alpha-tACS. Likewise, there were no changes in performing congruent numerosity trials. We therefore concluded that parietal alpha oscillations are causally linked to inhibitory abilities, and reinforced the view that these abilities are intrinsic to numerosity discrimination.

The influence of semantic processing and response latency on the SNARC effect.

The Spatial-Numerical Association of Response Code (SNARC) effect refers to the finding that small or large numbers elicit faster leftward or rightward responses, respectively. Traditionally, this effect has been thought to reflect the intrinsic spatial orientation of the mental number line (MNL account) and thus to be modulated by the amount of semantic processing required by the task. This study aimed to test this hypothesis. Participants performed two tasks requiring semantic processing (magnitude classification and parity judgement) and two tasks requiring the processing of non-semantic features of the number (phoneme detection and color judgement). Contrary to the MNL account, the SNARC effect in the four tasks was not modulated by the amount of semantic processing, but rather by response latency. These results provide evidence against the MNL account and in favor of alternative accounts (dual-route model, working memory account).

Psychometric evaluation of the Russian version of the flourishing scale in a sample of older adults living in Siberia.

BACKGROUND: The development of measures of psychological functioning has received less attention in Russia compared to other countries. Moreover, despite the growing interest in the psychological well-being of older adults, there is a lack of research on this segment of the population in Siberia. Therefore, in this study we aimed to evaluate the psychometric properties of the Russian version of the Flourishing Scale (FS) and to measure psychological functioning in a sample of older adults living in Siberia. METHODS: The FS was translated and adapted to Russian language and culture using the back-translation procedure. The Russian version was administered to 851 older adults (aged from 65 to 93 years, mean = 75.3; female = 510). A principal axis factor analysis (PFA) and a confirmatory factor analysis (CFA) were used to assess the structural validity. Cronbach's alpha coefficients (internal consistency) and item-total correlations were also analysed. To test the convergent validity, the FS was compared with other scales assessing mental well-being. RESULTS: The PFA and the CFA showed that the FS had good psychometric properties. A one-factor structure was a good model of fit, even if some items had a low loading (ranging between 0.39 and 0.80). The Cronbach's alpha value was 0.82 and the Cronbach's alpha values if an item were deleted ranged from 0.78 to 0.81. The item-total correlation coefficients ranged from 0.54 to 0.76. The FS also showed good convergent and divergent validity with other scales (correlation coefficients ranging from 0.39 to 0.54). The mean flourishing score (40.9) reported by the older adults in our sample is lower than that reported in previous studies. CONCLUSIONS: The Russian version of the FS seems to have good psychometric properties and to be a valid and reliable instrument to evaluate flourishing among Russian older adults. This study provides the first evaluation of an instrument that Russian researchers and policymakers can use to better understand the determinants of successful ageing in this society. Future studies should further assess the validity and reliability of the FS and should generalize these results to different groups (e.g., adolescent or workers).

The Developmental Trajectory of the Operational Momentum Effect.

Mental calculation is thought to be tightly related to visuospatial abilities. One of the strongest evidence for this link is the widely replicated operational momentum (OM) effect: the tendency to overestimate the result of additions and to underestimate the result of subtractions. Although the OM effect has been found in both infants and adults, no study has directly investigated its developmental trajectory until now. However, to fully understand the cognitive mechanisms lying at the core of the OM effect it is important to investigate its developmental dynamics. In the present study, we investigated the development of the OM effect in a group of 162 children from 8 to 12 years old. Participants had to select among five response alternatives the correct result of approximate addition and subtraction problems. Response alternatives were simultaneously presented on the screen at different locations. While no effect was observed for the youngest age group, children aged 9 and older showed a clear OM effect. Interestingly, the OM effect monotonically increased with age. The increase of the OM effect was accompanied by an increase in overall accuracy. That is, while younger children made more and non-systematic errors, older children made less but systematic errors. This monotonous increase of the OM effect with age is not predicted by the compression account (i.e., linear calculation performed on a compressed code). The attentional shift account, however, provides a possible explanation of these results based on the functional relationship between visuospatial attention and mental calculation and on the influence of formal schooling. We propose that the acquisition of arithmetical skills could reinforce the systematic reliance on the spatial mental number line and attentional mechanisms that control the displacement along this metric. Our results provide a step in the understanding of the mechanisms underlying approximate calculation and an important empirical constraint for current accounts on the origin of the OM effect.

Exploring predictors of life satisfaction and happiness among Siberian older adults living in Tomsk Region.

Despite the growing interest in studying factors affecting subjective well-being of older adults, little research has been conducted on vast territory of Siberia (Russia) with large population. To address this lack of evidence, we explored the relationship between subjective well-being and social aspects (social and emotional support, social network, and social activities), living conditions (standards of living and residence area), self-reported health, and demographic characteristics in older adults living in Tomsk Region, Siberia. Subjective well-being was measured by life satisfaction and happiness (each measured with one 11-point question). Sample included 489 community-dwelling respondents, aged 65 or older. We found that mean life satisfaction and happiness reported by our respondents were lower than those of European countries. Higher quality of social interaction, better standards of living, and being satisfied with own health were associated with higher life satisfaction and happiness. This study provides original data on a region barely investigated and suggests that Siberian older adults receive strong benefits from social support and from social network and that similar factors are related to subjective well-being both in Siberian and Eastern European older adults. Future studies should further explore the relationship between different kinds of social support (e.g., psychological vs. material support) and subjective well-being in different Siberian ethnic groups or regions.

Feasibility of Virtual Tablet-Based Group Exercise Among Older Adults in Siberia: Findings From Two Pilot Trials.

BACKGROUND: Regular physical activity has a positive effect on physical health, well-being, and life satisfaction of older adults. However, engaging in regular physical activity can be challenging for the elderly population because of reduced mobility, low motivation, or lack of the proper infrastructures in their communities. OBJECTIVE: The objective of this paper was to study the feasibility of home-based online group training-under different group cohesion settings-and its effects on adherence and well-being among Russian older adults. We focused particularly on the technology usability and usage and on the adherence to the training (in light of premeasures of social support, enjoyment of physical activity, and leg muscle strength). As a secondary objective, we also explored the effects of the technology-supported intervention on subjective well-being and loneliness. METHODS: Two pilot trials were carried out exploring two different group cohesion settings (weak cohesion and strong cohesion) in the period from 2015 to 2016 in Tomsk, Russian Federation. A total of 44 older adults (59-83 years) participated in the two pilots and followed a strength and balance training program (Otago) for 8 weeks with the help of a tablet-based virtual gym app. Participants in each pilot were assigned to an interaction condition, representing the online group exercising, and an individual condition, representing a home-based individual training. Both conditions featured persuasion strategies but differed in the ability to socialize and train together. RESULTS: Both interaction and individual groups reported a high usability of the technology. Trainees showed a high level of technology acceptance and, particularly, a high score in intention to future use (4.2-5.0 on a 5-point Likert scale). Private texting (short service message [SMS]) was used more than public texting, and the strong cohesion condition resulted in more messages per user. Joint participations to training sessions (copresence) were higher for the social group with higher cohesion. The overall adherence to the training was 74% (SD 27%). Higher levels of social support at baseline were associated with higher adherence in the low cohesion condition (F1,18=5.23, P=.03), whereas in the high cohesion, such association was not found. Overall improvement in the satisfaction with life score was observed between pre and post measures (F1,31=5.85, P=.02), but no decrease in loneliness. CONCLUSIONS: Online group exercising was proven feasible among healthy independently living older adults in Russia. The pilots suggest that a physical training performed in a virtual environment positively affect the life satisfaction of the trainees, but it does not provide support for a decrease in loneliness. High cohesion groups are preferable for group exercising, especially to mitigate effects of low social support on adherence. Further research in motivating group interactions in training settings is needed.

Effects of online group exercises for older adults on physical, psychological and social wellbeing: a randomized pilot trial.

BACKGROUND: Intervention programs to promote physical activity in older adults, either in group or home settings, have shown equivalent health outcomes but different results when considering adherence. Group-based interventions seem to achieve higher participation in the long-term. However, there are many factors that can make of group exercises a challenging setting for older adults. A major one, due to the heterogeneity of this particular population, is the difference in the level of skills. In this paper we report on the physical, psychological and social wellbeing outcomes of a technology-based intervention that enable online group exercises in older adults with different levels of skills. METHODS: A total of 37 older adults between 65 and 87 years old followed a personalized exercise program based on the OTAGO program for fall prevention, for a period of eight weeks. Participants could join online group exercises using a tablet-based application. Participants were assigned either to the Control group, representing the traditional individual home-based training program, or the Social group, representing the online group exercising. Pre- and post- measurements were taken to analyze the physical, psychological and social wellbeing outcomes. RESULTS: After the eight-weeks training program there were improvements in both the Social and Control groups in terms of physical outcomes, given the high level of adherence of both groups. Considering the baseline measures, however, the results suggest that while in the Control group fitter individuals tended to adhere more to the training, this was not the case for the Social group, where the initial level had no effect on adherence. For psychological outcomes there were improvements on both groups, regardless of the application used. There was no significant difference between groups in social wellbeing outcomes, both groups seeing a decrease in loneliness despite the presence of social features in the Social group. However, online social interactions have shown to be correlated to the decrease in loneliness in the Social group. CONCLUSION: The results indicate that technology-supported online group-exercising which conceals individual differences in physical skills is effective in motivating and enabling individuals who are less fit to train as much as fitter individuals. This not only indicates the feasibility of training together despite differences in physical skills but also suggests that online exercise might reduce the effect of skills on adherence in a social context. However, results from this pilot are limited to a small sample size and therefore are not conclusive. Longer term interventions with more participants are instead recommended to assess impacts on wellbeing and behavior change.

'How many' and 'how much' dissociate in the parietal lobe.

We investigated whether two features that are fundamental for quantity processing, namely numerosity and continuous quantity - or 'how many' versus 'how much' - may dissociate in the parietal lobe. Fourteen mathematically-normal participants performed a well-established numerosity discrimination task after receiving continuous theta burst transcranial magnetic stimulation (TBS) over the left or right intraparietal sulcus (IPS) or the Vertex. We performed a detailed analysis of accuracy (based on the Weber Fraction, wf), which distinguished between trials in which numerosity was anti-correlated or 'incongruent' to other continuous measures of quantity, and trials in which numerosity and other continuous features were 'congruent'. Congruent trials can be processed by integrating numerosity or continuous quantity features like cumulative area since they correlate. Instead incongruent trials can only be processed based on numerosity and requires inhibiting cumulative area or other continuous quantity features like dot size and would lead to incorrect judgment if these features are used as a proxy for numerosity. We found an increase of wf, i.e., weakened numerosity processing in incongruent but not congruent trials following left IPS-TBS, which suggests that numerosity processing was impaired while continuous quantity processing remained unchanged. Moreover, wf increased in congruent but not in incongruent trials following right IPS stimulation. We concluded that left and right parietal are respectively critical for numerosity discrimination, i.e., 'how many' or alternatively for response selection, and for integrating numerosity and continuous quantity features.

Asymmetric activation spreading in the multiplication associative network due to asymmetric overlap between numerosities semantic representations?

Simple multiplication facts are thought to be organised in a network structure in which problems and solutions are associated. Converging evidence suggests that the ability for solving symbolic arithmetic problems is based on an approximate number system (ANS). Most theoretical stances concerning the metric underlying the ANS converge on the assumption that the representational overlap between two adjacent numbers increases as the numerical magnitude of the numbers increases. Given a number N, the overlap between N and N+1 is larger than the overlap between N and N-1. Here, we test whether this asymmetric overlap influences the activation spreading within the multiplication associative network (MAN). When verifying simple multiplication problems such as 8×4 participants were slower in rejecting false but related outcomes that were larger than the actual outcome (e.g., 8×4=36) than rejecting smaller related outcomes (e.g., 8×4=28), despite comparable numerical distance from the correct result (here: 4). This effect was absent for outcomes which are not part of either operands table (e.g., 8×4=35). These results suggest that the metric of the ANS influences the activation spreading within the MAN, further substantiating the notion that symbolic arithmetic is grounded in the ANS.

Operand-order effect in multiplication and addition: the long-term effects of reorganization processand acquisition sequence.

Butterworth, Marchesini, and Girelli (2003) showed that children solved multiplications faster when the larger operand was first (e.g., 5 · 2) than when the smaller operand was first (e.g., 2 · 5). This result was interpreted according to the reorganization hypothesis, which states that, as children begin to switch from counting-based strategies (e.g., repeated additions) to direct retrieval, non-retrieval strategies generate an advantage for the larger-operand-first order. In two experiments we showed that order preferences also persist into adulthood. With additions, the larger-operand-first order was solved faster than the inverse order. With multiplications we obtained a novel result: Largeroperand-first problems were solved faster when at least one operand was smaller than 5, whereas smaller-operand-first problems were solved faster when both operands were larger than 5. Since the reorganization process alone cannot explain our results, we propose that order preferences are also influenced by the sequence in which the members of a commuted pair are acquired.

Number skills are maintained in healthy ageing.

Numerical skills have been extensively studied in terms of their development and pathological decline, but whether they change in healthy ageing is not well known. Longer exposure to numbers and quantity-related problems may progressively refine numerical skills, similar to what happens to other cognitive abilities like verbal memory. Alternatively, number skills may be sensitive to ageing, reflecting either a decline of number processing itself or of more auxiliary cognitive abilities that are involved in number tasks. To distinguish between these possibilities we tested 30 older and 30 younger participants on an established numerosity discrimination task requiring to judge which of two sets of items is more numerous, and on arithmetical tasks. Older participants were remarkably accurate in performing arithmetical tasks although their numerosity discrimination (also known as 'number acuity') was impaired. Further analyses indicate that this impairment was limited to numerosity trials requiring inhibiting information incongruent to numerosity (e.g., fewer but larger items), and that this also correlated with poor inhibitory processes measured by standard tests. Therefore, rather than a numerical impairment, poor numerosity discrimination is likely to reflect elderly's impoverished inhibitory processes. This conclusion is supported by simulations with a recent neuro-computational model of numerosity perception, where only the specific degradation of inhibitory processes produced a pattern that closely resembled older participants' performance. Numeracy seems therefore resilient to ageing but it is influenced by the decline of inhibitory processes supporting number performance, consistent with the 'Inhibitory Deficit' Theory.

Transfer of cognitive training across magnitude dimensions achieved with concurrent brain stimulation of the parietal lobe.

Improvement in performance following cognitive training is known to be further enhanced when coupled with brain stimulation. Here we ask whether training-induced changes can be maintained long term and, crucially, whether they can extend to other related but untrained skills. We trained overall 40 human participants on a simple and well established paradigm assessing the ability to discriminate numerosity--or the number of items in a set--which is thought to rely on an "approximate number sense" (ANS) associated with parietal lobes. We coupled training with parietal stimulation in the form of transcranial random noise stimulation (tRNS), a noninvasive technique that modulates neural activity. This yielded significantly better and longer lasting improvement (up to 16 weeks post-training) of the precision of the ANS compared with cognitive training in absence of stimulation, stimulation in absence of cognitive training, and cognitive training coupled to stimulation to a control site (motor areas). Critically, only ANS improvement induced by parietal tRNS + Training transferred to proficiency in other parietal lobe-based quantity judgment, i.e., time and space discrimination, but not to quantity-unrelated tasks measuring attention, executive functions, and visual pattern recognition. These results indicate that coupling intensive cognitive training with tRNS to critical brain regions resulted not only in the greatest and longer lasting improvement of numerosity discrimination, but importantly in this enhancement being transferable when trained and untrained abilities are carefully chosen to share common cognitive and neuronal components.

Collective enumeration.

Many joint decisions in everyday life (e.g., Which bar is less crowded?) depend on approximate enumeration, but very little is known about the psychological characteristics of counting together. Here we systematically investigated collective approximate enumeration. Pairs of participants made individual and collective enumeration judgments in a 2-alternative forced-choice task and when in disagreement, they negotiated joint decisions via verbal communication and received feedback about accuracy at the end of each trial. The results showed that two people could collectively count better than either one alone, but not as well as expected by previous models of collective sensory decision making in more basic perceptual domains (e.g., luminance contrast). Moreover, such collective enumeration benefited from prior, noninteractive practice showing that social learning of how to combine shared information about enumeration required substantial individual experience. Finally, the collective context had a positive but transient impact on an individual's enumeration sensitivity. This transient social influence may be explained as a motivational factor arising from the fact that members of a collective must take responsibility for their individual decisions and face the consequences of their judgments.