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The spatial-size association of response codes (SSARC) effect refers to the finding that left-hand responses are faster (and more accurate) to physically small/er as compared to physically large/r objects, whereas right-hand responses are faster (and more accurate) to large/r as compared to small/er objects (e.g., Ren, Nicholls, Ma, & Chen, 2011; Wühr & Seegelke, 2018). Hence, the SSARC effect provides evidence for the existence of associations or overlap between the cognitive representations of size and space. Until now, the SSARC effect has been studied in one direction only, that is, with size as the critical stimulus feature and location as the critical response feature. Here, we ask whether SSARC effects can also be obtained in the opposite direction, that is, with location as the critical stimulus feature and size as the critical response feature. Moreover, we seek to compare SSARC effects in both directions (size -> location vs. location -> size) in order to determine whether the associations in both directions are of similar strength or not.

The purpose of the study is to investigate whether the congruency or incongruency between the size and the location of a stimulus affects the processing (and responding) to that stimulus. Previous research has demonstrated a compatibility effect between physical stimulus size and left vs. right response locations. In particular, participants respond faster and more accurate with a left-hand response to small/er stimuli than to large/r stimuli, whereas the opposite is true for right-hand responses (Wühr & Seegelke, 2018). This physical stimulus size-response location compatibility effect occurs not only when stimulus size is task-relevant, but also when it is irrelevant, suggesting that stimulus size can activate the associated response in an automatic manner. Together, the pattern suggests associations between physical sizes and left/right locations with smaller sizes being more strongly associated to left than right locations, and larger sizes being more strongly associated to right than left locations. Yet, in previous studies, the presence of these associations has been demonstrated between stimuli and responses, suggesting that stimulus size can activate (i.e., prime) a response at an associated location. In the present study, we want to determine whether similar priming effects occur during stimulus processing when size and location are two features of the same stimulus. Therefore, in our experiment, stimuli will vary in color (green, red), size (small, large) and location (left, right). There will be three different task conditions, in which participants respond compatibly to color, or size, or location. We are mainly interested in the presence of a congruency effect between stimulus size and stimulus location and whether this congruency effect will interact with task.

The spatial-numerical association of response codes (SNARC) effect is one of the most prominent and well-studied phenomena of the last three decades. It refers to the finding that left-hand responses are faster (and more accurate) to small as compared to large numbers, whereas right-hand responses are faster (and more accurate) to large as compared to small numbers (e.g., Dehaene, Bossini, & Giraux, 1993). Hence, the SNARC effect provides evidence for the existence of associations between numbers and locations. Interestingly, the SNARC effect has apparently been studied in one direction only, that is, with number as the critical stimulus feature and location as the critical response feature. Here, we ask whether SNARC effects can also be obtained in the opposite direction, that is, with location as the critical stimulus feature and number as the critical response feature. Moreover, we seek to compare SNARC effects in both directions (number -> location vs. location -> number) in order to determine whether the associations in both directions are of similar strength or not.

The spatial-numerical association of response codes (SNARC) effect is one of the most prominent and well-studied phenomena of the last three decades. It refers to the finding that left-hand responses are faster (and more accurate) to small as compared to large numbers, whereas right-hand responses are faster (and more accurate) to large as compared to small numbers (e.g., Dehaene, Bossini, & Giraux, 1993). Hence, the SNARC effect provides evidence for the existence of associations between numbers and locations. Interestingly, the SNARC effect has apparently been studied in one direction only, that is, with number as the critical stimulus feature and spatial location as the critical response feature. Here, we ask whether SNARC effects can also be obtained in the opposite direction, that is, with spatial location as the critical stimulus feature and number as the critical response feature. Moreover, we seek to compare SNARC effects in both directions (number -> location vs. location -> number) in order to determine whether the associations in both directions are of similar strength or not.

The spatial-size association of response code (SSARC) effect refers to the finding of better performance with the left hand to small stimuli and with the right hand to large stimuli, as compared to the reverse mapping. In the present study, we investigated which response coding is responsible for the emergence of the SSARC effect. We observed a SSARC effect only with response selection between hands but not between fingers of one hand, indicating that the responses are coded relative to the body midline. Further, we observed a SSARC effect with parallel arms but not with crossed arms, suggesting that both the anatomical side of the effector and its external spatial position contribute to the response code. However, using a reaching task as compared to keypresses, the SSARC effect followed the arms, suggesting that the crucial spatial response code refers more strongly to the anatomical side of the effector rather than to the external spatial response position. These findings document a strong influence of anatomically- or body-based coding on the SSARC effect, are at odds with the proposition of a generalized magnitude system that utilizes a common, external-spatial metric, and point toward a categorical nature of response codes underlying the SSARC.

Research on effects of S-R compatibility or S-R correspondence has produced evidence suggesting associations between (numerical or physical) stimulus size and spatial dimensions, such as the horizontal position of a (left or right) response. For example, the spatial-numerical association of response codes (SNARC) effect is a prominent piece of evidence for associations between numerical stimulus size and response position. The SNARC effect refers to the finding that left-hand responses are faster (and more accurate) to small as compared to large numbers, whereas right-hand responses are faster (and more accurate) to large as compared to small numbers (e.g., Dehaene, Bossini, & Giraux, 1993). Similarly, compatibility and correspondence effects between physical stimulus size and (horizontal) response positions have provided evidence for the existence of associations between the latter two dimensions. In this case, left-hand responses are faster (and more accurate) to small as compared to large stimuli, whereas right-hand responses are faster (and more accurate) to large as compared to small stimuli (e.g., Wühr & Seegelke, 2018, 2019). In the present experiment, we aim at investigating whether irrelevant context stimuli can produce a correspondence effect between the (relative) physical size of a target stimulus and left/right responses. In our experiment, participants have to respond to the color of a centrally presented target stimulus by pressing a left or a right key. The target, which is always presented in the same size, is either flanked by a pair of smaller stimuli (small context) or by a pair of larger stimuli (large context).

The purpose of the study is closer investigating the nature of the response codes that are (automatically) activated by the physical size of visual stimuli. Previous research has demonstrated a compatibility effect between physical stimulus size and left vs. right response positions. In particular, participants respond faster and more accurate with a left-hand response to small/er stimuli than to large/r stimuli, whereas the opposite is true for right-hand responses. This physical stimulus size - response position compatibility effect occurs not only when stimulus size is task-relevant, but also when it is irrelevant, suggesting that stimulus size can activate the associated response in an automatic manner. Notably, in previous studies, participants always responded bimanually, that is, participants pressed a left key with one (usually the left) hand, and a right key with the other (usually the right) hand. In the present study, we want to determine whether the effect can also occur with unimanual responses, performed either with the left or right hand, and whether there are differences between the unimanual conditions. Therefore, participants will respond to a small or a large stimulus with three different response sets (unimanual left, bimanual, unimanual right). With each response set, participants will respond with a compatible S-R mapping (small-left, large-right) and with an incompatible mapping (small-right, large-left), to determine the size of the compatibility effect for each response set (and participant).

The purpose of the study is closer investigating the nature of the response codes that are (automatically) activated by the physical size of visual stimuli. Previous research has demonstrated a compatibility effect between physical stimulus size and left vs. right response positions. In particular, participants respond faster and more accurate with a left-hand response to small/er stimuli than to large/r stimuli, whereas the opposite is true for right-hand responses. This physical stimulus size - response position compatibility effect occurs not only when stimulus size is task-relevant, but also when it is irrelevant, suggesting that stimulus size can activate the associated response in an automatic manner. Notably, in previous studies, spatial response position was always confounded with anatomical hand status (i.e., participants pressed a left key with the left hand, and a right key with the right hand). In the present study, we want to determine whether response position or anatomical hand status is more important for the compatibility effect. Therefore, participants will respond to a small or large stimulus with a compatible S-R mapping (small-left, large-right) or with an incompatible mapping (small-right, large-left). In addition, participants will perform the two mapping conditions with parallel arms in one part of the experiment, and with crossed arms in another part of the experiment.

Pen-and-paper tests of sustained attention, such as the d2 test, require participants to search several lines of stimuli for predefined target stimuli and to mark this stimulus with a pen. Notably, however, available tests of sustained attention differ in how targets should be marked. In particular, in the d2 test of sustained attention (and its successor, the d2-R), participants are supposed to ignore nontargets and to mark each target with a single stroke (dash). In contrast, in the FAIR-2 test of sustained attention, participants are supposed to draw a continuous line below the currently inspected stimulus line, and to mark each target with an upward spike. We presume that the FAIR-2 test imposes higher demands on visuomotor control, as compared to the d2 test, and therefore visuomotor abilities should have a higher impact on the results of the former, as compared to the latter, test.

Many pen-and-paper tests of sustained attention (e.g., d2 test, FAIR test) require participants to search for a set of predefined target stimuli among a set of distractor stimuli. It is known that repeated testing with pen-and-paper tests of sustained attention improves performance, but the sources of these practice benefits are unknown. When doing a test for the first time, participants may learn about many different features of the test (such as targets, distractors, target positions, distractor positions) and each of these learning processes may benefit performance when the test is repeated. The purpose of the present study is to investigate the role of learning stimulus (i.e., target and distractor) locations for practice benefits with a pen-and-paper test of selective attention. We used two versions of a pen-and-paper test of sustained attention, which required to search for a set of targets among a set of distractors. The two versions of the test involved the same set of targets and the same set of distractors. Moreover, in both version of the test, locations of targets and distractors were repeated every fourth line (as in the original version of the d2 test), but the two versions differed in the exact locations of targets and distractors. One group of participants was tested twice with the same version of the test (location-repetition condition), whereas another group of participants was tested with two different versions of the test (location-change condition).

Previous studies have demonstrated a compatibility effect between physical stimulus size and horizontal response location (e.g., Wühr & Seegelke, 2018; Journal of Cognition). A mapping that requires a left-hand response to a small stimulus and a right-hand response to a large stimulus allows for faster and more accurate responses than the reverse mapping. Because all previous studies on the compatibility effect have required manual responses, we do not yet know whether the effect is confined to manual responses or not. Hence, the purpose of the present experiment was (a) to test whether the compatibility effect between physical stimulus size and response location would also occur in vocal responses, and (b) to compare the compatibility effect in manual and vocal responses. Previous studies have demonstrated that effects of spatial S-R correspondence do not only occur with manual (i.e., spatial) responses, but also with vocal (i.e., nonspatial) responses (e.g., Wühr, 2006, Acta Psychologica). Hence, one might expect that the compatibility effect between physical stimulus size and horizontal response location also occurs with vocal responses.

Previous studies have demonstrated a compatibility effect between physical stimulus size and horizontal response location (e.g., Wühr & Seegelke, 2018; Journal of Cognition). A mapping that requires a left-hand response to a small stimulus and a right-hand response to a large stimulus allows for faster and more accurate responses than the reverse mapping. Some informal observations, and the results of an unpublished pilot study, suggested that handedness may affect this compatibility effect. Therefore, the main purpose of the present experiment was to test whether and how handedness would affect the compatibility effect between physical stimulus size and response location. We expected that the effect was stronger in right-handed as compared to left-handed people. An additional purpose of our experiment was to investigate whether differences in grip or hand strength might be related to differences in the size of the compatibility effect both between and within groups.

Many pen-and-paper tests of sustained attention (e.g., d2 test, FAIR test) require participants to search for a set of predefined target stimuli among a set of distractor stimuli. It is known that repeated testing with pen-and-paper tests of sustained attention improves performance, but the sources of these practice benefits are unknown. When doing a test for the first time, participants may learn about many different features of the test (such as targets, distractors, target positions, distractor positions) and each of these learning processes may benefit performance when the test is repeated. The purpose of the present study is to investigate the role of learning a particular set of distractor stimuli for practice benefits with a pen-and-paper test of selective attention. We used two versions of a pen-and-paper test of sustained attention, which required to search for a set of targets among a set of distractors. The two versions of the test involved the same set of three targets, but two different sets of five distractors each. Targets and distractors occupied the same locations in both versions of the test. One group of participants was tested twice with the same version of the test (distractor-repetition condition), whereas another group of participants was tested with two different versions of the test (distractor-change condition).

Many pen-and-paper tests of sustained attention (e.g., d2 test, FAIR test) require participants to search for a set of predefined target stimuli among a set of distractor stimuli. It is known that repeated testing with pen-and-paper tests of sustained attention improves performance, but the sources of these practice benefits are unknown. In particular, when doing a test for the first time, participants may learn about many different features of the test (such as targets, distractors, target positions, distractor positions) and each of these learning processes may benefit performance when the test is repeated. The purpose of the present study is to investigate the role of learning a particular set of target stimuli for practice benefits with a pen-and-paper test of selective attention. We used two versions of a pen-and-paper test of sustained attention, which required to search for a set of targets among a set of distractors. The two versions of the test involved different sets of targets (test 1: t1, t2, t3; test 2: t4, t5, t6), but the same set of distractors (i.e., d1, d2, d3). Moreover, targets and distractors occupied the same locations in both versions of the test. One group of participants was tested twice with the same version of the test (target-repetition condition), whereas another group of participants (target-change condition) was tested with two different versions of the test.

The spatial-numerical association of response codes (SNARC) effect is one of the most prominent and well-studied phenomena of the last three decades. It refers to the finding that left-hand responses are faster (and more accurate) to small as compared to large numbers, whereas right-hand responses are faster (and more accurate) to large as compared to small numbers (e.g., Dehaene, Bossini, & Giraux, 1993). It has long been discussed whether absolute or relative numerical size is responsible for the SNARC effect. In their classic study, Dehaene et al. (1993, Experiment 3) addressed the issue by measuring the impact of different stimulus ranges on the SNARC effect. In particular, they compared SNARC effects for a set of smaller numbers (i.e., 1-5) with SNARC effects for a set of larger numbers (i.e., 4-8). If absolute size was important, SNARC effects should differ between sets; if relative size was important, similar SNARC effects should occur for the two sets. Moreover, if absolute size was important, similar SNARC effects should occur for the intermediate-sized stimuli shared by the sets (i.e., 4 and 5), whereas different effects should occur for these stimuli if relative size was important. Results of Dehaene et al. supported the relative-size-matters hypothesis. Ben Nathan, Salti, Shaki & Algom (2009) argued that the Dehaene et al. results were not conclusive because absolute and relative size were confounded within each block of their experiment. Therefore, Ben Nathan et al. conducted a study in which the relative size of each target stimulus was manipulated within blocks, by using a roving standard. In particular, in each trial of their experiment, participants saw a sequence of two digits, and judged whether the second digit (the target) was smaller or larger than the first (the standard). The S-R mapping of this judgment varied between blocks. Hence, with this manipulation, the same digit (e.g., 6) could occur as relatively small (if the preceding standard was 7) or as relatively large (if the preceding standard was 5). Results showed strong SNARC-like effects of relative size, but no effects of absolute size. Hence, the authors argued that relative, and not absolute, numerical size would produce the SNARC effect. The experimental method used by Ben Nathan et al. (2009) is not devoid of problems either. In particular, the serial magnitude-judgment task requires participants to judge if a target is “larger than” or “smaller than” a standard. Importantly, the larger-than relation is associated with a rightward pointing arrowhead (>), whereas the smaller-than relation is associated with leftward pointing arrowhead (