Catch the star! Spatial information activates the manual motor system

Experiential traces first: Does holding a location in visuospatial working memory affect the processing of space-associated words?

This study aimed to systematically examine whether actively maintaining a visual location in working memory can influence the processing of spatially related words. In five experiments, we asked participants to maintain either the location or the shape of a visually presented stimulus in working memory so that it could later be compared with a test stimulus concerning the relevant target features. In between, we presented participants with words that refer to objects typically encountered in the upper or lower vertical space (roof vs. root, respectively). The task participants performed as a response to these words differed between experiments. In Experiments 1-3, participants performed a lexical decision task, in Experiment 4 they performed a semantic task (deciding whether the word refers to an occupation), and in Experiment 5 they performed a spatial task (deciding whether the word refers to something in the upper or lower visual field.) Only in Experiment 5 did we observe an interaction between the position of the visual stimulus held in working memory (up vs. down) and the meaning of the spatial words (associated with up vs. down). Our results therefore suggest that actively maintaining a stimulus location in working memory does not automatically affect the processing of spatially related words, but does so if the relevant spatial dimension is made highly salient by the task. The results are thus in line with studies showing a strong context-dependency of embodiment effects and thus allow the conclusion that language processing proper is not operating on a sensorimotor representational format.

Breathing shifts visuo-spatial attention

Considering recent findings that breathing influences cognitive processes, two experiments explored the relationship between breathing and visuo-spatial attention. In Experiment 1, a lateralized probe detection task was inserted into the breathing cycles of 21 healthy adults to probe effects of breathing on the distribution of spatial attention. In Experiment 2 (N = 26), the Posner cueing task measured breathing-contingent detection speed for lateralized probes after endogenous or exogenous cueing. We consistently found faster responses for left probes after exhalation and for right probes after inhalation in both experiments. Breathing also affected the speed of re-alignment of spatial attention after invalid cueing in Experiment 2. This novel breathing bias shows that our ability to encode visuo-spatial information systematically fluctuates during breathing.

How to not induce SNAs: The insufficiency of directional force

People respond faster to smaller numbers in their left space and to larger numbers in their right space. Here we argue that movements in space contribute to the formation of spatial-numerical associations (SNAs). We studied the impact of continuous isometric forces along the horizontal or vertical cardinal axes on SNAs while participants performed random number production and arithmetic verification tasks. Our results suggest that such isometric directional force do not suffice to induce SNAs.

Spatial-numerical associations without a motor response? Grip force says 'Yes'

In numerical processing, the functional role of Spatial-Numerical Associations (SNAs, such as the association of smaller numbers with left space and larger numbers with right space, the Mental Number Line hypothesis) is debated. Most studies demonstrate SNAs with lateralized responses, and there is little evidence that SNAs appear when no response is required. We recorded passive holding grip forces in no-go trials during number processing. In Experiment 1, participants performed a surface numerical decision task ("Is it a number or a letter?"). In Experiment 2, we used a deeper semantic task ("Is this number larger or smaller than five?"). Despite instruction to keep their grip force constant, participants' spontaneous grip force changed in both experiments: Smaller numbers led to larger force increase in the left than in the right hand in the numerical decision task (500-700 ms after stimulus onset). In the semantic task, smaller numbers again led to larger force increase in the left hand, and larger numbers increased the right-hand holding force. This effect appeared earlier (180 ms) and lasted longer (until 580 ms after stimulus onset). This is the first demonstration of SNAs with passive holding force. Our result suggests that (1) explicit motor response is not a prerequisite for SNAs to appear, and (2) the timing and strength of SNAs are task-dependent. (216 words).

Abstract concepts: external influences, internal constraints, and methodological issues

There is a longstanding and widely held misconception about the relative remoteness of abstract concepts from concrete experiences. This review examines the current evidence for external influences and internal constraints on the processing, representation, and use of abstract concepts, like truth, friendship, and number. We highlight the theoretical benefit of distinguishing between grounded and embodied cognition and then ask which roles do perception, action, language, and social interaction play in acquiring, representing and using abstract concepts. By reviewing several studies, we show that they are, against the accepted definition, not detached from perception and action. Focussing on magnitude-related concepts, we also discuss evidence for cultural influences on abstract knowledge and explore how internal processes such as inner speech, metacognition, and inner bodily signals (interoception) influence the acquisition and retrieval of abstract knowledge. Finally, we discuss some methodological developments. Specifically, we focus on the importance of studies that investigate the time course of conceptual processing and we argue that, because of the paramount role of sociality for abstract concepts, new methods are necessary to study concepts in interactive situations. We conclude that bodily, linguistic, and social constraints provide important theoretical limitations for our theories of conceptual knowledge.