Carrying groceries: More items in early trips than in later trips or the reverse? Implications for pre-crastination.

Returning home from the grocery store with a car full of groceries requires decisions about how many bags to carry when. If the decisions exemplify procrastination, people should carry more bags per trip in late trips than in early trips (putting the hard work off until later), but if the decisions exemplify the recently discovered phenomenon of pre-crastination (Rosenbaum et al. in Psychol Sci 25: 1487-1496, 2014), people should carry more bags per trip in early trips than in late trips (doing the hard work early). To distinguish between these possibilities, we asked university students to carry 5 or 11 dodgeballs from one bin to another 4, 8, 12, or 16 feet away in as many trips as they wished. A random half of the subjects did the tasks with an additional requirement to memorize and then recall 7 digits after carrying all the balls from the home to the target bin. Consistent with pre-crastination, participants carried the most balls per trip in early trips, and consistent with the hypothesis that pre-crastination relates to memory load, the number of balls carried per trip was affected by the presence of a memory load. The results add to the growing evidence for the generality of pre-crastination.

What matters in making demand-based decisions: Time alone or difficulty too?

Which task is easier, doing arithmetic problems of specified form for some specified duration, or carrying a bucket of specified weight over some specified distance? If it is possible to choose between the "more cognitive" task and the "more physical" task, how are the difficulty levels of the tasks compared? We conducted two experiments in which participants chose the easier of two tasks, one that involved solving addition or multiplication problems (Experiment 1) or addition problems with different numbers of addends (Experiment 2) for varying amounts of time (in both experiments), and one that involved carrying a bucket of different weights over a fixed distance (in both experiments). We found that the probability of choosing to do the bucket task was higher when the bucket was empty than when it was weighted, and increased when the cognitive task was harder and its duration grew. We could account for the choice probabilities by mapping the independent variables onto one abstract variable, Φ. The functional identity of Φ remains to be determined. It could be interpreted as an inferred effort variable, subjective duration, or an abstract, amodal common code for difficulty.

Effort avoidance is not simply error avoidance.

Little is known about how effort is represented for different kinds of tasks. Recently, we suggested that it would help to establish empirical benchmarks for this problem. Accordingly, Feghhi and Rosenbaum (Journal of Experimental Psychology: Human Perception and Performance, 45:983-994, 2019) estimated how many additional digits to be memorized corresponded to navigating through a narrow gap versus a wide gap. The estimates were based on a study in which participants chose between walking paths with associated memory demands. We found that participants were equally willing to choose to walk through a narrow gap as to walk through a wide gap when the narrow-gap walk required memorization of 0.55 fewer digits on average than the wide-gap walk. In the present experiment, we sought to replicate and extend this previous finding in two ways: (1) by presenting the memory digits in auditory rather than visual form to test the hypothesis that participants used phonological recoding of the visually presented digits; and (2) by providing a new metric of the relative difficulty of navigation errors compared to recall errors. We provided 36 university students with two action/memorization options per trial and asked them to choose the easier option. Each option had varying degrees of physical demand (walking through a wide or narrow gap) and mental demand (memorizing 6, 7, or 8 digits). We expected performance to be comparable to what we observed earlier with visually presented digits to be memorized, and this prediction was confirmed. We also used a new metric to show that navigation errors were implicitly judged to be 17% more costly than recall errors. The fact that this percentage was not 0 indicates that reducing percent error was not the only basis for reducing effort.

Does attention solve the "apples-and-oranges" problems of judging task difficulty and task order?

How do we compare the difficulty of different kinds of tasks, and how we do sequence tasks of different kinds when the basis for the ordering is the tasks' difficulty levels? The ability to do these things requires a common currency, but the identity of that currency, if it exists, is unknown. We hypothesized that people may believe that the time that attention is paid to tasks enables people to compare and sequence tasks of different kinds. To evaluate this hypothesis, we tested three groups of participants. One group estimated the proportion of time that performance of a task requires attention-what we called attention time proportions or ATPs. We obtained ATPs for tasks that were "more intellectual" (counting) and others that were "more physical" (locomotion). Two additional groups made 2-alternative-forced-choice decisions about the relative ease and preferred sequencing of all possible pairs of tasks for which ATPs were independently obtained. We found that ATPs predicted judgments of task difficulty and preferred task order.

End-state comfort meets pre-crastination.

Research on motor planning has revealed two seemingly contradictory phenomena. One is the end-state comfort effect, the tendency to grasp objects in physically awkward ways for the sake of comfortable or easy-to-control final postures (Rosenbaum et al., Attention and Performance XIII: Motor representation and control, Lawrence Erlbaum Associates, Hillsdale, New Jersey, 1990). The other is pre-crastination, the tendency to hasten the completion of tasks even at the expense of extra physical effort (Rosenbaum et al., Psychol Sci 25:1487-1496, 2014). End-state comfort seems to reflect emphasis on final states, whereas pre-crastination seems to reflect emphasis on initial states. How can both effects exist? We sought to resolve this seeming conflict by noting, first, that the effects have been tested in different contexts. End-state comfort has been tested with grasping, whereas pre-crastination has been tested with walking plus grasping. Second, both effects may reflect planning that aids aiming, as already demonstrated for end-state comfort but not yet tested for pre-crastination. We tested the two effects in a single walk-and-grasp task and found that demands on aiming influenced both effects, although precrastination was not fully influenced by changes in the demands of aiming. We conclude that end-state comfort and precrastination are both aiming-related, but that precrastination also reflects a desire to hasten early task completion.

Starting or finishing sooner? Sequencing preferences in object transfer tasks.

When tasks are performed, other tasks are postponed, at least implicitly. Little is known about how task sequencing is determined. We examined task sequencing in object transfer tasks for which either task could easily or logically come before the other. The task was to transfer ping pong balls from two buckets into a bowl. To perform the task, participants walked down a corridor, picked up one of two buckets (their choice), carried it to the end of the corridor, transferred the balls from the bucket into a bowl, carried the bucket back to the start position, and then did the same with the other remaining bucket. As in an earlier study where just one of two buckets had to be carried to the end of a corridor (Rosenbaum et al. Psychol Sci 25(7):1487-1496, 2014), participants showed a marked tendency to start with the near bucket. The near-bucket preference was modulated only to a small extent by the number of balls that could be emptied into the bowl. The relative lack of importance of the number of balls to be transferred (to finish the first task more quickly or to get closer to the end goal of transferring all balls into the bowl) was further demonstrated by the fact that the effect of the number of balls to be transferred did not depend on how the emptying was supposed to occur (by pouring the balls or placing the balls one at a time into the bowl), or by whether the instruction focused on filling the bowl or emptying the buckets. The results suggest that the near-bucket preference reflects a strong inclination to start the task (sub-goal) as soon as possible rather than complete the task (sub-goal) as soon as possible. Starting the task as soon as possible may be related to the affordance triggered by the sight of the near object or by the freedom to perform without having to inhibit a reach for a bucket when the performer is empty-handed. Starting a task sooner may free up cognitive resources for subsequent decision-making.

How do reaching and walking costs affect movement path selection?

Although reaching and walking are commonly coordinated, their coordination has been little studied. We investigated decision-making related to reaching and walking in connection with a recently discovered phenomenon called pre-crastination-the tendency to expend extra effort in the service of hastening goal or sub-goal completion. In the earlier studies where pre-crastination was discovered, participants decided which of two buckets to carry to the end of a walkway, picking the bucket they thought was easier. Surprisingly, the majority of participants chose to carry the bucket that was closer to the start position, which meant that the bucket they chose had to be carried farther than the bucket they did not choose. Here we inquired into participants' sensitivity to reaching effort and walking effort by varying how far participants had to reach to pick up a bucket, how heavy the bucket was, and how far participants had to walk with the bucket they chose. We found that participants were willing to lean and reach far to pick up an empty bucket that was a shorter walk from the start position. However, as reaching costs and carrying costs increased, participants prioritized shorter reaches over shorter walking distances. The results show that although pre-crastination is a robust tendency, there are limits to the kinds of costs people are willing to incur to complete sub-goals as soon as possible.

Potters Make Shorter Pots Under Conditions of Reduced Sensory Input.

Although people have made clay pots for millennia, little behavioral research has explored how they do so. We were specifically interested in potters' use of auditory, haptic, and visual feedback. We asked what would happen if one or two of these sources of feedback were removed and potters tried to create pots of a given height, stopping when they thought they had reached that height. We asked students in a pottery class to build simple clay vessels either when they had full sensory feedback (in the control condition for all participants) or when they had reduced input from one modality (in Experiment 1) or two modalities (in Experiment 2). Participants were asked to stop building the vessels when they thought the vessels were 5 in. high. We found that participants produced shorter vessels when one or more forms of sensory feedback was reduced. The degree of shortening did not depend on the type or number of reduced sensory channels. The results are consistent with a control hypothesis where potters must have learned how to use sensory feedback from the modalities to help them control their ceramic creations. The results help highlight the importance of the intimate connections between perception and action.

Bimanual comfort depends on how extreme either hand's posture is, not on which hand is in the more extreme posture.

Although hand preference is one of the best known features of performance, a recent study of object transfer behavior (Coelho, Studenka, & Rosenbaum, J Exp Psychol Human Percept Perform, 40:718-730, 2014) showed that people place greater emphasis on using the hand that avoids extreme joint angles than on using the hand they normally prefer. In the present study, we sought converging evidence for the hypothesis that adopting midrange joint angles by either hand (the preferred-posture hypothesis) is more important than using the preferred hand in particular to adopt midrange joint angles (the preferred-hand hypothesis). We asked participants to hold both of their hands in different orientations and to rate their comfort. Consistent with the preferred-posture hypothesis but contrary to the preferred-hand hypothesis, the bimanual comfort ratings were more strongly affected by how extreme the two hands' postures were than by which of the hands was in the more extreme posture. The data support a theory of action planning, the posture-based motion planning theory, which says that whole-body postural comfort is a key ingredient for physical action planning.

Haptic feedback helps bipedal coordination.

The present study investigated whether special haptic or visual feedback would facilitate the coordination of in-phase, cyclical feet movements of different amplitudes. Seventeen healthy participants sat with their feet on sliding panels that were moved externally over the same or different amplitudes. The participants were asked to generate simultaneous knee flexion-extension movements, or to let their feet be dragged, resulting in reference foot displacements of 150 mm and experimental foot displacements of 150, 120, or 90 mm. Four types of feedback were given: (1) special haptic feedback, involving actively following the motions of the sliders manipulated by two confederates, (2) haptic feedback resulting from passive motion, (3) veridical visual feedback, and (4) enhanced visual feedback. Both with respect to amplitude assimilation effects, correlations and standard deviation of relative phase, the results showed that enhanced visual feedback did not facilitate bipedal independence, but haptic feedback with active movement did. Implications of the findings for movement rehabilitation contexts are discussed.

Four questions for passive frame theory.

Four questions are raised about the passive frame theory of Morsella et al.: (1) What is the relation of the theory to the response-selection-bottleneck view of attention? (2) Does the theory accommodate the contents of consciousness? (3) What about animals without skeletal muscles? (4) How do the contents of consciousness change with the development of automaticity?

Pre-crastination: hastening subgoal completion at the expense of extra physical effort.

In this article, we describe a phenomenon we discovered while conducting experiments on walking and reaching. We asked university students to pick up either of two buckets, one to the left of an alley and one to the right, and to carry the selected bucket to the alley's end. In most trials, one of the buckets was closer to the end point. We emphasized choosing the easier task, expecting participants to prefer the bucket that would be carried a shorter distance. Contrary to our expectation, participants chose the bucket that was closer to the start position, carrying it farther than the other bucket. On the basis of results from nine experiments and participants' reports, we concluded that this seemingly irrational choice reflected a tendency to pre-crastinate, a term we introduce to refer to the hastening of subgoal completion, even at the expense of extra physical effort. Other tasks also reveal this preference, which we ascribe to the desire to reduce working memory loads.

Does precrastination explain why some observers are suboptimal in a visual search task?

How do we decide where to search for a target? Optimal search relies on first considering the relative informational value of different locations and then executing eye movements to the best options. However, many participants consistently move their eyes to locations that can be easily ascertained to neither contain the target nor provide new information about the target's location. Here, we asked whether this suboptimal search behaviour represents a specific example of a general tendency towards precrastination: starting sub-goals of a task before they are needed, and in so doing, spending longer time on doing the task than is necessary. To test this hypothesis, we asked 200 participants to do two tasks: retrieve two heavy buckets (one close and one far) and search for a line segment. Precrastination is defined as consistently picking up the closer bucket first, versus the more efficient strategy of picking up the farther bucket first. Search efficiency is the proportion of fixations directed to more cluttered regions of the search array. Based on the pilot data, we predicted an association of precrastination with inefficient search strategies. Personality inventories were also administered to identify stable characteristics associated with these strategies. In the final dataset, there was no clear association between search strategy and precrastination, nor did these correlate strongly with any of the personality measures collected. This article received in-principle acceptance (IPA) at Royal Society Open Science on 29 January 2020. The accepted Stage 1 version of the manuscript, not including results and discussion, may be found at https://osf.io/p2sjx. This preregistration was performed prior to data collection and analysis.

End-state comfort and joint configuration variance during reaching.

This study joined two approaches to motor control. The first approach comes from cognitive psychology and is based on the idea that goal postures and movements are chosen to satisfy task-specific constraints. The second approach comes from the principle of motor abundance and is based on the idea that control of apparently redundant systems is associated with the creation of multi-element synergies stabilizing important performance variables. The first approach has been tested by relying on psychophysical ratings of comfort. The second approach has been tested by estimating variance along different directions in the space of elemental variables such as joint postures. The two approaches were joined here. Standing subjects performed series of movements in which they brought a hand-held pointer to each of four targets oriented within a frontal plane, close to or far from the body. The subjects were asked to rate the comfort of the final postures, and the variance of their joint configurations during the steady state following pointing was quantified with respect to pointer endpoint position and pointer orientation. The subjects showed consistent patterns of comfort ratings among the targets, and all movements were characterized by multi-joint synergies stabilizing both pointer endpoint position and orientation. Contrary to what was expected, less comfortable postures had higher joint configuration variance than did more comfortable postures without major changes in the synergy indices. Multi-joint synergies stabilized the pointer position and orientation similarly across a range of comfortable/uncomfortable postures. The results are interpreted in terms conducive to the two theoretical frameworks underlying this work, one focusing on comfort ratings reflecting mean postures adopted for different targets and the other focusing on indices of joint configuration variance.

Thinking on your feet: Anticipatory foot placements in repeated bimanual object displacements.

Effective handling of objects requires proper use of the hands. If the object handling is done while standing or walking, it also requires proper use of the feet. We asked how people position their feet to meet future and ongoing object-handling demands. In previous research on this topic, participants walked to a table and picked up an object for a single displacement from one place to another. These studies shed light on sensitivity to kinematics but, strictly speaking, may not have revealed anything about sensitivity to dynamics. In the present study, we asked participants to walk to a table to move an object back and forth over different distances and at different rates. Prior to walking to the table, participants had full knowledge of what the task would be. By using a rhythmic rather than discrete object placement task, we could analyze participants' sensitivity to dynamics as well as kinematics. Consistent with our expectation that participants would tune their foot separations to demands related to dynamics, we found that stance width was wider for long than for short object displacements and was more pronounced for high displacement rates than for low displacement rates. Also consistent with our expectations about planning, these effects were evident as soon as participants reached the table. Our results add to the limited research on coordinated action of the hands and feet in purposeful object manipulation.

The tiger on your tail: choosing between temporally extended behaviors.

The time spent choosing between temporally extended behaviors cannot, in general, last as long as the behaviors themselves; otherwise, the tiger on your tail would have you for lunch. Previous reaction time studies provide little information on this topic, which was explored in the study reported here by showing participants images of scenes for which they could choose a left or right walking-and-reaching path. The paths they chose were nearly identical to ones chosen by participants who actually performed the task in a previous study. Moreover, the times participants took to choose the actions were about 5 times shorter than the times it took to perform them. The choice-time data were inconsistent with the idea that participants picked the path with a lower cost after mentally simulating the paths one after the other. Showing real-world scenes and having participants choose actions for them holds promise for future research in cognitive psychology, ecological psychology, and behavioral ecology.

Motor planning in primates.

Vaesen asks whether goal maintenance and planning ahead are critical for innovative tool use. We suggest that these aptitudes may have an evolutionary foundation in motor planning abilities that span all primate species. Anticipatory effects evidenced in the reaching behaviors of lemurs, tamarins, and rhesus monkeys similarly bear on the evolutionary origins of foresight as it pertains to tool use.

Determining the relative difficulty and preferred ordering of mental and physical tasks.

How do people determine the relative difficulty of mental tasks and physical tasks, and how do they determine the preferred order of such tasks? Is it harder to make such decisions if 1 task is mainly mental and the other is mainly physical than if both tasks are the same kind? To address these questions, we conducted 3 experiments. In experiment 1 we asked participants to judge the relative difficulty and preferred ordering of mental tasks (math problems). In experiment 2 we asked participants to judge the relative difficulty and preferred ordering of physical tasks (moving a bucket back and forth). In experiment 3 we asked participants to judge the relative difficulty and preferred ordering of the same mental and physical tasks as in the first 2 experiments but with 1 of the tasks being mental and the other being physical. We reasoned that if mental task difficulty and physical task difficulty share a common code and if task ordering is systematically related to task difficulty, then judgments in experiment 3 should be as systematic as judgments in Experiments 1 and 2. The results confirmed the prediction and helped extend the notion of common codes for perception and performance to the evaluation of task difficulty and task ordering. A surprising finding was that mental difficulty was implicitly judged to be more important than physical difficulty for the tasks and population studied here. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Deciding what to do: Observations from a psycho-motor laboratory, including the discovery of pre-crastination.

A great deal of research has concerned choices of goods or services with different values receivable at various times. Temporal discounting - the magnification of values that can be obtained sooner rather than later - has proven to be immensely important in this regard. In the present article, we shift the focus from the receipt of goods or services to the performance of tasks. We show that temporal discounting also applies to task choices. Pre-crastination, the phenomenon we point to, was discovered by Rosenbaum, Gong, and Potts (2014) and is the tendency to hasten tasks even at the expense of extra energy. Pre-crastination was discovered in a study of psycho-motor performance, where the focus was on biomechanical factors affecting task choices. In the present article, we review that research, showing how the tendency found in the initial experiments are in fact illustrative of a more general motor-control tendency to inhibit easy forms of movement for the sake of later performance goals. Such inhibitory control may also be the basis for pre-crastination, provided one assumes that pre-crastination keeps working memory as clear as possible. A wide range of behavioral choices fit under the rubric of pre-crastination, such as answering emails too soon, submitting articles before they are ready, judging others before they should be judged, convicting others to get cases over with, and, in the worst case, going to war prematurely. Lack of temperance in these choices may seem to arise from impulsivity, but we argue against that view. The desire to "clear the decks" to be prepared for new challenges is, we suggest, a more apt account of pre-crastination.

Think then act, or act then think? Double-response reaction times shed light on decision dynamics in precrastination.

People often try to complete tasks as soon as possible, even at the expense of extra effort-a phenomenon called precrastination (Rosenbaum et al., 2014). Because precrastination is so widespread-as in answering emails too quickly, submitting papers before they have been polished, or, on larger scales, convicting people in the rush to judgment, or even going to war in the rush for revenge-it is important to understand its basis. Building on previous work on this phenomenon, we focused on two plausible accounts of it. According to the behavioral account, there is a desire to act for the sake of acting itself. According to the cognitive account, there is a desire to shorten one's mental to-do list so cognitive resources can be directed to other things. We invented a new task to distinguish between these hypotheses. Our participants made yes-no decisions under the requirement that they always respond twice per trial. We found that participants took longer for the first choice than the second and rarely changed their minds, even when second response accuracy was emphasized. This outcome went against the behavioral account, which predicted shorter first-response times than second-response times and lower (near chance) first-response accuracies than second-response accuracies. Instead, the data clearly showed that participants did all or most of their decision-making up front. The double-response reaction time task provides a new tool for studying decision dynamics. (PsycInfo Database Record (c) 2022 APA, all rights reserved).