David F. Pick

Equine color perception revisited

Abstract An attempt to replicate Grzimek (1952; Z. Tierpsychol., 27: 330–338) is reported where a Quarter-Horse mare chose between colored and gray stimuli for food reinforcement. Stimuli varied across a broad range of reflectance values. A double-blind procedure with additional controls for auditory, olfactory, tactile, and position cues was used. The subject could reliably discriminate blue (462 nm) vs. gray, and red (700 nm) vs. gray without regard to reflectance (P

Stimulus-response compatibility with wheel-rotation responses: Will an incompatible response coding be used when a compatible coding is possible?

Three experiments were conducted in which subjects responded to left-right tones with clockwise-counterclockwise rotations of a steering wheel using one of two stimulus-response assignments. When the hands were at the bottom of the wheel, where hand movement is opposite to wheel movement, subjects coded responses according to the frame that yielded a compatible mapping when the instructions did not emphasize either hand or wheel movements (Experiment 1). When instructions emphasized hand movements, responses were coded relative to the hand-referenced frame (Experiment 2), and when the wheel controlled a visual cursor, responses were coded relative to a cursor-referenced frame (Experiment 3). Coding with respect to these frames occurred even when the resulting mapping was incompatible.

Display-control arrangement correspondence and logical recoding in the Hedge and Marsh reversal of the Simon effect

When left and right keypresses are made to stimuli in left and right locations, and stimulus location is irrelevant to the task, responses are typically faster when stimulus location corresponds with response location than when it does not (the Simon effect). This effect reverses when the relevant stimulus-response mapping is incompatible, with responses being slower when stimulus and response locations correspond (the Hedge and Marsh reversal). Simon et al. (Acta Psychol. 47 (1981) 63) reported an exception to the Hedge and Marsh reversal for a situation in which the relevant stimulus dimension was the color of a centered visual stimulus and the irrelevant location information was left or right tone location. In contrast, similar experiments have found a reversal of the Simon effect for tone location when relevant visual locations were mapped incompatibly to responses. We conducted four experiments to investigate this discrepancy. Both results were replicated. With an incompatible mapping, irrelevant tone location showed a small reverse Simon effect when the relevant visual dimension was physical location but not when the color of a centered stimulus or the direction in which an arrow pointed conveyed the visual location information. The reversal occurred in a more standard Hedge and Marsh task in which the irrelevant dimension was location of the colored stimulus, but only when the response keys were visibly labeled. Several of the results suggest that display-control arrangement correspondence is the primary cause of the Hedge and Marsh reversal, with logical recoding playing only a secondary role.

Acquisition and transfer of attention allocation strategies in a multiple-task work environment

Objective: Payoff effects on strategy development and change were assessed in a synthetic work environment, SYNWORK1. Background: Many work settings require several tasks to be performed concurrently. It is important to know how the strategies used in performing the respective tasks vary with payoffs. Method: Sixty students performed four tasks in SYNWORK1, for which points are received for correct responses and lost for incorrect responses. Individual-task payoffs were varied between participants and were changed after 8 and 12 sessions to examine the effects of a previous strategy on development of a new strategy. Results: Participants were sensitive to initial payoffs and modified their strategies when payoffs changed. However, residual effects of prior payoffs were evident. Conclusion: Payoffs for multiple-task environments need to be explicit, and practice should be provided for strategy development. When payoffs change, strategies adopted reflect current and previous payoffs. Application: The findings can be applied to the design of payoff schedules for multiple-task environments.

Deconstructing Marilyn: Robust effects of face contexts on stimulus—response compatibility

Hommel and Lippa (1995) found a left—right spatial compatibility effect with respect to a background context of Marilyn Monroe’s face, rotated 90° clockwise or counterclockwise from upright, when subjects responded to up or down stimuli by pressing a left or a right key. They interpreted their results as providing evidence for object-based coding of stimulus location. We conducted four experiments in order to evaluate the reliability of this face context effect, to control for possible artifacts and evaluate alternative explanations, and to establish generalizability to other face contexts. This was accomplished by using not only the original photograph, but also a mirror-reversed image, chimeric faces composed from the left or the right sides of the original photograph, an outline drawing face, and a circle with markings for facial features. Our results were much stronger than those of Hommel and Lippa, and the face context effect was found for all of the face variations. Our experiments also provided evidence to suggest that asymmetric coding of the up and down locations contributes to performance in the face context as well.

Lateralized warning tones produce typical irrelevant-location effects on choice reactions

Simon, Acosta, and Mewaldt (1975) reported an experiment in which a 200-Hz warning-tone, presented in the left or right ear, was followed by an imperative stimulus of 500 Hz in either ear, to which a left- or right-key press was to be made. Simon et al. found a correspondence effect for warning location and response location (i.e., faster reactions when warning and response locations corresponded than when they did not) when the stimulus-response mapping was incompatible but not when it was compatible. These findings stand in contrast to typical results of (1) a correspondence effect for irrelevant location information when the mapping is compatible and (2) a reversed correspondence effect (i.e., faster responses when stimulus and response location do not correspond) when the mapping is incompatible. We conducted a direct replication of Simon et al.’s experiment and another experiment that differed only in the imperative stimulus being visual, in order to determine whether there are unique aspects of their method that yield atypical results. Our results failed to replicate those reported by Simon et al. but instead showed the patterns of correspondence effects typically found with other procedures, suggesting that the warning-signal method produces irrelevant-location effects consistent with those produced by other methods.

Coding controlled and triggered cursor movements as action effects: influences on the auditory Simon effect for wheel-rotation responses.

Four experiments investigated influences of irrelevant action effects on response selection in Simon tasks for which tone pitch was relevant and location irrelevant, and responses were clockwise- counterclockwise wheel rotations. When the wheel controlled left-right movement of a cursor in a direction opposite an instructed left-right hand-movement goal, the Simon effect was reduced. When the wheel was held at the bottom, this reduction was due to some participants coding responses relative to the cursor and others relative to the hands. However, when the wheel was held at the top, it was due to participants integrating cursor movements with hand movements as a single action concept. In contrast, a cursor triggered by the wheel movement showed little influence on the Simon effect, even when contiguity and contingency with the wheel movements were high. Experience with the controlled cursor in a prior trial block or between trials established a causal relation that enabled participants to code the triggered cursor as belonging to the action concept and thus reduce the Simon effect. Multiple factors determine the influence of an irrelevant action effect on performance.

An empirical evaluation of the SYNWORK1 multiple-task work environment

SYNWORK1 is a multiple-task work environment that allows up to four tasks (memory search, arithmetic, visual monitoring, and auditory monitoring) to be performed concurrently. Experiments were conducted to evaluate performance and subjective workload for each individual task and all combinations of tasks at two presentation rates. At the slower default rates, the three experiment-paced tasks were not very demanding, and improvements with practice were due primarily to the subject-paced arithmetic task. Doubling the presentation rates made the demands of all tasks more comparable and decreased the influence of arithmetic performance. SYNWORK1 is useful for comparisons between populations of individuals and evaluations of arousal-related variables, and, with modification, could provide a tool for assessing basic issues in multiple-task performance.

Allocation of effort as a function of payoffs for individual tasks in a multitasking environment

SYNWORK1 software allows the examination of how payoffs affect the allocation of effort by people when they perform four different tasks (memory search, arithmetic, visual monitoring, and auditory monitoring). In a previous study (Wang, Proctor, & Pick, 2007), we showed that participants adopted multitasking strategies allocating relative effort appropriate to payoff differences between the arithmetic and memory tasks, but that they exhibited residual effects of prior payoffs when the payoffs were switched. In the present study, we varied the payoff in two different experiments for only one of these tasks, the memory task in Experiment 1 and the arithmetic task in Experiment 2. Doing this allowed consideration of performance for both the task for which payoff changed explicitly and the other cognitive task, for which the payoff difference was implicit (i.e., relative to the explicit payoff that was manipulated). Although participants adjusted performance on the task for which the payoff explicitly varied, the payoff manipulation had less effect than did the explicit payoff manipulations for both tasks used previously. Also, the change in effort on a task resulting from explicitly increasing its payoff was less than that from decreasing the payoff. SYNWORK1 is a good environment for studying multitasking, but has several limitations that need to be addressed to provide a synthetic work environment that allows investigation of a wider range of theoretically relevant issues.

Effects of face and inanimate-object contexts on stimulus–response compatibility

Prior studies have shown that a left–right spatial compatibility effect occurs for vertically oriented stimuli relative to a background context of a face rotated 90° clockwise or counterclockwise from upright. For stimuli presented at the location of the eyes, the mapping of the right eye to a right response and the left eye to a left response, as would be viewed by the participant, yields better performance than does the opposite mapping. An issue of current interest in social cognition is whether animate objects are processed differently from inanimate ones. We investigated this issue in two experiments in which we compared the compatibility effects obtained with inanimate objects to those obtained with animate, face stimuli. The results showed left–right compatibility effects from the participant’s perspective for vehicles and faces from frontal and profile views, as well as for a road sign. Our findings indicate that coding of stimulus location relative to an external frame of reference is not restricted to face backgrounds.