Oliver Lindemann

Semantic activation in action planning

Four experiments investigated activation of semantic information in action preparation. Participants either prepared to grasp and use an object (e.g., to drink from a cup) or to lift a finger in association with the objects position following a go/no-go lexical-decision task. Word stimuli were consistent to the action goals of the object use (Experiment 1) or to the finger lifting (Experiment 2). Movement onset times yielded a double dissociation of consistency effects between action preparation and word processing. This effect was also present for semantic categorizations (Experiment 3), but disappeared when introducing a letter identification task (Experiment 4). In sum, our findings indicate that action semantics are activated selectively in accordance with the specific action intention of an actor.

Getting a grip on numbers: Numerical magnitude priming in object grasping

To investigate the functional connection between numerical cognition and action planning, the authors required participants to perform different grasping responses depending on the parity status of Arabic digits. The results show that precision grip actions were initiated faster in response to small numbers, whereas power grips were initiated faster in response to large numbers. Moreover, analyses of the grasping kinematics reveal an enlarged maximum grip aperture in the presence of large numbers. Reaction time effects remained present when controlling for the number of fingers used while grasping but disappeared when participants pointed to the object. The data indicate a priming of size-related motor features by numerals and support the idea that representations of numbers and actions share common cognitive codes within a generalized magnitude system.

Finger Counting Habits in Middle Eastern and Western Individuals: An Online Survey:

The current study documents the presence of cultural differences in the development of finger counting strategies. About 900 Middle Eastern (i.e., Iranian) and Western (i.e., European and American) individuals reported in an online survey how they map numbers onto their fingers when counting from 1 to 10. The analysis of these bimanual counting patterns revealed clear cross-cultural differences in the hand and finger starting preferences: While most Western individuals started counting with the left hand and associated the number 1 with their thumb, most Middle Eastern respondents preferred to start counting with the right hand and preferred to map the number 1 onto their little finger. The transition between the two hands during counting showed equal proportions of symmetry-based and spatial continuity-based patterns in the two cultures. Implications of these findings for numerical cognition and for the origin of the well-known association between numbers and space are discussed.

The function of words: Distinct neural correlates for words denoting differently manipulable objects

Recent research indicates that language processing relies on brain areas dedicated to perception and action. For example, processing words denoting manipulable objects has been shown to activate a fronto-parietal network involved in actual tool use. This is suggested to reflect the knowledge the subject has about how objects are moved and used. However, information about how to use an object may be much more central to the conceptual representation of an object than information about how to move an object. Therefore, there may be much more fine-grained distinctions between objects on the neural level, especially related to the usability of manipulable objects. In the current study, we investigated whether a distinction can be made between words denoting (1) objects that can be picked up to move (e.g., volumetrically manipulable objects: bookend, clock) and (2) objects that must be picked up to use (e.g., functionally manipulable objects: cup, pen). The results show that functionally manipulable words elicit greater levels of activation in the fronto-parietal sensorimotor areas than volumetrically manipulable words. This suggests that indeed a distinction can be made between different types of manipulable objects. Specifically, how an object is used functionally rather than whether an object can be displaced with the hand is reflected in semantic representations in the brain.

Effects of intentional motor actions on embodied language processing

Embodied theories of language processing suggest that this motor simulation is an automatic and necessary component of meaning representation. If this is the case, then language and action systems should be mutually dependent (i.e., motor activity should selectively modulate processing of words with an action-semantic component). In this paper, we investigate in two experiments whether evidence for mutual dependence can be found using a motor priming paradigm. Specifically, participants performed either an intentional or a passive motor task while processing words denoting manipulable and nonmanipulable objects. The performance rates (Experiment 1) and response latencies (Experiment 2) in a lexical-decision task reveal that participants performing an intentional action were positively affected in the processing of words denoting manipulable objects as compared to nonmanipulable objects. This was not the case if participants performed a secondary passive motor action (Experiment 1) or did not perform a secondary motor task (Experiment 2). The results go beyond previous research showing that language processes involve motor systems to demonstrate that the execution of motor actions has a selective effect on the semantic processing of words. We suggest that intentional actions activate specific parts of the neural motor system, which are also engaged for lexical-semantic processing of action-related words and discuss the beneficial versus inhibitory nature of this relationship. The results provide new insights into the embodiment of language and the bidirectionality of effects between language and action processing.

Coding strategies in number space: Memory requirements influence spatial–numerical associations

The tendency to respond faster with the left hand to relatively small numbers and faster with the right hand to relatively large numbers (spatial numerical association of response codes, SNARC effect) has been interpreted as an automatic association of spatial and numerical information. We investigated in two experiments the impact of task-irrelevant memory representations on this effect. Participants memorized three Arabic digits describing a left-to-right ascending number sequence (e.g., 3–4–5), a descending sequence (e.g., 5–4–3), or a disordered sequence (e.g., 5–3–4) and indicated afterwards the parity status of a centrally presented digit (i.e., 1, 2, 8, or 9) with a left/right keypress response. As indicated by the reaction times, the SNARC effect in the parity task was mediated by the coding requirements of the memory tasks. That is, a SNARC effect was only present after memorizing ascending or disordered number sequences but disappeared after processing descending sequences. Interestingly, the effects of the second task were only present if all sequences within one experimental block had the same type of order. Taken together, our findings are inconsistent with the idea that spatial–numerical associations are the result of an automatic and obligatory cognitive process but do suggest that coding strategies might be responsible for the cognitive link between numbers and space.

Spatial interferences in mental arithmetic: Evidence from the motion–arithmetic compatibility effect

Recent research on spatial number representations suggests that the number space is not necessarily horizontally organized and might also be affected by acquired associations between magnitude and sensory experiences in vertical space. Evidence for this claim is, however, controversial. The present study now aims to compare vertical and horizontal spatial associations in mental arithmetic. In Experiment 1, participants solved addition and subtraction problems and indicated the result verbally while moving their outstretched right arm continuously left-, right-, up-, or downwards. The analysis of the problem-solving performances revealed a motion–arithmetic compatibility effect for spatial actions along both the horizontal and the vertical axes. Performances in additions was impaired while making downward compared to upward movements as well as when moving left compared to right and vice versa in subtractions. In Experiment 2, instead of being instructed to perform active body movements, participants calculated while the problems moved in one of the four relative directions on the screen. For visual motions, only the motion–arithmetic compatibility effect for the vertical dimension could be replicated. Taken together, our findings provide first evidence for an impact of spatial processing on mental arithmetic. Moreover, the stronger effect of the vertical dimension supports the idea that mental calculations operate on representations of numerical magnitude that are grounded in a vertically organized mental number space.

Context effects in embodied lexical-semantic processing

The embodied view of language comprehension proposes that the meaning of words is grounded in perception and action rather than represented in abstract amodal symbols. Support for embodied theories of language processing comes from behavioral studies showing that understanding a sentence about an action can modulate congruent and incongruent physical responses, suggesting motor involvement during comprehension of sentences referring to bodily movement. Additionally, several neuroimaging studies have provided evidence that comprehending single words denoting manipulable objects elicits specific responses in the neural motor system. An interesting question that remains is whether action semantic knowledge is directly activated as motor simulations in the brain, or rather modulated by the semantic context in which action words are encountered. In the current paper we investigated the nature of conceptual representations using a go/no-go lexical decision task. Specifically, target words were either presented in a semantic context that emphasized dominant action features (features related to the functional use of an object) or non-dominant action features. The response latencies in a lexical decision task reveal that participants were faster to respond to words denoting objects for which the functional use was congruent with the prepared movement. This facilitation effect, however, was only apparent when the semantic context emphasized corresponding motor properties. These findings suggest that conceptual processing is a context-dependent process that incorporates motor-related knowledge in a flexible manner.

Object manipulation and motion perception: evidence of an influence of action planning on visual processing.

In 3 experiments, the authors investigated the bidirectional coupling of perception and action in the context of object manipulations and motion perception. Participants prepared to grasp an X-shaped object along one of its 2 diagonals and to rotate it in a clockwise- or a counterclockwise direction. Action execution had to be delayed until the appearance of a visual go signal, which induced an apparent rotational motion in either a clockwise- or a counterclockwise direction. Stimulus detection was faster when the direction of the induced apparent motion was consistent with the direction of the concurrently intended manual object rotation. Responses to action-consistent motions were also faster when the participants prepared the manipulation actions but signaled their stimulus detections with another motor effector (i.e., with a foot response). Taken together, the present study demonstrates a motor-visual priming effect of prepared object manipulations on visual motion perception, indicating a bidirectional functional link between action and perception beyond object-related visuomotor associations.

Expyriment: A Python library for cognitive and neuroscientific experiments

Expyriment is an open-source and platform-independent lightweight Python library for designing and conducting timing-critical behavioral and neuroimaging experiments. The major goal is to provide a well-structured Python library for script-based experiment development, with a high priority being the readability of the resulting program code. Expyriment has been tested extensively under Linux and Windows and is an all-in-one solution, as it handles stimulus presentation, the recording of input/output events, communication with other devices, and the collection and preprocessing of data. Furthermore, it offers a hierarchical design structure, which allows for an intuitive transition from the experimental design to a running program. It is therefore also suited for students, as well as for experimental psychologists and neuroscientists with little programming experience.