Influence of bias on visuospatial and verbal compatibility effects in mixed-mapping environments

Exploring the role of stimulus code-response modality compatibility on the spatial Stroop effect

This study investigated the compatibility of stimulus codes and response modalities and how it mediated the spatial Stroop effect. Stimulus code (word, arrow and moving dots), response modality (voice, keypress and mouse movement), directional information (left and right) and physical location (centre, left and right) of the stimulus were manipulated. Participants responded to the directional information of the stimulus. Spatial interference was expected when the stimulus' directional information and physical location were incongruent. Results showed that more compatible pairings for the three response modalities were word-voice, arrow-keypress and arrow-movement. Incongruent spatial location delayed the reaction time for all response modalities with the word, speeded up the vocal and keypress responses with the moving dots, and had no effect with the arrow. Arrow was thus recommended for conveying directional information on interfaces. This study demonstrated that spatial interference was mediated by the stimulus code, response modality and their compatibility.

PRACTITIONER SUMMARY

This study manipulated three stimulus codes and three response modalities to examine how stimulus–response compatibility mediated the spatial Stroop effect. Spatial interference appeared with the word and moving dots, but not arrow stimulus, for vocal, keypress and mouse responses. Arrow was therefore recommended to convey directional information on an interface.

Interference between accustomed number-space mappings and unacquainted letter-space mappings in a button press task

OBJECTIVE

We aimed to investigate how ordered mappings (e.g., left-to-right and right-to-left order representations) would interfere with each other.

BACKGROUND

Mental representations of numbers and letters are linked with spatial representation and can be changed intentionally.

METHOD

The experiment consisted of three sessions. In the digit-alone session, two digits randomly selected from [1], [2], and [3] were shown. If the two digits were the same, participants pressed the button corresponding to the digit, and if the digits differed, they pressed the remaining button. The response buttons were ordered [1][2][3] from the left. In the letter-alone session, three different button configurations were prepared: sequential [A][B][C], reversed [C][B][A], or partially reversed [B][A][C]. The same-versus-different rules were basically identical to those in the digit task. In the mixed session, trials of the digit task and those of the letter task were randomly mixed.

RESULTS

We found that two ordinal representations did not interfere with each other when they shared the same direction of order ([1][2][3] vs. [A][B][C]), two ordinal mappings interfered with each other when they had different directions of order ([1][2][3] vs. [C][B] [A]), and an ordinal mapping ([1][2][3]) was affected by a nonordinal mapping ([B][A][C]), but the nonordinal mapping was less affected by the ordinal mapping.

CONCLUSION

The mapping between ordinal information and space can be modulated by top-down processes, and it is prone to interference depending on the nature of another coexisting mapping.

APPLICATION

Our findings may be used in designing response assignments for input devices for multiple functions.

Effect of prior practice on the stimulus-response compatibility effect in a mixed mapping environment

A stimulus-response compatibility (SRC) effect is obtained when performance is better with compatible mappings than with incompatible mappings. When mappings are mixed within a task, the SRC effect is often eliminated or reversed.The present study examines how 1,600 trials with different practice tasks can affect the response selection process in these mixed mapping environments. Participants were assigned to one of three practice groups: mixed mapping, pure compatible mapping, and pure incompatible mapping. Subsequently, all participants performed an experimental session in which compatible and incompatible trials were mixed.The SRC effect was eliminated in the experimental mixed mapping session, regardless of practice condition. The results suggest that practice does not change the need to suppress the direct response selection route in a mixed mapping task. However, reaction time distributions and sequential analyses were modulated by practice condition, which indicates that the new associations acquired during practice may activate new routes that interact with preexisting ones.