Samuel Shaki

Published claims should be reproducible, yielding the same result when the same analysis is applied to the same data^1,2. Here we assess reproducibility in a stratified random sample of 600 papers published from 2009 to 2018 in 62 journals spanning the social and behavioural sciences. The authors of 144 (24.0%, 95% confidence interval (CI) = 20.8-27.6%) papers made data available to assess reproducibility and, for 38 others, we obtained source data to reconstruct the dataset. We assessed 143 out of the 182 available datasets and found that 76.6 (53.6%, 95% CI = 45.8-60.7%) papers were rated as precisely reproducible and 105.0 (73.5%, 95% CI = 66.4-80.0%) were rated as at least approximately reproducible (within 15% of the original effects or within 0.05 of original P values) after inverse weighting each of the 551 claims by the number of claims per paper. We observed higher reproducibility for papers from political science and economics compared with other fields, for more recent papers compared with older papers and for papers from journals that require data sharing. Implementation of measures to verify that research is reproducible is needed to support trustworthiness in the complex enterprise of knowledge production^3,4.

Pursuing replicability — independent evidence for previous claims — is important for creating generalizable knowledge^1,2. Here we attempted replications of 274 claims of positive results from 164 quantitative papers published from 2009 to 2018 in 54 journals in the social and behavioural sciences. Replications were high powered on average to detect the original effect size (median of 99.6%), used original materials when relevant and available, and were peer reviewed in advance through a standardized internal protocol. Replications showed statistically significant results in the original pattern for 151 of 274 claims (55.1% (95% confidence interval (CI) 49.2–60.9%)) and for 80.8 of 164 papers (49.3% (95% CI 43.8–54.7%)), weighed for replicating multiple claims per paper. We observed modest variation in replication rates across disciplines (42.5–63.1%), although some estimates had high uncertainty. The median Pearson’s r effect size was 0.25 (95% CI 0.21–0.27) for original studies and 0.10 (95% CI 0.09–0.13) for replication studies, an 82.4% (95% CI 67.8–88.2%) reduction in shared variance. Thirteen methods for evaluating replication success provided estimates ranging from 28.6% to 74.8% (median of 49.3%). Some decline in effect size and significance is expected based on power to detect original effects and regression to the mean because we replicated only positive results. We observe that challenges for replicability extend across social–behavioural sciences, illustrating the importance of identifying conditions that promote or inhibit replicability^3,4.

Reading direction is a central determinant of spatial–numerical associations, yet evidence from right-to-left (RL) readers remains inconsistent, ranging from weakened to reversed spatial-numerical associations (SNAs). Shaki et al. (2009) provided the only systematic cross-cultural comparison controlling for reading direction of both words and digits. They reported canonical SNAs in Canadian left-to-right (LR) readers, no SNAs in Hebrew readers with mixed habits (RL words, LR digits), and a reversed SNAs in Palestinian adults with consistent RL reading. Subsequent studies produced mixed results for populations with similar reading profiles, potentially reflecting uncontrolled bilingualism, differing directional habits, and culturally shaped spatial routines, such as object counting and finger counting. Given the theoretical importance of a reverse SNAs and the absence of a successful replication of this finding in standard parity tasks, the present study replicates Shaki et al. (2009), using the refined go/no-go methodology while additionally documenting participants’ object- and finger-counting preferences. We will test German LR readers, Israeli mixed-direction readers, and Palestinian RL readers with adequately powered samples (n = 39 per subgroup). This replication will clarify whether and how culturally transmitted directional habits contribute to spatial–numerical mappings.

There is a long debate about how the meaning of words cues our spatial attention. For implicitly spatial words such as “ROOF” or “BASEMENT”, it was recently shown that processing both the cue word and a subsequent spatial target stimulus was necessary for spatial congruity effects to emerge. Here we challenge this work by documenting that word cues alone suffice to induce congruity effects if they are processed deeply. Sixty-three healthy adults detected vertically displaced targets after looking at centrally presented cue words under three counterbalanced instructions, imposing increasing processing depth: Lexical decision, non-spatial categorization, and spatial categorization. Target detection speed revealed spatial congruity effects for both spatial and non-spatial categorization but not for lexical decision. An interpretation in terms of covert attention deployment was corroborated by concomitant vertical displacements of eye gaze. Our results reveal minimal requirements for covert and overt semantic cueing of spatial attention.

Mental arithmetic is widely studied, both with symbolic digits and with non-symbolic dot patterns that require operand estimation. Several studies reported surprising biases in adults’ performance with both formats while their direction (over/underestimation in addition/subtraction) remains controversial (operational momentum effect or OM; Prado & Knops, Prado and Knops, Psychonomic Bulletin & Review, in Press., 2024). Theoretical accounts of OM make opposing predictions, thus enabling a decisive test: Using symbolic stimuli and responses, we enabled accurate operand encoding and result reporting, thus leaving mental calculation as only source of bias. Importantly, we manipulated operand order through calculation instructions (e.g., “29 + 19” vs. “add 19 to 29”) to assess the crucial role of first operand size as cognitive anchor. With both auditory (Experiment 1, N = 30) and visual presentation (Experiment 2, N = 30), we observed reverse OM, i.e., overestimations in subtraction and underestimations in addition. Importantly, this instance of operation-based anchoring was independent of a second anchoring effect related to operand order: A large operand is a stronger anchor when mentioned first. Our discovery of both operation-based and order-based anchoring extends the well-known anchoring effect into mental arithmetic and eliminates several competing theories about the origin of OM.

How do words with either explicit or implicit spatial meanings (e.g., DOWN, BOOT) shift our attention? Recent studies, presenting prime words followed by probe targets, suggested that, for implicit spatial words, both the spatial meaning of prime words and the target locations must be processed to induce congruency benefits. Here we examined the functional necessity of the latter location component. 91 healthy adults discriminated target letters that followed explicit or implicit spatial words. Words either did or did not have to be semantically processed. Target discrimination speed was used to compute congruency benefits. With explicit prime words, spatial congruency effects emerged without semantic processing instructions. In contrast, with implicit prime words, only instructing their semantic processing ensured a congruency benefit. This shows that, for implicit spatial words, spatial processing of target locations is not necessary; instead, processing the spatial connotation of the prime, together with the identity of the target, can induce congruency benefits. Our results help to understand previous conflicting findings.

Language processing is influenced by sensorimotor experiences. Here, we review behavioral evidence for embodied and grounded influences in language processing across six linguistic levels of granularity. We examine (a) sub-word features, discussing grounded influences on iconicity (systematic associations between word form and meaning); (b) words, discussing boundary conditions and generalizations for the simulation of color, sensory modality, and spatial position; (c) sentences, discussing boundary conditions and applications of action direction simulation; (d) texts, discussing how the teaching of simulation can improve comprehension in beginning readers; (e) conversations, discussing how multi-modal cues improve turn taking and alignment; and (f) text corpora, discussing how distributional semantic models can reveal how grounded and embodied knowledge is encoded in texts. These approaches are converging on a convincing account of the psychology of language, but at the same time, there are important criticisms of the embodied approach and of specific experimental paradigms. The surest way forward requires the adoption of a wide array of scientific methods. By providing complimentary evidence, a combination of multiple methods on various levels of granularity can help us gain a more complete understanding of the role of embodiment and grounding in language processing.

This chapter offers an overview on the bidirectional enrichment between the cognitive science of embodied cognition and other disciplines. First, the dynamic discourse between philosophy and embodied cognition is presented to convey mutual theoretical developments. Then, comparative psychology is described as a fruitful experimental domain to inform about the crucial role of organism–environment interaction in the evolution of adaptive behaviours during phylogeny. Third, the anthropological approach is introduced to inform about the influence of culturally determined learning on cognition during ontogeny. In the end, the field of robotics is briefly discussed to highlight how perception of the body constitutes a fundamental framework for extracting information from the world, and thus for the development of neural structures responsible for cognition and learning.

It is still unclear how spatially associated concepts (e.g., directional expressions, object names, metaphors) shape our cognitive experience. Here, two ex

To construct a coherent multi-modal percept, vertebrate brains extract low-level features (such as spatial and temporal frequencies) from incoming sensory signals. However, because frequency processing is lateralized with the right hemisphere favouring low frequencies while the left favours higher frequencies, this introduces asymmetries between the hemispheres. Here, we describe how this lateralization shapes the development of several cognitive domains, ranging from visuo-spatial and numerical cognition to language, social cognition, and even aesthetic appreciation, and leads to the emergence of asymmetries in behaviour. We discuss the neuropsychological and educational implications of these emergent asymmetries and suggest future research approaches.